Jed Buchwald: Isaac Newton and the Philosophy of Science

00:00:00.000 | The following is a conversation with Jed Buchwald,

00:00:03.640 | a professor of history and a philosopher of science

00:00:06.480 | at Caltech, interested especially in the development

00:00:10.720 | of scientific concepts and the instruments used to create

00:00:14.320 | and explore new effects and ideas in science.

00:00:19.320 | To support this podcast,

00:00:21.040 | please check out our sponsors in the description.

00:00:24.160 | This is the Lex Friedman Podcast,

00:00:26.840 | and here is my conversation with Jed Buchwald.

00:00:30.400 | Does science progress via paradigm shifts and revolutions,

00:00:36.440 | as philosopher Thomas Kuhn said,

00:00:38.220 | or does it progress gradually?

00:00:39.920 | What do you think?

00:00:41.320 | - Well, I got into this field

00:00:43.640 | 'cause I was Tom Kuhn's research assistant 50 years ago,

00:00:47.480 | 52 years ago. - Wow.

00:00:49.120 | - He pulled me into it out of physics instead.

00:00:52.640 | So I know his work pretty well,

00:00:54.480 | and in the years when I was at MIT running an institute,

00:00:58.520 | he was then in the philosophy department,

00:01:00.720 | used to come over all the time

00:01:02.840 | to the talks we held and so on.

00:01:05.680 | So what would I say about that?

00:01:07.800 | He, of course, developed his ideas a lot over the years.

00:01:11.520 | The thing that he's famous for,

00:01:13.400 | the structure of scientific revolutions, came out in '62.

00:01:17.840 | And as you just said, it offered an outline

00:01:24.240 | for what he called a paradigmatic structure,

00:01:26.600 | namely the notion that you have to look

00:01:29.840 | at what scientists do as forming a community

00:01:33.360 | of investigators, and that they're trying

00:01:36.560 | to solve various puzzles, as he would put it,

00:01:39.560 | that crop up, figuring out how this works,

00:01:42.720 | how that works, and so on.

00:01:44.520 | And of course, they don't do it out of the blue.

00:01:46.400 | They do it within a certain framework.

00:01:49.260 | The framework can be pretty vague.

00:01:51.280 | He called it a paradigm.

00:01:53.160 | And his notion was that eventually,

00:01:55.760 | they run into troubles, or what he called anomalies,

00:01:59.360 | that kind of cracks things.

00:02:01.320 | Somebody new comes along

00:02:03.360 | with a different way of doing it, et cetera.

00:02:05.720 | Do I think things work that way?

00:02:07.480 | No, not really.

00:02:08.620 | Tom and I used to have lengthy discussions

00:02:12.160 | about that over the years.

00:02:13.700 | I do think there is a common structure

00:02:19.600 | that formulates both theoretical

00:02:21.920 | and experimental practices.

00:02:24.520 | And historians nowadays of science

00:02:26.440 | like to refer to scientific work

00:02:28.800 | as what scientists practice.

00:02:30.840 | It's almost craftsman-like.

00:02:33.200 | They can usually adapt in various ways.

00:02:38.480 | And I can give you all kinds of examples of that.

00:02:42.000 | I once wrote a book on the origins

00:02:44.760 | of wave theory of light, and that is one

00:02:47.740 | of the paradigmatic examples that Tom used,

00:02:51.160 | only it didn't work that way exactly.

00:02:54.480 | Because he thought that what happened was

00:02:57.960 | that the wave theory ran into trouble

00:03:02.160 | with a certain phenomenon which it couldn't crack.

00:03:05.800 | Well, it turned out that, in fact,

00:03:07.640 | historically, that phenomenon was actually

00:03:11.560 | not relevant later on to the wave theory.

00:03:16.120 | And when the wave theory came in,

00:03:18.700 | the alternative to it which had prevailed,

00:03:20.780 | which was Newton's views of light as particles,

00:03:24.560 | that, it seemed, couldn't explain

00:03:26.440 | what the wave theory could explain.

00:03:28.440 | Again, not true.

00:03:29.900 | Not true.

00:03:32.320 | Much more complex than that.

00:03:33.840 | The wave theory offered the opportunity

00:03:36.640 | to deploy novel experimental and mathematical structures

00:03:41.640 | which gave younger scientists, mathematicians and others,

00:03:46.080 | the opportunity to effect, manufacture,

00:03:50.900 | make new sorts of devices.

00:03:54.260 | It's not that the alternative couldn't

00:03:56.060 | sort of explain these things,

00:03:58.420 | but it never was able to generate them de novo,

00:04:02.620 | as novelties.

00:04:04.060 | In other words, if you think of it

00:04:05.300 | as something scientists wanted to progress

00:04:08.740 | in the sense of finding new stuff to solve,

00:04:12.300 | then I think what often happens is

00:04:14.300 | that it's not so much that the prevailing view

00:04:17.260 | can't crack something as that it doesn't give you

00:04:20.420 | the opportunity to do new stuff.

00:04:23.340 | - When you say new stuff,

00:04:24.340 | are we referring to experimental science here

00:04:26.780 | or new stuff in the space of new theories?

00:04:29.900 | - Could be both.

00:04:30.900 | Could be both, actually.

00:04:32.980 | - So how does that, can you maybe elaborate

00:04:34.780 | a little bit on the story of the wave view?

00:04:36.820 | - Sure.

00:04:37.660 | The prevailing view of light, at least in France,

00:04:41.860 | where the wave theory really first took off,

00:04:44.240 | although it had been introduced in England by Thomas Young,

00:04:47.400 | the prevailing theory dates back to Newton,

00:04:50.140 | that light is a stream of particles,

00:04:52.720 | and that refraction and reflection

00:04:54.660 | involve sort of repulsive and attractive forces

00:04:58.420 | that deflect and bend the paths of these particles.

00:05:02.000 | Newton was not able successfully to deal with

00:05:06.060 | the phenomenon of what happens when light

00:05:09.140 | goes past a knife's edge or a sharp edge,

00:05:13.100 | what we now call diffraction.

00:05:15.580 | He had cooked up something about it

00:05:18.860 | that no mathematical structure could be applied.

00:05:21.420 | Thomas Young first, but really this guy named

00:05:25.640 | Augustin Fresnel in France, deployed, in Fresnel's case,

00:05:30.640 | rather advanced calculus forms of mathematics

00:05:36.040 | which enabled computations to be done

00:05:39.240 | and observations to be melded with these computations

00:05:43.500 | in a way that you could not do or see how to do with Newton.

00:05:47.900 | Did that mean that the Newtonian explanation

00:05:50.800 | of what goes on in diffraction fails?

00:05:53.720 | Not really.

00:05:54.900 | You can actually make it work,

00:05:59.020 | but you can't generate anything new out of it.

00:06:02.160 | Whereas, using the mathematics of wave optics

00:06:07.080 | in respect to a particular phenomenon called polarization,

00:06:11.320 | which ironically was discovered by partisans

00:06:14.320 | of Newton's way of doing things,

00:06:16.640 | you were able to generate devices

00:06:19.360 | which reflect light and crystals, do various things,

00:06:24.160 | that the Newtonian way could accommodate

00:06:28.600 | only after the fact.

00:06:30.840 | They couldn't generate it from the beginning.

00:06:33.400 | And so, if you want to be somebody

00:06:36.360 | who is working a novel vein,

00:06:39.480 | which increasingly becomes the case

00:06:41.360 | with people who become what we now call physicists

00:06:46.200 | in the 1820s, '30s, and '40s in particular,

00:06:49.900 | then that's the direction you're gonna go.

00:06:51.900 | But there were holdouts until the 1850s.

00:06:55.440 | - I wanna try to elaborate on the nature

00:06:57.440 | of the disagreement you have with Thomas Kuhn.

00:06:59.320 | So, do you still believe in paradigm shifts?

00:07:01.800 | Do you still see that there's ideas

00:07:04.440 | that really have a transformational effect on science?

00:07:07.800 | The nature of the disagreement has to do

00:07:10.760 | with how those paradigm shifts come to be?

00:07:14.580 | - How they come to be and how they change.

00:07:18.240 | I certainly think they exist.

00:07:20.640 | How strong they may be at any given time

00:07:24.280 | is maybe not quite as powerful as Tom thought in general.

00:07:29.360 | Although, towards the end of his life,

00:07:30.920 | he was beginning to develop different modifications

00:07:35.760 | of his original way of thinking.

00:07:38.080 | But I don't think that the changes happened

00:07:40.240 | quite so neatly, if you will,

00:07:44.600 | in reaction to novel experimental observations.

00:07:49.400 | They can be much more complex than that.

00:07:51.400 | - In terms of neatness,

00:07:55.720 | how much of science progresses by individual lone geniuses

00:08:00.720 | and how much by the messy collaboration

00:08:04.240 | of competing and cooperating humans?

00:08:09.240 | - I don't think you can cut that with a knife

00:08:16.680 | to say it's this percent and that percent.

00:08:20.000 | It's almost always the case that there are one or two

00:08:25.280 | or maybe three individuals who are sort of central

00:08:30.280 | to what goes on when things begin to shift.

00:08:34.980 | Are they inevitably and solely responsible

00:08:40.240 | for what then begins to happen in a major way?

00:08:45.240 | I think not.

00:08:47.120 | It depends.

00:08:47.960 | You can go very far back with this,

00:08:52.460 | even into antiquity, to see what goes on.

00:08:55.120 | The major locus we always talk about from the beginning

00:09:00.600 | is if you're talking about Galileo's work on motion,

00:09:03.620 | for example, were there ways of accommodating it

00:09:08.040 | that others could adapt to

00:09:10.260 | without buying into the whole scheme?

00:09:12.420 | Yes.

00:09:13.260 | Did it eventually evolve and start convincing people

00:09:17.960 | because you could also do other things with it

00:09:21.100 | that you couldn't otherwise do?

00:09:23.260 | Also yes.

00:09:24.700 | Let me give you an example.

00:09:26.300 | The great French mathematician philosopher Descartes,

00:09:30.060 | who was a mechanical philosopher,

00:09:32.900 | he believed the world was matter in motion,

00:09:36.460 | he never thought much of what Galileo had done

00:09:39.020 | in respect to motion because he thought,

00:09:41.580 | well, at best it's some sort of approximative scheme

00:09:44.160 | or something like that.

00:09:45.940 | But one of his initial, I wouldn't call him a disciple,

00:09:50.980 | but follower who then broke with him in a number of ways,

00:09:54.220 | was a man named Christian Huygens,

00:09:56.500 | who was, along with Newton,

00:09:57.980 | one of the two greatest scientists of the 17th century.

00:10:02.220 | Huygens is older than Newton.

00:10:04.060 | And Huygens nicely deployed Galilean relationships

00:10:09.060 | in respect to motion to develop all sorts of things,

00:10:13.940 | including the first pendulum-governed clock,

00:10:19.440 | and even figured out how to build one

00:10:21.480 | which keeps perfect time, except it didn't work.

00:10:24.760 | But he had the mathematical structure for it.

00:10:27.240 | - How well known is Huygens?

00:10:28.560 | - Oh, very well known.

00:10:29.560 | - Should I know him well?

00:10:31.200 | - Yes, you should.

00:10:32.480 | - Interesting.

00:10:33.360 | - You should definitely know him well.

00:10:34.720 | - No, no, no, no, no.

00:10:35.960 | Can we define should here?

00:10:37.920 | - Okay.

00:10:38.760 | - Because I don't.

00:10:39.680 | - Right.

00:10:40.520 | - Yeah, can you define should?

00:10:48.880 | - Should means this.

00:10:50.700 | If you had taken up to a second year of physics courses,

00:10:54.840 | you should, you would have heard his name

00:10:57.360 | because one of the fundamental principles in optics

00:10:59.960 | is called Huygens' principle.

00:11:02.040 | - Okay. - Okay?

00:11:04.400 | - Yeah, so I have, and I have heard his name.

00:11:07.120 | - There you go.

00:11:08.000 | - No, but I don't remember.

00:11:08.840 | - But you don't remember.

00:11:09.880 | - So I mean, there's a very different thing

00:11:12.560 | between names attached to principles and laws and so on

00:11:16.760 | that you sometimes let go of,

00:11:18.240 | you just remember the equations of the principles themselves

00:11:21.640 | and the personalities of science.

00:11:23.800 | And there's certain personalities,

00:11:25.720 | certain human beings that stand out.

00:11:28.480 | And that's why there's a sense to which the lone inventor,

00:11:32.920 | the lone scientist is the way I personally,

00:11:36.520 | I mean, I think a lot of people think about

00:11:38.520 | the history of science is these lone geniuses.

00:11:41.740 | Without them, the sense is,

00:11:43.560 | if you remove Newton from the picture,

00:11:45.800 | if you remove Galileo from the picture,

00:11:48.440 | then science would, there's almost a feeling like

00:11:51.600 | it would just have stopped there.

00:11:54.000 | Or at the very least, there's a feeling like

00:11:56.680 | it would take much longer to develop

00:11:58.320 | the things that were developed.

00:11:59.400 | Is that a silly way to look at the history of science?

00:12:02.000 | - That's not entirely incorrect, I suppose.

00:12:05.620 | I find it difficult to believe that had Galileo not existed

00:12:13.920 | that eventually someone like Huygens, for instance,

00:12:17.920 | given the context of the time,

00:12:20.500 | what was floating around in the belief structure

00:12:24.800 | concerning the nature of the world and so on,

00:12:27.880 | the developments in mathematics and whatnot,

00:12:31.240 | that sooner or later,

00:12:33.400 | whether it would have been exactly the same or not,

00:12:36.540 | I cannot say, but would things have evolved?

00:12:40.880 | Yes.

00:12:42.480 | - If we look at the long arc of history of science

00:12:47.480 | from back when we were in the caves

00:12:52.640 | trying to knock two rocks together

00:12:55.240 | or maybe make a basic tool to a long time from now,

00:13:01.120 | many centuries from now,

00:13:03.120 | when human civilization finally destroys itself.

00:13:06.400 | If we look at that history,

00:13:08.720 | and imagine you're a historian at the end,

00:13:12.340 | like with the fire of the apocalypse coming upon us,

00:13:16.120 | and you look back at this time in the 21st century,

00:13:20.240 | how far along are we on that arc?

00:13:23.440 | Do you sense?

00:13:25.120 | Have we invented and discovered everything

00:13:27.080 | that's to be discovered, or are we at like below 1%?

00:13:30.840 | - (laughs) Well--

00:13:32.900 | - You're gonna get a lot of absurd questions today.

00:13:35.600 | I apologize.

00:13:36.560 | - It's a lugubrious picture you're painting there.

00:13:40.040 | - I don't even know what the word lugubrious means,

00:13:42.280 | but I love it.

00:13:43.120 | (laughs)

00:13:43.960 | Lugubrious.

00:13:44.780 | - Well, let me try and separate the question

00:13:48.680 | of whether we're all going to die in an apocalypse

00:13:51.320 | in several hundred years or not

00:13:53.000 | from the question of where science may be sitting.

00:13:57.840 | - Take that as an assumption.

00:13:59.760 | - Okay.

00:14:00.600 | I find that hard to say.

00:14:04.840 | And I find it hard to say

00:14:06.480 | because in the deepest sense of the term,

00:14:12.800 | as it's usually deployed by philosophers of science today,

00:14:18.000 | I'm not fundamentally a realist.

00:14:21.100 | That is to say, I think our access

00:14:25.360 | to the inner workings of nature

00:14:30.140 | is inevitably mediated by what we can do

00:14:35.060 | with the materials and factors around us.

00:14:39.680 | We can probe things in various ways.

00:14:42.480 | Does that mean that I don't think that the standard model

00:14:46.800 | in quantum electrodynamics is incorrect?

00:14:48.860 | Of course not.

00:14:50.320 | I wouldn't even dream of saying such a thing.

00:14:52.520 | It can do a lot,

00:14:53.820 | especially when it comes to figuring out what's happening

00:14:58.220 | in very large, expensive particle accelerators

00:15:02.820 | and applying results in cosmology and so on as well.

00:15:07.680 | Do I think that we have inevitably probed

00:15:13.740 | the depths of reality through this?

00:15:16.180 | I do not agree with Steven Weinberg,

00:15:18.180 | who thinks we have, about such things.

00:15:21.140 | Do I, on the other hand, think that the way

00:15:25.320 | in which science has been moving for the last 100 years,

00:15:29.020 | physics in particular is what I have in mind,

00:15:31.820 | will continue on the same course?

00:15:35.740 | In that sense, I don't,

00:15:37.300 | because we're not going to be building bigger and bigger

00:15:39.940 | and more and more expensive machines

00:15:42.920 | to rip apart particles in various ways.

00:15:46.480 | In which case, what are physicists gonna do?

00:15:49.120 | They'll turn their attention to other aspects.

00:15:51.760 | There are all sorts of things we've never explained.

00:15:55.300 | About the material world, we don't have theories

00:15:58.960 | that go beyond a certain point for all sorts of things.

00:16:02.580 | We can, can we, for example, start with the standard model

00:16:07.300 | and work our way up all the way to chemical transformations?

00:16:11.460 | You can make an argument about it,

00:16:13.840 | and you can justify things, but that's in chemistry,

00:16:17.420 | that's not the way people work.

00:16:19.480 | They work with much higher level

00:16:20.900 | quantum mechanical relationships and so on.

00:16:23.980 | So this notion of the deep theory to explain everything

00:16:28.220 | is a longstanding belief,

00:16:33.220 | which goes back pretty far,

00:16:37.140 | although I think it only takes its fullest form

00:16:40.180 | sometime in towards the end of the 19th century.

00:16:45.200 | - So maybe we just speak to that,

00:16:46.940 | you're referring to a hope, a dream,

00:16:50.140 | a reality of coming up with a theory of everything

00:16:53.500 | that explains everything.

00:16:55.180 | So there's a very specific thing

00:16:57.120 | that that currently means in physics,

00:16:59.540 | is the unification of the laws of physics.

00:17:02.300 | But I'm sure in antiquity or before,

00:17:05.860 | it meant maybe something else,

00:17:07.260 | or is it always about physics?

00:17:08.940 | 'Cause I mean, I think as you've kind of implied,

00:17:12.000 | in physics there's a sense

00:17:15.300 | once you get to the theory of everything,

00:17:16.740 | you've understood everything.

00:17:18.460 | But there's a very deep sense

00:17:19.980 | in which you've actually understood not very much at all.

00:17:22.600 | You've understood at that particular level how things work,

00:17:25.980 | but you don't understand how the abstractions

00:17:28.140 | on top of abstractions form,

00:17:29.960 | all the way to the chemistry, to the human mind,

00:17:31.920 | and the human societies, and all those kinds of things.

00:17:35.140 | So maybe you can speak to the theory of everything

00:17:38.500 | and its history, and comment on what the heck

00:17:41.460 | does that even mean, a theory of everything.

00:17:43.740 | - Well, I don't think you can go back that far

00:17:46.540 | with something like that.

00:17:47.660 | Maybe to the, at best to the 17th century.

00:17:51.500 | If you go back all the way in antiquity,

00:17:53.300 | there are of course discussions

00:17:55.300 | about the nature of the world.

00:17:59.140 | But first of all, you have to recognize

00:18:03.140 | that the manipulative character of physics and chemistry,

00:18:10.700 | the probing of, let me put it this way.

00:18:16.380 | We assume, and have assumed for a long time,

00:18:21.060 | I'll come back to when in a moment,

00:18:23.300 | that if I take a little device,

00:18:26.480 | which is really complicatedly made,

00:18:29.040 | out of all kinds of things,

00:18:30.940 | and I put a piece of some material in it,

00:18:34.340 | and I monkey around with it,

00:18:36.340 | and do all kinds of unnatural things to it,

00:18:39.100 | things that wouldn't happen naturally,

00:18:41.780 | and I find out how it behaves and whatnot,

00:18:44.820 | and then I try and make an argument

00:18:46.900 | about how that really applies,

00:18:49.240 | even in the natural world

00:18:50.660 | without any artificial structures and so on,

00:18:54.380 | that's not a belief that was widely held

00:18:58.020 | by pretty much anyone until sometime maybe in the 1500s.

00:19:03.020 | And when it was first held,

00:19:05.240 | it was held by people we now call alchemists.

00:19:09.020 | So alchemy was the first,

00:19:10.540 | the early days of the theory of everything,

00:19:12.340 | of a dream of a theory of everything.

00:19:14.120 | I would put it a little differently.

00:19:15.900 | I think it's more along the way,

00:19:18.600 | a dream that by probing nature

00:19:22.940 | in artificially constructed ways,

00:19:26.420 | we can find out what's going on deep down there.

00:19:30.460 | - So that's distinct from science being an observing thing,

00:19:37.740 | where you observe nature and you study nature.

00:19:40.860 | You're talking about probing,

00:19:42.500 | like messing with nature to understand it.

00:19:45.660 | - Indeed I am.

00:19:46.700 | But that of course is the very essence

00:19:48.620 | of experimental science.

00:19:51.400 | You have to manipulate nature

00:19:56.280 | to find out things about it.

00:19:58.400 | And then you have to convince others

00:20:01.920 | that you haven't so manipulated it

00:20:05.120 | that what you've done is to produce

00:20:07.300 | what amounts to fake, artifactual behavior

00:20:11.080 | that doesn't really hold purely naturally.

00:20:14.880 | - So where are we today in your sense

00:20:17.920 | to jump around a little bit with the theory of everything?

00:20:21.280 | Maybe a quick kind of sense you have

00:20:25.640 | about the journey in the world of physics

00:20:28.680 | that we're taking towards the theory of everything.

00:20:31.800 | - Well, I'm of course not a practicing physicist.

00:20:34.940 | I mean, I was trained in physics at Princeton

00:20:37.720 | a long time ago.

00:20:39.000 | - Until Thomas Kuhn stole you away.

00:20:41.560 | - More or less.

00:20:42.400 | I was taking graduate courses

00:20:44.320 | in those days in general relativity.

00:20:46.120 | I was an undergraduate,

00:20:47.200 | but I moved up and then I took a course with him.

00:20:51.000 | - Well, you made the mistake of being compelled

00:20:54.280 | by charismatic philosophers and never looked back.

00:20:57.400 | - I suppose so in a way.

00:21:00.040 | And from what I understand,

00:21:03.340 | talking especially to my friends at Caltech,

00:21:06.520 | like Kip Thorne and others,

00:21:10.880 | the fundamental notion is that actually the laws

00:21:15.880 | that even at the deepest level we can sort of divine

00:21:21.200 | and work with in the universe that we inhabit

00:21:26.480 | are perhaps quite unique to this particular universe

00:21:31.380 | as it formed at the Big Bang.

00:21:33.260 | The question is, how deep does it go?

00:21:39.480 | If you are very mathematically inclined,

00:21:42.080 | the prevailing notion for several decades now

00:21:45.960 | has been what's called string theory,

00:21:47.980 | but that has not been able to figure a way

00:21:54.520 | to generate probative experimental evidence,

00:21:58.840 | although it's pretty good apparently at accommodating things.

00:22:02.100 | And then the question is, what's before the Big Bang?

00:22:07.800 | Or actually the word before doesn't mean anything

00:22:10.320 | given the nature of time,

00:22:11.680 | but why do we have the laws that prevail in our universe?

00:22:16.680 | Well, there is a notion that those laws prevail

00:22:23.960 | in our universe because if they didn't, we wouldn't be here.

00:22:28.960 | (laughs)

00:22:30.760 | - That's a bit of a cyclical,

00:22:32.000 | but nevertheless a compelling definition.

00:22:34.800 | And there's all kinds of things

00:22:36.160 | like it seems like the unification of those laws

00:22:40.760 | could be discovered by looking inside of a black hole

00:22:43.200 | 'cause you get both the general relativity

00:22:45.080 | and the quantum mechanics, quantum field theory in there.

00:22:48.280 | Experimentally, of course,

00:22:50.600 | there's a lot of interesting ideas.

00:22:52.040 | We can't really look close to the Big Bang,

00:22:54.360 | can't look that far back.

00:22:56.080 | There's Caltech and MIT will let go,

00:22:58.720 | look at gravitational waves,

00:23:00.280 | perhaps allows us to march backwards and so on.

00:23:03.160 | Yeah, it's a really exciting space.

00:23:04.480 | And there's, of course, the theory of everything

00:23:08.000 | like with a lot of things in science

00:23:10.440 | captivates the dreams of those

00:23:12.080 | who are perhaps completely outside of science.

00:23:14.680 | It's the dream of discovering the key

00:23:16.840 | to how the nature of how everything works.

00:23:20.580 | And that feels deeply human.

00:23:25.640 | That's perhaps the thing,

00:23:26.800 | the basic elements of what makes up a scientist in the end

00:23:31.600 | is that curiosity, that longing to understand.

00:23:34.740 | Let me ask, you mentioned a disagreement

00:23:39.760 | with Weinberg on reality.

00:23:42.020 | Could you elaborate a little bit?

00:23:44.760 | - Well, obviously I don't disagree

00:23:48.440 | with Steve Weinberg on physics itself.

00:23:51.360 | I wouldn't know enough to even begin to do that.

00:23:54.680 | And clearly, he's one of the founders

00:23:56.720 | of the standard model and so on,

00:23:58.920 | and it works to a level of accuracy

00:24:02.800 | that no physical theory has ever worked at before.

00:24:05.620 | I suppose the question in my mind is something that

00:24:11.860 | in one way could go back to the philosopher Immanuel Kant

00:24:16.760 | in the 18th century,

00:24:18.120 | namely, can we really ever convince ourselves

00:24:24.480 | that we have come to grips with something

00:24:29.120 | that is not in itself knowable to us by our senses

00:24:34.120 | or even except in the most remote way

00:24:41.240 | through the complex instruments that we make

00:24:44.560 | as to what it is that underlies everything.

00:24:47.320 | Can we corral it with mathematics

00:24:50.640 | and experimental structures?

00:24:52.280 | Yes.

00:24:54.100 | Do I think that a particular way of corralling nature

00:24:58.880 | will inevitably play itself out?

00:25:02.080 | I don't know.

00:25:03.520 | It always has.

00:25:05.160 | I'll put it to you that way.

00:25:06.660 | - So the basic question is, can we know reality?

00:25:13.520 | Is that the Kant question?

00:25:18.860 | Is that the Weinberg question?

00:25:22.720 | We humans with our brains, can we comprehend reality?

00:25:27.720 | Sounds like a very trippy question

00:25:31.220 | 'cause a lot of it rests on definitions of know

00:25:34.420 | and comprehend and reality, but get to the bottom of it.

00:25:38.580 | Turtles on top of turtles, can we get to the bottom turtle?

00:25:43.980 | - Well-- - And say hello.

00:25:46.720 | - Maybe I can put it to you this way.

00:25:51.160 | In a way that I often begin discussions in a class

00:25:56.160 | on the history of science and so on

00:26:02.680 | and say I'm looking at you.

00:26:05.780 | - Yes.

00:26:06.620 | - You are in fact a figment of my imagination.

00:26:10.260 | - You have a messed up imagination, yes.

00:26:13.900 | - Well, what do I mean by that?

00:26:16.480 | If I were a dragonfly looking at you,

00:26:20.960 | whatever my nervous system would form

00:26:26.980 | by way of a perceptual structure

00:26:31.040 | would clearly be utterly different

00:26:34.620 | from what my brain and perceptual system altogether

00:26:39.620 | is forming when I look at you.

00:26:42.900 | Who's right?

00:26:46.840 | Who?

00:26:48.460 | Is it me or the dragonfly?

00:26:50.740 | - Well, the dragonfly is certainly very impressive

00:26:56.420 | so I don't know, but yes, the observer matters.

00:27:00.180 | - Well-- - What is that supposed

00:27:06.620 | to tell us about objective reality?

00:27:08.760 | - Well, I think it means that it's very difficult

00:27:12.940 | to get beyond the constructs that our perceptual system

00:27:17.940 | is leading us to.

00:27:21.640 | When we make apparatus and devices and so on,

00:27:25.340 | we're still making things, the results of which

00:27:28.840 | or the outputs of which we process perceptually

00:27:32.180 | in various ways.

00:27:33.780 | And an analogy I like to use with students sometimes

00:27:37.720 | is this, all right, they all have their laptops open

00:27:40.360 | in front of them, of course, okay?

00:27:42.500 | And I've sent them something to read.

00:27:47.460 | And I say, okay, click on it and open it up.

00:27:50.140 | So PDF opens up.

00:27:51.620 | I said, what are you looking at?

00:27:53.700 | They said, well, I'm looking at the paper that you sent me.

00:27:57.140 | I said, no, you're not.

00:27:59.140 | What you're looking at is a stream of light

00:28:01.780 | coming off LEDs or LCDs coming off a screen.

00:28:06.780 | And I said, what happens when you use your mouse

00:28:09.780 | and move that fake piece of paper on the screen around?

00:28:14.320 | What are you doing?

00:28:15.360 | You're not moving a piece of paper around, are you?

00:28:17.500 | You're moving a construct around,

00:28:20.340 | a construct that's being processed

00:28:22.900 | so that our perceptual system can interact with it

00:28:26.660 | in the way we interact with pieces of paper.

00:28:30.940 | But it's not real.

00:28:33.240 | - So are there things outside of the reach of science?

00:28:40.040 | Can you maybe, as an example, talk about consciousness?

00:28:45.040 | I'm asking for a friend, trying to figure this thing out.

00:28:48.060 | - Well, boy, I mean, I read a fair bit about that,

00:28:54.920 | but I certainly can't really say much about it.

00:28:58.640 | I'm a materialist in the deepest sense of the term.

00:29:06.640 | I don't think there is anything out there

00:29:09.400 | except material structures which interact in various ways.

00:29:14.400 | Do I think, for example,

00:29:16.720 | that this bottle of water is conscious?

00:29:19.280 | No, I do not.

00:29:20.460 | Although, how would I know?

00:29:23.240 | I can't talk to it.

00:29:25.120 | But, so what do--

00:29:26.640 | - It's a hypothesis you have.

00:29:28.000 | It's an opinion, an educated opinion that may be very wrong.

00:29:31.440 | - Well, I know that you're conscious

00:29:32.880 | because I can interact directly with you.

00:29:35.400 | But am I?

00:29:36.760 | - Well, unless you're a figment of my imagination, of course.

00:29:39.200 | - No, or I'm a robot that's able to generate the illusion.

00:29:43.480 | - Yes.

00:29:44.320 | - The illusion of consciousness effectively enough

00:29:47.480 | to facilitate a good conversation.

00:29:49.400 | 'Cause we humans do want to pretend

00:29:51.040 | that we're talking to other conscious beings

00:29:52.720 | 'cause that's how we respect them.

00:29:53.920 | If it's not conscious, we don't respect them.

00:29:56.240 | We're not good at talking to robots.

00:29:57.520 | - That's true.

00:29:58.360 | Of course, we generalize from our own inner sense,

00:30:00.680 | which is the kind of thing Descartes said

00:30:03.040 | from the beginning.

00:30:04.280 | We generalize from that.

00:30:05.640 | But I do think that consciousness must be something,

00:30:10.640 | whatever it is, that occurs as a result

00:30:14.680 | of some particular organizational structure

00:30:17.480 | of material elements.

00:30:20.920 | - Does materialism mean that it's all

00:30:24.520 | within the reach of science?

00:30:27.060 | - My sense would be that, especially as neuroscience,

00:30:33.960 | progresses more and more.

00:30:36.840 | And at Caltech, we just built a whole neuroscience arena

00:30:41.320 | and so on.

00:30:42.280 | And as more knowledge is gained about the ways

00:30:46.720 | in which animals, when they behave,

00:30:50.620 | what patterns show up at various parts of the brain

00:30:54.680 | and nervous system, and perhaps extending it

00:30:57.680 | to humans eventually as well,

00:31:00.640 | we'll get more of a handle on what brain activity

00:31:05.640 | is associated with experiences that we have as humans.

00:31:10.680 | Can we move from the brain activity to the experiences

00:31:18.800 | in terms of our, no, you can't.

00:31:21.940 | Perception is perception.

00:31:23.520 | - That's a hypothesis once again.

00:31:27.520 | - Maybe consciousness is just one of the laws of physics

00:31:32.520 | that's yet to be discovered.

00:31:35.440 | Maybe it permeates all matter.

00:31:37.840 | Maybe it's as simple as trying to plug it in

00:31:41.800 | and plug into the ability to generate

00:31:45.720 | and control that kind of law of physics

00:31:48.460 | that would crack open, or we would understand

00:31:52.120 | that the bottle of water is in fact conscious,

00:31:54.760 | just much less conscious than us humans.

00:31:57.020 | And then we would be able to then generate

00:31:59.840 | beings that are more conscious.

00:32:01.400 | - Well, that'll be unfortunate.

00:32:03.400 | I'd have to stop drinking the water after that.

00:32:06.440 | - Every time you take a sip,

00:32:08.640 | there's a little bit of a suffering going on.

00:32:11.440 | - Right.

00:32:12.360 | - What to use the most interesting, beautiful moments

00:32:16.360 | in the history of science?

00:32:17.600 | What stands out?

00:32:18.600 | And then we can pull at that thread.

00:32:21.320 | - Right.

00:32:23.360 | Well, I like to think of events that have

00:32:27.960 | a major impact and involve both beautiful,

00:32:33.540 | conceptual, mathematical,

00:32:37.960 | if we're talking physical structures work,

00:32:40.220 | and are associated as well

00:32:42.180 | with probing experimental situations.

00:32:46.720 | So among my favorites is one of the most famous,

00:32:51.640 | which was the young Isaac Newton's work

00:32:55.840 | with the colors produced

00:32:57.680 | when you pass sunlight through a prism.

00:32:59.780 | And why do I like that?

00:33:02.880 | It's not profoundly mathematical in one sense,

00:33:08.000 | doesn't need it initially.

00:33:09.880 | It needs the following though,

00:33:11.760 | which begins to show you, I think,

00:33:13.620 | a little bit about what gets involved

00:33:15.660 | when you've got a smart individual

00:33:17.200 | who's trying to monkey around with stuff

00:33:19.240 | and finds new things about it.

00:33:21.180 | First, let me say that the notion,

00:33:24.200 | the prevailing notion going back to antiquity,

00:33:26.660 | was that colors are produced in a sense

00:33:30.560 | by modifying or tinting white light,

00:33:34.400 | that they're modifications of white light.

00:33:37.240 | In other words, the colors are not in the sunlight

00:33:40.660 | in any way, okay?

00:33:42.520 | Now, what Newton did following experiments

00:33:47.160 | done by Descartes before him,

00:33:48.840 | who came to very different conclusions,

00:33:51.120 | he took a prism, you might ask,

00:33:54.560 | where do you get prisms in the 1660s?

00:33:57.000 | - That's a good question.

00:33:58.720 | - County fairs, they were very popular.

00:34:01.040 | They were pretty crude with bubbles in them and everything,

00:34:04.040 | but they produced colors,

00:34:05.200 | so you could buy them at county fairs and things,

00:34:07.320 | very popular.

00:34:08.200 | - Oh, so they were modifying the white light

00:34:10.480 | to create colors.

00:34:11.320 | - Well, they were creating colors from it, well known.

00:34:16.080 | And what he did was the following.

00:34:18.280 | He was by this time, even though he's very young,

00:34:21.520 | a very good mathematician.

00:34:23.960 | And he could use the then known laws

00:34:27.520 | for how light behaves when it goes through glass

00:34:30.640 | to calculate what should happen

00:34:33.080 | if you took light from the sun,

00:34:35.200 | passed it from a hole through a little hole,

00:34:38.680 | then hit the prism, goes out of the prism,

00:34:41.840 | goes, strikes a wall a long distance away,

00:34:44.200 | and makes a splash of light.

00:34:45.760 | Nevermind the colors for a moment,

00:34:47.600 | makes a splash of light there.

00:34:49.440 | He was very smart.

00:34:51.120 | First of all, he abstracts from the colors themselves,

00:34:55.700 | even though that's what everybody's

00:34:56.760 | paying attention to initially.

00:34:59.400 | And 'cause what he knows is this.

00:35:00.800 | He knows that if you take this prism

00:35:03.400 | and you turn it to a certain particular angle,

00:35:07.220 | that he knew what it should be

00:35:09.800 | 'cause he could calculate things.

00:35:11.880 | Very few other people in Europe at the time

00:35:15.160 | could calculate things like he could.

00:35:18.080 | That if you turn the prism to that particular angle,

00:35:21.680 | then the sun, which is of course a circle,

00:35:24.560 | when its light passes through this little hole

00:35:27.920 | and then into the prism,

00:35:29.500 | on the far distant wall should still make a circle.

00:35:33.880 | But it doesn't.

00:35:36.580 | It makes a very long image, okay?

00:35:41.000 | And this led him to a very different conception

00:35:44.960 | of light indicating that there are different types

00:35:47.760 | of light in the sunlight.

00:35:49.560 | Now, to go beyond that,

00:35:51.560 | what's particularly interesting I think is the following.

00:35:54.720 | When he published this paper,

00:35:58.880 | which got him into a controversy,

00:36:01.280 | he really didn't describe at all what he did.

00:36:03.840 | He just gave you some numbers.

00:36:05.380 | Now, I just told you that you had to set this prism

00:36:08.520 | at a certain angle, right?

00:36:11.180 | You would think, 'cause we do have his notes and so on,

00:36:15.220 | you would think that he took some kind of complicated

00:36:19.980 | measuring device to set the prism.

00:36:22.180 | He didn't.

00:36:23.340 | He held it in his hand, that's all.

00:36:26.460 | And he twiddled it around.

00:36:28.580 | And what was he doing?

00:36:30.460 | It turns out that when you twiddle the prism around

00:36:34.420 | at the point where you should get a circle from a circle,

00:36:38.540 | it also is the place where the image

00:36:41.140 | does not move very fast.

00:36:43.460 | So if you wanna get close to there, you just twiddle it.

00:36:47.160 | This is manipulative experimentation,

00:36:51.020 | taking advantage through his mathematical knowledge

00:36:55.940 | of the inherent inaccuracies that let you come

00:37:00.340 | to exact conclusions,

00:37:02.860 | regardless of the built-in problematics of measurement.

00:37:07.900 | He's the only one I know of doing anything like that

00:37:11.740 | at the time. - At the time.

00:37:12.700 | - Yeah.

00:37:13.940 | - Well, even still, there's very few people

00:37:15.980 | that are able to calculate as well as he did

00:37:19.040 | to be a theoretician and an experimentalist,

00:37:23.740 | like in the same moment.

00:37:25.240 | (laughs)

00:37:26.460 | Right?

00:37:27.460 | - It's true, although until really the,

00:37:32.460 | well into the 20th century,

00:37:37.160 | maybe the beginning of the 20th century,

00:37:38.940 | really most of the most significant experimental results

00:37:43.940 | produced in the 1800s,

00:37:47.620 | which laid the foundations for light, electricity,

00:37:50.740 | electrodynamics, and so on,

00:37:52.800 | even hydrodynamics and whatnot,

00:37:57.220 | were also produced by people who are both

00:38:00.960 | excellent calculators,

00:38:03.340 | very talented mathematicians,

00:38:06.540 | and good with their hands experimentally.

00:38:09.600 | - And then that led to the 21st century

00:38:13.580 | with Enrico Fermi,

00:38:14.860 | that one of the last people that was able to do that,

00:38:19.860 | both of those things very well,

00:38:22.120 | and that he built a little device called an atomic bomb

00:38:27.120 | that has some positives and negatives.

00:38:29.220 | - Yeah, well, right, of course,

00:38:30.820 | that actually did involve some pretty large-scale,

00:38:34.180 | elaborate equipment too.

00:38:35.660 | - Yeah, well, holding a prism in your hands, same thing.

00:38:38.900 | - Right, no.

00:38:39.940 | - What's the controversy that Newton got into

00:38:42.780 | with that paper when he published it?

00:38:44.760 | - Well, in a number of ways,

00:38:49.220 | it's a complicated story.

00:38:51.140 | There was a very talented character known as a mechanic.

00:38:56.140 | Mechanic means somebody who was a craftsman

00:38:59.700 | who could build and make really good stuff,

00:39:02.020 | and he was very talented.

00:39:03.380 | His name was Robert Hooke,

00:39:05.180 | and he was the guy who,

00:39:07.180 | at the weekly meetings of the Royal Society in London,

00:39:10.380 | and Newton's not in London,

00:39:11.500 | you know, he's at Cambridge, he's a young guy,

00:39:14.140 | he would demonstrate new things,

00:39:16.100 | and he was very clever.

00:39:18.220 | And he had written a book, in fact,

00:39:20.380 | called "The Micrographia,"

00:39:21.940 | which, by the way, he used a microscope

00:39:25.980 | to make the first depictions of things like a fly's eye,

00:39:30.140 | the structure of, you know, it had a big influence.

00:39:32.540 | And in there, he also talked about light.

00:39:35.140 | And so he had a different view of light.

00:39:36.820 | And when he read what Newton wrote,

00:39:39.660 | he had a double reaction.

00:39:41.300 | On the one hand, he said,

00:39:42.580 | "Anything in there that is correct, I already knew.

00:39:47.140 | "And anything that I didn't already know

00:39:49.940 | "is probably not right anyway."

00:39:52.060 | (Luke laughs)

00:39:54.500 | - Ah, gotta love egos.

00:39:56.380 | Okay, can we just step back?

00:39:58.940 | Can you say, who was Isaac Newton?

00:40:02.460 | What are the things he contributed to this world

00:40:05.380 | in the space of ideas?

00:40:06.860 | - Wow. (laughs)

00:40:10.060 | Who was he?

00:40:13.580 | He was born in 1642,

00:40:18.580 | and near the small town of Grantham in England.

00:40:22.700 | In fact, the house he was born in,

00:40:26.220 | and that his mother died in,

00:40:27.740 | is still there and can be visited.

00:40:32.220 | His father died before he was born.

00:40:36.300 | And his mother eventually remarried

00:40:40.700 | a man named Reverend Smith,

00:40:43.180 | whom Newton did not like at all,

00:40:46.820 | because Reverend Smith took his mother away

00:40:52.180 | to live with him a few miles away,

00:40:54.420 | leaving Newton to be brought up

00:40:55.900 | more or less by his grandmother over there.

00:40:58.740 | And he had huge resentment about that his whole life.

00:41:03.100 | - I think that gives you a little inkling

00:41:05.020 | that a little bit of trauma in childhood,

00:41:08.540 | maybe a complicated father-son relationship

00:41:10.940 | can be useful to create a good scientist.

00:41:14.100 | - Could be, although this case it would be right,

00:41:15.740 | the absent father, non-father relationship, so to speak.

00:41:20.660 | He was known as a kid, little that we do know,

00:41:23.500 | for being very clever about flying kites

00:41:28.460 | and there are stories about him putting candles

00:41:32.380 | and flying kites and scaring the living devil

00:41:36.180 | out of people at night by doing that and things like that.

00:41:39.220 | Making things, most of the physicists

00:41:44.220 | and natural philosophers I've dealt with

00:41:46.820 | actually as children were very fond of making

00:41:51.160 | and playing with things.

00:41:52.860 | I can't think of one I know of who wasn't actually.

00:41:56.140 | They're very good with their hands and whatnot.

00:41:58.980 | He was, his mother wanted him to take over the manor.

00:42:04.820 | It was a kind of farming manor.

00:42:09.180 | They were the class of what are known as yeomans.

00:42:12.220 | There are stories that he wasn't very good at that.

00:42:15.500 | One day, one of the stories is he's sitting out in the field

00:42:18.620 | and the cows come home without him

00:42:21.060 | and he doesn't know what's going, anyway.

00:42:24.740 | He had relatives and he manages to get to Cambridge,

00:42:28.660 | sent to Cambridge 'cause he's known to be smart.

00:42:31.180 | He's read books that he got from local dignitaries

00:42:34.420 | and some relatives and he goes there

00:42:37.480 | as what's known as a subsizer.

00:42:39.100 | What does that mean?

00:42:40.260 | Well, it's not too pleasant.

00:42:41.480 | Basically, a subsizer was a student

00:42:44.260 | who had to clean the bedpans of the richer kids.

00:42:47.860 | - Okay. - Right?

00:42:49.280 | That didn't last too long.

00:42:51.180 | He makes his way and he becomes absorbed

00:42:55.940 | in some of the new ways of thinking

00:42:59.480 | that are being talked about on the parts of Descartes

00:43:03.300 | and others as well.

00:43:04.280 | There's also the traditional curriculum which he follows

00:43:07.740 | and we have his notes.

00:43:09.560 | We have his student notebooks and so on.

00:43:11.980 | We can see gradually this young man's mind

00:43:15.820 | focusing and coming to grips with deeper questions

00:43:20.100 | of the nature of the world and perception even

00:43:23.500 | and how we know things and also probing

00:43:26.900 | and learning mathematical structures to such an extent

00:43:31.580 | that he builds on some of the investigations

00:43:35.440 | that had been done in the period before him

00:43:38.420 | to create the foundations of a way of investigating

00:43:42.580 | processes that happen and change continuously

00:43:46.900 | instead of by leaps and bounds and so on,

00:43:49.660 | forming the foundation of what we now call the calculus.

00:43:52.580 | - Yeah.

00:43:53.500 | So can you maybe just paint a little bit of a picture,

00:43:57.180 | you've already started, of what were the things

00:44:02.180 | that bothered him the most, that stood out to him

00:44:06.140 | the most about the traditional curriculum,

00:44:10.260 | about the way people saw the world?

00:44:12.340 | You mentioned discrete versus continuous.

00:44:14.700 | Is there something where he began thinking

00:44:16.740 | in a revolutionary way?

00:44:18.540 | 'Cause it's fascinating.

00:44:19.820 | Most of us go to college, Cambridge or otherwise,

00:44:24.460 | and we just kind of take what we hear as gospel, right?

00:44:29.460 | Like not gospel, but as like facts.

00:44:33.600 | You don't begin to sort of see how can I expand

00:44:37.660 | on this aggressively or how can I challenge everything

00:44:41.260 | that I hear, like rigorously, mathematically,

00:44:45.860 | through the, I mean, I don't even know how rigorous

00:44:48.700 | the mathematics was at that point.

00:44:50.220 | I'm sure it was geometry and so on, no calculus, huh?

00:44:53.680 | - There are elements of what turned into the calculus

00:44:58.620 | that predate Newton, but--

00:45:00.700 | - How much rigor was there?

00:45:02.140 | How much--

00:45:03.180 | - Well, rigor, no.

00:45:04.900 | - And then, of course, no scientific method, not really.

00:45:08.860 | I mean, somewhat, I mean, appreciation of data.

00:45:13.420 | - Ah, that is a separate question

00:45:15.300 | from a question of method.

00:45:16.860 | Appreciation of data is a significant question

00:45:20.020 | as to what you do with data.

00:45:21.380 | There's lots of things you're asking.

00:45:23.300 | - I apologize.

00:45:24.140 | So maybe let's backtrack, and the first question is

00:45:27.020 | was there something that was bothering him

00:45:29.100 | that he especially thought he could contribute or work on?

00:45:33.440 | - Well, of course, we can't go back and talk to him,

00:45:37.140 | but we do have these student notebooks.

00:45:39.500 | There's two of them.

00:45:40.900 | One's called the philosophical questions,

00:45:43.300 | and the other is called the waste book.

00:45:45.420 | The philosophical questions has discussions

00:45:47.960 | of the nature of reality and various issues concerning it,

00:45:51.460 | and the waste book has things that have to do with motion

00:45:55.300 | in various ways, what happens in collisions

00:45:58.260 | and things of that sort, and it's a complicated story,

00:46:01.920 | but what's among the things that I think are interesting

00:46:04.460 | is he took notes in the philosophical questions

00:46:08.740 | on stuff that was traditionally given to you

00:46:13.740 | in the curriculums going back several hundred years,

00:46:17.880 | namely on what scholars refer to as scholastic

00:46:22.880 | or neo-scholastic ways of thinking about the world

00:46:27.420 | dating back to the reformulation of Aristotle

00:46:30.300 | in the Middle Ages by Thomas Aquinas in the church,

00:46:34.300 | and this is a totally different way

00:46:35.700 | of thinking about things, which actually connects

00:46:37.860 | to something we were saying a moment ago.

00:46:39.860 | For instance, so I'm wearing a blue shirt,

00:46:44.620 | and I will sometimes ask students, where is the blue?

00:46:48.920 | And they'll usually say, well, it's in your shirt,

00:46:52.260 | and then some of them get clearer, and they say,

00:46:53.980 | well, no, you know, light is striking it,

00:46:56.420 | photons are re-emitted, they strike the back of your retina,

00:46:59.740 | and et cetera, et cetera, and I said, yes.

00:47:02.340 | You, what that means is that the blue

00:47:05.420 | is actually an artifact of our perceptual system

00:47:10.140 | considered as the percept of blue.

00:47:13.820 | It's not out there, it's in here, right?

00:47:18.180 | That's not how things were thought about

00:47:21.060 | well into the 16th century.

00:47:24.080 | The general notion dating back

00:47:26.520 | even to Aristotelian antiquity

00:47:29.020 | and formalized by the 12th century

00:47:32.580 | at Paris, Oxford, and elsewhere

00:47:36.580 | is that qualities are there in the world.

00:47:40.480 | They're not in us.

00:47:43.520 | We have senses, and our senses can be wrong.

00:47:47.060 | You know, you could go blind, things like that,

00:47:49.940 | but if they're working properly,

00:47:52.500 | you get the actual qualities of the world.

00:47:55.620 | Now that break, which is occurring

00:47:59.180 | towards the end of the 16th century

00:48:01.980 | and is most visible in Descartes,

00:48:04.860 | is the break between conceiving

00:48:07.400 | that the qualities of the world

00:48:09.940 | are very different from the qualities that we perceive,

00:48:14.900 | that in fact, the qualities of the world

00:48:17.060 | consist almost entirely in shapes of various kinds

00:48:22.060 | and maybe hard particles or whatever,

00:48:26.180 | but not colors, not sounds, not smells,

00:48:32.180 | not softness and hardness.

00:48:34.500 | They're not in the world.

00:48:35.740 | They're in us.

00:48:36.720 | That break, Newton is picking up as he reads Descartes.

00:48:41.960 | He's gonna disagree with a lot in Descartes,

00:48:44.400 | but that break, he is, among other things,

00:48:48.540 | picking up very strongly,

00:48:50.460 | and that underlies a lot of the way he works later on

00:48:54.920 | when he becomes skeptical of the evidence

00:48:57.460 | provided by the senses.

00:49:00.540 | - Yeah, that's actually, I don't know,

00:49:03.020 | the way you're describing it is so powerful.

00:49:05.220 | It just makes me realize how liberating that is

00:49:08.740 | as a scientist, as somebody who's trying

00:49:12.060 | to understand reality,

00:49:13.460 | that our senses is just,

00:49:16.880 | our senses are not to be trusted,

00:49:21.700 | that reality is to be investigated

00:49:24.540 | through tools that are beyond our senses.

00:49:27.860 | - Yes.

00:49:29.420 | - Or that improve our senses.

00:49:30.940 | - Or improve our senses.

00:49:32.580 | - In some ways.

00:49:33.640 | - That's pretty powerful.

00:49:35.700 | I mean, that is, for a human being,

00:49:39.120 | that's like Einstein level.

00:49:42.140 | For a human being to realize I can't trust my own senses

00:49:48.660 | at that time, that's pretty trippy.

00:49:53.000 | - It's coming in, it's coming in,

00:49:55.700 | and I think it arises probably a fair number

00:50:00.700 | of decades before that, perhaps in part

00:50:04.040 | with all chemical experimentation and manipulations

00:50:07.660 | that you have to go through elaborate structures

00:50:10.400 | to produce things and ways you think about it.

00:50:15.320 | But let me give you an example that I think

00:50:17.440 | you might find interesting because it's from,

00:50:20.180 | it involves that guy named Hook

00:50:22.060 | that Newton had an argument with.

00:50:25.140 | And he had lots of arguments with Hook,

00:50:28.020 | although Hook was a very clever guy

00:50:29.980 | and gave him some things that stimulated him later.

00:50:32.940 | Anyway, Hook, who was argumentative,

00:50:37.060 | and he really was convinced that the only way

00:50:40.480 | to gain real knowledge of nature

00:50:44.140 | is through carefully constructed devices.

00:50:48.100 | And he was an expert mechanic, if you will,

00:50:51.860 | at building such things.

00:50:54.020 | Now, there was a rather wealthy man in Danzig

00:50:59.020 | by the name of Hevelius, Latinized name.

00:51:05.420 | He was a brewer in town.

00:51:07.860 | And he had become fascinated with the telescope.

00:51:11.560 | This is 30 years or so, 20 or 30 years

00:51:14.980 | after the telescope had moved out and become more common.

00:51:19.220 | And he built a large observatory

00:51:20.860 | on the top of his brewery, actually.

00:51:25.620 | And working with his wife,

00:51:27.900 | they used these very elaborately constructed

00:51:32.900 | brass and metal instruments to make observations

00:51:36.940 | of positions of the stars.

00:51:38.660 | And he published a whole new catalog of where the stars are.

00:51:42.900 | And he claimed it was incredibly accurate.

00:51:46.060 | He claimed it was so accurate

00:51:47.780 | that nothing had ever come close to it.

00:51:49.940 | Hook reads this, and he says, "Wait a minute.

00:51:53.100 | You didn't use a telescope here of any kind,

00:51:55.940 | because what's the point?

00:51:57.980 | Unless you do something to the telescope,

00:51:59.820 | all you see are dots with stars.

00:52:02.020 | You just use your eye.

00:52:03.380 | Your eyes can't be that good.

00:52:04.940 | It's impossible."

00:52:06.800 | So what did Hook do to prove this?

00:52:08.300 | He said, "What you should have done

00:52:09.920 | is you should have put a little device in the telescope

00:52:12.880 | that lets you measure distances between these dots.

00:52:15.780 | You didn't do that, and 'cause you didn't,

00:52:18.180 | there's no way you could have been that good."

00:52:20.420 | At two successive meetings of the Royal Society,

00:52:25.420 | he hauls the members out into the courtyard,

00:52:29.980 | and he takes a card,

00:52:31.860 | and he makes successive black and white stripes on the card.

00:52:36.140 | And he pastes the card up on a wall,

00:52:38.300 | and he takes them one by one.

00:52:39.620 | He says, "Now, move back," looking at it,

00:52:43.600 | presumably with one eye, "until you can't tell

00:52:46.180 | the black ones from the white stripes."

00:52:48.860 | He says, "That, I can then measure the distance.

00:52:52.220 | I can see the angles.

00:52:53.820 | I can give a number, then, for what is the best possible,

00:52:58.820 | what we would call perceptual acuity of human vision."

00:53:04.180 | And it turned out, he thought,

00:53:06.500 | to be something like 10 or more times worse

00:53:11.240 | than this guy Hevelius had claimed.

00:53:13.260 | So obviously, he says, "Look, Hevelius," right.

00:53:16.140 | Well, years ago, I calculated Hevelius's numbers,

00:53:21.140 | and so on, using modern tables from NASA, and so on,

00:53:25.700 | and they are even more accurate than Hevelius claimed.

00:53:28.700 | And worse than that,

00:53:30.140 | the Royal Society sent a young astronomer named Halley

00:53:35.020 | over to Danzig to work with him, and Halley writes back,

00:53:38.820 | and he says, "I couldn't believe it,

00:53:40.720 | but I could, he taught me how to do it,

00:53:42.980 | and I could get just as good as he, how is it possible?"

00:53:46.140 | Well, here, this shows you something very interesting

00:53:48.700 | about experiments, perception, and everything else.

00:53:52.140 | Hooke was right, but he was also wrong.

00:53:54.640 | He was wrong for the right reasons,

00:53:58.660 | and he was right for the wrong reasons.

00:54:00.660 | And what do I mean by that?

00:54:02.020 | What he actually found was the number

00:54:07.860 | for what we now call 20/20 vision.

00:54:10.340 | He was right.

00:54:11.700 | You can't tell, except a few people, much better than that.

00:54:15.700 | But he was observing the wrong thing.

00:54:19.180 | What Hevelius was observing was a bright dot,

00:54:24.280 | a star, moving past a pointer.

00:54:28.860 | Our eyes are rather similar to frogs' eyes.

00:54:34.180 | You know, I'm sure you've heard the story,

00:54:36.060 | if I hold a dead fly on a string in front of a frog

00:54:40.640 | and don't move it, the frog pays no attention.

00:54:43.100 | As soon as I move the fly,

00:54:45.780 | the frog immediately tongue lats out,

00:54:48.300 | because the visual system of the frog responds to motion.

00:54:52.780 | So does ours, and our acuity for distinguishing motion

00:54:57.660 | from statics, five or more times better.

00:55:01.020 | - Yeah, that's fascinating.

00:55:02.740 | Damn, and of course, I mean, maybe you can comment

00:55:07.980 | on their understanding of the human perceptual system

00:55:12.040 | at the time was probably really terrible.

00:55:14.440 | Like, yeah, like I've recently been working

00:55:16.680 | with just almost as a fun side thing with vision scientists

00:55:20.240 | and peripheral vision, it's a beautiful,

00:55:23.680 | complex mess, that whole thing.

00:55:25.760 | We still don't understand all the weird ways

00:55:28.020 | that human perception works,

00:55:29.720 | and they were probably terrible at it.

00:55:33.240 | They probably didn't have any conception

00:55:35.160 | of peripheral vision or the fovea,

00:55:38.000 | or I mean, basically anything.

00:55:41.760 | - They had some, I mean, because actually it was Newton

00:55:44.520 | himself who probed a lot of this.

00:55:46.280 | For instance, Newton, the young Newton,

00:55:50.400 | trying to work his way around what's going on with colors,

00:55:53.960 | wanted to try and distinguish colors that occur

00:55:58.080 | through natural processes out there,

00:56:00.800 | and colors that are a result of our eyes

00:56:03.540 | not operating right.

00:56:04.560 | So you know what he did?

00:56:05.920 | It's a famous thing.

00:56:07.040 | He took a stick, and he stuck that stick

00:56:10.840 | under his lower eyelid and pushed up on his eyeball.

00:56:14.680 | And what that did would produce colored circles

00:56:19.680 | at diametrically opposite positions

00:56:22.520 | of the stick in the eyeball,

00:56:23.840 | and he moved it around to see how they moved,

00:56:26.380 | trying to distinguish.

00:56:27.840 | - Legit.

00:56:29.240 | - Right?

00:56:30.200 | I always have to tell my students don't do this, but.

00:56:34.520 | - Or do it if you wanna be great

00:56:37.080 | and remembered by human history.

00:56:39.720 | There's a lot of equivalent to sticking a stick

00:56:42.840 | into your eye in modern day that may pay off in the end.

00:56:47.360 | Okay.

00:56:48.200 | As a small aside, is the Newton and the apple story true?

00:56:55.240 | - No.

00:56:56.060 | - Was it a different fruit?

00:56:58.400 | - As a colleague of mine named Simon Schaffer

00:57:03.520 | in England once said on a NOVA program

00:57:06.320 | that we were both on,

00:57:08.240 | the role of fruit in the history of science

00:57:11.280 | has been vastly exaggerated.

00:57:13.040 | - Okay.

00:57:14.920 | So was there any, I mean, to zoom out, moments of epiphany.

00:57:19.920 | Is there something to moments of epiphany?

00:57:24.640 | Or again, this is the paradigm shift versus the gradualism.

00:57:28.160 | - There is a shift.

00:57:30.000 | It's a much more complex one than that.

00:57:32.580 | And we, as it happens, a colleague of mine

00:57:37.580 | and I are writing a paper right now

00:57:39.880 | on one of the aspects of these things

00:57:42.840 | based on the work that many of our colleagues have done

00:57:45.080 | over the last 30 and 40 years.

00:57:47.540 | Let me try and see if I could put it to you this way.

00:57:52.600 | Newton, until the early 1670s,

00:58:00.420 | and probably really until a fair time after that,

00:58:04.880 | first of all, was not very interested

00:58:06.840 | in questions of motion.

00:58:08.840 | He was working actually in all chemical relationships

00:58:12.700 | or what is called by historians, chymistry,

00:58:15.480 | a kind of early modern chemical structure.

00:58:18.300 | Colleagues of ours at Indiana

00:58:20.600 | have even reproduced the amalgams that, anyway.

00:58:24.160 | His way of thinking about motion

00:58:28.160 | involved a certain set of relationships

00:58:33.040 | which was not conducive to any application

00:58:38.040 | that would yield computationally direct results

00:58:45.180 | for things like planetary motions,

00:58:47.440 | which he wasn't terribly interested in anyway.

00:58:49.940 | He enters a correspondence

00:58:54.900 | with his original nemesis, Robert Hooke.

00:58:58.620 | And Hooke says, "Well, have you ever thought about,"

00:59:00.740 | and then Hooke tells him,

00:59:02.120 | "A certain way you might think about it."

00:59:04.060 | And when Newton hears that,

00:59:05.860 | he recognizes that there is a way to inject time

00:59:10.740 | that would enable him to solve certain problems.

00:59:13.580 | It's not that there was anything he thought before

00:59:18.740 | that was contrary to that way of thinking.

00:59:21.680 | It's just that that particular technical insight

00:59:26.680 | was not something that, for a lot of reasons

00:59:30.140 | that are complex, had never occurred to him at all.

00:59:34.340 | And that sent him a different way of thinking.

00:59:37.360 | But to answer your question about the Apple business,

00:59:39.820 | which is always about gravity and the moon

00:59:42.320 | and all of that being, no.

00:59:44.120 | The reason there is that the idea

00:59:48.700 | that what goes on here in the neighborhood of the earth

00:59:53.700 | and what goes on at the moon, let us say,

00:59:58.000 | remind the sun and the planet,

01:00:00.320 | can be due to a direct relationship

01:00:03.440 | between the earth, let's say, and the moon,

01:00:07.140 | is contrary to fundamental beliefs

01:00:12.120 | held by many of the mechanical philosophers,

01:00:15.340 | as they're called at the time,

01:00:16.720 | in which everything has to involve

01:00:18.800 | at least a sequence of direct contacts.

01:00:21.200 | Has to be something between here and there that's involved.

01:00:25.480 | And Hooke, probably not thinking terribly deeply about it,

01:00:31.480 | based on what he said, along with others,

01:00:34.640 | like the architect and mathematician Christopher Wren,

01:00:37.760 | hearkened back to the notion that, well,

01:00:40.080 | maybe there is a kind of magnetic relationship

01:00:43.660 | between the moon and maybe the planets

01:00:45.820 | and the earth and gravity and so on.

01:00:48.020 | Vague, but establishing a direct connection somehow,

01:00:51.760 | however it's happening, forget about it.

01:00:53.860 | Newton wouldn't have cared about that

01:00:56.700 | if that's all they said, but it was when Hooke

01:00:59.280 | mentioned this different way of thinking about the motion,

01:01:03.000 | a way he could certainly have thought of

01:01:04.720 | 'cause it does not contradict anything.

01:01:06.680 | Newton is a brilliant mathematician,

01:01:10.840 | and he could see that you could suddenly start

01:01:14.040 | to do things with that that you otherwise wouldn't.

01:01:18.520 | This led eventually to another controversy with Hooke,

01:01:21.480 | in which Hooke said, well, after Newton published

01:01:23.920 | his great Principia, I gave him how to do this.

01:01:27.160 | And then Newton, of course, got ticked off about that

01:01:29.320 | and said, well, listen to this.

01:01:31.160 | I did everything, and 'cause he had a picayune little idea,

01:01:34.760 | he thinks he can take credit for it.

01:01:36.640 | - Okay.

01:01:38.480 | So his ability to play with his ideas mathematically

01:01:43.120 | is what solidified the initial intuition

01:01:45.720 | that you could have.

01:01:46.800 | Was that the first time he was born the idea

01:01:48.600 | that you have action at a distance,

01:01:50.760 | that you can have forces without contact,

01:01:54.240 | which is another revolutionary idea?

01:01:56.040 | - I would say that in the sense of dealing

01:02:01.840 | with the mechanics of force-like effects

01:02:06.840 | considered to act at some distance,

01:02:11.360 | it is novel with both Hooke and Newton at the time.

01:02:16.360 | The notion that two things might interact at a distance

01:02:21.700 | with one another without direct contact,

01:02:23.400 | that goes back to antiquity.

01:02:25.600 | Only there it was thought of more as a sympathetic reaction

01:02:29.800 | to a magnet and a piece of iron.

01:02:33.120 | They have a kind of mutual sympathy for one another.

01:02:36.840 | - Like what, love?

01:02:39.360 | What are we talking about?

01:02:40.200 | - Well, actually, they do sometimes talk like that.

01:02:42.920 | - That it's love.

01:02:43.840 | See, now I talk like that all the time.

01:02:48.080 | I think love is somehow in consciousness

01:02:50.560 | are forces of physics that are yet to be discovered.

01:02:53.600 | Okay, now there's the other side of things,

01:02:58.600 | which is calculus, that you began to talk about.

01:03:02.640 | So Newton brought a lot of things to this world.

01:03:04.480 | One of them is calculus.

01:03:05.920 | What is calculus?

01:03:09.040 | And what was Newton's role in bringing it to life?

01:03:14.040 | What was it like?

01:03:15.920 | What was the story of bringing calculus to this world?

01:03:19.080 | - Well, since the publication starting many decades ago

01:03:24.960 | by Tom Whiteside, who's now deceased,

01:03:27.680 | of Newton's mathematical papers,

01:03:29.840 | we know a lot about how he was pushing things

01:03:33.140 | and how he was developing things.

01:03:34.760 | It's a complex question.

01:03:37.240 | To say what calculus is,

01:03:38.960 | calculus is the set of mathematical techniques

01:03:42.760 | that enable you to investigate

01:03:45.080 | what we now call functions, mathematical functions,

01:03:49.940 | which are continuous, that is,

01:03:52.840 | that are not formed out of discrete sets,

01:03:56.720 | like the counting numbers, for instance.

01:03:59.860 | Newton, there were already

01:04:05.760 | procedures for solving problems involving such things

01:04:10.760 | as finding areas under curves and tangents to curves

01:04:17.320 | by using geometrical structures,

01:04:20.920 | but only for certain limited types of curves, if you will.

01:04:25.920 | Newton, as a young man, we know this is what happened,

01:04:32.800 | is looking at a formula which involves an expansion

01:04:37.800 | in separate terms, polynomial terms, as we say,

01:04:43.720 | for certain functions.

01:04:46.280 | I know I wanna get complicated here about this,

01:04:49.080 | and he realizes it could be generalized,

01:04:52.680 | and he tries the generalization,

01:04:54.880 | and that leads him to an expansion formula

01:04:58.760 | called the binomial theorem.

01:05:01.200 | That enables him to move ahead with the notion

01:05:04.920 | that if I take something that has a certain value,

01:05:09.640 | and I add a little bit to it,

01:05:11.540 | and I use this binomial theorem and expand things out,

01:05:15.040 | I can begin to do new things,

01:05:17.520 | and the new things that he begins to do

01:05:19.860 | leads him to a recognition that the calculations of areas

01:05:24.840 | and the calculations of tangents to curves

01:05:28.360 | are reciprocal to one another,

01:05:31.400 | and the procedures that he develops

01:05:35.080 | is a particular form of the calculus

01:05:37.880 | in which he considers small increments

01:05:43.320 | and then continuous flows and changes of curves and so on,

01:05:48.320 | and we have relics of it in physics today,

01:05:52.800 | the notation in which you put a dot over a variable

01:05:57.580 | indicating the rate of change of the variable.

01:06:00.200 | That's Newton's original type of notation.

01:06:03.080 | The dot, yeah, the dot notation.

01:06:07.460 | Possibly independently of Newton,

01:06:14.000 | because he didn't publish this thing,

01:06:15.720 | although he became quite well-known

01:06:18.360 | as quite a brilliant young man,

01:06:20.320 | in part because people heard about his work and so on.

01:06:27.000 | When another young man by the name of Gottfried Leibniz

01:06:32.000 | visited London, and he heard about these things,

01:06:37.000 | it is said that he independently develops

01:06:41.360 | his form of the calculus,

01:06:42.920 | which is actually the form we use today,

01:06:45.320 | both in notation and perhaps

01:06:47.040 | in certain fundamental ways of thinking.

01:06:50.080 | It has remained a controversial point

01:06:53.360 | as to where exactly and how much independently

01:06:57.360 | Leibniz did it.

01:06:58.640 | Leibniz aficionados think and continue to maintain

01:07:02.440 | he did it completely independently.

01:07:04.440 | Newton, when he became president of the Royal Society,

01:07:07.480 | put together a group to go on the attack,

01:07:10.320 | saying, "No, he must have taken everything."

01:07:12.960 | We don't know, but I will tell you this.

01:07:16.860 | About 25 or so years ago,

01:07:20.480 | a scholar who's a professor at Indiana now

01:07:24.040 | named Domenico Melli got his hands

01:07:27.240 | on a Leibniz manuscript called the 10 Taman,

01:07:31.600 | which was Leibniz's attempt to produce an alternative

01:07:35.600 | to Newton's mechanics.

01:07:37.960 | And it comes to some conclusions

01:07:39.760 | that you have in Newton's mechanics.

01:07:42.280 | Well, he published that, but Melli got the manuscript.

01:07:45.480 | And what Melli found out was that Leibniz

01:07:48.320 | reverse engineered the Principia and cooked it backwards

01:07:53.200 | so that he could get the results he wanted.

01:07:55.680 | Now--

01:07:56.520 | - That was for the mechanics,

01:07:57.340 | so that means his mind allows for that kind of thing.

01:07:59.720 | - Some people--

01:08:01.160 | - You're breaking some news today.

01:08:02.720 | You're starting some old drama.

01:08:04.400 | - Some people think so.

01:08:06.040 | I think most historians of mathematics

01:08:08.000 | do not agree with that.

01:08:09.920 | A friend of mine, rather well-known physicist,

01:08:13.620 | unfortunately died a couple years ago,

01:08:15.200 | named Mike Nauenberg at UC Santa Cruz,

01:08:18.680 | had some evidence along those lines.

01:08:21.440 | Didn't pass mustard with many of my friends

01:08:24.680 | who are historians of math.

01:08:26.480 | In fact, I edit with a historian of math

01:08:28.760 | a technical journal, and we were unable

01:08:31.900 | to publish it in there because we couldn't get it through

01:08:35.080 | any of our colleagues.

01:08:37.160 | But I remain suspicious.

01:08:40.160 | - What is it about those tense relationships

01:08:45.080 | and that kind of drama?

01:08:46.320 | Einstein doesn't appear to have much of that drama.

01:08:49.440 | Nobody claimed, I haven't heard claims that they've,

01:08:53.520 | perhaps 'cause it's such crazy ideas,

01:08:56.480 | of any of his major inventions, major ideas,

01:09:01.400 | being those that are, basically,

01:09:04.080 | I came up with it first or independently.

01:09:06.720 | There's not, as far as I'm aware,

01:09:09.000 | not many people talk about general relativity,

01:09:11.500 | especially in those terms, but with Newton,

01:09:14.520 | that was the case.

01:09:16.120 | I mean, is that just a natural outgrowth

01:09:20.000 | of how science works?

01:09:21.080 | Is there going to be personalities that,

01:09:23.240 | I'm not saying this about Leibniz, but maybe I am,

01:09:25.900 | that there's people who steal ideas for the,

01:09:29.960 | because of ego, because of all those kinds of things.

01:09:35.240 | - I don't think it's all that common, frankly.

01:09:37.660 | The Newton book, Leibniz, Contre-Temps, and so on,

01:09:43.240 | well, you're at the beginnings of a lot of things there,

01:09:45.880 | and so on.

01:09:46.720 | These are difficult and complex times as well.

01:09:50.520 | These are times in which science as an activity

01:09:55.520 | pursued by other than, let us say,

01:09:59.120 | interested aristocrats,

01:10:02.400 | is becoming something somewhat different.

01:10:04.840 | It's not a professional community of investigators

01:10:08.720 | in the same way.

01:10:10.440 | It's also a period in which procedures and rules,

01:10:15.440 | practice are being developed to avoid attacking

01:10:21.980 | one another directly and pulling out a sword

01:10:24.520 | to cut off the other guy's head if he disagrees with you,

01:10:27.560 | and so on.

01:10:29.000 | So it's a very different period.

01:10:31.840 | Controversies happen, people get angry.

01:10:34.520 | I can think of a number of others,

01:10:36.680 | including in the development of optics

01:10:38.780 | in the 19th century and so on.

01:10:41.560 | And it can get hot under the collar.

01:10:43.760 | Sometimes one character who's worked an area extensively,

01:10:49.840 | whether they've come up with something

01:10:51.560 | terribly novel or not,

01:10:53.080 | and somebody else kind of moves in

01:10:55.840 | and does completely different novel things,

01:10:59.320 | the first guy gets upset about it

01:11:01.640 | because he's sort of muscled in

01:11:03.880 | to what I thought was my area.

01:11:06.160 | You find that sort of stuff.

01:11:07.640 | - But do you have examples of cases

01:11:09.860 | where it worked out well?

01:11:11.300 | Like that competition is good for the progress of science?

01:11:15.100 | - Yeah, it almost always is good in that sense.

01:11:18.460 | - Just painful for the individuals involved.

01:11:20.300 | - Can be, yeah.

01:11:21.140 | It doesn't have to be nasty, although sometimes it is.

01:11:25.300 | - So on the space, like for the example of the optics,

01:11:27.700 | could you comment on that one?

01:11:29.020 | - Well, yeah, sure.

01:11:30.260 | Let me, there's several, but I could give you...

01:11:32.940 | All right, so I'll give you this example

01:11:37.500 | that probably is the most pertinent.

01:11:40.700 | The first polytechnic school, like MIT or Caltech,

01:11:48.460 | was actually founded in France

01:11:50.820 | during the French Revolution.

01:11:52.080 | It exists today.

01:11:53.220 | It's the École Polytechnique, right?

01:11:56.200 | Two people who were there were two young men

01:12:01.620 | in the '90s, 1790s, named on the one hand,

01:12:06.280 | François Arago and the other, Jean-Baptiste Biot.

01:12:09.820 | They both lived a long time, well into the 1850s.

01:12:13.700 | Arago became a major administrator of science

01:12:17.300 | and Biot's career started to peter out

01:12:21.020 | after about the late teens.

01:12:23.580 | Now, they are sent on an expedition,

01:12:28.580 | which was one of the expeditions

01:12:30.420 | involving measuring things to start the metric system.

01:12:34.420 | There's a lot more to that story.

01:12:35.720 | Anyway, they come back, Arago gets separated.

01:12:40.060 | He's captured by pirates, actually.

01:12:45.060 | Wounds up in Tangier, escapes, is captured again.

01:12:50.900 | Everybody thinks he's dead.

01:12:53.220 | He gets back to Paris and so on.

01:12:55.580 | He's greeted as a hero and whatnot.

01:12:57.860 | In the meantime, Biot has pretty much published

01:13:00.640 | some of the stuff that he's done

01:13:01.880 | and Arago doesn't get much credit for it

01:13:03.860 | and Arago starts to get very angry.

01:13:06.780 | Biot is known for this kind of thing.

01:13:10.300 | So Arago, anyway, Biot starts investigating

01:13:15.300 | a new phenomenon in optics

01:13:18.480 | involving something called polarization.

01:13:21.460 | And he writes all kinds of stuff on it.

01:13:23.700 | Arago looks into this and decides

01:13:28.620 | to write some things as well.

01:13:29.980 | And actually, Biot gets mostly interested in it

01:13:33.420 | when he finds out that Arago is doing stuff.

01:13:36.660 | Now, Biot is actually the better scientist in a lot of ways.

01:13:40.400 | But Arago is furious about this.

01:13:43.500 | So furious that he actually demands and forces

01:13:47.500 | the leader of French science, Laplace,

01:13:50.220 | the Marquis de Laplace, and cohorts to write a note

01:13:55.220 | in the published journal saying, oh, excuse us.

01:14:02.520 | Actually, Arago, et cetera, et cetera, blah, blah.

01:14:05.860 | So Arago continues to just hold this antipathy

01:14:10.860 | and fear of Biot.

01:14:13.580 | So what happens?

01:14:15.140 | 1815, Napoleon is finished at Waterloo.

01:14:20.140 | A young Frenchman by the name of Augustin Fresnel

01:14:25.160 | who's in the army is going back to his home

01:14:29.100 | on the north coast of France in Normandy.

01:14:31.180 | He passes through Paris.

01:14:33.080 | Arago is friends with Fresnel's uncle

01:14:36.360 | who's the head of the École des Beaux-Arts at the time.

01:14:41.500 | Anyway, Fresnel is already interested

01:14:44.400 | in certain things in light.

01:14:45.920 | He talks to Arago.

01:14:47.080 | Arago tells him a few things.

01:14:48.760 | Fresnel goes home.

01:14:50.240 | Fresnel is a brilliant experimenter.

01:14:54.160 | He observes things and he's a very good mathematician.

01:14:59.160 | Calculates things.

01:15:00.240 | He writes something up.

01:15:01.360 | He sends it to Arago.

01:15:02.840 | Arago looks at it and Arago says to himself,

01:15:06.240 | I can use this to get back at Biot.

01:15:09.720 | He brings Fresnel to Paris, sets him up in a room

01:15:13.880 | at the observatory where Arago is

01:15:16.120 | for Fresnel to continue his work.

01:15:18.440 | Paper after paper comes out,

01:15:20.560 | undercutting everything Biot had done.

01:15:26.640 | - What is it about jealousy and just envy

01:15:31.200 | that could be an engine of creativity and productivity

01:15:35.200 | versus like an Einstein where it seems like not?

01:15:39.760 | I don't know which one is better.

01:15:42.280 | I guess it depends on the personality.

01:15:43.880 | Both are useful engines in science.

01:15:46.100 | - Well, in this particular story,

01:15:48.220 | it's maybe even more interesting

01:15:50.960 | because Fresnel himself, the young guy,

01:15:53.480 | he knew what Arago was doing with him

01:15:56.560 | and he didn't like it.

01:15:58.200 | He didn't want to get with, he wrote his brother,

01:16:00.240 | said I don't want to get in an argument with Biot.

01:16:03.240 | I just want to do my stuff.

01:16:05.400 | Arago is using him but it's because Arago

01:16:08.760 | kept pushing him to go into certain areas

01:16:11.720 | that stuff kept coming out.

01:16:13.800 | - Ego is beautiful.

01:16:18.680 | Okay, but back to Newton.

01:16:21.000 | There's a bunch of things I want to ask

01:16:22.600 | but sort of let's say since we're on the Leibniz

01:16:26.280 | and the topic of drama, let me ask another drama question.

01:16:29.920 | Why was Newton a complicated man?

01:16:32.100 | We're breaking news today.

01:16:36.920 | This is like--

01:16:37.760 | - I am right, why was he complicated?

01:16:40.200 | His brain structure was different.

01:16:43.000 | I don't know why.

01:16:43.880 | He had a complicated young life as we've said.

01:16:47.500 | He had always been very self-contained and solitary.

01:16:54.960 | He had acquaintances and friends

01:16:57.480 | and when he moved to London eventually,

01:16:59.600 | he had quite a career.

01:17:01.320 | A career for instance that led him

01:17:03.720 | when he was famous by then, the 1690s.

01:17:06.560 | He moves to London, he becomes first warden of the mint.

01:17:11.560 | The mint is what produces coins

01:17:13.760 | and coinage was a complicated thing

01:17:15.800 | 'cause there was counterfeiting going on

01:17:18.240 | and he becomes master of the mint to the extent

01:17:21.880 | and a guy at MIT wrote a book about this a little bit.

01:17:25.640 | We wrote something on it too.

01:17:27.320 | I forget his name was Levin.

01:17:28.760 | That Newton sent investigators out to catch these guys

01:17:34.400 | and sent at least one of them,

01:17:35.960 | a famous one named Challoner to the gallows.

01:17:38.580 | One of the reasons he probably was

01:17:45.000 | so particularly angry at Challoner

01:17:47.460 | was Challoner had apparently said some nasty things

01:17:50.880 | about Newton in front of parliament at some point.

01:17:54.240 | - Fair enough.

01:17:55.080 | - That was apparently not a good idea.

01:17:57.720 | - Well, he had a bit of a temper

01:17:58.800 | so Newton had a bit of a temper.

01:17:59.840 | - Clearly, clearly.

01:18:02.220 | But he even as a young man at Cambridge,

01:18:07.220 | though he doesn't come from wealth,

01:18:09.400 | he attracts people who recognize his smarts.

01:18:14.400 | There's a young fellow named Humphrey Newton,

01:18:18.160 | shared his rooms.

01:18:19.360 | These students always shared rooms with one another,

01:18:22.740 | became his kind of amanuensis

01:18:25.200 | to write down what Newton was doing and so on.

01:18:30.200 | And there were others over time

01:18:33.760 | who he befriended in various ways and so on.

01:18:37.120 | He was solitary.

01:18:38.800 | He had, as far as we know,

01:18:41.880 | no relationships with either women or men

01:18:44.900 | in anything other than a formal way.

01:18:48.920 | The only--

01:18:49.760 | - Those get in the way, relationships.

01:18:51.400 | - Right.

01:18:52.240 | Well, I mean, he was,

01:18:53.600 | I don't know if he was close to his mother.

01:18:57.000 | I mean, she passed away, everything left him.

01:18:59.280 | He went to be with her after she died.

01:19:02.080 | He was close to his niece, Catherine Barton,

01:19:05.920 | who basically came to run his household

01:19:08.680 | when he moved to London and so on.

01:19:13.200 | And she married a man named Conduit

01:19:16.480 | who became one of the people

01:19:19.400 | who controlled Newton's legacy later on and so on.

01:19:23.680 | So he, and you can even see the house,

01:19:27.440 | the townhouse that Newton lived in in those days,

01:19:29.920 | still there.

01:19:31.520 | - So there's the story of Newton coming up

01:19:34.440 | with quite a few ideas during a pandemic.

01:19:37.520 | We're on the outskirts of a pandemic ourselves.

01:19:42.760 | - Right.

01:19:43.600 | - And a lot of people use that example

01:19:45.280 | as motivation for everybody while they're in lockdown

01:19:48.200 | to get stuff done.

01:19:50.040 | So what's that about?

01:19:51.600 | Can you tell the story of that?

01:19:53.300 | - Well, I can.

01:19:54.140 | Let me first say that, of course,

01:19:55.760 | we've been teaching over Zoom lately.

01:19:58.880 | - There was no Zoom back then?

01:20:00.280 | - There was no Zoom back then.

01:20:02.280 | Although it wouldn't have made much difference

01:20:03.720 | because the story was Newton was so complicated

01:20:05.800 | in his lectures that at one point,

01:20:07.880 | Humphrey Newton actually said that he might as well

01:20:10.680 | have just been lecturing to the walls

01:20:11.960 | 'cause nobody was there to listen to it.

01:20:14.560 | So what difference?

01:20:15.840 | But--

01:20:16.680 | - Also not a great teacher, huh?

01:20:18.960 | - If you look at his optical notes,

01:20:21.280 | if that's what he's reading from--

01:20:23.120 | - Oh boy, okay.

01:20:24.180 | - No.

01:20:26.360 | (both laughing)

01:20:28.000 | - So what can you say about that whole journey

01:20:31.440 | through the pandemic that resulted in so much innovation

01:20:35.760 | in such a short amount of time?

01:20:37.440 | - Well, I mean, there's two times that he goes home.

01:20:42.320 | Would he have been able to do it and do do it

01:20:45.200 | if he'd stayed at Cambridge?

01:20:46.440 | I think he would have.

01:20:48.000 | I don't think it really,

01:20:49.840 | although I do like to tell my advanced students

01:20:52.040 | when I lecture on the history of physics

01:20:53.600 | to the physics and chemistry students,

01:20:56.520 | especially we've been doing it over Zoom in the last year,

01:20:59.160 | when we get to Newton and so on,

01:21:00.720 | 'cause these kids are 21, 22,

01:21:03.600 | I like to say, well, you know,

01:21:05.160 | when Newton was your age and he had to go home

01:21:08.880 | during an epidemic, do you know what he produced?

01:21:12.460 | - So can you actually summarize this

01:21:13.940 | for people who don't know how old was Newton

01:21:15.900 | and what did he produce?

01:21:17.260 | - Well, Newton goes up to Cambridge, as it said,

01:21:21.020 | when he's 18 years old in 1660.

01:21:23.820 | And the so-called miraculous year,

01:21:28.700 | the annus mirabilis, where you get the development

01:21:32.180 | in the calculus and in optical discoveries especially,

01:21:36.380 | is 1666, right?

01:21:39.180 | So he's what, 24 years old at the time.

01:21:43.100 | But judging from the notebooks that I mentioned,

01:21:47.340 | he's already before that come to an awful lot

01:21:51.100 | of developments over the previous couple of years.

01:21:55.520 | Doesn't have much to do with the fact

01:21:58.720 | that he twice went home.

01:22:00.840 | It is true that the optical experiments

01:22:04.140 | that we talked of a while ago

01:22:05.640 | with the light on the wall moving up and down

01:22:07.880 | were done at home.

01:22:09.180 | In fact, you can visit the very room he did it in

01:22:12.360 | to this day.

01:22:13.940 | Yeah, it's very cool.

01:22:15.260 | And if you look through the window in that room,

01:22:18.020 | there is an apple tree out there in the garden.

01:22:21.460 | - So you might be wrong about this.

01:22:23.660 | You're lying to me.

01:22:24.940 | Maybe there's an apple involved after all.

01:22:27.660 | - It's not the same apple tree, but it's cuttings.

01:22:29.940 | - How do you know?

01:22:31.620 | - They don't last that long, but it's 400 years ago.

01:22:34.740 | - Oh, not this.

01:22:35.800 | (laughing)

01:22:37.840 | - Oh, wow, I continue with the dumbest questions.

01:22:40.000 | Okay, so you're saying that perhaps going home was not--

01:22:44.560 | - It may have given him an opportunity

01:22:47.320 | to work things through.

01:22:48.600 | And after all, he did make use of that room

01:22:51.520 | and he could do things like put a shade over the window,

01:22:54.720 | move things around, cut holes in it and do stuff.

01:22:58.100 | Probably in his rooms at Cambridge, he maybe not.

01:23:01.680 | Although when he stayed at Cambridge,

01:23:05.140 | subsequently became a fellow.

01:23:07.380 | And then the first, actually the second

01:23:09.820 | Lucasian professor there, he was actually really

01:23:13.060 | the first one because Isaac Barrow,

01:23:16.500 | who was the mathematician, professor of optics

01:23:19.300 | who recognized Newton's genius,

01:23:21.260 | gave up what would have been his position

01:23:24.500 | because he recognized,

01:23:26.020 | Newton may not have learned too much from him,

01:23:29.520 | although they did interact.

01:23:31.180 | And so Newton was the first Lucasian professor really,

01:23:34.820 | the one that Stephen Hawking held 'til he died.

01:23:38.020 | And we know that the rooms that he had there at Cambridge,

01:23:43.860 | subsequently, 'cause rooms are still there,

01:23:46.300 | he built an alchemical furnace outside,

01:23:48.580 | did all sorts of stuff in those rooms.

01:23:50.540 | And don't forget, you didn't have to do too much

01:23:55.480 | as a Lucasian professor.

01:23:57.420 | Every so often, you had to go give these lectures,

01:24:00.240 | whether anybody was there or not,

01:24:01.980 | and deposit the notes for the future,

01:24:06.720 | which is how we have all those things.

01:24:08.780 | - Oh, they were stored and now we have them,

01:24:12.860 | and now we know just how terrible of a teacher Newton was.

01:24:16.100 | - Yeah, but we know how brilliant these notes are.

01:24:18.020 | In fact, the second volume of Newton's,

01:24:20.960 | of the notes really on the great book

01:24:24.100 | that he published, "The Optics,"

01:24:25.740 | which he published in 1704,

01:24:28.140 | that has just been finished

01:24:30.880 | with full annotations and analysis

01:24:33.480 | by the greatest analyst of Newton's optics, Alan Shapiro,

01:24:37.800 | who retired a few years ago at the University of Minnesota

01:24:41.560 | and been working on Newton's optics

01:24:43.820 | ever since I knew him and before,

01:24:46.360 | and I've known him since 1976.

01:24:49.800 | - Is there something you could say broadly

01:24:53.720 | about either that work on optics

01:24:56.200 | or Principia itself as something

01:24:59.740 | that I've never actually looked at as a piece of work?

01:25:03.300 | Is it powerful in itself,

01:25:08.560 | or is it just an important moment in history

01:25:12.060 | in terms of the amount of inventions that are within,

01:25:14.880 | the amount of ideas that are within,

01:25:17.400 | or is it a really powerful work in itself?

01:25:20.720 | - Well, it is a powerful work in itself.

01:25:22.560 | You can see this guy coming to grips with

01:25:27.560 | and pushing through and working his way around

01:25:31.720 | complicated and difficult issues,

01:25:34.320 | melding experimental situations

01:25:39.160 | which nobody had worked with before,

01:25:40.820 | even discovering new things,

01:25:42.560 | trying to figure out ways of putting this together

01:25:44.720 | with mathematical structures,

01:25:46.400 | succeeding and failing at the same time,

01:25:49.360 | and we can see him doing that.

01:25:52.080 | - I mean, what is contained within Principia?

01:25:57.080 | I don't even know, in terms of the scope of the work.

01:26:00.680 | - All right.

01:26:01.520 | - Is it the entirety of the body of work of Newton?

01:26:04.320 | - No, no, no, no, no.

01:26:05.160 | The Principia Mathematica--

01:26:06.800 | - Is he calculus?

01:26:08.560 | - Well, he, all right, so.

01:26:10.840 | The Principia's divided into three books.

01:26:14.880 | - Excellent.

01:26:15.720 | - Book one contains his version of the laws of motion,

01:26:20.820 | and the application of those laws

01:26:23.540 | to figure out when a body moves in certain curves

01:26:28.120 | and is forced to move in those curves

01:26:30.480 | by forces directed to certain fixed points,

01:26:33.600 | what is the nature of the mathematical formula

01:26:37.760 | for those forces?

01:26:39.160 | That's all that book one is about,

01:26:41.400 | and it contains not the kind of version of the calculus

01:26:45.740 | that uses algebra of the sort

01:26:48.540 | that I was trying to explain before,

01:26:51.320 | but is done in terms of ratios

01:26:55.700 | between geometric line segments

01:26:58.940 | when one of the line segments goes very, very small.

01:27:02.800 | It's called a kind of limiting procedure,

01:27:05.540 | which is calculus, but it's a geometrically structured,

01:27:09.560 | although it's clearly got algebraic elements in it as well,

01:27:14.120 | and that makes the Principia's mathematical structure

01:27:18.120 | rather hard for people who aren't studying it today

01:27:21.600 | to go back to.

01:27:24.520 | Book two contains his work on what we now call hydrostatics

01:27:29.520 | and a little bit about hydrodynamics,

01:27:35.480 | a fuller development of the concept of pressure,

01:27:38.100 | which is a complicated concept,

01:27:43.040 | and book three applies what he did in book one

01:27:47.260 | to the solar system,

01:27:48.720 | and it is successful partially

01:27:52.520 | because the only way that you can exactly solve,

01:27:58.680 | the only types of problems you can exactly solve

01:28:01.720 | in terms of the interactions of two particles

01:28:06.720 | governed by gravitational force between them

01:28:09.520 | is for only two bodies.

01:28:12.000 | If there's more than two, let's say it's A, B, and C,

01:28:15.640 | A acts on B, B acts on C, C acts on A,

01:28:19.440 | you cannot solve it exactly.

01:28:22.540 | You have to develop techniques.

01:28:24.340 | The fullest sets of techniques are really only developed

01:28:27.920 | about 30 or 40 years after Newton's death

01:28:30.460 | by French mathematicians like Laplace.

01:28:35.460 | Newton tried to apply his structure

01:28:39.060 | to the sun, earth, moon,

01:28:41.980 | 'cause the moon's motion is very complicated.

01:28:45.220 | The moon, for instance,

01:28:47.260 | exactly repeats its observable position among the stars

01:28:52.220 | only every 19 years.

01:28:53.920 | That is, if you look up where the moon is among the stars

01:28:58.740 | at certain times, and it changes, it's complicated.

01:29:02.580 | That's, by the way, that was discovered,

01:29:04.540 | that was discovered by the Babylonians.

01:29:07.780 | - That fact, the 19 years.

01:29:10.220 | - Thousands of years ago, yes.

01:29:11.700 | - And then you have that little piece of data,

01:29:13.780 | and how do you make sense of it?

01:29:15.220 | I mean, that is data, and you have to--

01:29:17.220 | - And it's complicated.

01:29:18.660 | So Newton actually kind of reverse engineered

01:29:22.380 | a technique that had been developed by a man named Horrocks

01:29:26.300 | using certain laws of Kepler's

01:29:28.580 | to try and get around this thing,

01:29:30.180 | and Newton then sort of, my understanding,

01:29:33.140 | I've never studied this,

01:29:34.100 | has sort of reversed it and fit it together

01:29:37.820 | with his force calculations by way of an approximation.

01:29:42.220 | And was able to construct a model to make some predictions.

01:29:47.220 | - It fit things backwards pretty well.

01:29:51.700 | - Okay, where does data fit into this?

01:29:56.940 | We kind of earlier in the discussion mentioned data

01:30:01.940 | as part of the scientific method.

01:30:04.660 | How important was data to Newton?

01:30:09.180 | So like you mentioned Prism and playing with it

01:30:12.740 | and looking at stuff

01:30:13.900 | and then coming up with calculations and so on.

01:30:16.260 | Where does data fit into any of his ideas?

01:30:18.840 | - All right, well, let me say two things first.

01:30:21.320 | One, we rarely use the phrase scientific method anymore

01:30:25.380 | because there is no one easily describable such method.

01:30:30.380 | I mean, humans have been playing around with the world

01:30:34.620 | and learning how to repetitively do things

01:30:37.060 | and make things happen ever since humans became humans.

01:30:41.180 | - Do you have a preferred definition

01:30:44.060 | of the scientific method?

01:30:45.140 | What are the various--

01:30:46.580 | - No, I don't.

01:30:47.900 | I prefer to talk about

01:30:49.580 | the considered manipulation of artificial structures

01:30:57.820 | to produce results that can be worked together

01:31:03.780 | with schemes to construct other devices

01:31:07.660 | and make predictions if you will

01:31:12.340 | about the way such things will work.

01:31:14.460 | - So ultimately it's about producing other devices.

01:31:17.260 | It's like leads you down--

01:31:19.100 | - I think so principally.

01:31:20.780 | I mean, you may have data if you will,

01:31:24.220 | like astronomical data obtained otherwise and so on,

01:31:28.060 | but yes.

01:31:28.900 | But number two here is this question of data.

01:31:32.700 | What is data in that sense?

01:31:34.740 | See, when we talk about data today,

01:31:37.080 | we have a kind of complex notion

01:31:41.620 | which reverts to even issues of statistics

01:31:45.700 | and measurement procedures and so on.

01:31:48.940 | So let me put it to you this way.

01:31:51.540 | So let's say I had a ruler in front of me.

01:31:55.140 | - Go on.

01:31:55.980 | - And it's marked off in little black marks

01:31:58.460 | separated by let's say distances called a millimeter.

01:32:03.460 | Okay, now I make a mark on this piece of paper here.

01:32:06.860 | So I made a nice black mark, right?

01:32:10.260 | Nice black mark.

01:32:11.620 | And I ask you, I want you to measure that

01:32:13.340 | and tell me how long it is.

01:32:14.700 | You're gonna take the ruler,

01:32:18.020 | you're gonna put it next to it,

01:32:19.580 | and you're gonna look,

01:32:22.360 | and it's not gonna sit,

01:32:24.580 | even if you put one end as close as you can

01:32:27.020 | on one black mark,

01:32:28.340 | the other end probably isn't gonna be

01:32:30.020 | exactly on a black mark.

01:32:31.780 | Well, you'll say it's closer to this or that.

01:32:34.140 | You'll write down a number.

01:32:35.660 | And I say, okay, take the ruler away a minute.

01:32:37.740 | I take this away, come back in five minutes,

01:32:40.420 | put the piece of paper down, do it again.

01:32:42.800 | You're gonna probably come up with a different number.

01:32:45.620 | And you're gonna do that a lot of times.

01:32:48.060 | And then if I tell you,

01:32:49.060 | I want you to give me your best estimate

01:32:51.500 | of what the actual length of that thing is,

01:32:54.060 | what are you gonna do?

01:32:55.700 | You're going to average all of these numbers.

01:32:59.900 | Why?

01:33:00.740 | - Statistics.

01:33:06.100 | - Well, yes, statistics.

01:33:08.860 | There's lots of ways of going around it,

01:33:11.000 | but the average is the best estimate

01:33:14.020 | on the basis of what's called the central limit theorem,

01:33:17.620 | a statistical theorem.

01:33:18.740 | We were talking about things

01:33:20.640 | that were not really developed

01:33:22.180 | until the 1750s, '60s, and '70s.

01:33:25.100 | Newton died in 1727.

01:33:27.020 | - The intuition perhaps was there.

01:33:28.900 | - Not really.

01:33:29.900 | I'll tell you what people did, including Newton,

01:33:32.580 | although Newton is partially the one exception.

01:33:35.860 | We talked a while ago about this guy, Christian Huygens.

01:33:39.220 | He measured lots of things.

01:33:41.060 | And he was a good mechanic himself.

01:33:44.580 | He and his brother ground lenses.

01:33:46.780 | Huygens, I told you,

01:33:47.700 | developed the first pendulum mechanism,

01:33:49.740 | pendulum-driven clock with a mechanism and so on.

01:33:53.780 | Also, a spring watch,

01:33:56.180 | where he got into a controversy

01:33:57.380 | with Hooke over that, by the way.

01:33:59.040 | - What's with these mechanics and the controversy?

01:34:02.980 | - Well, they get an argument.

01:34:04.980 | Well, we also have Huygens' notes.

01:34:08.500 | They're preserved at Leiden University in Holland.

01:34:13.100 | He's Dutch.

01:34:13.940 | For his work in optics, which was extensive.

01:34:17.900 | We don't have time to go into that, except the following.

01:34:21.020 | Number of years ago, I went through those things,

01:34:23.320 | because in this optical theory that he had,

01:34:26.500 | there are four numbers that you've got to be able

01:34:30.220 | to get good numbers on to be able to predict other things.

01:34:34.600 | So what would we do today?

01:34:36.980 | What, in fact, was done at the end of the 18th century

01:34:39.220 | when somebody went back to this?

01:34:40.900 | You do what you just, I told you to do with the ruler.

01:34:43.380 | You make a lot of measurements and average results.

01:34:45.940 | We have Huygens' notes.

01:34:48.420 | He did make a lot of measurements.

01:34:51.180 | One after the other after the other.

01:34:53.140 | But when he came to use the numbers for calculations,

01:34:58.720 | and indeed when he published things at the end of his life,

01:35:02.380 | he gives you one number,

01:35:04.880 | and it's not the average of any of them.

01:35:07.080 | It's just one of them.

01:35:08.940 | Which one was it?

01:35:10.320 | The one that he thought he got so good at working

01:35:17.600 | by practice that he put down the one

01:35:20.160 | he was most confident in.

01:35:21.860 | That was the general procedure at the time.

01:35:25.880 | You wouldn't publish a paper in which you wrote down

01:35:29.200 | six numbers and said, well, I measured this six times.

01:35:32.460 | Let me put them together.

01:35:33.700 | None of them is really, they would have said,

01:35:36.540 | the right number, but I'll put them together

01:35:39.500 | and give you a good number.

01:35:41.980 | No, you would have been thought of that,

01:35:43.380 | you don't know what you're doing.

01:35:44.860 | - Yeah, by the way, there's just an inkling

01:35:49.760 | of value to that approach.

01:35:51.600 | Just an inkling.

01:35:54.580 | We sometimes use statistics as a thing that,

01:35:57.240 | like, oh, that solves all the problems.

01:35:59.900 | We'll just do a lot of it and we'll take the average,

01:36:02.360 | or whatever it is, as many excellent books on mathematics

01:36:05.300 | have highlighted the flaws in our approach

01:36:09.240 | to certain sciences that rely heavily on statistics.

01:36:13.760 | Okay, let me ask you again for a friend

01:36:16.400 | about this alchemy thing.

01:36:19.660 | You know, it'd be nice to create gold,

01:36:21.760 | but it also seems to come into play quite a bit

01:36:25.580 | throughout the history of science,

01:36:27.760 | perhaps in positive ways in terms of its impact.

01:36:30.940 | Can you say something to the history of alchemy?

01:36:34.100 | - A little bit. - And its impact?

01:36:35.560 | - Sure.

01:36:36.460 | It used to be thought, two things.

01:36:41.000 | One, that alchemy, which dates certainly back

01:36:45.120 | to the Islamic period in Islam,

01:36:48.320 | you're talking, you know, 11th, 12th, 13th centuries

01:36:52.760 | among Islamic natural philosophers and experimenters.

01:36:56.780 | But it used to be thought that alchemy,

01:36:59.640 | which picked up strikingly in the 15th, 16th century,

01:37:04.640 | 1500s and thereabouts, was a sort of mystical procedure

01:37:10.720 | involving all sorts of strange notions and so on.

01:37:14.120 | And that's not entirely untrue,

01:37:17.680 | but it is substantially untrue in that alchemists

01:37:21.760 | were engaged in what was known as chrysopoea,

01:37:26.760 | that is, looking for ways to transform

01:37:31.080 | invaluable materials into valuable ones.

01:37:36.680 | But in the process of doing so or attempting to do so,

01:37:41.480 | they learned how to create complex amalgams

01:37:46.480 | of various kinds.

01:37:49.240 | They used very elaborate apparatus, glass alembics,

01:37:53.920 | in which they would use heat

01:37:55.820 | to produce chemical decompositions.

01:37:58.540 | They would write down and observe these compositions.

01:38:02.160 | And many of the so-called really strange-looking

01:38:05.560 | alchemical formulas and statements

01:38:07.480 | where they'll say something like,

01:38:09.080 | I can't produce it, but it'll be,

01:38:11.200 | the soul of Mars will combine with this, et cetera, et cetera.

01:38:16.200 | These, it has been shown, are almost all actual formulas

01:38:22.240 | for how to engage in the production of complex amalgams

01:38:26.840 | and what to do.

01:38:28.440 | And by the time of Newton,

01:38:31.120 | Newton was reading the works of a fellow

01:38:35.260 | by the name of Starkey, who was actually,

01:38:37.360 | came from Harvard shortly before,

01:38:42.020 | in which things had progressed, if you will,

01:38:46.660 | to the point where the procedure turns

01:38:49.440 | into what historians call chrysopoea,

01:38:52.240 | which basically runs into the notion of thinking

01:38:56.120 | that these things are made out of particles.

01:38:59.220 | This is the mechanical philosophy.

01:39:02.580 | Can we engage in processes, chemical processes,

01:39:05.760 | to rearrange these things,

01:39:07.880 | which is not so stupid after all.

01:39:10.280 | I mean, we do it, except we happen to do it in reactors,

01:39:12.920 | not in chemical processes,

01:39:15.640 | unless, of course, it had happened

01:39:17.320 | that cold fusion had worked, which it didn't.

01:39:19.560 | Well, right.

01:39:22.280 | So that's the way they're thinking about these things.

01:39:26.400 | There's a kind of mix.

01:39:27.280 | And Newton engages extensively

01:39:30.240 | in those sorts of manipulations.

01:39:32.480 | In fact, more in that than almost anything else,

01:39:36.760 | except for his optical investigations.

01:39:40.680 | If you look through the latter parts of the 1670s,

01:39:44.560 | the last five, six, seven years or so of that,

01:39:47.600 | there's more on that than there is on anything else.

01:39:51.160 | He's not working on mechanics.

01:39:52.760 | He's pretty much gone pretty far in optics.

01:39:56.040 | He'll turn back to optics later on.

01:39:58.520 | - So optics and alchemy,

01:40:00.520 | so what you're saying is Isaac Newton liked shiny things.

01:40:04.040 | - Well, actually, if you go online

01:40:07.200 | and look at what Bill Newman,

01:40:08.760 | the professor at Bloomington, Indiana, has produced,

01:40:13.340 | you'll find the very shiny thing called the star regulus,

01:40:17.120 | which Newton describes as having produced

01:40:19.420 | according to a particular way,

01:40:21.160 | which Newman figured out and was able to do it.

01:40:24.160 | And it's very shiny.

01:40:26.120 | - There you go, proves the theorem.

01:40:28.960 | - Can I ask you about God, religion,

01:40:31.160 | and its role in Newton's life?

01:40:33.760 | Was there helpful, constructive,

01:40:39.840 | or destructive influences of religion

01:40:45.040 | in his work and in his life?

01:40:48.200 | - Well, there you begin to touch on a complex question.

01:40:50.960 | The role that God played

01:40:54.800 | would be an interesting question to answer

01:40:57.400 | should one go and be able to speak

01:40:59.140 | with this invisible character who doesn't exist.

01:41:01.720 | But putting that aside for the moment.

01:41:03.640 | - Yeah, we don't like to talk about others

01:41:05.240 | while they're not here, so.

01:41:06.960 | - Right.

01:41:08.480 | Newton is a deeply religious man,

01:41:11.640 | not unusually so, of course, for the time.

01:41:13.800 | Clearly, his upbringing,

01:41:21.840 | and perhaps his early experiences,

01:41:25.000 | have exacerbated that in a number of ways,

01:41:28.480 | that he takes a lot of things personally,

01:41:30.760 | and he finds perhaps solace in thinking

01:41:34.840 | about a sort of governing, abstract,

01:41:39.560 | rule-making, exacting deity.

01:41:43.720 | I think there is little question

01:41:48.560 | that his conviction that you can figure things out

01:41:54.560 | has a fair bit to do with his profound belief

01:41:59.560 | that this rule-maker doesn't do things arbitrarily.

01:42:05.700 | Newton does not think that miracles have happened

01:42:10.680 | since maybe the time of Christ, if then,

01:42:14.300 | and not in the same way.

01:42:15.560 | He was, for instance, an anti-Trinitarian.

01:42:18.520 | He did not hold that Christ had a divine being,

01:42:22.240 | but was rather endowed with certain powers

01:42:24.760 | by the rule-maker and whatnot.

01:42:27.300 | And he did not think that some of the tales

01:42:33.320 | of the Old Testament with various miracles and so on

01:42:38.800 | occurred in anything like that way.

01:42:40.760 | Some may have, some may not have.

01:42:42.600 | Like everybody else, of course,

01:42:45.280 | he did think that creation had happened

01:42:47.080 | about 6,000 years ago.

01:42:49.960 | - Wait, really?

01:42:51.000 | - Oh, yeah, sure.

01:42:52.840 | Well, biblical chronology can give you a little bit

01:42:55.120 | about that, it's a little controversial, but sure.

01:42:57.800 | - Interesting, wow.

01:42:59.920 | - The deity created the universe 6,000 years ago.

01:43:04.920 | - And that didn't interfere with his playing around

01:43:09.200 | with the sun and the moon and the--

01:43:10.800 | - Oh, no, because he's figuring out,

01:43:12.320 | he's watching the brilliant construction

01:43:16.280 | that this perfect entity--

01:43:19.400 | - Did 6,000 years ago.

01:43:21.760 | - Yeah, has produced.

01:43:22.800 | - Plus or minus a few years.

01:43:24.640 | - Well, if you go with Bishop Boshler, it's 4004 BCE.

01:43:28.120 | Wanna be precise about it.

01:43:32.160 | - We always, and this is a serious program,

01:43:35.040 | we always wanna be precise.

01:43:36.440 | (both laughing)

01:43:38.560 | Okay, let me ask another ridiculous question.

01:43:40.880 | If Newton were to travel forward in time

01:43:45.520 | and visit with Einstein and have a discussion

01:43:49.920 | about space-time and general relativity,

01:43:54.920 | that conception of time and that conception of gravity,

01:43:58.200 | what do you think that discussion will go like?

01:44:02.000 | - Put that way, I think Newton would sit there in shock

01:44:06.000 | and say, "I have no idea what you're talking about."

01:44:08.560 | If, on the other hand, there's a time machine,

01:44:11.800 | you go back and bring a somewhat younger Newton,

01:44:14.880 | not a man my age, say, I mean, he lived a long time,

01:44:20.260 | into his mid-80s, but take him when he's in his 40s,

01:44:24.100 | let's say, bring him forward

01:44:26.380 | and don't immediately introduce him to Einstein.

01:44:29.180 | Let's take him for a ride on a railroad.

01:44:32.820 | Let him experience the railroad.

01:44:34.340 | - Oh, that's right.

01:44:36.140 | - Take him around and show him a sparking machine.

01:44:41.140 | He knows about sparks.

01:44:45.940 | Sending off sparks.

01:44:48.100 | Show him wires, have him touch the wires

01:44:51.480 | and get a little shock.

01:44:53.180 | Show him a clicking telegraph machine of the kind.

01:44:58.180 | Then let him hear the clicks

01:45:00.460 | in a telephone receiver and so on.

01:45:03.120 | Do that for a couple of months.

01:45:05.780 | Let him get accustomed to things.

01:45:07.620 | Then take him into, not Einstein yet,

01:45:11.140 | let's say we're taking him into the 1890s.

01:45:14.340 | Einstein is a young man then.

01:45:16.020 | We take him into some of the laboratories.

01:45:19.100 | We show him some of the equipment, the devices.

01:45:22.500 | Not the most elaborate ones.

01:45:24.420 | We show him certain things.

01:45:25.460 | We educate him bit by bit.

01:45:28.220 | - Oh, the optics, maybe focus on that.

01:45:29.940 | - Certainly on optics.

01:45:31.740 | You begin to show him things.

01:45:33.660 | He's a brilliant human being.

01:45:36.280 | I think bit by bit, he would begin to see what's going on.

01:45:42.660 | But if you just dumped him in front of Einstein,

01:45:44.820 | he'd sit there, his eyes would glaze over.

01:45:46.980 | - I mean, I guess it's almost a question

01:45:51.780 | of how big of a leap,

01:45:55.940 | how many leaps have been taken in science

01:45:58.740 | that go from Newton to Einstein?

01:46:00.980 | We sometimes in a compressed version of history

01:46:03.020 | think that not much.

01:46:06.460 | - Oh, that's totally wrong.

01:46:08.960 | A lot.

01:46:10.260 | Huge amounts.

01:46:11.620 | In multifarious ways,

01:46:13.860 | involving fundamental conceptions,

01:46:15.780 | mathematical structures,

01:46:17.400 | the evolution of novel experimentation and devices,

01:46:20.240 | the organization of science, everything.

01:46:23.020 | - Everything.

01:46:23.860 | I mean, to a point where I wonder

01:46:25.740 | even if Newton was,

01:46:27.260 | like you said 40, but even like 30.

01:46:32.620 | So he's very, like if he would be able to catch up

01:46:36.180 | with the conception of everything.

01:46:37.420 | I wonder as a scientist,

01:46:39.620 | how much you load in from age five

01:46:43.980 | about this world in order to be able to conceive

01:46:46.500 | of the world of ideas that push that science forward.

01:46:51.500 | I mean, you mentioned the railroad

01:46:53.340 | and all those kinds of things.

01:46:54.840 | That might be fundamental to our ability to invent

01:46:58.720 | even when it doesn't directly obviously seem relevant.

01:47:02.300 | - Well, yes.

01:47:07.900 | I mean, the railroad, the steam engine,

01:47:11.340 | the Watt engine, et cetera.

01:47:13.620 | I mean, that was really the Watt engine,

01:47:16.340 | was developed pretty,

01:47:17.380 | although Watt knew Joseph Black,

01:47:19.580 | a chemist, scientist, and so on,

01:47:22.020 | did stuff on heat,

01:47:23.220 | was developed pretty much independently

01:47:25.140 | of the developing thoughts about heat at the time.

01:47:30.140 | But what it's not independent of

01:47:35.040 | is the evolution of practice

01:47:38.240 | in the manufacture and construction of devices

01:47:42.440 | which can do things in extraordinarily novel ways,

01:47:46.640 | and the premium being gradually placed

01:47:49.340 | on calculating how you can make them more efficient.

01:47:52.500 | That is of a piece with a way of thinking about the world

01:47:58.440 | in which you're controlling things and working it.

01:48:02.400 | It's something that humans have been doing

01:48:04.620 | for a long time,

01:48:05.560 | but in this more concerted and structured way,

01:48:10.560 | I think you really don't find it in the fullest sense

01:48:15.160 | until well into the 1500s

01:48:19.720 | and really not fully until the 17th century later on.

01:48:24.000 | - So Newton had this year of miracles.

01:48:29.480 | I wonder if I could ask you briefly about Einstein

01:48:33.240 | and his year of miracles.

01:48:34.580 | I've been reading, re-reading, revisiting

01:48:38.880 | the brilliance of the papers

01:48:41.660 | that Einstein published in the year 1905,

01:48:44.700 | one of which won him the Nobel Prize,

01:48:46.380 | the photoelectric effect,

01:48:47.860 | but also Brownian motion, special theory of relativity,

01:48:52.340 | and of course the old E equals MC squared.

01:48:56.620 | Is there, does that make sense to you

01:49:02.060 | that these two figures had such productive years

01:49:05.800 | that there's this moment of genius?

01:49:08.800 | Maybe if we zoom out,

01:49:10.960 | I mean, my work is very much in artificial intelligence,

01:49:14.360 | so wondering about the nature of intelligence.

01:49:18.000 | Like how did we, how did evolution on Earth produce genius

01:49:23.000 | that could come up with so much in so little time?

01:49:28.560 | To me, that gives me hope

01:49:30.080 | that one person can change the world

01:49:33.640 | in such a small amount of time.

01:49:35.200 | - Well, of course, there are precedents for,

01:49:40.200 | in both Newton's and Einstein's cases,

01:49:43.520 | for elements of what we're finding there,

01:49:45.920 | it's, you know, and so on.

01:49:48.480 | Well, I have no idea.

01:49:49.740 | You know, I'm sure you must have read,

01:49:51.280 | it was kind of a famous story,

01:49:52.820 | that after Einstein died, he donated his brain

01:49:56.880 | and they sliced it up

01:49:57.920 | to see if they could find something unusual there.

01:50:00.380 | Nothing unusual visibly in there.

01:50:04.180 | So I have, clearly, there are people

01:50:09.180 | who for various reasons,

01:50:11.420 | maybe both intrinsic and extrinsic

01:50:14.760 | in the sense of experience and so on,

01:50:17.660 | are capable of coming up with these extraordinary results.

01:50:22.660 | Many years ago, when I was a student,

01:50:26.540 | a friend of mine came in and said,

01:50:28.000 | did you read about, did you read this?

01:50:29.640 | I forget what, anyway, there was a story in the paper.

01:50:33.040 | It was about, I think it was a young woman,

01:50:36.940 | who was, she couldn't speak,

01:50:41.860 | and she was somewhere on the autism spectrum.

01:50:45.140 | She could not read other people's affect in any way,

01:50:52.920 | but she could sit down at a piano,

01:50:56.880 | and having heard it once,

01:50:59.920 | and then run variations on the most complex

01:51:03.960 | pianistic works of Chopin and others.

01:51:08.840 | Right, now how?

01:51:10.760 | - Some aspect of our mind is able to tune in

01:51:18.000 | in some aspect of reality and become a master of it,

01:51:21.620 | and every once in a while, that means coming up

01:51:24.360 | with breakthrough ideas in physics.

01:51:26.240 | Yeah, how the heck does that happen?

01:51:30.240 | - Who knows?

01:51:31.440 | - Jed, I'd like to say thank you so much

01:51:33.200 | for spending your valuable time with me today.

01:51:35.000 | That was a really fascinating conversation.

01:51:37.160 | I've learned so much about Isaac Newton,

01:51:39.000 | who's one of the most fascinating figures in human history,

01:51:41.560 | so thank you so much for talking to me.

01:51:43.000 | - A pleasure, enjoyed it very much.

01:51:44.760 | - Thanks for listening to this conversation

01:51:48.000 | with Jed Buchwald.

01:51:50.080 | To support this podcast,

01:51:51.520 | please check out our sponsors in the description.

01:51:54.400 | And now, let me leave you with some words from Thomas Kuhn,

01:51:58.400 | a philosopher of science.

01:51:59.900 | The answers you get depend on the questions you ask.

01:52:04.120 | Thank you for listening, and hope to see you next time.

01:52:08.080 | (upbeat music)

01:52:10.660 | (upbeat music)

01:52:13.240 | [BLANK_AUDIO]

Jed Buchwald: Isaac Newton and the Philosophy of Science | Lex Fridman Podcast #214

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