Difference between revisions of "Alan Kay CS1 talk at UCLA (2010)"

Latest revision as of 21:59, 6 December 2017

let me introduce professor LDK professor LMK is best known for pioneering

work on object-oriented programming language

we've done graphical user interface design and

for coining the phrase the best way to predict

the future is can be invented into

in 2003 prevention Allen can receive

receive a ACM Turing award

it considered to be the Nobel Prize of computing

from work on object-oriented programming that is welcome

question ok thank you

ok the ground

rules here are asked questions

whenever you have one because

these classes go quickly just

hink of all the money you're paying for hardly getting any

thing in a in an hour

so programming languages in

programming one of the problems of talking

about this in general especially in one class is

that there have been several thousand

programming languages designed and

implemented over the years at any given time since

the early 60s

there have been somewhere between 150 to

200 languages in standard use and

these languages are

rather different from each other in

certain ways and rather similar to each other in

other ways and so it's very hard to come up with interesting

generalizations and

what we're really talking about

here is programming and programming

is the simplest

thing to describe its we do something in the computer

does something and if it does what we wanted

it to do both of us are successful

programming languages are usually the vehicle

for this and you

can think of user interfaces

as kind of an impoverished

kind of programming language

they used to be richer and

that the

you did in the user interface who are part and parcel

of the kinds of programming you could do and I'm going

to show you a few of those things today so I thought

what I do is first to

just look at a couple of ideas in programming

and programming languages and be able to do

it so I don't have to explain

some programming language you've never seen before

I'm going to take a programming language that

is currently in use by about 3 million children

called etoys it's the

parent of another widely

used programming language for children called

scratch and

some of the same people worked on both of those

and so I'll first take a look at what that

experience is like and so

the basic idea in this

style of doing programming it's

now has a name called

live coding but fact

live coding goes all the way back to the early

60s it just never was in the style of

the punch card unix approach

black screen

by terminal way of doing things so

the idea is that you

just make

things in a variety of ways and the computer responds

to them there's no no visible compiling or

we're editing so pick

up some paint one of the things

that kids like is to

do things that adults do so

you can ask

them why don't you draw a car

from the top view

put on some headlights

and we were a disney for

a while and so the thing we learned at disney is you must

always put on some specular reflections

like that and

this this gives you a graphical object

and it does the kind of things you'd expect with a

graphical object I can give it a name here i'll call

it car and what's interesting about this object

is it has another view this is the symbolic

view of this object and

so here's a

property of it called the heading of it says

the heading is 0 and if i

rotate the car you can see it's showing

me two degrees from north minus

and plus and this is interface is

reflexive so if i go in here and

right so everything is by

connected here and also

here here's a behavior

of the car turn by five if i click it

it turns the car if i drag it out

it makes me a little script if

i get the script is now just infinitely

looping and

if

i pull

out another thing each time I'm doing

this is the there's a compilation

going on but it's sub-second so

it's actually compiling code underneath

it and I can

actually even drive my little car

the zero makes it go straight

but in

fact it's hard to drive the car this way

and it's a little bit like kissing your sisters

we really want to have a

steering wheel so

we'll just

make a steering wheel

and we'll

call it wheel and

again we look inside here we see

same kind of audit it's just got a different costume

on it and again it has a

heading and

I get

the same behavior from it but notice that

we got the car to turn by

changing this number here

and that's kind of an invitation of picking up this value

and dropping it into the script and

now

we get to do this

so you're just starting out

here but let

ell you if you program in the language here at UCLA that

doesn't allow you to do this little demo right

off the bat something is wrong because

we're looking at something that goes back 40 years

this is just because you don't know

what you're getting into here I'm just

o show you that there doesn't have to be a compile

phase it doesn't have to be edits of files can

all be done lickety-split

okay so I've got a little car

there and the other thing I can do is

make lots of them

so I'm going to play a game

got a red car and a blue car and

I'm going to make them small

can you see

them blue guy and the red guy there and

the two programs i'm going to run here

this little kids system has automatic

multitasking as many tasks as you want

so I'm going to say

go forward by one and turn randomly

and this one says

do this guy and

if a

blue guy sees touches a red guy then

make the blue guy red so this is like an infection

programming and so if i say go

at the top here i'm plotting the

infected against the non-infected you

can see that the big

open space here that the village is is kind

of like a long time constant the

probability that the two guys are going to hit is fairly

low so i'm going to get that behavior but

what

about a thousand

all

of a sudden I get that so it's another thing

language doesn't allow me to make objects

by the hundreds of thousands and run them in parallel then

worry about what kind of language you're programming it

so the kids with this little program that they wrote

there's no mystery here they

wrote this program so now they can

explore by saying well okay

how about 200

and again the

sparseness acts like a longer time constant

between infections but

eventually

they all died

and

we get this

longer thing so the kids will say okay well

how about 80

so now they're starting to root for

the ones that are maybe

nope

so this is kind of an experiment in system

dynamics for 10 year olds

and it's

something that many parts the world don't

actually understand on any terms because

this first curve that i showed the

one that went up rapidly is like typhoid and

so if this last one was a disease what

would it be like what these things would it be

blurt it out

let's

ee it's a disease that's already killed 100 million people

yeah come on

remember you're in it you're right UCLA now

yeah so

why does it kill that many people when

typhoid is much much more virulent the

answer is unless you know

that a contagious

incurable deadly disease is always

going to kill everybody off no matter

what the time constant is you're not going to do

anything when it doesn't look like anything's going on

remember people are also being born so

for a while when AIDS is doing its work the

population is actually still rising and

if you don't happen to know this

feature of system dynamics you

might just ignore it or say it's

just for minorities or something like that then

all of a sudden you've got a majority

of your population infected okay so that's a

little thought experiment that children can do

it's

important because if you think about what is it that we need

to know today it's not so much knowing

that two plus two equals four or how

to compute a tip

for a waiter actually has to do

systems dynamics because the world particularly

biologically is more connected in more ways

than it ever has been before and also

our

people in Congress in Washington could

do well to do a few of these experiments because

they'd actually have some sense of how

unstable systems are

and you shouldn't monkey with them

okay so back back here we'll we'll

turn this guy off and I got

to two other quick little experiments

here first one

is to make a little robot car now that we made one that can be

driven and for that I will need a track

so I get

sort of a brown track

here and

robots

need sensors so I need to put a sensor

on this guy

so I'll just draw one in here

like this

we'll use this to track

where are we where we actually are and now

we need to make a program we can think out

this program first so one of

do with children is get them to go around the wall over their classroom

with their eyes closed and

the way to do that they soon find out

is you go until you hit the wall and then you turn

but as soon as you lose the wall you have to go back

into it you keep on going

if you don't do that right away you

may lose where the wall actually is so

right that that little

program we

want the car car is always going to go forward

so I can get that we're going to test whether we're

touching the wall or not here's

a test that will test

let's

see how about the

cars blue

color sees the walls brown

color and then we have to figure out which

way to turn here

ok I'm going to

put in two turns by fives but let's think it through

so if we don't have the wall here

which way do we want to turn

five or minus

55 ok

so that's no and so for

yes we'll just take a guess and try minus 5

here and we'll

okay who can see what

the flaw with this program it is

somebody tell

me

well don't worry about efficiency

we aren't humans

aren't efficient but we're smart

what's the condition under which it can lose this

wall

it's going to do with the Sun but

if I made a sharp turn right

it's got a fixed radius to get back

so probably when I lose the wall I

might even want to stop the car slowed it way way

down to give me a real chance of contacting

the wall again okay

so that's

a little experiment in making

a feedback thing now what I want to do is to

turn

this thing into a wriggly worm and to

do that I

want to make a script that is going to change

its

shape so here's my little thing

it says car look like something but

I don't have anything to make it look like

so I will

somebody

now somebody isn't talking

ok

so now I'm going to draw

a couple of pictures for the wriggly worm part of

this

will

make a blue top and

maybe a brown bottom

here and just

to test this out

this one is called sketch one so

if I say do it okay so that worked

and but I

need another one in order to make it wriggle

so i will

make

a twin to it right here

go with the wriggle the other way

ok

now i need to move back and forth between each

one of these and to choose which one of these i'm

going to need something that we might call a little data

structure here i'm going to

now i'm

going to look again see all of the objects here

have the same kind of user interface

and going to look down here and see oh yeah

here's here's the cursor here's one that

says the holders player at the cursor

so i'm going to put that in there and

here's the cursor

control so i'm going to toss that

in there and I'm going to say what I want

o do is just increase the cursor over and over again and

so now I'll start this

script up and you see what it's doing

here ok now we could have put

that in as a feature for the children but

hen

the children wouldn't understand how to do animation so

trying to teach somebody something you don't want too many features

you want them to actually do the programming

themselves it meanwhile the children have

forgotten about these other scripts that are

there so I could turn on

this one and drive the

drives a little worm around

or

what

about this one

okay so

okay so that's

kind of simple programming and

the other thing that you want to be able

to get a handle on pretty early in your programming

career as meta programming and

meta programming in this case

means I want to I want to make another language other

than etoys and I'm

going to do it for the particle

system kinds of stuff

so here's the

these are now eat I objects in

there these are the scripts

for the whole interpreter I'm going to

use the animate remember the animation thing so

if you know a little bit about program counters the anime

animation system is rather like running a program counter

along when you're doing animations what you're doing

is saying display the the guy

that's that's there in this case

we're going to execute instructions and so

I'm actually going to turn on the eval

here you can see it

may be a little quivering a little bit here it's dying

for some input and then the

the instructions are going

to be implemented using these scripts which have already

written and now I just have to build

the instruction and

so this one's is a test that

says if you can move this

one says then move okay so

now it's executing that construction and this

one says if

a blue guy hits a

red guy then make them both red

let's see if we're lucky here

yep okay

so programming it and again

when you're when you're taking that java class

and you spent the first couple of

weeks not really writing a program yet think

about what's like to write another programming language in

java should be really

easy but it isn't okay

so

f the theories about designing programming languages

is because

children are part of our world

and children grow up in to be being us

we should be able to have them be able

to start learning how to program this

is we're learning how to program and

then if you do that well the

stuff that children find easy

and powerful or actually clues for

how to design a programming language yourself

okay and so what we've been looking at

here is here's computer memory and

down a

flyspeck in

the machine is actually some

logic gates on a chip

one corner of the chip

and

round it is nano code

microcode on

the chip itself and

that might be an 86

architecture kind of chip but most of the chips are done

the same way there's some

simple logic like this is the arithmetic is

our registers the arithmetic unit and

so forth then it's made into

a slightly more complicated processor by putting

a lowest level of programming they're

in pretty elemental terms that's not always easy to

write these low-level

programs and then

nobody wants to program in that

so in this case

what we're looking at is a virtual machine

coated

ultimately in these terms

that makes the computer

look like a small talk machine and at

this level there's an area on there

manifested where the display is going to go

and then in that

we write a development system

you still haven't seen yes

I'm not going to

but thank you for the thought that's

too complicated small talk is a programming language that's

all we need to know it has a development system

that's written in itself

and the

e toya system that you saw which

is putting up this slide here

is written in small talk and

then I just

made a little interpreter in the

etoys machine for doing the rule-based particle

system stuff and this is a very typical

way of going about handling

problems it's not

the only way some

people like to program down here and write tons

of programs to deal with the very same problems another

way of doing it is fine languages that

fit the problems gracefully and then the amount

of code you have to write to get to the next level is

not that large and all

of this is kind of an example of

Turing's idea of

being able to simulate any kind of mechanism on

a relatively simple mechanism

that has a few pieces of logic in a fair

amount of memory okay so

that's the kitty world

now let's

a look at the adult world where we're going to go from

programs that have tens

of lines in the kiddie world but can still do interesting things

to adult programs which tend to have

zillions of lines and are

surprisingly weak and in

order to come up with a metric for this I'm going

to use a metric of lines of code

it's not the only metric you could use but a

line of code is something that a programmer has to write so

it is one kind of unit of work and it's also unit

of space so

a 400-page book has 20,000

could

be English but it could be code

could be in machine

code it could be and see it could be in Java and

a foot of books is about

300,000 lines and a meter of

books stacked up like this is a million

line so that's a good metric million lines of

code per meter and stacked up books and

the Empire State

Building is twenty-two

thousand books high and

440 million lines of code

right so

if you've ever heard anybody heard of any programming systems

that have 400 million lines of code

yes though come on

yeah yeah take a look

at our government sometime in

fact if you look at your own little

only the laptop

if you happen to be running Microsoft the operating

system is about 120 million lines of

code remember there's just the operating system it hasn't

done anything for you yet just sitting

there and then Microsoft Office is over

a hundred million lines of code

so that's

220 million lines of code it's about

seven eleven thousand books of code

anybody

ever read all that code no way

very few people who read

it all have read eleven thousand books of anything I

can guarantee you if you read it all

not going to read eleven thousand books of code so

most of the code has never been over

viewed by any single person or even any single

group in fact much of the code in there

is code that isn't even run but

out because they don't know whether it's run or not

and this is it this

is a problem on the other hand

the looking at it from

the standpoint of writing code the

when you look at the actual features

you get for this 220

million lines of code it doesn't seem like it should be

should take 220 million lines of code

just shouldn't back the first time around it

was done it Xerox PARC did about

half of this and it only took ten thousand lines of code

so something happened some

kind of explosion of complications

and complexity and here

just to make you feel better I located a

large financial products company whose name

I will not put here that has more

than 400 million lines of code in its

primary offerings to its customers so

this is what they are actually maintained

and you can tell they're a little old-fashioned

because their user interface is given in terms

of screens which harks back to the

mainframes they have a hundred and seventy thousand

screens they have to deal with and

that's about 20,000 books or

almost an empire state building

worth of code

however if you're looking

for a job you came to UCLA to learn to

program and get a job it's just this kind of stuff that

you actually have to learn about because that is what

business is mired in right now this is

hiring people this is why they're crying for programmers

not to do better

but just to take care of the mess that is

already there think about that

okay

so I'm going to stick

to I'll show you a couple

of examples in the time that's left of what might be done

part of personal competed these several hundred

millions of lines of code

okay so let's take a look at

this problem from a slightly different perspective

over

here we've got some gates

over here we've got a

problem this is what

we need we need to do something over

here and the question is is what is it going to take us to get

from there to there these days and

so in terms of machine code

lots of the kinds of things I'm

about or literally billions of lines of code because

machine code is written one instruction per line of code

and maybe

see gives

eight to ten machine

code instructions per line of code so maybe something

that would be billions would

be hundreds of millions in C

and we can imagine

a higher level language

than C not

the job is that much higher level language

higher level in C but could

imagine something higher level you can imagine something

higher level imagine something it might do a lot

of these tasks in just thousands of lines of

code and the question is why

do

we stay here down at the gear level for

most of the programmatic that is still done today

and there's

hot not a lot of the organization

of code at this level which is a little bit more like

the way biology organizes itself

almost none of this still

being done

ok so the

programming effort comes down as we go to higher and

higher level languages

but computer

science has not actually been

up to the challenge of

putting in the amount of invention that's necessary

to make programming systems that do this amount

of work for us so we can think of and in

between is just a lot of work for any kind of

because there's packaging this documentation

there's debuggers there's an

enormous amount of work that has to be done and

the idea is that with more

work which gets tougher as you come this

way you actually reduce the general programming

effort so this is not popular so virtually

all of the programming in business in the u.s.

today is done at this level still and

this is a level that is really not different from the

level of programming in the 60s almost

nothing has changed new languages

have come along but they have not up their level in

any significant way

but

just to go against the tide here even

though you're going to be studying a lot of this stuff here

I just want to make you aware of these

ideas down here which if you're interested in research

and in making things better you might poke

your head in two now

what's funny about history is

that there are people who are absolute

geniuses who transcend

the time in which they live so

50 years ago

there was no computer graphics

this is the guy who invented computer graphics

and he also invented

object-oriented design

systems so

he actually did the work in 62 and

wrote it up in 63 so this is still

the 50th anniversary of this I thought you'd like to see

what this very first

interactive graphic system looked

like and what it could do now the first thing you have to

visualize is this guy is sitting

here with a pointer in his hand a

light pen but he's in a computer that is about

eight times maybe 10 times the

size of this room it

was close to the size of at least the first franz

hall building it

had its own roof it was the

building and it was

computer and from three o'clock in the morning to six o'clock

in the morning they let this one guy play

around with it and so

here's what he did and by the way this is not actually a computer

display it just was an oscilloscope that

put up spots so the first thing he had to

do was to write programs that would make lines

and arcs and and so forth

and about a third of the capacity

of this enormous machine was used just to make

a simulated graphics display because there were

no graphics this place okay so

this will give you an idea

so it gets

some ink

and

he just sketches in this flange because look at he's pointing

at it now and he's giving it a constraint

to make everybody mutually perpendicular and

what you saw there was sketchpad solving the problem

for him all

right so this way you program this system

was by telling it what you wanted

to have true and sketchpad and figure out how to have

it be true same idea here make these two guys parallel

now the constraint is

collinearity put

these lines down these dashes I'm putting in here

down on top of

the guidelines

now he says

okay let's make the guidelines transparent and

now we've got a hole in the flange and

you notice it has continued

assuming the first clipping window ever

done is that actually the drawing is

done on a sheet of virtual paper about a third

of a mile square now he wants

to make a rivet

he's going to use the center here for

and now he's going to do the same trick

he's going to say to these guys take

these guys to make them all mutually poopin perpendicular

that's going to drag the crosspieces

that's going to drag the

top of the rivet now he's going to show

I'll

start off with different initial starting conditions

till get something that obeys the constraints

that i gave it now i could have put in absolute numbers in

there you could have putted ratios

this is why it's called sketch pad

the idea is you should be able to work

quickly get a rough idea of it

and then tell the computer the rules that if

they were solved was completed

okay now he's

showing that what he drew is

not just a rivet

but it what it's what we call

class in an object-oriented language which

he called a master so what he

there was the master drawing of a rivet and

what he's manipulating here is an instance of

so

now he's showing yeah

I can make more instances of the rivet

and I can make them different

sizes and so forth

but he forgot that cross P

so he goes to the master makes those guys transparent and we

can see the rivet feels the instances of

the rivet feels those things then

the last part of this demo

is

that he can take

anything that he is

constructed and make it into a master so

now this is a master drawing of a flange

with a rivet in it and now

he's

making instances of those

ok so

this is a yes go ahead

yeah yeah

in fact on the larger movie which you can find online

you can see the sheet is populated with lots

of different things on it yes oh

okay okay so

so

you have to realize this is a PhD thesis this is done in

one year by one person and

what the contributions

were is first interactive

computer graphics object-oriented

design structures

constraints for

programming so you didn't program it using

sequential code at all and

one

of the great final

things he did was to show how you could make a

bridge simulation without

sketchpad knowing about bridges ahead of time

because the whole point of this thing was that sketch pad

know ahead of time what you were going to try and do in

it the ideas you should be able to do everything in

fact the all

of these drawings were made by sketch pad and the

the text here these each

text figure is actually a drawing and sketch pad so

there's a master for f and everywhere

there's an F there's an instance of it so the whole system

was done and this thing and I wants to ask

ivan how could you have done computer

graphics object oriented design and

constraint based programming

all by yourself in one year and he said well I didn't know

it was hard since

then ok so the bridge there's

no movie of the bridge because it took the

supercomputer back in 1962

about 20 seconds for each time step

on it because of the computer

power of this computer the size of a building was about

card today

but

to

celebrate the anniversary of

this system a couple of the guys at viewpoints

Burke freudenberg and Yoshi Yoshi ki o Shiva

made a version of this

of this bridge

sketch n and

we put in the twinkling there

so it looked like the display back then and

move

things in you can turn on gravity

ou can hang

away from it

even when it settles down

it has

a really settle down if I turn on the decimal points here

see if still wiggling

just like wheel bridges

do and

I can tenderize

me to watch what happens when I stick

this beam in here take a look

at the numbers of the stress and strain around it

when I drop this guy in here and

notice the sky over on the

Left felt that ripple across

yeah

so one

of the main things that's got people

going from sketchpad most it was too

hard for people to really know what to do

with but one thing they were sure about was they

needed better looking display so here's the very

thing rendered with them with a modern display and we

can do a few more tricks like

we can give letters wait

okay

and we programmed this a little bit differently than

fact we've done this several times now one of the

students in this class last year Matthew Goldberg

what did

an internship with us and

did a different version of

this did a nice job of

it we programmed it

up in terms of three

constraints not

constraints that Ivan used but a different kind

of constraint for instance this one looks suspiciously like it

might have something to do with gravity so

this is way to think of is this the three line

program here so if I turn this off

so all we've got left is the spring

tension here should

all know laut which it does so we'll turn

gravity back on again

and this

bottom guy is the constraint for

these pins so

this bridge is pinned together and if I turn

off the pin constraint that's holding everything

together in this simulation

yeah so remember

all those costumes that's all that bridge

was and we can repurpose those costumes

into something else like the

user interface of this system I'm giving

the right so this is a

system that we programmed ourselves at viewpoints

and it's a system

I'm giving this talking I'm not obviously not using PowerPoint

because you can't program in PowerPoint and

I'm using it to show you i'm

going to show you one example because that's all I have time

for

and that is how the graphics in this

we're programmed now

usually the graphics in your personal computer are

about half a million to a million lines of code to

do all of the

compositing and so forth

and what we're going to look at here is just take a look

at the rendering part

of this a render of being

able to paint a pixel with the right

shade so Dan a meringue here is a graduate

student at UC San Diego works with us came

up with this formula so it's a nice little piece of math

to represent it here's a

programming language that is as close to the formula as

possible it's about twice the size of the

math but it actually runs and it handles all rendering

stuff done like

this and

I'll just to give you

now we have this

flow of stuff with this programming

graphics language sets up and

what we what we wind up getting is

something that's very complex to look at

and debug but Bret Victor look them

up on Google did this visualizer

that's created automatically from the

code i just showed you and this

is a live system so

here's a tourney i'm going to turn

a addy into a

be here

and if i want to know where

this pixel and the rendering comes from i

can just put the mouse on it and

touches this if i want to see where this guy

is handled in the code if i want

to see how the pipeline

that's set up here of these

five small programs

here i can just go here if I want it where did this pixel come from

what

happens if I turn this

so when you're doing languages of

the future the system is going to have to also produce

the debuggers along with the languages

themselves okay I think I

think it's a hard stop at ten of so

I won't put any strain on you but if

you're interested hang around and ask some questions and with

Difference between revisions of "Alan Kay CS1 talk at UCLA (2010)"

Latest revision as of 21:59, 6 December 2017

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@@ Line 3: / Line 3: @@
 |id=WR1en4e2hA0
 |alignment=left
-|autoresize=false
+|autoresize=true
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+<subtitle id="0:0:5">let me introduce professor LDK professor  LMK is best known for pioneering</subtitle>
+<subtitle id="0:0:8"> work on  object-oriented programming language</subtitle>
+<subtitle id="0:0:11">we've done graphical user interface  design and</subtitle>
+<subtitle id="0:0:14"> for coining the phrase the  best way to predict</subtitle>
+<subtitle id="0:0:17"> the future is can be  invented into</subtitle>
+<subtitle id="0:0:20"> in 2003 prevention Allen  can receive</subtitle>
+<subtitle id="0:0:23"> receive a ACM Turing award</subtitle>
+<subtitle id="0:0:26">it considered to be the Nobel Prize of  computing</subtitle>
+<subtitle id="0:0:29"> from work on object-oriented  programming that is welcome</subtitle>
+<subtitle id="0:0:32"> question ok  thank you</subtitle>
+<subtitle id="0:0:35"></subtitle>
+<subtitle id="0:0:38"> ok the ground</subtitle>
+<subtitle id="0:0:41"> rules here are  asked questions</subtitle>
+<subtitle id="0:0:44"> whenever you have one  because</subtitle>
+<subtitle id="0:0:47"> these classes go quickly just</subtitle>
+<subtitle id="0:0:50">hink of all the money you're paying for  hardly getting any</subtitle>
+<subtitle id="0:0:53"> thing in a in an hour</subtitle>
+<subtitle id="0:0:56">  so programming languages in</subtitle>
+<subtitle id="0:0:59"> programming  one of the problems of talking</subtitle>
+<subtitle id="0:1:2"> about  this in general especially in one class  is</subtitle>
+<subtitle id="0:1:5"> that there have been several thousand</subtitle>
+<subtitle id="0:1:8">  programming languages designed and</subtitle>
+<subtitle id="0:1:11">  implemented over the years at any given  time since</subtitle>
+<subtitle id="0:1:14"> the early 60s</subtitle>
+<subtitle id="0:1:17"> there have been  somewhere between 150 to</subtitle>
+<subtitle id="0:1:20"> 200 languages  in standard use and</subtitle>
+<subtitle id="0:1:23"> these languages are</subtitle>
+<subtitle id="0:1:26">  rather different from each other in</subtitle>
+<subtitle id="0:1:29">  certain ways and rather similar to each  other in</subtitle>
+<subtitle id="0:1:32"> other ways and so it's very  hard to come up with interesting</subtitle>
+<subtitle id="0:1:35">  generalizations and</subtitle>
+<subtitle id="0:1:38"></subtitle>
+<subtitle id="0:1:41"> what we're really  talking about</subtitle>
+<subtitle id="0:1:44"> here is programming and  programming</subtitle>
+<subtitle id="0:1:47"> is the simplest</subtitle>
+<subtitle id="0:1:50"> thing to  describe its we do something in the  computer</subtitle>
+<subtitle id="0:1:53"> does something and if it does  what we wanted</subtitle>
+<subtitle id="0:1:56"> it to do both of us are  successful</subtitle>
+<subtitle id="0:1:59"> programming languages are  usually the vehicle</subtitle>
+<subtitle id="0:2:2"> for this and you</subtitle>
+<subtitle id="0:2:5"> can  think of user interfaces</subtitle>
+<subtitle id="0:2:8"> as kind of an  impoverished</subtitle>
+<subtitle id="0:2:11"> kind of programming  language</subtitle>
+<subtitle id="0:2:14"> they used to be  richer and</subtitle>
+<subtitle id="0:2:17"> that the</subtitle>
+<subtitle id="0:2:20">you did in the user interface who are  part and parcel</subtitle>
+<subtitle id="0:2:23"> of the kinds of  programming you could do and I'm going</subtitle>
+<subtitle id="0:2:26">to show you a few of those things today  so I thought</subtitle>
+<subtitle id="0:2:29"> what I do is first to</subtitle>
+<subtitle id="0:2:32"> just  look at a couple of ideas in programming</subtitle>
+<subtitle id="0:2:35">  and programming languages and be able to  do</subtitle>
+<subtitle id="0:2:38"> it so I don't have to explain</subtitle>
+<subtitle id="0:2:41"> some  programming language you've never seen  before</subtitle>
+<subtitle id="0:2:44"> I'm going to take a programming  language that</subtitle>
+<subtitle id="0:2:47"> is currently in use by  about 3 million children</subtitle>
+<subtitle id="0:2:50"> called etoys  it's the</subtitle>
+<subtitle id="0:2:53"> parent of another widely</subtitle>
+<subtitle id="0:2:56"> used  programming language for children called</subtitle>
+<subtitle id="0:2:59">  scratch and</subtitle>
+<subtitle id="0:3:2"> some of the same people  worked on both of those</subtitle>
+<subtitle id="0:3:5"> and so I'll  first take a look at what that</subtitle>
+<subtitle id="0:3:8">  experience is like and so</subtitle>
+<subtitle id="0:3:11"> the basic idea  in this</subtitle>
+<subtitle id="0:3:14"> style of doing programming it's</subtitle>
+<subtitle id="0:3:17">  now has a name called</subtitle>
+<subtitle id="0:3:20"> live coding but  fact</subtitle>
+<subtitle id="0:3:23"> live coding goes all the way back  to the early</subtitle>
+<subtitle id="0:3:26"> 60s it just never was in  the style of</subtitle>
+<subtitle id="0:3:29"> the punch card unix  approach</subtitle>
+<subtitle id="0:3:32"> black screen</subtitle>
+<subtitle id="0:3:35"> by terminal way of  doing things so</subtitle>
+<subtitle id="0:3:38"> the idea is that you</subtitle>
+<subtitle id="0:3:41">  just make</subtitle>
+<subtitle id="0:3:44"> things in a variety of ways  and the computer responds</subtitle>
+<subtitle id="0:3:47"> to them  there's no no visible compiling or</subtitle>
+<subtitle id="0:3:50"> we're  editing so pick</subtitle>
+<subtitle id="0:3:53"> up some paint one of the  things</subtitle>
+<subtitle id="0:3:56"> that kids like is to</subtitle>
+<subtitle id="0:3:59"> do things  that adults do so</subtitle>
+<subtitle id="0:4:2"> you can ask</subtitle>
+<subtitle id="0:4:5"> them why  don't you draw a car</subtitle>
+<subtitle id="0:4:8"> from the top view</subtitle>
+<subtitle id="0:4:11">  put on some headlights</subtitle>
+<subtitle id="0:4:17">and we were a disney for</subtitle>
+<subtitle id="0:4:20"> a while and so  the thing we learned at disney is you  must</subtitle>
+<subtitle id="0:4:23"> always put on some specular  reflections</subtitle>
+<subtitle id="0:4:26"></subtitle>
+<subtitle id="0:4:29"> like that and</subtitle>
+<subtitle id="0:4:32"> this this  gives you a graphical object</subtitle>
+<subtitle id="0:4:35"> and it does  the kind of things you'd expect with a</subtitle>
+<subtitle id="0:4:38">graphical object I can give it a name  here i'll call</subtitle>
+<subtitle id="0:4:41"> it car and what's  interesting about this object</subtitle>
+<subtitle id="0:4:44"> is it has  another view this is the symbolic</subtitle>
+<subtitle id="0:4:47"> view  of this object and</subtitle>
+<subtitle id="0:4:50"> so here's a</subtitle>
+<subtitle id="0:4:53"> property  of it called the heading of it says</subtitle>
+<subtitle id="0:4:56"> the  heading is 0 and if i</subtitle>
+<subtitle id="0:4:59"> rotate the car you  can see it's showing</subtitle>
+<subtitle id="0:5:2"> me two degrees from  north minus</subtitle>
+<subtitle id="0:5:5"> and plus and this is  interface is</subtitle>
+<subtitle id="0:5:8"> reflexive so if i go in  here and</subtitle>
+<subtitle id="0:5:11"> right so everything is by</subtitle>
+<subtitle id="0:5:14">  connected here and also</subtitle>
+<subtitle id="0:5:17"> here here's a  behavior</subtitle>
+<subtitle id="0:5:20"> of the car turn by five if i  click it</subtitle>
+<subtitle id="0:5:23"> it turns the car if i drag it  out</subtitle>
+<subtitle id="0:5:26"> it makes me a little script if</subtitle>
+<subtitle id="0:5:29"> i get  the script is now just infinitely</subtitle>
+<subtitle id="0:5:32">  looping and</subtitle>
+<subtitle id="0:5:35"> if</subtitle>
+<subtitle id="0:5:38"> i pull</subtitle>
+<subtitle id="0:5:41"> out another thing  each time I'm doing</subtitle>
+<subtitle id="0:5:44"> this is the there's  a compilation</subtitle>
+<subtitle id="0:5:47"> going on but it's  sub-second so</subtitle>
+<subtitle id="0:5:50"> it's actually compiling  code underneath</subtitle>
+<subtitle id="0:5:53"> it and I can</subtitle>
+<subtitle id="0:5:56"> actually  even drive my little car</subtitle>
+<subtitle id="0:5:59"> the zero makes  it go straight</subtitle>
+<subtitle id="0:6:2"> but in</subtitle>
+<subtitle id="0:6:5"> fact it's hard to  drive the car this way</subtitle>
+<subtitle id="0:6:8"> and it's a little  bit like kissing your sisters</subtitle>
+<subtitle id="0:6:11"> we really  want to have a</subtitle>
+<subtitle id="0:6:14"> steering wheel so</subtitle>
+<subtitle id="0:6:17">we'll just</subtitle>
+<subtitle id="0:6:20"> make a steering wheel</subtitle>
+<subtitle id="0:6:23"></subtitle>
+<subtitle id="0:6:26"> and  we'll</subtitle>
+<subtitle id="0:6:29"> call it wheel and</subtitle>
+<subtitle id="0:6:32"> again we look  inside here we see</subtitle>
+<subtitle id="0:6:35">same kind of audit it's just got a  different costume</subtitle>
+<subtitle id="0:6:38"> on it and again it has  a</subtitle>
+<subtitle id="0:6:41"> heading and</subtitle>
+<subtitle id="0:6:44"> I get</subtitle>
+<subtitle id="0:6:47"> the same behavior  from it but notice that</subtitle>
+<subtitle id="0:6:50"> we got the car  to turn by</subtitle>
+<subtitle id="0:6:53"> changing this number here</subtitle>
+<subtitle id="0:6:56"> and  that's kind of an invitation of picking  up this value</subtitle>
+<subtitle id="0:6:59"> and dropping it into the  script and</subtitle>
+<subtitle id="0:7:2"> now</subtitle>
+<subtitle id="0:7:5"> we get to do this</subtitle>
+<subtitle id="0:7:8"> so  you're just starting out</subtitle>
+<subtitle id="0:7:11"> here but let</subtitle>
+<subtitle id="0:7:14">ell you if you program in the language  here at UCLA that</subtitle>
+<subtitle id="0:7:17"> doesn't allow you to  do this little demo right</subtitle>
+<subtitle id="0:7:20"> off the bat  something is wrong because</subtitle>
+<subtitle id="0:7:23"> we're looking  at something that goes back 40 years</subtitle>
+<subtitle id="0:7:26">  this is just because you don't know</subtitle>
+<subtitle id="0:7:29"> what  you're getting into here I'm just</subtitle>
+<subtitle id="0:7:32">o show you that there doesn't have to  be a compile</subtitle>
+<subtitle id="0:7:35"> phase it doesn't have to be  edits of files can</subtitle>
+<subtitle id="0:7:38"> all be done  lickety-split</subtitle>
+<subtitle id="0:7:41"> okay so I've got a little  car</subtitle>
+<subtitle id="0:7:44"> there and the other thing I can do  is</subtitle>
+<subtitle id="0:7:47"></subtitle>
+<subtitle id="0:7:50"> make lots of them</subtitle>
+<subtitle id="0:7:53"> so I'm going to  play a game</subtitle>
+<subtitle id="0:7:56"> got a red car and a blue car  and</subtitle>
+<subtitle id="0:7:59"> I'm going to make them small</subtitle>
+<subtitle id="0:8:2"> can you  see</subtitle>
+<subtitle id="0:8:5"> them blue guy and the red guy there  and</subtitle>
+<subtitle id="0:8:8"> the two programs i'm going to run  here</subtitle>
+<subtitle id="0:8:11"> this little kids system has  automatic</subtitle>
+<subtitle id="0:8:14"> multitasking as many tasks as  you want</subtitle>
+<subtitle id="0:8:17"> so I'm going to say</subtitle>
+<subtitle id="0:8:20"> go forward  by one and turn randomly</subtitle>
+<subtitle id="0:8:23"> and this one  says</subtitle>
+<subtitle id="0:8:26"> do this guy and</subtitle>
+<subtitle id="0:8:29">  if a</subtitle>
+<subtitle id="0:8:32"> blue guy sees touches a red guy  then</subtitle>
+<subtitle id="0:8:35"> make the blue guy red so this is  like an infection</subtitle>
+<subtitle id="0:8:38"> programming and so if  i say go</subtitle>
+<subtitle id="0:8:41"> at the top here i'm plotting  the</subtitle>
+<subtitle id="0:8:44"> infected against the non-infected  you</subtitle>
+<subtitle id="0:8:47"> can see that the big</subtitle>
+<subtitle id="0:8:50"> open space here  that the village is is kind</subtitle>
+<subtitle id="0:8:56"> of like a long time constant the</subtitle>
+<subtitle id="0:8:59">probability that the two guys are going  to hit is fairly</subtitle>
+<subtitle id="0:9:2"> low so i'm going to get  that behavior but</subtitle>
+<subtitle id="0:9:5"> what</subtitle>
+<subtitle id="0:9:8"> about a thousand</subtitle>
+<subtitle id="0:9:17"> all</subtitle>
+<subtitle id="0:9:20"> of a sudden I get that so it's  another thing</subtitle>
+<subtitle id="0:9:23">language doesn't allow me to make  objects</subtitle>
+<subtitle id="0:9:26"> by the hundreds of thousands and  run them in parallel then</subtitle>
+<subtitle id="0:9:29">worry about what kind of language you're  programming it</subtitle>
+<subtitle id="0:9:32"> so the kids with this  little program that they wrote</subtitle>
+<subtitle id="0:9:35"> there's  no mystery here they</subtitle>
+<subtitle id="0:9:38"> wrote this program  so now they can</subtitle>
+<subtitle id="0:9:41"> explore by saying well  okay</subtitle>
+<subtitle id="0:9:44"> how about 200</subtitle>
+<subtitle id="0:9:47"></subtitle>
+<subtitle id="0:9:50"> and again the</subtitle>
+<subtitle id="0:9:53">  sparseness acts like a longer time  constant</subtitle>
+<subtitle id="0:9:56"> between infections but</subtitle>
+<subtitle id="0:9:59">eventually</subtitle>
+<subtitle id="0:10:2"> they all died</subtitle>
+<subtitle id="0:10:5"> and</subtitle>
+<subtitle id="0:10:8"> we get this</subtitle>
+<subtitle id="0:10:11">longer thing so the kids will say okay  well</subtitle>
+<subtitle id="0:10:14"> how about 80</subtitle>
+<subtitle id="0:10:29">so now they're starting to root for</subtitle>
+<subtitle id="0:10:32"> the  ones that are maybe</subtitle>
+<subtitle id="0:10:35"> nope</subtitle>
+<subtitle id="0:10:41">so this is kind of an experiment in  system</subtitle>
+<subtitle id="0:10:44"> dynamics for 10 year olds</subtitle>
+<subtitle id="0:10:47"> and  it's</subtitle>
+<subtitle id="0:10:50"> something that many parts the world  don't</subtitle>
+<subtitle id="0:10:53"> actually understand on any terms  because</subtitle>
+<subtitle id="0:10:56"> this first curve that i showed  the</subtitle>
+<subtitle id="0:10:59"> one that went up rapidly is like  typhoid and</subtitle>
+<subtitle id="0:11:2"></subtitle>
+<subtitle id="0:11:5"> so if this last one was a  disease what</subtitle>
+<subtitle id="0:11:8"> would it be like what these  things would it be</subtitle>
+<subtitle id="0:11:11"> blurt it out</subtitle>
+<subtitle id="0:11:14"> let's</subtitle>
+<subtitle id="0:11:17">ee it's a disease that's already killed  100 million people</subtitle>
+<subtitle id="0:11:20"> yeah come on</subtitle>
+<subtitle id="0:11:23"> remember  you're in it you're right UCLA now</subtitle>
+<subtitle id="0:11:26"> yeah  so</subtitle>
+<subtitle id="0:11:29"> why does it kill that many people  when</subtitle>
+<subtitle id="0:11:32"> typhoid is much much more virulent  the</subtitle>
+<subtitle id="0:11:35"> answer is unless you know</subtitle>
+<subtitle id="0:11:38"> that a  contagious</subtitle>
+<subtitle id="0:11:41"> incurable deadly disease is  always</subtitle>
+<subtitle id="0:11:44"> going to kill everybody off no  matter</subtitle>
+<subtitle id="0:11:47"> what the time constant is you're  not going to do</subtitle>
+<subtitle id="0:11:50"> anything when it doesn't  look like anything's going on</subtitle>
+<subtitle id="0:11:53"> remember  people are also being born so</subtitle>
+<subtitle id="0:11:56"> for a  while when AIDS is doing its work the</subtitle>
+<subtitle id="0:11:59">  population is actually still rising and</subtitle>
+<subtitle id="0:12:2">  if you don't happen to know this</subtitle>
+<subtitle id="0:12:5"> feature  of system dynamics you</subtitle>
+<subtitle id="0:12:8"> might just ignore  it or say it's</subtitle>
+<subtitle id="0:12:11"> just for minorities or  something like that then</subtitle>
+<subtitle id="0:12:14"> all of a sudden  you've got a majority</subtitle>
+<subtitle id="0:12:17"> of your population  infected okay so that's a</subtitle>
+<subtitle id="0:12:20"> little thought  experiment that children can do</subtitle>
+<subtitle id="0:12:23">it's</subtitle>
+<subtitle id="0:12:26"> important because if you think  about what is it that we need</subtitle>
+<subtitle id="0:12:29"> to know  today it's not so much knowing</subtitle>
+<subtitle id="0:12:32"> that two  plus two equals four or how</subtitle>
+<subtitle id="0:12:35"> to compute a  tip</subtitle>
+<subtitle id="0:12:38"> for a waiter actually has to do</subtitle>
+<subtitle id="0:12:41">systems dynamics because the world  particularly</subtitle>
+<subtitle id="0:12:44"> biologically is more  connected in more ways</subtitle>
+<subtitle id="0:12:47"> than it ever has  been before and also</subtitle>
+<subtitle id="0:12:50"> our</subtitle>
+<subtitle id="0:12:53"> people in  Congress in Washington could</subtitle>
+<subtitle id="0:12:56"> do well to  do a few of these experiments because</subtitle>
+<subtitle id="0:12:59">  they'd actually have some sense of how</subtitle>
+<subtitle id="0:13:2">  unstable systems are</subtitle>
+<subtitle id="0:13:5"> and you shouldn't  monkey with them</subtitle>
+<subtitle id="0:13:8"> okay so back back here  we'll we'll</subtitle>
+<subtitle id="0:13:11"> turn this guy off and I got</subtitle>
+<subtitle id="0:13:14">  to two other quick little experiments</subtitle>
+<subtitle id="0:13:17">  here first one</subtitle>
+<subtitle id="0:13:20"> is to make a little robot  car now that we made one that can be</subtitle>
+<subtitle id="0:13:23">  driven and for that I will need a track</subtitle>
+<subtitle id="0:13:26">  so I get</subtitle>
+<subtitle id="0:13:29"> sort of a brown track</subtitle>
+<subtitle id="0:13:32"> here and</subtitle>
+<subtitle id="0:13:35">robots</subtitle>
+<subtitle id="0:13:38"> need sensors so I need to put a  sensor</subtitle>
+<subtitle id="0:13:41"> on this guy</subtitle>
+<subtitle id="0:13:44"> so I'll just draw one  in here</subtitle>
+<subtitle id="0:13:50">like this</subtitle>
+<subtitle id="0:13:53"> we'll use this to track</subtitle>
+<subtitle id="0:13:56"> where  are we where we actually are and now</subtitle>
+<subtitle id="0:13:59"> we  need to make a program we can think out</subtitle>
+<subtitle id="0:14:2">  this program first so one of</subtitle>
+<subtitle id="0:14:5">do with children is get them to go  around the wall over their classroom</subtitle>
+<subtitle id="0:14:8">  with their eyes closed and</subtitle>
+<subtitle id="0:14:11"> the way to do  that they soon find out</subtitle>
+<subtitle id="0:14:14"> is you go until  you hit the wall and then you turn</subtitle>
+<subtitle id="0:14:17">but as soon as you lose the wall you  have to go back</subtitle>
+<subtitle id="0:14:20"> into it you keep on  going</subtitle>
+<subtitle id="0:14:23"> if you don't do that right away  you</subtitle>
+<subtitle id="0:14:26"> may lose where the wall actually is  so</subtitle>
+<subtitle id="0:14:29"> right that that little</subtitle>
+<subtitle id="0:14:32"> program we</subtitle>
+<subtitle id="0:14:35">  want the car car is always going to go  forward</subtitle>
+<subtitle id="0:14:38"> so I can get that we're going to  test whether we're</subtitle>
+<subtitle id="0:14:41"> touching the wall or  not here's</subtitle>
+<subtitle id="0:14:44"> a test that will test</subtitle>
+<subtitle id="0:14:47"> let's</subtitle>
+<subtitle id="0:14:50">  see how about the</subtitle>
+<subtitle id="0:14:53"> cars blue</subtitle>
+<subtitle id="0:14:56"> color sees  the walls brown</subtitle>
+<subtitle id="0:14:59"> color and then we have  to figure out which</subtitle>
+<subtitle id="0:15:2"> way to turn here</subtitle>
+<subtitle id="0:15:5"></subtitle>
+<subtitle id="0:15:8"> ok  I'm going to</subtitle>
+<subtitle id="0:15:11"> put in two turns by fives  but let's think it through</subtitle>
+<subtitle id="0:15:14"> so if we  don't have the wall here</subtitle>
+<subtitle id="0:15:17"> which way do we  want to turn</subtitle>
+<subtitle id="0:15:20"> five or minus</subtitle>
+<subtitle id="0:15:23"> 55 ok</subtitle>
+<subtitle id="0:15:26"> so  that's no and so for</subtitle>
+<subtitle id="0:15:29"> yes we'll just take  a guess and try minus 5</subtitle>
+<subtitle id="0:15:32"> here and we'll</subtitle>
+<subtitle id="0:15:41">okay who can see what</subtitle>
+<subtitle id="0:15:44"> the flaw with this  program it is</subtitle>
+<subtitle id="0:15:47"> somebody tell</subtitle>
+<subtitle id="0:15:50"> me</subtitle>
+<subtitle id="0:15:53"> well  don't worry about efficiency</subtitle>
+<subtitle id="0:15:56"> we aren't  humans</subtitle>
+<subtitle id="0:15:59"> aren't efficient but we're smart</subtitle>
+<subtitle id="0:16:2">what's the condition under which it can  lose this</subtitle>
+<subtitle id="0:16:5"> wall</subtitle>
+<subtitle id="0:16:8"> it's going to do with the  Sun but</subtitle>
+<subtitle id="0:16:11"> if I made a sharp turn right</subtitle>
+<subtitle id="0:16:14">  it's got a fixed radius to get back</subtitle>
+<subtitle id="0:16:17"> so  probably when I lose the wall I</subtitle>
+<subtitle id="0:16:20"> might  even want to stop the car slowed it way  way</subtitle>
+<subtitle id="0:16:23"> down to give me a real chance of  contacting</subtitle>
+<subtitle id="0:16:26"> the wall again okay</subtitle>
+<subtitle id="0:16:29"> so that's</subtitle>
+<subtitle id="0:16:32">  a little experiment in making</subtitle>
+<subtitle id="0:16:35"> a feedback  thing now what I want to do is to</subtitle>
+<subtitle id="0:16:38"> turn</subtitle>
+<subtitle id="0:16:41">  this thing into a wriggly worm and to</subtitle>
+<subtitle id="0:16:44"> do  that I</subtitle>
+<subtitle id="0:16:47"> want to make a script that is  going to change</subtitle>
+<subtitle id="0:16:50"> its</subtitle>
+<subtitle id="0:16:53"> shape so here's my  little thing</subtitle>
+<subtitle id="0:16:56"> it says car look like  something but</subtitle>
+<subtitle id="0:16:59"> I don't have anything to  make it look like</subtitle>
+<subtitle id="0:17:2"> so I will</subtitle>
+<subtitle id="0:17:5"> somebody</subtitle>
+<subtitle id="0:17:11">now somebody isn't talking</subtitle>
+<subtitle id="0:17:14"> ok</subtitle>
+<subtitle id="0:17:17"> so now I'm  going to draw</subtitle>
+<subtitle id="0:17:20"> a couple of pictures for  the wriggly worm part of</subtitle>
+<subtitle id="0:17:23"> this</subtitle>
+<subtitle id="0:17:26"> will</subtitle>
+<subtitle id="0:17:29"> make  a blue top and</subtitle>
+<subtitle id="0:17:32"> maybe a brown bottom</subtitle>
+<subtitle id="0:17:35"> here  and just</subtitle>
+<subtitle id="0:17:38"> to test this out</subtitle>
+<subtitle id="0:17:41"> this one is  called sketch one so</subtitle>
+<subtitle id="0:17:44"> if I say do it okay  so that worked</subtitle>
+<subtitle id="0:17:47"> and but I</subtitle>
+<subtitle id="0:17:50"> need another  one in order to make it wriggle</subtitle>
+<subtitle id="0:17:53"> so i  will</subtitle>
+<subtitle id="0:17:56"> make</subtitle>
+<subtitle id="0:17:59"> a twin to it right here</subtitle>
+<subtitle id="0:18:2"></subtitle>
+<subtitle id="0:18:5"> go  with the wriggle the other way</subtitle>
+<subtitle id="0:18:8"> ok</subtitle>
+<subtitle id="0:18:11"> now i  need to move back and forth between each</subtitle>
+<subtitle id="0:18:14">one of these and to choose which one of  these i'm</subtitle>
+<subtitle id="0:18:17"> going to need something that  we might call a little data</subtitle>
+<subtitle id="0:18:20"> structure  here i'm going to</subtitle>
+<subtitle id="0:18:26">now i'm</subtitle>
+<subtitle id="0:18:29"> going to look again see all of  the objects here</subtitle>
+<subtitle id="0:18:32"> have the same kind of  user interface</subtitle>
+<subtitle id="0:18:35"> and going to look down  here and see oh yeah</subtitle>
+<subtitle id="0:18:38"> here's here's the  cursor here's one that</subtitle>
+<subtitle id="0:18:41"> says the holders  player at the cursor</subtitle>
+<subtitle id="0:18:44"> so i'm going to put  that in there and</subtitle>
+<subtitle id="0:18:47"> here's the cursor</subtitle>
+<subtitle id="0:18:50">  control so i'm going to toss that</subtitle>
+<subtitle id="0:18:53"> in  there and I'm going to say what I want</subtitle>
+<subtitle id="0:18:56">o do is just increase the cursor over  and over again and</subtitle>
+<subtitle id="0:18:59"> so now I'll start  this</subtitle>
+<subtitle id="0:19:2"> script up and you see what it's  doing</subtitle>
+<subtitle id="0:19:5"> here ok now we could have put</subtitle>
+<subtitle id="0:19:8"> that  in as a feature for the children but</subtitle>
+<subtitle id="0:19:11">hen</subtitle>
+<subtitle id="0:19:14"> the children wouldn't understand  how to do animation so</subtitle>
+<subtitle id="0:19:17">trying to teach somebody something you  don't want too many features</subtitle>
+<subtitle id="0:19:20"> you want  them to actually do the programming</subtitle>
+<subtitle id="0:19:23">  themselves it meanwhile the children  have</subtitle>
+<subtitle id="0:19:26"> forgotten about these other scripts  that are</subtitle>
+<subtitle id="0:19:29"> there so I could turn on</subtitle>
+<subtitle id="0:19:32"> this  one and drive the</subtitle>
+<subtitle id="0:19:35"> drives a little worm  around</subtitle>
+<subtitle id="0:19:38"> or</subtitle>
+<subtitle id="0:19:41"> what</subtitle>
+<subtitle id="0:19:44"> about this one</subtitle>
+<subtitle id="0:19:53">okay so</subtitle>
+<subtitle id="0:19:56"> okay so that's</subtitle>
+<subtitle id="0:19:59"> kind of simple  programming and</subtitle>
+<subtitle id="0:20:2"> the other thing that you  want to be able</subtitle>
+<subtitle id="0:20:5"> to get a handle on  pretty early in your programming</subtitle>
+<subtitle id="0:20:8"> career  as meta programming and</subtitle>
+<subtitle id="0:20:11"> meta programming  in this case</subtitle>
+<subtitle id="0:20:14"> means I want to I want to  make another language other</subtitle>
+<subtitle id="0:20:17"> than etoys  and I'm</subtitle>
+<subtitle id="0:20:20"> going to do it for the particle</subtitle>
+<subtitle id="0:20:23">  system kinds of stuff</subtitle>
+<subtitle id="0:20:26"> so here's the</subtitle>
+<subtitle id="0:20:29">  these are now eat I objects in</subtitle>
+<subtitle id="0:20:32"> there  these are the scripts</subtitle>
+<subtitle id="0:20:35"> for the whole  interpreter I'm going to</subtitle>
+<subtitle id="0:20:38"> use the animate  remember the animation thing so</subtitle>
+<subtitle id="0:20:41"> if you  know a little bit about program counters  the anime</subtitle>
+<subtitle id="0:20:44"> animation system is rather  like running a program counter</subtitle>
+<subtitle id="0:20:47"> along  when you're doing animations what you're  doing</subtitle>
+<subtitle id="0:20:50"> is saying display the the guy</subtitle>
+<subtitle id="0:20:53">  that's that's there in this case</subtitle>
+<subtitle id="0:20:56"> we're  going to execute instructions and so</subtitle>
+<subtitle id="0:20:59"> I'm  actually going to turn on the eval</subtitle>
+<subtitle id="0:21:2"> here  you can see it</subtitle>
+<subtitle id="0:21:5"> may be a little quivering  a little bit here it's dying</subtitle>
+<subtitle id="0:21:8"> for some  input and then the</subtitle>
+<subtitle id="0:21:11"> the instructions are  going</subtitle>
+<subtitle id="0:21:14"> to be implemented using these  scripts which have already</subtitle>
+<subtitle id="0:21:17"> written and  now I just have to build</subtitle>
+<subtitle id="0:21:20"> the instruction  and</subtitle>
+<subtitle id="0:21:23"> so this one's is a test that</subtitle>
+<subtitle id="0:21:26"> says if  you can move this</subtitle>
+<subtitle id="0:21:29"> one says then move  okay so</subtitle>
+<subtitle id="0:21:32"> now it's executing that  construction and this</subtitle>
+<subtitle id="0:21:35"> one says if</subtitle>
+<subtitle id="0:21:38"> a blue  guy hits a</subtitle>
+<subtitle id="0:21:41"> red guy then make them both  red</subtitle>
+<subtitle id="0:21:44"> let's see if we're lucky here</subtitle>
+<subtitle id="0:21:47"> yep  okay</subtitle>
+<subtitle id="0:21:50"> so programming it and again</subtitle>
+<subtitle id="0:21:53"> when  you're when you're taking that java  class</subtitle>
+<subtitle id="0:21:56"> and you spent the first couple of</subtitle>
+<subtitle id="0:21:59">weeks not really writing a program yet  think</subtitle>
+<subtitle id="0:22:2"> about what's like to write another  programming language in</subtitle>
+<subtitle id="0:22:5"> java should be  really</subtitle>
+<subtitle id="0:22:8"> easy  but it isn't okay</subtitle>
+<subtitle id="0:22:11"> so</subtitle>
+<subtitle id="0:22:14"> so</subtitle>
+<subtitle id="0:22:17">f the theories about designing  programming languages</subtitle>
+<subtitle id="0:22:20"> is because</subtitle>
+<subtitle id="0:22:23">  children are part of our world</subtitle>
+<subtitle id="0:22:26"> and  children grow up in to be being us</subtitle>
+<subtitle id="0:22:29"> we  should be able to have them be able</subtitle>
+<subtitle id="0:22:32"> to  start learning how to program this</subtitle>
+<subtitle id="0:22:35"> is  we're learning how to program and</subtitle>
+<subtitle id="0:22:38"> then  if you do that well the</subtitle>
+<subtitle id="0:22:41"> stuff that  children find easy</subtitle>
+<subtitle id="0:22:44"> and powerful or  actually clues for</subtitle>
+<subtitle id="0:22:47"> how to design a  programming language yourself</subtitle>
+<subtitle id="0:22:50"> okay and  so what we've been looking at</subtitle>
+<subtitle id="0:22:53"> here is  here's computer memory and</subtitle>
+<subtitle id="0:22:56"> down a</subtitle>
+<subtitle id="0:22:59">  flyspeck in</subtitle>
+<subtitle id="0:23:2"> the machine is actually some</subtitle>
+<subtitle id="0:23:5">  logic gates on a chip</subtitle>
+<subtitle id="0:23:8"> one corner of the  chip</subtitle>
+<subtitle id="0:23:11"> and</subtitle>
+<subtitle id="0:23:14"> round it is nano code</subtitle>
+<subtitle id="0:23:17"> microcode  on</subtitle>
+<subtitle id="0:23:20"> the chip itself and</subtitle>
+<subtitle id="0:23:23"> that might be an  86</subtitle>
+<subtitle id="0:23:26"> architecture kind of chip but most of  the chips are done</subtitle>
+<subtitle id="0:23:29"> the same way there's  some</subtitle>
+<subtitle id="0:23:32"> simple logic like this is the  arithmetic is</subtitle>
+<subtitle id="0:23:35"> our registers the  arithmetic unit and</subtitle>
+<subtitle id="0:23:38"> so forth then it's  made into</subtitle>
+<subtitle id="0:23:41"> a slightly more complicated  processor by putting</subtitle>
+<subtitle id="0:23:44"> a lowest level of  programming they're</subtitle>
+<subtitle id="0:23:47"> in pretty elemental  terms that's not always easy to</subtitle>
+<subtitle id="0:23:50"> write  these low-level</subtitle>
+<subtitle id="0:23:53"> programs and then</subtitle>
+<subtitle id="0:23:56"> nobody  wants to program in that</subtitle>
+<subtitle id="0:23:59"> so in this case</subtitle>
+<subtitle id="0:24:2">what we're looking at is a virtual  machine</subtitle>
+<subtitle id="0:24:5"> coated</subtitle>
+<subtitle id="0:24:8"> ultimately in these terms</subtitle>
+<subtitle id="0:24:11">  that makes the computer</subtitle>
+<subtitle id="0:24:14"> look like a  small talk machine and at</subtitle>
+<subtitle id="0:24:17"> this level  there's an area on there</subtitle>
+<subtitle id="0:24:20">manifested where the display is going to  go</subtitle>
+<subtitle id="0:24:23">  and then in that</subtitle>
+<subtitle id="0:24:26"> we write a development  system</subtitle>
+<subtitle id="0:24:29"> you still haven't seen yes</subtitle>
+<subtitle id="0:24:32"> I'm  not going to</subtitle>
+<subtitle id="0:24:35"> but thank you for the  thought that's</subtitle>
+<subtitle id="0:24:38"> too complicated small  talk is a programming language that's</subtitle>
+<subtitle id="0:24:41">  all we need to know it has a development  system</subtitle>
+<subtitle id="0:24:44"> that's written in itself</subtitle>
+<subtitle id="0:24:47"> and the</subtitle>
+<subtitle id="0:24:50">  e toya system that you saw which</subtitle>
+<subtitle id="0:24:53"> is  putting up this slide here</subtitle>
+<subtitle id="0:24:56"> is written in  small talk and</subtitle>
+<subtitle id="0:24:59"> then I just</subtitle>
+<subtitle id="0:25:2"> made a little  interpreter in the</subtitle>
+<subtitle id="0:25:5"> etoys machine for  doing the rule-based particle</subtitle>
+<subtitle id="0:25:8"> system  stuff and this is a very typical</subtitle>
+<subtitle id="0:25:11"> way of  going about handling</subtitle>
+<subtitle id="0:25:14"> problems it's not</subtitle>
+<subtitle id="0:25:17">  the only way some</subtitle>
+<subtitle id="0:25:20"> people like to program  down here and write tons</subtitle>
+<subtitle id="0:25:23"> of programs to  deal with the very same problems another</subtitle>
+<subtitle id="0:25:26">  way of doing it is fine languages that</subtitle>
+<subtitle id="0:25:29">  fit the problems gracefully and then the  amount</subtitle>
+<subtitle id="0:25:32"> of code you have to write to get  to the next level is</subtitle>
+<subtitle id="0:25:35"> not that large and  all</subtitle>
+<subtitle id="0:25:38"> of this is kind of an example of</subtitle>
+<subtitle id="0:25:41">Turing's idea of</subtitle>
+<subtitle id="0:25:44"> being able to simulate  any kind of mechanism on</subtitle>
+<subtitle id="0:25:47"> a relatively  simple mechanism</subtitle>
+<subtitle id="0:25:50"> that has a few pieces  of logic in a fair</subtitle>
+<subtitle id="0:25:53"> amount of memory okay  so</subtitle>
+<subtitle id="0:25:56"> that's the kitty world</subtitle>
+<subtitle id="0:25:59"> now let's</subtitle>
+<subtitle id="0:26:2">a look at the adult world where we're  going to go from</subtitle>
+<subtitle id="0:26:5"> programs that have tens</subtitle>
+<subtitle id="0:26:8">of lines in the kiddie world but can  still do interesting things</subtitle>
+<subtitle id="0:26:11"> to adult  programs which tend to have</subtitle>
+<subtitle id="0:26:14"> zillions of  lines and are</subtitle>
+<subtitle id="0:26:17"> surprisingly weak and in</subtitle>
+<subtitle id="0:26:20">order to come up with a metric for this  I'm going</subtitle>
+<subtitle id="0:26:23"> to use a metric of lines of  code</subtitle>
+<subtitle id="0:26:26"> it's not the only metric you could  use but a</subtitle>
+<subtitle id="0:26:29"> line of code is something that  a programmer has to write so</subtitle>
+<subtitle id="0:26:32"> it is one  kind of unit of work and it's also unit</subtitle>
+<subtitle id="0:26:35">of space  so</subtitle>
+<subtitle id="0:26:38"> a 400-page book has 20,000</subtitle>
+<subtitle id="0:26:41">could</subtitle>
+<subtitle id="0:26:44"> be English but it could be code</subtitle>
+<subtitle id="0:26:47">  could be in machine</subtitle>
+<subtitle id="0:26:50"> code it could be and  see it could be in Java and</subtitle>
+<subtitle id="0:26:53"> a foot of  books is about</subtitle>
+<subtitle id="0:26:56"> 300,000 lines and a meter  of</subtitle>
+<subtitle id="0:26:59"> books stacked up like this is a  million</subtitle>
+<subtitle id="0:27:2"> line so that's a good metric  million lines of</subtitle>
+<subtitle id="0:27:5"> code per meter and  stacked up books and</subtitle>
+<subtitle id="0:27:8"></subtitle>
+<subtitle id="0:27:11"> the Empire State</subtitle>
+<subtitle id="0:27:14">  Building is twenty-two</subtitle>
+<subtitle id="0:27:17"> thousand books  high and</subtitle>
+<subtitle id="0:27:20"> 440 million lines of code</subtitle>
+<subtitle id="0:27:23"> right  so</subtitle>
+<subtitle id="0:27:26"> if you've ever heard anybody heard of  any programming systems</subtitle>
+<subtitle id="0:27:29"> that have 400  million lines of code</subtitle>
+<subtitle id="0:27:32"> yes though come on</subtitle>
+<subtitle id="0:27:38">yeah yeah take a look</subtitle>
+<subtitle id="0:27:41"> at our government  sometime in</subtitle>
+<subtitle id="0:27:44"> fact if you look at your own  little</subtitle>
+<subtitle id="0:27:47"> only the laptop</subtitle>
+<subtitle id="0:27:50"> if you happen to  be running Microsoft the operating</subtitle>
+<subtitle id="0:27:53">  system is about 120 million lines of</subtitle>
+<subtitle id="0:27:56">code remember there's just the operating  system it hasn't</subtitle>
+<subtitle id="0:27:59"> done anything for you  yet just sitting</subtitle>
+<subtitle id="0:28:2"> there and then  Microsoft Office is over</subtitle>
+<subtitle id="0:28:5"> a hundred  million lines of code</subtitle>
+<subtitle id="0:28:8"> so that's</subtitle>
+<subtitle id="0:28:11"> 220  million lines of code it's about</subtitle>
+<subtitle id="0:28:14"> seven  eleven thousand books of code</subtitle>
+<subtitle id="0:28:17"> anybody</subtitle>
+<subtitle id="0:28:20">  ever read all that code no way</subtitle>
+<subtitle id="0:28:23"> very few  people who read</subtitle>
+<subtitle id="0:28:26"> it all have read eleven  thousand books of anything I</subtitle>
+<subtitle id="0:28:29"> can  guarantee you if you read it all</subtitle>
+<subtitle id="0:28:32">not going to read eleven thousand books  of code so</subtitle>
+<subtitle id="0:28:35"> most of the code has never  been over</subtitle>
+<subtitle id="0:28:38"> viewed by any single person or  even any single</subtitle>
+<subtitle id="0:28:41"> group in fact much of  the code in there</subtitle>
+<subtitle id="0:28:44"> is code that isn't  even run but</subtitle>
+<subtitle id="0:28:47">out because they don't know whether it's  run or not</subtitle>
+<subtitle id="0:28:50"> and this is it this</subtitle>
+<subtitle id="0:28:53"> is a  problem on the other hand</subtitle>
+<subtitle id="0:28:56"> the looking at  it from</subtitle>
+<subtitle id="0:28:59"> the standpoint of writing code  the</subtitle>
+<subtitle id="0:29:2"> when you look at the actual features</subtitle>
+<subtitle id="0:29:5">  you get for this 220</subtitle>
+<subtitle id="0:29:8"> million lines of  code it doesn't seem like it should be</subtitle>
+<subtitle id="0:29:11">  should take 220 million lines of code</subtitle>
+<subtitle id="0:29:14">  just shouldn't back the first time  around it</subtitle>
+<subtitle id="0:29:17"> was done it Xerox PARC did  about</subtitle>
+<subtitle id="0:29:20"> half of this and it only took ten  thousand lines of code</subtitle>
+<subtitle id="0:29:23"> so something  happened some</subtitle>
+<subtitle id="0:29:26"> kind of explosion of  complications</subtitle>
+<subtitle id="0:29:29"> and complexity and here</subtitle>
+<subtitle id="0:29:32">  just to make you feel better I located a</subtitle>
+<subtitle id="0:29:35">  large financial products company whose  name</subtitle>
+<subtitle id="0:29:38"> I will not put here that has more</subtitle>
+<subtitle id="0:29:41">  than 400 million lines of code in its</subtitle>
+<subtitle id="0:29:44">  primary offerings to its customers so</subtitle>
+<subtitle id="0:29:47">  this is what they are actually  maintained</subtitle>
+<subtitle id="0:29:50">  and you can tell they're a little  old-fashioned</subtitle>
+<subtitle id="0:29:53"> because their user  interface is given in terms</subtitle>
+<subtitle id="0:29:56"> of screens  which harks back to the</subtitle>
+<subtitle id="0:29:59">mainframes they have a hundred and  seventy thousand</subtitle>
+<subtitle id="0:30:2"> screens they have to  deal with and</subtitle>
+<subtitle id="0:30:5"> that's about 20,000 books  or</subtitle>
+<subtitle id="0:30:8"> almost an empire state building</subtitle>
+<subtitle id="0:30:11"> worth  of code</subtitle>
+<subtitle id="0:30:14"> however if you're looking</subtitle>
+<subtitle id="0:30:17"> for a  job you came to UCLA to learn to</subtitle>
+<subtitle id="0:30:20"> program  and get a job it's just this kind of  stuff that</subtitle>
+<subtitle id="0:30:23"> you actually have to learn  about because that is what</subtitle>
+<subtitle id="0:30:26"> business is  mired in right now this is</subtitle>
+<subtitle id="0:30:29">hiring people this is why they're crying  for programmers</subtitle>
+<subtitle id="0:30:32"> not to do better</subtitle>
+<subtitle id="0:30:35"> but  just to take care of the mess that is</subtitle>
+<subtitle id="0:30:38">  already there think about that</subtitle>
+<subtitle id="0:30:41"> okay</subtitle>
+<subtitle id="0:30:44"> so  I'm going to stick</subtitle>
+<subtitle id="0:30:47"> to I'll show you a  couple</subtitle>
+<subtitle id="0:30:50"> of examples in the time that's  left of what might be done</subtitle>
+<subtitle id="0:30:56">part of personal competed these several  hundred</subtitle>
+<subtitle id="0:30:59"> millions of lines of code</subtitle>
+<subtitle id="0:31:2"> okay  so let's take a look at</subtitle>
+<subtitle id="0:31:5"> this problem  from a slightly different perspective</subtitle>
+<subtitle id="0:31:8">over</subtitle>
+<subtitle id="0:31:11"> here we've got some gates</subtitle>
+<subtitle id="0:31:14"> over here  we've got a</subtitle>
+<subtitle id="0:31:17"> problem this is what</subtitle>
+<subtitle id="0:31:20"> we need  we need to do something over</subtitle>
+<subtitle id="0:31:23"> here and  the question is is what is it going to  take us to get</subtitle>
+<subtitle id="0:31:26"> from there to there these  days and</subtitle>
+<subtitle id="0:31:29"></subtitle>
+<subtitle id="0:31:32"> so in terms of machine code</subtitle>
+<subtitle id="0:31:35">  lots of the kinds of things I'm</subtitle>
+<subtitle id="0:31:38">about or literally billions of lines of  code because</subtitle>
+<subtitle id="0:31:41"> machine code is written one  instruction per line of code</subtitle>
+<subtitle id="0:31:44"> and maybe</subtitle>
+<subtitle id="0:31:47">  see gives</subtitle>
+<subtitle id="0:31:50"> eight to ten machine</subtitle>
+<subtitle id="0:31:53"> code  instructions per line of code so maybe  something</subtitle>
+<subtitle id="0:31:56"> that would be billions would</subtitle>
+<subtitle id="0:31:59">  be hundreds of millions in C</subtitle>
+<subtitle id="0:32:2">  and we can imagine</subtitle>
+<subtitle id="0:32:5"> a higher level  language</subtitle>
+<subtitle id="0:32:8"> than C not</subtitle>
+<subtitle id="0:32:11"> the job is that much  higher level language</subtitle>
+<subtitle id="0:32:14"> higher level in C  but could</subtitle>
+<subtitle id="0:32:17"> imagine something higher level  you can imagine something</subtitle>
+<subtitle id="0:32:20"> higher level  imagine something it might do a lot</subtitle>
+<subtitle id="0:32:23"> of  these tasks in just thousands of lines  of</subtitle>
+<subtitle id="0:32:26"> code and the question is why</subtitle>
+<subtitle id="0:32:29"> do</subtitle>
+<subtitle id="0:32:32"> we  stay here down at the gear level for</subtitle>
+<subtitle id="0:32:35">  most of the programmatic that is still  done today</subtitle>
+<subtitle id="0:32:38"> and there's</subtitle>
+<subtitle id="0:32:41"> hot not a lot of  the organization</subtitle>
+<subtitle id="0:32:44"> of code at this level  which is a little bit more like</subtitle>
+<subtitle id="0:32:47"> the way  biology organizes itself</subtitle>
+<subtitle id="0:32:50"> almost none of  this still</subtitle>
+<subtitle id="0:32:53"> being done</subtitle>
+<subtitle id="0:32:56"> ok so the</subtitle>
+<subtitle id="0:32:59">  programming effort comes down as we go  to higher and</subtitle>
+<subtitle id="0:33:2"> higher level languages</subtitle>
+<subtitle id="0:33:5"> but  computer</subtitle>
+<subtitle id="0:33:8"> science has not actually been</subtitle>
+<subtitle id="0:33:11">  up to the challenge of</subtitle>
+<subtitle id="0:33:14"> putting in the  amount of invention that's necessary</subtitle>
+<subtitle id="0:33:17"> to  make programming systems that do this  amount</subtitle>
+<subtitle id="0:33:20"> of work for us so we can think of  and in</subtitle>
+<subtitle id="0:33:23"> between is just a lot of work for  any kind of</subtitle>
+<subtitle id="0:33:26">because there's packaging this  documentation</subtitle>
+<subtitle id="0:33:29"> there's debuggers there's  an</subtitle>
+<subtitle id="0:33:32"> enormous amount of work that has to  be done and</subtitle>
+<subtitle id="0:33:35"> the idea is that with more</subtitle>
+<subtitle id="0:33:38">  work which gets tougher as you come this</subtitle>
+<subtitle id="0:33:41">  way you actually reduce the general  programming</subtitle>
+<subtitle id="0:33:44"> effort so this is not  popular so virtually</subtitle>
+<subtitle id="0:33:47"> all of the  programming in business in the u.s.</subtitle>
+<subtitle id="0:33:50">  today is done at this level still and</subtitle>
+<subtitle id="0:33:53">this is a level that is really not  different from the</subtitle>
+<subtitle id="0:33:56"> level of programming  in the 60s almost</subtitle>
+<subtitle id="0:33:59"> nothing has changed  new languages</subtitle>
+<subtitle id="0:34:2"> have come along but they  have not up their level in</subtitle>
+<subtitle id="0:34:5"> any  significant way</subtitle>
+<subtitle id="0:34:8"> but</subtitle>
+<subtitle id="0:34:11">  just to go against the tide here even</subtitle>
+<subtitle id="0:34:14">though you're going to be studying a lot  of this stuff here</subtitle>
+<subtitle id="0:34:17"> I just want to make  you aware of these</subtitle>
+<subtitle id="0:34:20"> ideas down here which  if you're interested in research</subtitle>
+<subtitle id="0:34:23"> and in  making things better you might poke</subtitle>
+<subtitle id="0:34:26"> your  head in two now</subtitle>
+<subtitle id="0:34:29"> what's funny about  history is</subtitle>
+<subtitle id="0:34:32"> that there are people who are  absolute</subtitle>
+<subtitle id="0:34:35"> geniuses who transcend</subtitle>
+<subtitle id="0:34:38"> the time  in which they live so</subtitle>
+<subtitle id="0:34:41"> 50 years ago</subtitle>
+<subtitle id="0:34:44"> there  was no computer graphics</subtitle>
+<subtitle id="0:34:47"> this is the guy  who invented computer graphics</subtitle>
+<subtitle id="0:34:50"> and he  also invented</subtitle>
+<subtitle id="0:34:53"> object-oriented design</subtitle>
+<subtitle id="0:34:56">  systems so</subtitle>
+<subtitle id="0:34:59"> he actually did the work in  62 and</subtitle>
+<subtitle id="0:35:2"> wrote it up in 63 so this is  still</subtitle>
+<subtitle id="0:35:5"> the 50th anniversary of this I  thought you'd like to see</subtitle>
+<subtitle id="0:35:8"> what this very  first</subtitle>
+<subtitle id="0:35:11"> interactive graphic system looked</subtitle>
+<subtitle id="0:35:14">  like and what it could do now the first  thing you have to</subtitle>
+<subtitle id="0:35:17"> visualize is this guy  is sitting</subtitle>
+<subtitle id="0:35:20"> here with a pointer in his  hand a</subtitle>
+<subtitle id="0:35:23"> light pen but he's in a computer  that is about</subtitle>
+<subtitle id="0:35:26"> eight times maybe 10 times  the</subtitle>
+<subtitle id="0:35:29"> size of this room it</subtitle>
+<subtitle id="0:35:32"> was close to  the size of at least the first franz</subtitle>
+<subtitle id="0:35:35">  hall building it</subtitle>
+<subtitle id="0:35:38"> had its own roof it was  the</subtitle>
+<subtitle id="0:35:41"> building and it was</subtitle>
+<subtitle id="0:35:44">computer and from three o'clock in the  morning to six o'clock</subtitle>
+<subtitle id="0:35:47"> in the morning  they let this one guy play</subtitle>
+<subtitle id="0:35:50"> around with  it and so</subtitle>
+<subtitle id="0:35:53"> here's what he did and by the  way this is not actually a computer</subtitle>
+<subtitle id="0:35:56">  display it just was an oscilloscope that</subtitle>
+<subtitle id="0:35:59">  put up spots so the first thing he had  to</subtitle>
+<subtitle id="0:36:2"> do was to write programs that would  make lines</subtitle>
+<subtitle id="0:36:5"> and arcs and and so forth</subtitle>
+<subtitle id="0:36:8"> and  about a third of the capacity</subtitle>
+<subtitle id="0:36:11"> of this  enormous machine was used just to make</subtitle>
+<subtitle id="0:36:14"> a  simulated graphics display because there  were</subtitle>
+<subtitle id="0:36:17"> no graphics this place okay so</subtitle>
+<subtitle id="0:36:20"> this  will give you an idea</subtitle>
+<subtitle id="0:36:23">  so it gets</subtitle>
+<subtitle id="0:36:26"> some ink</subtitle>
+<subtitle id="0:36:32">and</subtitle>
+<subtitle id="0:36:35"> he just sketches in this flange  because look at he's pointing</subtitle>
+<subtitle id="0:36:38"> at it now  and he's giving it a constraint</subtitle>
+<subtitle id="0:36:41"> to make  everybody mutually perpendicular and</subtitle>
+<subtitle id="0:36:44">  what you saw there was sketchpad solving  the problem</subtitle>
+<subtitle id="0:36:47"> for him all</subtitle>
+<subtitle id="0:36:50"> right so this  way you program this system</subtitle>
+<subtitle id="0:36:53"> was by  telling it what you wanted</subtitle>
+<subtitle id="0:36:56"> to have true  and sketchpad and figure out how to have</subtitle>
+<subtitle id="0:36:59">it be true same idea here make these two  guys parallel</subtitle>
+<subtitle id="0:37:2"></subtitle>
+<subtitle id="0:37:5"> now the constraint is</subtitle>
+<subtitle id="0:37:8">  collinearity put</subtitle>
+<subtitle id="0:37:11"> these lines down these  dashes I'm putting in here</subtitle>
+<subtitle id="0:37:14"> down on top  of</subtitle>
+<subtitle id="0:37:17"> the guidelines</subtitle>
+<subtitle id="0:37:23">now he says</subtitle>
+<subtitle id="0:37:26"> okay let's make the  guidelines transparent and</subtitle>
+<subtitle id="0:37:29"> now we've got  a hole in the flange and</subtitle>
+<subtitle id="0:37:32"> you notice it  has continued</subtitle>
+<subtitle id="0:37:35"> assuming the first  clipping window ever</subtitle>
+<subtitle id="0:37:38"> done is that  actually the drawing is</subtitle>
+<subtitle id="0:37:41"> done on a sheet  of virtual paper about a third</subtitle>
+<subtitle id="0:37:44"> of a mile  square now he wants</subtitle>
+<subtitle id="0:37:47"> to make a rivet</subtitle>
+<subtitle id="0:37:50"> he's  going to use the center here for</subtitle>
+<subtitle id="0:37:56">and now he's going to do the same trick</subtitle>
+<subtitle id="0:37:59">  he's going to say to these guys take</subtitle>
+<subtitle id="0:38:2">these guys to make them all mutually  poopin perpendicular</subtitle>
+<subtitle id="0:38:5"> that's going to  drag the crosspieces</subtitle>
+<subtitle id="0:38:8"> that's going to  drag the</subtitle>
+<subtitle id="0:38:11"> top of the rivet now he's going  to show</subtitle>
+<subtitle id="0:38:14"> I'll</subtitle>
+<subtitle id="0:38:17"> start off with different  initial starting conditions</subtitle>
+<subtitle id="0:38:20">till get something that obeys the  constraints</subtitle>
+<subtitle id="0:38:23"> that i gave it now i could  have put in absolute numbers in</subtitle>
+<subtitle id="0:38:26"> there  you could have putted ratios</subtitle>
+<subtitle id="0:38:29"> this is why  it's called sketch pad</subtitle>
+<subtitle id="0:38:32"> the idea is you  should be able to work</subtitle>
+<subtitle id="0:38:35"> quickly get a  rough idea of it</subtitle>
+<subtitle id="0:38:38"> and then tell the  computer the rules that if</subtitle>
+<subtitle id="0:38:41"> they were  solved was completed</subtitle>
+<subtitle id="0:38:44"> okay now he's</subtitle>
+<subtitle id="0:38:47">  showing that what he drew is</subtitle>
+<subtitle id="0:38:50"> not just a  rivet</subtitle>
+<subtitle id="0:38:53"> but it what it's what we call</subtitle>
+<subtitle id="0:38:56">class in an object-oriented language  which</subtitle>
+<subtitle id="0:38:59"> he called a master so what he</subtitle>
+<subtitle id="0:39:2">there was the master drawing of a rivet  and</subtitle>
+<subtitle id="0:39:5"> what he's manipulating here is an  instance of</subtitle>
+<subtitle id="0:39:14">so</subtitle>
+<subtitle id="0:39:17"> now he's showing yeah</subtitle>
+<subtitle id="0:39:20"> I can make more  instances of the rivet</subtitle>
+<subtitle id="0:39:23"> and I can make  them different</subtitle>
+<subtitle id="0:39:26"> sizes and so forth</subtitle>
+<subtitle id="0:39:29"> but he  forgot that cross P</subtitle>
+<subtitle id="0:39:32"> so he goes to the  master makes those guys transparent and  we</subtitle>
+<subtitle id="0:39:35"> can see the rivet feels the instances  of</subtitle>
+<subtitle id="0:39:38"> the rivet feels those things then</subtitle>
+<subtitle id="0:39:41"> the  last part of this demo</subtitle>
+<subtitle id="0:39:44"> is</subtitle>
+<subtitle id="0:39:47"> that he can  take</subtitle>
+<subtitle id="0:39:50"> anything that he is</subtitle>
+<subtitle id="0:39:53"> constructed and  make it into a master so</subtitle>
+<subtitle id="0:39:56"> now this is a  master drawing of a flange</subtitle>
+<subtitle id="0:39:59"> with a rivet  in it and now</subtitle>
+<subtitle id="0:40:2"> he's</subtitle>
+<subtitle id="0:40:5"> making instances of  those</subtitle>
+<subtitle id="0:40:8"> ok so</subtitle>
+<subtitle id="0:40:11"> this is a yes go ahead</subtitle>
+<subtitle id="0:40:29">yeah yeah</subtitle>
+<subtitle id="0:40:32"> in fact on the larger movie  which you can find online</subtitle>
+<subtitle id="0:40:35"> you can see  the sheet is populated with lots</subtitle>
+<subtitle id="0:40:38"> of  different things on it yes oh</subtitle>
+<subtitle id="0:40:41"> okay okay  so</subtitle>
+<subtitle id="0:40:44"> so</subtitle>
+<subtitle id="0:40:47"> you have to realize this is a PhD  thesis this is done in</subtitle>
+<subtitle id="0:40:50"> one year by one  person and</subtitle>
+<subtitle id="0:40:53"> what the contributions</subtitle>
+<subtitle id="0:40:56"> were  is first interactive</subtitle>
+<subtitle id="0:40:59"> computer graphics  object-oriented</subtitle>
+<subtitle id="0:41:2"> design structures</subtitle>
+<subtitle id="0:41:5">  constraints for</subtitle>
+<subtitle id="0:41:8"> programming so you  didn't program it using</subtitle>
+<subtitle id="0:41:11"> sequential code  at all and</subtitle>
+<subtitle id="0:41:14"> one</subtitle>
+<subtitle id="0:41:17"> of the great final</subtitle>
+<subtitle id="0:41:20"> things  he did was to show how you could make a</subtitle>
+<subtitle id="0:41:23">  bridge simulation without</subtitle>
+<subtitle id="0:41:26"> sketchpad  knowing about bridges ahead of time</subtitle>
+<subtitle id="0:41:29">because the whole point of this thing  was that sketch pad</subtitle>
+<subtitle id="0:41:32">know ahead of time what you were going  to try and do in</subtitle>
+<subtitle id="0:41:35"> it the ideas you should  be able to do everything in</subtitle>
+<subtitle id="0:41:38"> fact the all</subtitle>
+<subtitle id="0:41:41">of these drawings were made by sketch  pad and the</subtitle>
+<subtitle id="0:41:44"> the text here these each</subtitle>
+<subtitle id="0:41:47">text figure is actually a drawing and  sketch pad so</subtitle>
+<subtitle id="0:41:50"> there's a master for f and  everywhere</subtitle>
+<subtitle id="0:41:53"> there's an F there's an  instance of it so the whole system</subtitle>
+<subtitle id="0:41:56"> was  done and this thing and I wants to ask</subtitle>
+<subtitle id="0:41:59">  ivan how could you have done computer</subtitle>
+<subtitle id="0:42:2">  graphics object oriented design and</subtitle>
+<subtitle id="0:42:8">constraint based programming</subtitle>
+<subtitle id="0:42:11"> all by  yourself in one year and he said well I  didn't know</subtitle>
+<subtitle id="0:42:14"> it was hard since</subtitle>
+<subtitle id="0:42:17"> then ok so  the bridge there's</subtitle>
+<subtitle id="0:42:20"> no movie of the  bridge because it took the</subtitle>
+<subtitle id="0:42:23"> supercomputer  back in 1962</subtitle>
+<subtitle id="0:42:26"> about 20 seconds for each  time step</subtitle>
+<subtitle id="0:42:29"> on it because of the computer</subtitle>
+<subtitle id="0:42:32">power of this computer the size of a  building was about</subtitle>
+<subtitle id="0:42:35">card  today</subtitle>
+<subtitle id="0:42:38"> but</subtitle>
+<subtitle id="0:42:41"> to</subtitle>
+<subtitle id="0:42:44"> celebrate the anniversary  of</subtitle>
+<subtitle id="0:42:47"> this system a couple of the guys at  viewpoints</subtitle>
+<subtitle id="0:42:50"> Burke freudenberg and Yoshi  Yoshi ki o Shiva</subtitle>
+<subtitle id="0:42:53"> made a version of this</subtitle>
+<subtitle id="0:42:56">  of this bridge</subtitle>
+<subtitle id="0:42:59"> sketch n and</subtitle>
+<subtitle id="0:43:2"> we put in  the twinkling there</subtitle>
+<subtitle id="0:43:5"> so it looked like  the display back then and</subtitle>
+<subtitle id="0:43:8">move</subtitle>
+<subtitle id="0:43:11"> things in you can turn on gravity</subtitle>
+<subtitle id="0:43:14">ou can hang</subtitle>
+<subtitle id="0:43:17"> away from it</subtitle>
+<subtitle id="0:43:20"> even when it  settles down</subtitle>
+<subtitle id="0:43:23"> it has</subtitle>
+<subtitle id="0:43:26"> a really settle down  if I turn on the decimal points here</subtitle>
+<subtitle id="0:43:29"> see  if still wiggling</subtitle>
+<subtitle id="0:43:32"> just like wheel  bridges</subtitle>
+<subtitle id="0:43:35"> do and</subtitle>
+<subtitle id="0:43:38"> I can tenderize</subtitle>
+<subtitle id="0:43:41"> me to  watch what happens when I stick</subtitle>
+<subtitle id="0:43:44"> this  beam in here take a look</subtitle>
+<subtitle id="0:43:47"> at the numbers  of the stress and strain around it</subtitle>
+<subtitle id="0:43:50"> when  I drop this guy in here and</subtitle>
+<subtitle id="0:43:53"> notice the  sky over on the</subtitle>
+<subtitle id="0:43:56"> Left felt that ripple  across</subtitle>
+<subtitle id="0:44:2">yeah</subtitle>
+<subtitle id="0:44:5"> so one</subtitle>
+<subtitle id="0:44:8"> of the main things that's  got people</subtitle>
+<subtitle id="0:44:11"> going from sketchpad most it  was too</subtitle>
+<subtitle id="0:44:14"> hard for people to really know  what to do</subtitle>
+<subtitle id="0:44:17"> with but one thing they were  sure about was they</subtitle>
+<subtitle id="0:44:20"> needed better  looking display so here's the very</subtitle>
+<subtitle id="0:44:23">thing rendered with them with a modern  display and we</subtitle>
+<subtitle id="0:44:26"> can do a few more tricks  like</subtitle>
+<subtitle id="0:44:29"> we can give letters wait</subtitle>
+<subtitle id="0:44:38">okay</subtitle>
+<subtitle id="0:44:41"> and we programmed this a little bit  differently than</subtitle>
+<subtitle id="0:44:44"> fact we've done this  several times now one of the</subtitle>
+<subtitle id="0:44:47"> students in  this class last year Matthew Goldberg</subtitle>
+<subtitle id="0:44:50">  what did</subtitle>
+<subtitle id="0:44:53"> an internship with us and</subtitle>
+<subtitle id="0:44:56"> did a  different version of</subtitle>
+<subtitle id="0:44:59"> this did a nice job  of</subtitle>
+<subtitle id="0:45:2"> it we programmed it</subtitle>
+<subtitle id="0:45:5"> up in terms of  three</subtitle>
+<subtitle id="0:45:8"> constraints not</subtitle>
+<subtitle id="0:45:11">constraints that Ivan used but a  different kind</subtitle>
+<subtitle id="0:45:14"> of constraint for  instance this one looks suspiciously  like it</subtitle>
+<subtitle id="0:45:17"> might have something to do with  gravity so</subtitle>
+<subtitle id="0:45:20"> this is way to think of is  this the three line</subtitle>
+<subtitle id="0:45:23"> program here so if I  turn this off</subtitle>
+<subtitle id="0:45:26"></subtitle>
+<subtitle id="0:45:29"> so all we've got left is  the spring</subtitle>
+<subtitle id="0:45:32"> tension here should</subtitle>
+<subtitle id="0:45:35"> all know  laut which it does so we'll turn</subtitle>
+<subtitle id="0:45:38"> gravity  back on again</subtitle>
+<subtitle id="0:45:47">and this</subtitle>
+<subtitle id="0:45:50"> bottom guy is the constraint  for</subtitle>
+<subtitle id="0:45:53"> these pins so</subtitle>
+<subtitle id="0:45:56"> this bridge is pinned  together and if I turn</subtitle>
+<subtitle id="0:45:59"> off the pin  constraint that's holding everything</subtitle>
+<subtitle id="0:46:2">  together in this simulation</subtitle>
+<subtitle id="0:46:17">yeah so remember</subtitle>
+<subtitle id="0:46:20"> all those costumes  that's all that bridge</subtitle>
+<subtitle id="0:46:23"> was and we can  repurpose those costumes</subtitle>
+<subtitle id="0:46:26"> into something  else like the</subtitle>
+<subtitle id="0:46:29"> user interface of this  system I'm giving</subtitle>
+<subtitle id="0:46:32"> the right so this is a</subtitle>
+<subtitle id="0:46:35">  system that we programmed ourselves at  viewpoints</subtitle>
+<subtitle id="0:46:38"> and it's a system</subtitle>
+<subtitle id="0:46:41"> I'm giving  this talking I'm not obviously not using  PowerPoint</subtitle>
+<subtitle id="0:46:44"> because you can't program in  PowerPoint and</subtitle>
+<subtitle id="0:46:47"></subtitle>
+<subtitle id="0:46:50"> I'm using it to show you  i'm</subtitle>
+<subtitle id="0:46:53"> going to show you one example  because that's all I have time</subtitle>
+<subtitle id="0:46:56"> for</subtitle>
+<subtitle id="0:46:59"></subtitle>
+<subtitle id="0:47:2"> and  that is how the graphics in this</subtitle>
+<subtitle id="0:47:8">we're programmed now</subtitle>
+<subtitle id="0:47:11"> usually the  graphics in your personal computer are</subtitle>
+<subtitle id="0:47:14">about half a million to a million lines  of code to</subtitle>
+<subtitle id="0:47:17"> do all of the</subtitle>
+<subtitle id="0:47:20"> compositing and  so forth</subtitle>
+<subtitle id="0:47:23"> and what we're going to look at  here is just take a look</subtitle>
+<subtitle id="0:47:26"> at the  rendering part</subtitle>
+<subtitle id="0:47:29"> of this a render of being</subtitle>
+<subtitle id="0:47:32">  able to paint a pixel with the right</subtitle>
+<subtitle id="0:47:35">  shade so Dan a meringue here is a  graduate</subtitle>
+<subtitle id="0:47:38"> student at UC San Diego works  with us came</subtitle>
+<subtitle id="0:47:41"> up with this formula so  it's a nice little piece of math</subtitle>
+<subtitle id="0:47:44"> to  represent it here's a</subtitle>
+<subtitle id="0:47:47"> programming  language that is as close to the formula  as</subtitle>
+<subtitle id="0:47:50"> possible it's about twice the size of  the</subtitle>
+<subtitle id="0:47:53"> math but it actually runs and it  handles all rendering</subtitle>
+<subtitle id="0:47:56"> stuff done like</subtitle>
+<subtitle id="0:47:59">  this and</subtitle>
+<subtitle id="0:48:2"> I'll just to give you</subtitle>
+<subtitle id="0:48:11">now we have this</subtitle>
+<subtitle id="0:48:14"> flow of stuff with this  programming</subtitle>
+<subtitle id="0:48:17"> graphics language sets up  and</subtitle>
+<subtitle id="0:48:20"> what we what we wind up getting is</subtitle>
+<subtitle id="0:48:23">  something that's very complex to look at</subtitle>
+<subtitle id="0:48:26">  and debug but Bret Victor look them</subtitle>
+<subtitle id="0:48:29"> up  on Google did this visualizer</subtitle>
+<subtitle id="0:48:32"> that's  created automatically from the</subtitle>
+<subtitle id="0:48:35"> code i  just showed you and this</subtitle>
+<subtitle id="0:48:38"> is a live  system so</subtitle>
+<subtitle id="0:48:41"> here's a tourney i'm going to  turn</subtitle>
+<subtitle id="0:48:44"> a addy into a</subtitle>
+<subtitle id="0:48:47"> be here</subtitle>
+<subtitle id="0:48:50"> and if i want  to know where</subtitle>
+<subtitle id="0:48:53"> this pixel and the  rendering comes from i</subtitle>
+<subtitle id="0:48:56"> can just put the  mouse on it and</subtitle>
+<subtitle id="0:48:59"> touches this if i want  to see where this guy</subtitle>
+<subtitle id="0:49:2"> is handled in the  code if i want</subtitle>
+<subtitle id="0:49:5"> to see how the pipeline</subtitle>
+<subtitle id="0:49:8">  that's set up here of these</subtitle>
+<subtitle id="0:49:11"> five small  programs</subtitle>
+<subtitle id="0:49:14"> here i can just go here if I  want it where did this pixel come from</subtitle>
+<subtitle id="0:49:17">what</subtitle>
+<subtitle id="0:49:20"> happens if I turn this</subtitle>
+<subtitle id="0:49:23"> so when  you're doing languages of</subtitle>
+<subtitle id="0:49:26"> the future the  system is going to have to also produce</subtitle>
+<subtitle id="0:49:29">  the debuggers along with the languages</subtitle>
+<subtitle id="0:49:32">  themselves okay I think I</subtitle>
+<subtitle id="0:49:35"> think it's a  hard stop at ten of so</subtitle>
+<subtitle id="0:49:38"> I won't put any  strain on you but if</subtitle>
+<subtitle id="0:49:41"> you're interested  hang around and ask some questions and  with</subtitle>