The following is a conversation with Jed Buckwald, a professor of history and a philosopher of
science at Caltech, interested especially in the development of scientific concepts
and the instruments used to create and explore new effects and ideas in science.
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This is the Lex Friedman podcast and here is my conversation with Jed Buckwald.
The science progressed via paradigm shifts and revolutions as philosopher Thomas Kuhn said,
or does it progress gradually? What do you think?
Well, I got into this field because I was Tom Kuhn's research assistant 50 years ago, 52 years
ago, he pulled me into it out of physics instead. So I know his work pretty well and in the years
when I was at MIT running an institute, he was then in the philosophy department used to come over
all the time to the talks we held and so on. So what would I say about that? He of course developed
his ideas a lot over the years. The thing that he's famous for, the structure of scientific
revolutions came out in 62. And as you just said, it offered an outline for what he called a
paradigmatic structure, namely the notion that you have to look at what scientists do is forming
a community of investigators and that they're trying to solve various puzzles, as he would put
it, that crop up, figuring out how this works, how that works and so on. And of course, they
don't do it out of the blue, they do it within a certain framework. The framework can be pretty vague.
He called it a paradigm. And his notion was that eventually they run into troubles or what he called
anomalies, that kind of cracks things, somebody new comes along with a different way of doing it,
etc. Do I think things work that way? No, not really. Tom and I used to have
like the discussions about that over the years. I do think there is a common structure
that formulates both theoretical and experimental practices. And historians nowadays of science
like to refer to scientific work as what scientists practice. It's almost craftsmen-like.
They can usually adapt in various ways. And I can give you all kinds of examples of that.
I once wrote a book on the origins of wave theory of light. And that is one of the
paradigmatic examples that Tom used, only it didn't work that way exactly. Because he thought
that what happened was that the wave theory ran into trouble with a certain phenomenon
which it couldn't crack. Well, it turned out that in fact historically that phenomenon was
actually not relevant later on to the wave theory. And when the wave theory came in,
the alternative to it which had prevailed, which was Newton's views, light as particles,
that it seemed couldn't explain what the wave theory could explain. Again, not true.
Not true. Much more complex than that. The wave theory offered the opportunity to deploy
novel experimental and mathematical structures which gave younger scientists, mathematicians
and others, the opportunity to effect, manufacture, make new sorts of devices. It's not that the
alternative couldn't sort of explain these things, but it never was able to generate them
de novo as novelties. In other words, if you think of it as something scientists want to
progress in the sense of finding new stuff to solve, then I think what often happens is that
it's not so much that the prevailing view can't crack something as that it doesn't give you the
opportunity to do new stuff. When you say new stuff, are we referring to experimental science
here or new stuff in the space of new theories? Could be both. Could be both actually. So how
does that, can you maybe elaborate a little bit on the story of the wave? Sure. The prevailing view
of light, at least in France, where the wave theory really first took off, although it had been
introduced in England by Thomas Young. The prevailing theory dates back to Newton that light
is a stream of particles and that refraction and reflection involve sort of repulsive and attractive
forces that deflect and bend the paths of these particles. Newton was not able successfully to
deal with the phenomenon of what happens when light goes past a knife's edge or a sharp edge,
what we now call diffraction. He had cooked up something about it that no mathematical structure
could be applied. Thomas Young first, but really this guy named Augustin Fresnel in France, deployed
in Fresnel's case, rather advanced calculus forms of mathematics, which enabled computations to be
done and observations to be melded with these computations in a way that you could not do or
see how to do with Newton. Did that mean that the Newtonian explanation of what goes on and
diffraction fails? Not really. You can actually make it work, but you can't generate anything new
out of it, whereas using the mathematics of wave optics in respect to a particular phenomenon
called polarization, which ironically was discovered by partisans of Newton's way of doing things,
you were able to generate devices which reflect light in crystals, do various things,
that the Newtonian way could accommodate only after the fact. They couldn't generate it from
the beginning. If you want to be somebody who is working a novel vein, which increasingly becomes
the case with people who become what we now call physicists in the 1820s, 30s, and 40s in particular,
then that's the direction you're going to go. But there were holdouts until the 1850s.
I want to try to elaborate on the nature of the disagreement you have with Thomas Kuhn.
So do you still believe in paradigm shifts? Do you still see that there are ideas that really
have a transformational effect on science? The nature of the disagreement has to do with how
those paradigm shifts come to be? How they come to be and how they change. I certainly think they
exist. How strong they may be at any given time is maybe not quite as powerful as Tom thought in
general, although towards the end of his life he was beginning to develop different modifications
of his original way of thinking. But I don't think that the changes happen quite so neatly,
if you will, in reaction to novel experimental observations. They get much more complex than
that. In terms of neatness, how much of science progresses by individual lone geniuses and how
much by the messy collaboration of competing and cooperating humans? I don't think you can cut that
with a knife to say it's this percent and that percent. It's almost always the case that there
are one or two or maybe three individuals who are sort of central to what goes on when things begin
to shift. Are they inevitably and solely responsible for what then begins to happen in a major way?
I think not. It depends. You can go very far back with this even into antiquity to see what goes on.
The major locus we always talk about from the beginning is if you're talking about Galileo's
work on motion, for example, were there ways of accommodating it that others could adapt to
without buying into the whole scheme? Yes. Did it eventually evolve and start convincing people
because you could also do other things with it that you couldn't otherwise do? Also, yes.
Let me give you an example. The great French mathematician philosopher Descartes,
who was a mechanical philosopher, he believed the world was matter in motion. He never thought
much of what Galileo had done in respect to motion because he thought, well, it bested some sort of
approximative scheme or something like that. One of his initial, I wouldn't call him a disciple,
but follower, who then broke with him in a number of ways, was a man named Christian Huygens,
who was along with Newton, one of the two greatest scientists of the 17th century. Huygens is older
than Newton. Huygens nicely deployed Galilean relationships in respect to motion to develop
all sorts of things, including the first pendulum-governed clock and even figured out how to build one,
which keeps perfect time, except it didn't work, but he had the mathematical structure for it.
How well-known is Huygens? Oh, very well-known. Should I know him well? Yes, you should.
Interesting. You should definitely know him well. No, no, no. Can we define should here?
Because I don't. Right. Can you define should? Should means this. If you had taken up to a
second year of physics courses, you would have heard his name because one of the fundamental
principles and optics is called Huygens principle. Okay. Yeah, so I have, and I have heard his name.
There you go. No, but I don't remember. But you don't remember. There's a very different thing
between names attached to principles and laws and so on that you sometimes let go of. You just
remember the equations of the principles themselves and the personalities of science.
And there's certain personalities, certain human beings that stand out. And that's why there's a
sense to which the lone inventor, the lone scientist is the way I personally, I mean,
I think a lot of people think about the history of science is these lone geniuses. Without them,
the sense is if you remove Newton from the picture, if you remove Galileo from the picture,
then science would, there's almost a feeling like it would just have stopped there. Or at the very
least, there's a feeling like it would take much longer to develop the things that were developed.
Is that a silly way to look at the history? That's not entirely incorrect, I suppose.
I find it difficult to believe that had Galileo not existed, that eventually someone like Huygens,
for instance, given the context of the time, what was floating around in the belief structure concerning
the nature of the world and so on, the developments in mathematics and whatnot,
that sooner or later, whether it would have been exactly the same or not, I cannot say.
But would things have evolved? Yes.
If we look at the long arc of history of science from, from back when we were in the caves,
trying to knock two rocks together, or maybe make a basic tool to
a long time from now, many centuries from now, when human civilization finally destroys itself.
If we look at that history and imagine you're a historian at the end, like would they fire
the apocalypse coming upon us? And you look back at this time in the 21st century,
how far along are we on that arc? Do you sense? Have we invented and discovered everything that's
to be discovered, or are we at like below 1%? Well, you're going to get a lot of absurd questions
today. I apologize. It's a Lugubrius picture you're painting there.
I don't even know what the word Lugubrius is, but I love it. Lugubrius.
Well, let me try and separate the question of whether we're all going to die in an apocalypse
in several hundred years or not from the question of where science may be sitting.
Take that as an assumption. Okay. I find that hard to say. And I find it hard to say
because in the deepest sense of the term, as it's usually deployed by philosophers of science today,
I'm not fundamentally a realist. That is to say, I think our access to the inner workings
of nature is inevitably mediated by what we can do with the materials and factors around us.
We can probe things in various ways. Does that mean that I don't think that the
standard model in quantum electrodynamics is incorrect? Of course not. I wouldn't even dream
of saying such a thing. It can do a lot, especially when it comes to figuring out what's happening
in very large, expensive particle accelerators and applying results in cosmology and so on as well.
Do I think that we have inevitably probed the depths of reality through this? I do not agree
with Stephen Weinberg, who thinks we have about such things. Do I, on the other hand,
think that the way in which science has been moving for the last 100 years, physics in particular is
what I have in mind, will continue on the same course in that sense? I don't, because we're not
going to be building bigger and bigger and more and more expensive machines to rip apart particles
in various ways. In which case, what are physicists going to do? They'll turn their
attention to other aspects. There are all sorts of things we've never explained about the material
world. We don't have theories that go beyond a certain point for all sorts of things. Can we,
for example, start with the standard model and work our way up all the way to chemical
transformations? You can make an argument about it and you can justify things, but that's in
chemistry, that's not the way people work. They work with much higher level quantum mechanical
relationships and so on. This notion of the deep theory to explain everything is a longstanding
belief, which goes back pretty far, although I think it only takes its fullest form sometime
in towards the end of the 19th century. Maybe we just speak to that. You're referring to a hope,
a dream, a reality of coming up with a theory of everything that explains everything,
so there's a very specific thing that that currently means in physics, is the unification
of the laws of physics, but I'm sure in antiquity or before it meant maybe something else or was
it always about physics? I think as you've kind of implied, in physics there's a sense once you
get to the theory of everything, you've understood everything, but there's a very deep sense in
which you've actually understood not very much at all. You've understood at that particular level
how things work, but you don't understand how the abstractions on top of abstractions form
all the way to the chemistry, to the human mind and the human societies and all those kinds of
things. Maybe you can speak to the theory of everything in its history and comment on what
the heck does that even mean, the theory of everything. Well, I don't think you can go back
that far with something like that, maybe at best to the 17th century. If you go back all the way
in antiquity, there are of course discussions about the nature of the world, but first of all,
you have to recognize that the manipulative character of physics and chemistry, the probing
of, let me put it this way, we assume and have assumed for a long time, I'll come back to when
in a moment, that if I take a little device which is really complicatedly made out of all kinds of
things and I put a piece of some material in it and I monkey around with it and do all kinds of
unnatural things to it, things that wouldn't happen naturally and I find out how it behaves
and whatnot and then I try and make an argument about how that really applies even in the natural
world without any artificial structures and so on. That's not a belief that was widely held
by pretty much anyone until sometime maybe in the 1500s and when it was first held,
it was held by people we now call alchemists.
So alchemy was the first, the early days of the theory of everything, of a dream of a theory of
everything. I would put it a little differently. I think it's more along the way a dream that by
probing nature in artificially constructed ways, we can find out what's going on deep down there.
So that's distinct from science being an observing thing where you observe nature
and you study nature. You're talking about probing, like messing with nature to understand it.
Indeed, I am and but that of course is the very essence of experimental science. You have to
manipulate nature to find out things about it and then you have to convince others that you
haven't so manipulated it that what you've done is to produce what amounts to fake
artifactual behavior that doesn't really hold purely naturally. So where are we today in your sense
to jump around a little bit with the theory of everything? Maybe a quick kind of sense you have
about the journey in the world of physics that we're taking towards the theory of everything.
Well, I'm of course not a practicing physicist. I mean, I was trained in physics at Princeton
a long time ago. Until Thomas Kuhn stole you away.
More or less. I was taking graduate courses in those days in general relativity. I was an
undergraduate but I moved up and then I took a course with him. Well, you made the mistake of
being compelled by charismatic philosophers and never looked back. I suppose so in a way.
And from what I understand, talking especially to my friends at Caltech,
like Kip Thorne and others, the fundamental notion is that actually the laws that even at
the deepest level we can sort of divine and work with in the universe that we inhabit
are perhaps quite unique to this particular universe as it formed at the Big Bang.
The question is, how deep does it go? If you are very mathematically inclined,
the prevailing notion for several decades now has been what's called string theory,
but that has not been able to figure a way to generate probative experimental evidence,
although it's pretty good apparently at accommodating things.
And then the question is, what's before the Big Bang? Or actually the word before doesn't mean
anything given the nature of time, but why do we have the laws that prevail in our universe?
Well, there is a notion that those laws prevail in our universe because if they didn't, we wouldn't
be here. That's a bit of a cyclical but nevertheless a compelling definition. And there's all kinds of
things like, it seems like the unification of those laws could be discovered by looking inside
of a black hole because you get both the general relativity and the quantum mechanics,
quantum field theory in there. Experimentally, of course, there's a lot of interesting ideas.
We can't really look close to the Big Bang. We can look that far back. This Caltech and MIT
will lie go looking at gravitational waves, perhaps allows us to march backwards and so on.
Yeah, it's really exciting space. And there's, of course, the theory of everything,
like with a lot of things in science, captivates the dreams of those who are perhaps completely
outside of science. It's the dream of discovering the key to how the nature of how everything works.
And that feels deeply human. That's perhaps the thing, the basic elements of what makes
a scientist in the end is that curiosity, that longing to understand.
Let me ask, you mentioned a disagreement with Weinberg on reality. Could you elaborate a little
bit? Well, obviously, I don't disagree with Steve Weinberg on physics itself. I wouldn't know enough
to even begin to do that. And clearly, you know, he's one of the founders of the standard model
and so on. And it works to a level of accuracy that no physical theory has ever worked at before.
I suppose the question in my mind is something that, in one way, could go back to
the philosopher Immanuel Kant in the 18th century, namely, can we really ever
convince ourselves that we have come to grips with something that is not in itself knowable
to us by our senses or even except in the most remote way through the complex instruments that
we make as to what it is that underlies everything. Can we corral it with mathematics and experimental
structures? Yes. Do I think that a particular way of corraling nature will inevitably play itself
out? I don't know. It always has. I'll put it to you that way.
All right. So the basic question is, can we know reality? Is that the Kant question?
Is that the Weinberg question? We humans with our brains, can we comprehend reality?
Sounds like a very trippy question because a lot of it rests on definitions of know and
comprehend in reality, but get to the bottom of it. It's turtles on top of turtles. Can we get
to the bottom turtle? Well, maybe I can put it to you this way in a way that I often begin
discussions in a class on the history of science and so on and say, I'm looking at you. Yes.
You are in fact a figment of my imagination. You have a messed up imagination. Yes. Well,
what do I mean by that? If I were a dragonfly looking at you, whatever my nervous system
would form by way of a perceptual structure would clearly be utterly different from what
my brain and perceptual system altogether is forming when I look at you.
Who's right? Is it me or the dragonfly?
Well, the dragonfly is certainly very impressive, so I don't know. But yes, it's the observer matters.
Well, what is that supposed to tell us about objective reality?
Well, I think it means that it's very difficult to get beyond the constructs that our perceptual
system is leading us to. When we make apparatus and devices and so on, we're still making things,
the results of which or the outputs of which we process perceptually in various ways. And an
analogy I like to use with the students sometimes is this. They all have their laptops open in front
of them, of course. And I've sent them something to read. And I say, okay, click on it and open it
up. So PDF opens up. I said, what are you looking at? They said, well, I'm looking at the paper that
you sent me. I said, no, you're not. What you're looking at is a stream of light coming off LEDs
or LCDs coming off a screen. And I said, what happens when you use your mouse and move that
fake piece of paper on the screen around? What are you doing? You're not moving a piece of paper
around, are you? You're moving a construct around, a construct that's being processed
so that our perceptual system can interact with it in the way we interact with pieces of paper.
But it's not real. So are there things outside of the reach of science? Can you maybe, as an example,
talk about consciousness, masking for a friend, trying to figure this thing out?
Well, boy, I mean, I read a fair bit about that, but I certainly don't
know. Can't really say much about it. I'm a materialist in the deepest sense of the term.
I don't think there is anything out there except material structures which interact
in various ways. Do I think, for example, that this bottle of water is conscious? No, I do not.
Although, how would I know? I can't talk to it. Yeah. But so what do-
It's a hypothesis, yeah. It's an opinion, an educated opinion that may be very wrong.
Well, I know that you're conscious because I can interact directly with you.
But am I? Well, unless you're a figment of my imagination, of course.
Nor am I a robot that's able to generate the illusion of consciousness effectively enough
to facilitate a good conversation because we humans do want to pretend that we're talking
to other conscious beings because that's how we respect them. If it's not conscious,
we don't respect them. We're not good at talking to robots.
That's true. Of course, we generalize from our own inner sense, which is the kind of thing Descartes
said from the beginning. We generalize from that. But I do think that consciousness must be
something, whatever it is, that occurs as a result of some particular organizational structure of
material elements. Does materialism mean that it's all within the reach of science?
My sense would be that, especially as neuroscience progresses more and more. And at Caltech,
we just built a whole neuroscience arena and so on. And as more knowledge is gained about the ways
in which animals, when they behave, what patterns show up at various parts of the brain and nervous
system, and perhaps extending it to humans eventually as well, we'll get more of a handle
on what brain activity is associated with experiences that we have as humans. Can we move
from the brain activity to the experiences in terms of our person? No, you can't. Perception
is perception. That's a hypothesis once again. Maybe consciousness is just one of the laws of
physics that's yet to be discovered. Maybe it permeates all matter. Maybe it's as simple as
trying to plug it in and plug into the ability to generate and control that kind of law of physics
that would crack open where we would understand that the bottle of water is in fact conscious,
just much less conscious than us humans. And then we would be able to then generate beings that are
more conscious. Well, that'll be unfortunate. I'd have to stop drinking the water after that.
Every time you take a sip, there's a little bit of a suffering going on. Right. What to use the
most interesting beautiful moments in the history of science? What stands out?
And then we can pull at that thread. Right. Well, I like to think of events that have
a major impact and involve both beautiful conceptual, mathematical, if we're talking
physical structures work and are associated as well with probing experimental situations.
So among my favorites is one of the most famous, which was the young Isaac Newton's work with
the colors produced when you pass sunlight through a prism. And why do I like that?
It's not profoundly mathematical in one sense. It doesn't need it initially. It needs the
following though, which begins to show you, I think, a little bit about what gets involved
when you've got a smart individual who's trying to monkey around with stuff and finds new things
about it. First, let me say that the notion, the prevailing notion going back to antiquity,
was that colors are produced in a sense by modifying or tinting white light, that they're
modifications of white light. In other words, the colors are not in the sunlight in any way.
Now, what Newton did following experiments done by Descartes before him, who came to very different
conclusions, he took a prism, you might ask, where do you get prisms in the 1660s, county fairs.
They were very popular. They were pretty crude with bubbles in them and everything,
but they produced colors. So you could buy them at county fairs and things very popular.
So they were modifying the white light to create colors.
Well, they were creating colors from it, well known. And what he did was the following. He was
by this time, even though he's very young, a very good mathematician. And he could use the then
known laws for how light behaves when it goes through glass to calculate what should happen
if you took light from the sun, passed it from a hole through a little hole, then hit the prism,
goes out of the prism, goes, strikes a wall a long distance away, and makes a splash of light.
Never mind the colors for a moment. Makes a splash of light there. He was very smart.
First of all, he abstracts from the colors themselves, even though that's what everybody's
paying attention to initially. Because what he knows is this. He knows that if you take this
prism and you turn it to a certain particular angle, that he knew what it should be because he
could calculate things. Very few other people in Europe at the time could calculate things
like he could. That if you turn the prism to that particular angle, then the sun, which is,
of course, a circle, when its light passes through this little hole and then into the prism,
on the far distant wall should still make a circle. But it doesn't. It makes a very long
image. This led him to a very different conception of light, indicating that there are different
types of light in the sunlight. Now, to go beyond that, what's particularly interesting, I think,
is the following. When he published this paper, which got him into a controversy,
he really didn't describe at all what he did. He just gave you some numbers.
Now, I just told you that you had to set this prism at a certain angle. You would think,
because we do have his notes and so on, you would think that he took some kind of complicated
measuring device to set the prism. He didn't. He held it in his hand. That's all. And he
twiddled it around. And what was he doing? It turns out that when you twiddled the prism around
at the point where you should get a circle from a circle, it also is the place where the image
does not move very fast. So if you want to get close to there, you just twiddle it. This is
manipulative experimentation taking advantage through his mathematical knowledge of the inherent
inaccuracies that let you come to exact conclusions, regardless of the built-in
problematics of measurement. He's the only one I know of doing anything like that at this time.
Well, even still, there's very few people that are able to have, to calculate as well as he did,
to be a theoretician and an experimentalist in the same moment. It's true, although until
the well into the 20th century, maybe the beginning of the 20th century, really,
most of the most significant experimental results produced in the 1800s,
which laid the foundations for light, electricity,
electrodynamics, and so on. Even hydrodynamics and whatnot were also produced by people who
were both excellent calculators, very talented mathematicians, and good with their hands
experimentally. And then that led to the 21st century with Enrico Fermi that
one of the last people that was able to do that, both of those things very well, and that
he built a little device called an atomic bomb that has some positives and negatives.
Well, right. Of course, that actually did involve some pretty large-scale elaborate equipment.
Yeah. Well, holding a resume in your hand is the same thing.
Right. No.
What's the controversy that Newton got into with that paper when he published it?
Well, in a number of ways, it's a complicated story. There was a very talented character
known as a mechanic. Mechanic means somebody who was a craftsman who could build and make
really good stuff. And he was very talented. His name was Robert Hook. And he was the guy who,
at the weekly meetings of the Royal Society in London, and Newton's not in London,
you know, he's at Cambridge, he's a young guy, he would demonstrate new things. And he was very
clever. And he had written a book, in fact, called The Micrographia, which by the way,
he used a microscope to make the first depictions of things like a fly's eye,
the structure of, you know, and had a big influence. And in there, he also talked about light.
And so he had a different view of light. And when he read what Newton was
wrote, he had a double reaction. On the one hand, he said, anything in there that is correct,
I already knew. And anything that I didn't already know is probably not right anyway.
Gotta love egos. Okay. Can we just step back? Can you say who was Isaac Newton?
And what are the things he contributed to this world in the space of ideas?
Wow. Who was he? He was born in 1642, and near the small town of Grantham in England.
In fact, the house he was born in and that his mother died in is still there and can be visited.
His father died before he was born. And his mother eventually remarried a man named Reverend Smith,
whom Newton did not like at all, because Reverend Smith took his mother away to live with him a
few miles away, leaving Newton to be brought up more or less by his grandmother over there.
And he had huge resentment about that his whole life.
I think that gives you a little inkling that a little bit of trauma and childhood,
maybe a complicated father-son relationship can be useful to create a good scientist.
Could be, although this case it would be right, the abs and father,
non-father relationship, so to speak. He was known as a kid, little that we do know for
being very clever about flying kites and there are stories about him putting candles and putting
flying kites and scaring the living devil out of people at night by doing that and
things like that, making things. Most of the physicists and natural philosophers I've dealt
with actually as children were very fond of making and playing with things. I can't think of one I
know of who wasn't actually. They were very good with their hands and whatnot. His mother wanted
him to take over the manner. It was a kind of farming manner. They were the class of what are
known as yeomans. There are stories that he wasn't very good at that. One day one of the stories
is he's sitting out in the field and the cows come home without him and he doesn't know what's
going on. Anyway, add relatives and he manages to get to Cambridge, sent to Cambridge because
he's known to be smart. He's read books that he got from local dignitaries and some relatives.
He goes there as what's known as a sub-sizer. What does that mean? Well, it's not too pleasant.
Basically, a sub-sizer was a student who had to clean the bedpans of the richer kids.
That didn't last too long. He makes his way and he becomes absorbed in some of the new ways
of thinking that are being talked about on the parts of Descartes and others as well. There's
also the traditional curriculum which he follows. We have his notes. We have his student notebooks
and so on. We can see gradually this young man's mind focusing and coming to grips with
deeper questions of the nature of the world and perception even and how we know things
and also probing and learning mathematical structures to such an extent that he builds on
some of the investigations that had been done in the period before him to create the foundations
of a way of investigating processes that happen and change continuously instead of by leaps and
bounds and so on forming the foundation of what we now call the calculus. Can you maybe
just paint a little bit of a picture? You've already started of what were the things that
bothered him the most that stood out to him the most about the traditional curriculum,
about the way people saw the world. You mentioned discrete versus continuous. Is there something
where he began thinking in a revolutionary way? Because it's fascinating. Most of us go to college,
Cambridge or otherwise, and we just kind of take what we hear as gospel. Not gospel but
as facts. You don't begin to see how can I expand on this aggressively or how can I challenge
everything that I hear rigorously, mathematically. I mean, I don't even know how rigorous the
mathematics was at that point. I'm sure it was geometry and so on. No calculus, huh?
There are elements of what turned into the calculus that predate Newton. But how much
rigor was there? How much? Well, rigor, no. And then of course, no scientific method,
not really. I mean, appreciation of data. That is a separate question from a question of method.
Appreciation of data is a significant question as to what you do with data. There's lots of
things you're asking. I apologize. So maybe let's backtrack in the first question. Was there
something that was bothering him that he especially thought he could contribute or work on?
Well, of course, we can't go back and talk to him. But we do have these student notebooks.
There's two of them. One's called the philosophical questions and the other is called the waste book.
The philosophical questions has discussions of the nature of reality and various issues
concerning it. And the waste book has things that have to do with motion in various ways,
what happens in collisions and things of that sort. And it's a complicated story. But what's
among the things that I think are interesting is he took notes in the philosophical questions
on stuff that was traditionally given to you in the curriculums going back
several hundred years, namely on what scholars refer to as scholastic or neoscholastic
ways of thinking about the world, dating back to the reformulation of Aristotle in the Middle
Ages by Thomas Aquinas in the church. And this is a totally different way of thinking about
things, which actually connects to something we were saying a moment ago. For instance,
so I'm wearing a blue shirt. And I will sometimes ask students, where is the blue?
And they'll usually say, well, it's in your shirt. And then some of them get clear and they say,
well, no, you know, light is striking. Photons are re-emitted. They strike the back of your retina
and et cetera, et cetera. And I said, yes. What that means is that the blue is actually
an artifact of our perceptual system considered as the percept of blue. It's not out there,
it's in here. That's not how things were thought about well into the 16th century.
The general notion dating back even to Aristotelian antiquity and formalized by the 12th century
at the Paris, Oxford and elsewhere is that qualities are there in the world.
They're not in us. We have senses and our senses can be wrong. You know, you could get blind,
things like that. But if they're working properly, you get the actual qualities of the world.
Now that break, which is occurring towards the end of the 16th century and is most visible in Descartes,
is the break between conceiving that the qualities of the world are very different
from the qualities that we perceive. That, in fact, the qualities of the world consist almost
entirely in shapes of various kinds and maybe hard particles or whatever, but not colors,
not sounds, not smells, not softness and hardness. They're not in the world. They're in us.
That break, Newton is picking up as he reads Descartes. He's going to disagree with a lot in Descartes,
but that break, he is, among other things, picking up very strongly and that underlies a lot
of the way he works later on when he becomes skeptical of the evidence provided by the senses.
Yeah, that's actually, I don't know, the way you're describing it is so powerful. It just makes me
realize how liberating that is as a scientist, as somebody who's trying to understand reality,
that our senses is just, our senses are not to be trusted, that reality is to be investigated
through tools that are beyond our senses. Yes. Or that improve our senses.
Improve our senses, in some ways. That's pretty powerful. I mean, that is,
for a human being, that's like Einstein level. For a human being to realize, I can't trust
my own senses at that time. That's pretty trippy. It's coming in. It's coming in. I think it arises
probably a fair number of decades before that, perhaps in part with all chemical experimentation
and manipulations, that you have to go through elaborate structures to produce things and ways
you think about it. But let me give you an example that I think you might find interesting because
it involves that guy named Hook that Newton had an argument with. He had lots of arguments with
Hook. Although Hook is a very clever guy and gave him some things that stimulated him later. Anyway,
Hook, who was argumentative, and he really was convinced that the only way to gain real knowledge
of nature is through carefully constructed devices. He was an expert mechanic, if you will,
at building such things. Now, there was a rather wealthy man
in Danzig by the name of Hevelius, Latinized name. He was a brewer in town. He had become
fascinated with the telescope. This is 30 years or so, 20 or 30 years after the telescope had moved
out and become more common. He built a large observatory on the top of his brewery, actually,
and working with his wife, they used these very elaborately constructed
grass and metal instruments to make observations of positions of the stars. He published a whole
new catalog of where the stars are. He claimed it was incredibly accurate. He claimed it was
so accurate that nothing had ever come close to it. Hook reads this and he says, wait a minute.
You didn't use a telescope here of any kind because what's the point?
Unless you do something to the telescope, all you see are dots with stars. You just use your eyes.
Your eyes can't be that good. It's impossible. So, what did Hook do to prove this? He said,
what you should have done is you should have put a little device in the telescope that lets you
measure distances between these dots. You didn't do that because you didn't. There's no way you
could have been that good. At two successive meetings of the Royal Society, he hauls the
members out into the courtyard and he takes a card and he makes successive black and white
stripes on the card and he paced the card up on a wall and he takes them one by one. He says,
now, move back looking at it, presumably with one eye, until you can't tell the black ones
from the white stripes. He says, that I can then measure the distance. I can see the angles.
I can give a number then for what is the best possible, what we would call perceptual acuity
of human vision. It turned out he thought to be something like 10 or more times worse than this
guy, Hevelius, had claimed. So, obviously, he says, Hook, Hevelius, well, years ago, I calculated
Hevelius's numbers and so on using modern tables from NASA and so on and they are even more accurate
than Hevelius claimed and worse than that, the Royal Society sent a young astronomer named Halley
over to Dunsig to work with him and Halley rides back and he says, I couldn't believe it,
but I could, he taught me how to do it and I could get just as good as he, how is it possible?
Well, here, and this shows you something very interesting about experiments,
perception and everything else. Hook was right, but he was also wrong. He was wrong for the right
reasons and he was right for the wrong reasons and what do I mean by that? What he actually found
was the number for what we now call 2020 vision. He was right. You can't tell except a few people
much better than that, but he was observing the wrong thing. What Hevelius was observing was a
bright dot, a star moving past a pointer. Our eyes are rather similar to frog's eyes. You know,
I'm sure you've heard the story, if I hold a dead fly on a string in front of a frog and
don't move it, the frog pays no attention. As soon as I move the fly, the frog immediately tongue
laps out because the visual system of the frog responds to motion. So does ours and our
acuity for distinguishing motion from statics, five or more times better.
Yeah, that's fascinating. Damn. And of course, maybe you can comment on their understanding
of the human perceptual system at the time was probably really terrible.
I've recently been working with just almost as a fun side thing with vision scientists
and peripheral vision. It's a beautiful, complex mess, that whole thing. We still don't
understand all the weird ways that human perception works, and they were probably terrible at it.
They probably didn't even have any conceptual peripheral vision or the fovea or, I mean,
basically anything. They had some, I mean, because actually it was Newton himself who
probed a lot of this. For instance, the young Newton trying to work his way around what's
going on with colors wanted to try and distinguish colors that occur through natural processes out
there and colors that are a result of our eyes not operating rights. You know what he did?
It's a famous thing. He took a stick and he stuck that stick under his lower eyelid and pushed up
on his eyeball, and what that did was produced colored circles at diametrically opposite positions
of the stick in the eyeball, and he moved it around to see how they moved, trying to distinguish.
Right? I always have to tell my students, don't do this, but...
Or do it if you want to be great and remembered by human history. There's a lot of equivalent to
sticking to your eye in modern day that may pay off in the end. Okay.
As a small aside, is the Newton and the Apple story true?
No.
Was it a different fruit?
As a colleague of mine named Simon Schaffer in England once said on a NOVA program that we were
both on, the role of fruit in the history of science has been vastly exaggerated.
Okay. Was there any, I mean, to zoom out, moments of epiphany?
Is there something to moments of epiphany? Again, this is the paradigm shift versus the
gradualism. There is a shift. It's a much more complex one than that.
And as it happens, a colleague of mine and I are writing a paper right now on one of the
aspects of these things based on the work that many of our colleagues have done over the last
30 and 40 years. Let me try and see if I could put it to you this way.
Okay. Newton until the early 1670s and probably really until a fair time after that,
first of all, was not very interested in questions of motion. He was working actually
in all chemical relationships or what is called by historians chemistry, a kind of early modern
chemical structure. Colleagues of ours at Indiana have even reproduced the amalgams that,
anyway, his way of thinking about motion involved a certain set of relationships
which was not conducive to any application that would yield computationally direct results
for things like planetary motions, which he wasn't terribly interested in anyway.
He enters a correspondence with his original nemesis, Robert Hooke, and Hooke says, well,
have you ever thought about and then Hooke tells him a certain way you might think about it?
And when Newton hears that, he recognizes that there is a way to inject time that would enable
him to solve certain problems. It's not that there was anything he thought before that was
contrary to that way of thinking. It's just that that particular technical insight was not something
that, for a lot of reasons that are complex, had never occurred to him at all. And that sent him
a different way of thinking. But to answer your question about the Apple business, which is always
about gravity and the moon and all of that being... No. The reason there is that the idea that what
goes on here in the neighborhood of the earth and what goes on at the moon, let us say, remind the
sun and the planet, can be due to a direct relationship between the earth, let's say,
and the moon is contrary to fundamental beliefs held by many of the mechanical philosophers,
as they're called at the time, in which everything has to involve at least a sequence of direct
contexts. It has to be something between here and there that's involved. And Hooke,
probably not thinking terribly deeply about it based on what he said, along with others like
the architect and mathematician Christopher Wren, hearkened back to the notion that, well, maybe
there is a kind of magnetic relationship between the moon and maybe the planets and the earth and
gravity and so on, vague, but establishing a direct connection somehow, however it's happening,
forget about it. Newton wouldn't have cared about that, if that's all they said, but it was when
Hooke mentioned this different way of thinking about the motion, a way he could certainly have
thought of because it does not contradict anything. Newton is a brilliant mathematician
and he could see that you could suddenly start to do things with that that you otherwise wouldn't
connect. And this led eventually to another controversy with Hooke in which Hooke said,
well, after Newton published his great Principia, I gave him how to do this. And then Newton,
of course, got ticked off about that and said, well, listen to this, I did everything and because
he had a pick of you and little idea, he thinks he can take credit for it. Okay.
So his ability to play with these ideas mathematically is what solidified the initial
intuition that you could have, was that the first time he was born the idea that you have
action at a distance, that you can have forces without contact, which is another revolutionary
idea. I would say that in the sense of dealing with the mechanics of force-like effects
considered to act at some distance, it is novel with both Hooke and Newton at the time,
the notion that two things might interact at a distance with one another without direct contact,
that goes back to antiquity. Only there it would thought of more as a sympathetic reaction
to a magnet and a piece of iron. They have a kind of mutual sympathy for one another.
Like what, love? What are we talking about? Well, actually, they do sometimes talk like that.
That is love. See, now I talk like that all the time. I think love is somehow in consciousness
or forces of physics that yet to be discovered. Okay. Now there's the other side of things,
which is calculus that you began to talk about. So Newton brought a lot of things to this world.
One of them is calculus. What is calculus? And what was Newton's role in bringing it
to life? What was it like? What was the story of bringing calculus to this world?
Well, since the publication starting many decades ago by Tom Whiteside, who's now deceased of
Newton's mathematical papers, we know a lot about how he was pushing things and how he was
developing things. It's a complex question to say what calculus is. Calculus is the set of
mathematical techniques that enable you to investigate what we now call functions, mathematical
functions, which are continuous. That is, that are not formed out of discrete sets like the
counting numbers, for instance. Newton, there were already procedures for solving problems
involving such things as finding areas to under curves and tangents to curves by using
geometrical structures, but only for certain limited types of curves, if you will. Newton as
a young man, we know this is what happened, is looking at a formula which involves an expansion
in separate terms, polynomial terms, as we say, for certain functions. I know I don't want to get
complicated here about this, but he realizes it could be generalized and he tries the generalization
and that leads him to an expansion formula called the binomial theorem. That enables him to move
ahead with the notion that if I take something that has a certain value and I add a little bit
to it and I use this binomial theorem and expand things out, I can begin to do new things. The
new things that he begins to do leads him to a recognition that the calculations of areas
and the calculations of tangents to curves are reciprocal to one another. The procedures that
he develops is a particular form of the calculus in which he considers small increments and then
continuous flows and changes of curves and so on. We have relics of it in physics today,
the notation in which you put a dot over a variable indicating the rate of change of the
variable. That's Newton's original type of notation. Possibly independently of Newton
because he didn't publish this thing, although he became quite well known as quite a brilliant
young man in part because people heard about his work and so on. When another young man by the
name of Gottfried Leibniz visited London and he heard about these things, it is said that he
independently develops his form of the calculus, which is actually the form we use today,
both in notation and perhaps in certain fundamental ways of thinking. It has remained a
controversial point as to where exactly and how much independently Leibniz did it. Leibniz
aficionados think and continue to maintain. He did it completely independently. Newton,
when he became president of the Royal Society, put together a group to go on the attack saying,
no, he must have taken everything. We don't know, but I will tell you this. About 25 or so years ago,
a scholar who's a professor at Indiana now named Domenico Melly got his hands on a Leibniz manuscript
called the Ten Taman, which was Leibniz's attempt to produce an alternative to Newton's mechanics.
It comes to some conclusions that you have in the Newton's mechanics. Well, he published that,
but Melly got the manuscript. What Melly found out was that Leibniz reverse engineered the
Principia and cooked it backwards so that he could get the results he wanted.
That was for the mechanics. That means his mind allows for that kind of thing.
You're breaking some use today. Some people think so. I think most historians of mathematics
do not agree with that. A friend of mine, a rather well-known physicist, unfortunately,
died a couple of years ago named Mike Nowenberg at UC Santa Cruz, had some evidence along those
lines. Didn't pass mustard with many of my friends who are historians of math. In fact,
I edit with a historian of math, a technical journal, and we were unable to publish it in
there because we couldn't get it through any of our colleagues. But I remain suspicious.
What is it about those tense relationships and that kind of drama? Einstein doesn't appear to
have much of that drama. Nobody claims—I haven't heard claims that they've—perhaps because
it's such crazy ideas of any of his major inventions, major ideas being those that are—basically,
I came up with it first or independently. As far as I'm aware, not many people talk about
general relativity, especially in those terms. But with Newton, that was the case.
Is that just a natural algorithm of how science works? Is there going to be personalities that—I'm
not saying this about Linus, but maybe I am—that there's people who steal ideas because of ego,
because of all those kinds of things? I don't think it's all that common, frankly.
The Newton hook, Leibniz, Contratomps, and so on. Well, you're at the beginnings of a lot
of things there and so on. These are difficult and complex times as well. These are times in which
science as an activity pursued by other than, let us say, interested aristocrats is becoming
something somewhat different. It's not a professional community of investigators in the
same way. It's also a period in which procedures and rules or practice are being developed to avoid
attacking one another directly and pulling out a sword to cut off the other guy's head,
if he disagrees with you, and so on. There's a very different period. Controversies happen.
People get angry. I can think of a number of others, including in the development of optics
in the 19th century and so on. It can get hot under the collar. Sometimes one character who's
worked an area extensively, whether they've come up with something terribly novel or not,
and somebody else kind of moves in and does completely different novel things. The first
guy gets upset about it because he's muscled into what I thought was my area. You find that
sort of stuff. Do you have examples of cases where it worked out well, like that competition is good
for the progress of science? Yeah, it almost always is good in that sense. It's just painful for
the individuals involved. It can be. It doesn't have to be nasty, although sometimes it is.
So on the space, like for the example of optics, could you comment on that one?
Well, yeah, sure. There are several, but I could give you...
All right. So I'll give you this example that probably is the most pertinent.
The first polytechnic school, like MIT or Caltech, was actually founded in France during
the French Revolution. It exists today. It's the, I call, polytechnique. Two people who were there
were two young men in the 90s, 1790s, named, on the one hand, François Aragault
and the other Jean-Baptiste Bio. They both lived a long time, well into the 1850s. Aragault became
a major administrator of science, and Bio's career started to peter out after about the late teens.
Now, they are sent on an expedition, which was one of the expeditions involving measuring things to
start the metric system. There's a lot more to that story. Anyway, they come back. Aragault gets
separated. He's captured by pirates, actually. Wounds up in Tangier, escapes, is captured again.
Everybody thinks he's dead. He gets back to Paris and so on. He's greeted as a hero and what not.
In the meantime, Bio has pretty much published some of the stuff that he's done. Aragault
doesn't get much credit for it. Aragault starts to get very angry. Bio is known for this kind of
thing. Aragault, anyway, Bio starts investigating a new phenomenon and optics involving something
called polarization. He writes all kinds of stuff on it. Aragault looks into this and decides to
write some things as well. Actually, Bio gets mostly interested in it when he finds out that
Aragault is doing stuff. Now, Bio is actually the better scientist in a lot of ways. Aragault is
furious about this. So furious that he actually demands and forces the leader of French science,
Laplace, the Marquis de Laplace, and cohorts to write a note in the published journal saying,
oh, excuse us. Actually, Aragault, et cetera, et cetera, blah, blah, blah. So Aragault continues to just hold this antipathy and fear of Bio.
So what happens? 1815, Napoleon is finished at Waterloo. A young Frenchman by the name of Augustin
Frenel, who was in the army, is going back to his home on the north coast of France in Normandy.
He passes through Paris. Aragault is friends with Frenel's uncle, who's the head of the
École des Beaux-Arts at the time. Anyway, Frenel is already interested in certain things in light.
He talks to Aragault. Aragault tells him a few things. Frenel goes home and Frenel is a brilliant
experimenter. He observes things, and he's a very good mathematician, calculates things.
He writes something up. He sends it to Aragault. Aragault looks at it, and Aragault says to himself,
I can use this to get back at Bio. He brings Frenel to Paris, sets him up in a room at the
observatory where Aragault is for Frenel to continue his work paper after paper comes out.
Now, undercutting everything Bio had done. What is it about jealousy and just envy that could
be an engine of creativity and productivity versus an Einstein where it seems like not?
I don't know which one is better. I guess it depends on the personality. Both are useful
engines in science. Well, in this particular story, it's maybe even more interesting because
Frenel himself, the young guy, he knew what Aragault was doing with him, and he didn't like it.
He didn't want to get with it. He wrote his brother said, I don't want to get an argument
with Bio. I just want to do my stuff. Aragault is using him, but it's because Aragault kept
pushing him to go into certain areas that stuff kept coming out. Ego is beautiful.
Okay, but back to Newton. There's a bunch of things I want to ask, but let's say since we're
on the Leibniz and the topic of drama, let me ask another drama question. Why was Newton a
complicated man? We're breaking news today. This is like... Right, why was he complicated?
His brain structure was different. I don't know why. He had a complicated young life, as we've said.
He had always been very self-contained and solitary. He had acquaintances and friends,
and when he moved to London eventually, he had quite a career. A career, for instance,
that led him when he was famous by then, the 1690s. He moves to London. He becomes first
warden of the Mint. The Mint is what produces coins, and coinage was a complicated thing because
there was counterfeiting going on, and he becomes master of the Mint to the extent.
A guy at MIT wrote a book about this a little bit. We wrote something on it too. I forget his name
was Levin. That Newton sent investigators out to catch these guys and sent at least one of them,
a famous one named Chaloner, to the gallows. One of the reasons he probably was so particularly
angry at Chaloner was Chaloner had apparently said some nasty things about Newton in front of
parliament at some point. That was apparently not a good idea. Well, he had a bit of a temper,
so he didn't have a bit of a temper. Clearly. Clearly. But even as a young man at Cambridge,
though he doesn't come from wealth, he attracts people who recognize his smarts.
There's a young fellow named Humphrey Newton, shared his rooms. These students always shared
rooms with one another, became his kind of eminuences to write down what Newton was doing,
and so on. There were others over time who he befriended in various ways, and so on. He was
solitary. As far as we know, no relationships with either women or men in anything other than a
formal way. Those get in the way relationships. Right. Well, I mean, I don't know if he was
close to his mother. I mean, she passed away. Everything left him. He went to be with her
after she died. He was close to his niece, Catherine Barton, who basically came to run his household
when he moved to London and so on. She married a man named Conduit, who became one of the
people who controlled Newton's legacy later on and so on. You can even see the house that
the townhouse that Newton lived in in those days still there. There's the story of Newton coming
up with quite a few ideas during a pandemic. We're on the outskirts of a pandemic ourselves,
and a lot of people use that example as motivation for everybody while they're in lockdown to get
stuff done. What's that about? Can you tell the story of that? I can. Let me first say that,
of course, we've been teaching over Zoom lately. There was no Zoom back then? There was no Zoom
back then. Although, it wouldn't have made much difference because the story was Newton was so
complicated in his lectures that at one point, Humphrey Newton actually said that he might as
well have just been lecturing to the walls because nobody was there to listen to it. What
difference? Also, not a great teacher, huh? If you look at his optical notes, if that's what
he's reading from. Oh, boy. Okay. No. So, what can you say about that whole journey through the
pandemic that resulted in so much innovation in such a short amount of time? Well, I mean,
there's two times that he goes home. Would he have been able to do it and do do it if he'd
stayed in Cambridge? I think he would have. I don't think it really, although I do like to
tell my advanced students when I lecture on the history of physics to the physics and chemistry
students, especially we've been doing it over Zoom the last year, when we get to Newton and so on,
because these kids are, you know, 21, 22. I like to say, well, you know, when Newton was your age
and he had to go home during an epidemic, do you know what he produced?
So, can you actually summarize this for people who don't know how old was Newton and what did he
produce? Well, Newton goes up to Cambridge, as it said, when he's 18 years old in the 1660.
And the so-called miraculous year, the Annus Mirabilis, where you get the
development in the calculus and in optical discoveries especially, is 1666. Right? So,
he's what, 24 years old at the time. But judging from his, the notebooks that I mentioned, he's
already, before that, come to an awful lot of developments over the previous couple of years.
Doesn't have much to do with the fact that he twice went home. It is true that the optical
experiments that we talked of a while ago with the light on the wall moving up and down,
were done at home. In fact, you can visit the very room he did it in to this day.
Yeah, it's very cool. And if you look through the window in that room,
there is an apple tree out there in the garden.
So, you might be wrong about this. I thought you were lying to me. Maybe there's an apple
involved after all. Well, it's not the same apple tree, but it's cuttings.
How do you know?
They don't last that long, but it's 400 years ago.
Oh, not this. Oh, wow. I continue with the dumbest questions.
Okay. So, you're saying that perhaps going home was not...
It may have given him an opportunity to work things through. And after all, he did make use
of that room, and he could do things like put a shade over the window, move things around,
cut holes in it, and do stuff. Probably in his rooms at Cambridge, he maybe not. Although,
when he stayed at Cambridge, subsequently, became a fellow, and then the first, actually,
the second Lucasian professor there, he was actually really the first one because Isaac Barrow,
who was the mathematician, professor of optics, recognized Newton's genius, gave up what would
have been his position because he recognized... Newton may not have learned too much from him,
although they didn't interact. And so, Newton was the first Lucasian professor, really,
the one that Stephen Hawking held till he died. And we know that the rooms that he had there at
Cambridge, subsequently, because rooms are still there, he built an all-chemical furnace outside,
did all sorts of stuff in those rooms. And don't forget, you didn't have to do too much
as a Lucasian professor. Every so often, you had to go give these lectures, whether anybody was there
or not, and deposit the notes for the future, which is how we have all those things.
Oh, they were stored, and now we have them, and now we know just how terrible of a teacher Newton
was. Yeah, but we know how brilliant these notes are. In fact, the second volume of Newton's
of the notes, really, on the great book that he published, The Optics, which he published in 1704,
that has just been finished with full annotations and analysis by the greatest analyst of Newton's
optics, Alan Shapiro, who retired a few years ago at the University of Minnesota and been working
on Newton's optics ever since I knew him and before, and I've known him since 1976.
Is there something you could say broadly about either that work on optics or print KPA itself
as something that I've never actually looked at as a piece of work?
Is it powerful in itself, or is it just an important moment in history in terms of the
amount of inventions that are within, the amount of ideas that are within, or is it a really powerful
work in itself? Well, it is a powerful work in itself. You can see this guy coming to grips with
and pushing through and working his way around complicated and difficult issues melding
experimental situations which nobody had worked with before, even discovering new things,
trying to figure out ways of putting this together with mathematical structures,
succeeding and failing at the same time, and we can see him doing that.
What is contained within print KPA? I don't even know in terms of the scope of the work.
All right. Is it the entirety of the body of work of Newton?
No, no, no, no. The print KPA mathematics.
Is it calculus?
Well, all right. So the print KPA is divided into three books.
Excellent.
Book one contains his version of the laws of motion and the application of those laws
to figure out when a body moves in certain curves and is forced to move in those curves
by forces directed to certain fixed points, what is the nature of the mathematical formula
for those forces? That's all that book one is about, and it contains not the kind of version
of the calculus that uses algebra of the sort that I was trying to explain before,
but is done in terms of ratios between geometric line segments when one of the line segments
goes very, very small. It's called the kind of limiting procedure, which is calculus,
but it's a geometrically structured, although it's clearly got algebraic elements in it as well.
That makes the print KPA's mathematical structure rather hard for people who aren't studying it
today to go back to. Book two contains his work on what we now call hydrostatics and a little
bit about hydrodynamics, a fuller development of the concept of pressure, which is a complicated
concept, and book three applies what he did in book one to the solar system, and it is successful
partially, because the only way that you can exactly solve, the only types of problems you can
exactly solve in terms of the interactions of two particles governed by gravitational force
between them is for only two bodies. If there's more than two, let's say it's A, B, and C,
A acts on B, B acts on C, C acts on A, you cannot solve it exactly. You have to develop techniques.
The fullest sets of techniques are really only developed about 30 or 40 years after Newton's
death by French mathematicians like Laplace. Newton tried to apply his structure to the
sun, earth, moon, because the moon's motion is very complicated. The moon, for instance,
exactly repeats its observable position among the stars only every 19 years.
That is, if you look up where the moon is among the stars at certain times, and it changes,
it's complicated. That's, by the way, that was discovered by the Babylonians.
That fact in 19 years.
Thousands of years ago, yes.
And then you have to develop a piece of data, and how do you make sense of it? That is data,
and you have to-
And it's complicated. So Newton actually kind of reverse engineered a technique that
had been developed by a man named Horrocks using certain laws of Kepler's to try and get around
this thing. And Newton then sort of, my understanding, I've never studied this, has sort of reversed it
and fit it together with his force calculations by way of an approximation.
And was able to construct a model to make some predictions?
It fit things backwards pretty well.
Okay. Where does data fit into this? We kind of earlier in the discussion
mentioned data as part of the scientific method. How important was data to Newton?
So like you mentioned Prism and playing with it and looking at stuff and then coming up with
calculations and so on, where does data fit into any of his ideas?
All right. Well, let me say two things first. One, we rarely use the phrase scientific method
anymore because there is no one easily describable such method. I mean, humans have been playing
around with the world and learning how to repetitively do things and make things happen
ever since humans became humans. Do you have a preferred definition of the
scientific method? What are the various? No, I don't. I prefer to talk about
the considered manipulation of artificial structures to produce results that can be
worked together with schemes to construct other devices and make
predictions, if you will, about the way such things will work.
So ultimately, it's about producing other devices. It's like leads you down.
I think so, principally. I mean, you may have data, if you will, like astronomical data
obtained otherwise and so on, but yes. But number two here is this question of data.
What is data in that sense? See, when we talk about data today, we have a kind of complex
notion which reverts to even issues of statistics and measurement procedures and so on. So let me
put it to you this way. So let's say I had a ruler in front of me. Go on. And it's marked off in
little black marks separated by, let's say, distances called a millimeter. Now I make a
mark on this piece of paper here. So I made a nice black mark, right? Nice black mark.
And I ask you, I want you to measure that and tell me how long it is.
You're going to take the ruler. You're going to put it next to it. And you're going to look.
And it's not going to sit, even if you put one in as close as you can on one black mark,
the other end probably isn't going to be exactly on a black mark. Well, you'll say it's closer to
this or that. You'll write down a number. And I say, okay, take the ruler away a minute. I take
this away. Come back in five minutes, put the piece of paper down, do it again. You're going to
probably come up with a different number. And you're going to do that a lot of times. And then
if I tell you, I want you to give me your best estimate of what the actual length of that thing
is, what are you going to do? You're going to average all of these numbers? Why?
Statistics.
Well, yes, statistics. There's lots of ways of going around it. But the average is the
best estimate on the basis of what's called the central limit theorem, a statistical theorem.
We were talking about things that were not really developed until the 1750s,
60s, and 70s. Newton died in 1727.
The intuition perhaps was there.
Not really. I'll tell you what people did, including Newton, although Newton is
partially the one exception. We talked a while ago about this guy, Christian Huygens.
He measured lots of things, and he was a good mechanic himself. He and his brother ground
lenses. Huygens, I told you, developed the first pendulum mechanism, pendulum-driven
clock with a mechanism, and so on. Also, a spring watch, where he got into a controversy with hook
over that, by the way.
What's with these mechanics and the controversy?
Well, we also have Huygens' notes. They're preserved at Leiden University in Holland,
he's Dutch, for his work in optics, which was extensive. We don't have time to go into that,
except the following. Number of years ago, I went through those things, because in this
optical theory that he had, there are four numbers that you've got to be able to get good
numbers on to be able to predict other things. What would we do today? What, in fact, was
done at the end of the 18th century, when somebody went back to this? I told you to do
with the ruler. You make a lot of measurements and average results. We have Huygens' notes.
He did make a lot of measurements, one after the other after the other. But when he came to use
the numbers for calculations, and indeed when he published things at the end of his life,
he gives you one number, and it's not the average of any of them. It's just one of them.
Which one was it? The one that he thought he got so good at working by practice that he put
down the one he was most confident in. That was the general procedure at the time. You wouldn't
publish a paper in which you wrote down six numbers and said, well, I measured this six times. Let
me put them together. None of them is really, they would have said the right number, but I'll
put them together and give you a good number. No, you would have been thought of that. You
don't know what you're doing. Yeah. By the way, there's just an inkling of value to that approach.
Just an inkling. We sometimes use statistics as a thing that, oh, that solves all the problems.
We'll just do a lot of it and we'll take the average or whatever it is. As many excellent
books and mathematics have highlighted the flaws in our approach to certain sciences
that rely heavily on statistics. Let me ask you again for a friend about this alchemy thing.
It'd be nice to create gold, but it also seems to come into play quite a bit throughout the
history of science, perhaps in positive ways in terms of its impact. Can you say something to
the history of alchemy? A little bit and its impact. Sure. It used to be thought two things.
One, that alchemy, which dates certainly back to the Islamic period in Islam, you're talking,
you know, 11th, 12th, 13th centuries among Islamic natural philosophers and experimenters.
But it used to be thought that alchemy, which picked up strikingly in the 15th, 16th century,
1500s and thereabouts, was a sort of mystical procedure involving all sorts of strange notions
and so on. That's not entirely untrue, but it is substantially untrue in that alchemists were
engaged in what was known as chrysopoia, that is, looking for ways to transform
invaluable materials into valuable ones. But in the process of doing so or attempting to do so,
they learned how to create complex amalgams of various kinds. They used very elaborate apparatus,
glass olympics, in which they would use heat to produce chemical decompositions. They would write
down and observe these compositions and many of the so-called really strange-looking alchemical
formulas and statements where they'll say something like, I can't produce it, but it'll be built,
the soul of Mars will combine with this, etc., etc. These, it has been shown,
are almost all actual formulas for how to engage in the production of complex amalgams
and what to do. By the time of Newton, Newton was reading the works of a fellow by the name
of Starkey, who actually came from Harvard shortly before, in which things had progressed,
if you will, to the point where the procedure turns into what historians call chrysopoia,
which basically runs into the notion of thinking that these things are made out of particles.
This is the mechanical philosophy. Can we engage in processes, chemical processes,
to rearrange these things? Which is not so stupid, after all. I mean, we do it, except we happen to
do it in reactors, not in chemical processes, unless, of course, it had happened that cold fusion
had worked, which it didn't. That's the way they're thinking about these things. There's a kind
of mix. Newton engages extensively in those sorts of manipulations. In fact, more in that than
almost anything else, except for his optical investigations. If you look through the latter
parts of the 1670s, the last five, six, seven years or so of that, there's more on that than there is
on anything else. He's not working on mechanics. He's pretty much gone pretty far in optics. He'll
turn back to optics later on. Optics and alchemy. What you're saying is Isaac Newton liked shiny
things. Well, actually, if you go online and look at what Bill Newman, the professor at Bloomington
Indiana, has produced, you'll find the very shiny thing called the Star Regulus, which Newton
describes as having produced, according to a particular way, which Newman figured out and
was able to do it. It's very shiny. There you go. Proves the theorem. Can I ask you about God,
religion, and its role in Newton's life? Was there helpful, constructive, or destructive
influences of religion in his work and in his life? Well, there you begin to touch on a complex
question. The role that God played would be an interesting question to answer. Should one go
and be able to speak with this invisible character who doesn't exist, but putting that aside for
the moment? Yeah, we don't like to talk about others while they're not here.
Newton is a deeply religious man, not unusually so, of course, with assignment.
Clearly, his upbringing and perhaps his early experiences have exacerbated that in a number
of ways, that he takes a lot of things personally, and he finds perhaps solace in thinking about
a sort of governing, abstract, rulemaking, exacting deity. I think there is little question
that his conviction that you can figure things out has a fair bit to do with his
profound belief that this rulemaker doesn't do things arbitrarily. Newton does not think that
miracles have happened since maybe the time of Christ, if then, and not in the same way. He was,
for instance, an anti-Trinitarian. He did not hold that Christ had a divine being but was rather
endowed with certain powers by the rulemaker and whatnot. He did not think that some of the
tales of the Old Testament with various miracles and so on occurred in anything like that way.
Some may have, some may not have. Like everybody else, of course, he did think that creation
had happened about 6,000 years ago. Wait, really? Oh, yeah, sure. Well, biblical chronology can give
you a little bit about that. It's a little controversial, but sure. Interesting. Wow.
The deity created the universe 6,000 years ago. That didn't interfere with his
playing around with the sun and the moon and the network. Oh, no, because he's figuring out,
he's watching the brilliant construction that this perfect entity did 6,000 years ago.
Yeah, has produced. Plus or minus a few years. Well, if you go with Bishop Usher, it's 4,004 BCE.
I want to be precise about it. We always, and this is a serious program, we always want to be
precise. Okay, let me ask another ridiculous question. If Newton were to travel forward in time
and visit with Einstein and have a discussion about spacetime and general relativity, that
conception of time and that conception of gravity, what do you think that discussion will go like?
Put that way, I think Newton would sit there and shock and say, I have no idea what you're talking
about. If, on the other hand, there's a time machine, you go back and bring a somewhat younger
Newton, not a man my age, say. I mean, he lived a long time into his mid-80s, but take him when
he's in his 40s, let's say. Bring him forward and don't immediately introduce him to Einstein.
Let's take him for a ride on a railroad. Let him experience the railroad. Oh, that's right.
Take him around and show him a sparking machine. He knows about sparks, sending off sparks,
show him wires, have him touch the wires and get a little shock,
show him a clicking telegraph machine of the kind, then let him hear the clicks in a telephone
receiver and so on. Do that for a couple of months. Let him get accustomed to things.
Then take him into, not Einstein yet, let's say we're taking him into the 1890s. Einstein is a
young man then. We take him into some of the laboratories. We show him some of the equipment,
the devices, not the most elaborate ones. We show him certain things. We educate him
bit by bit. The optics, maybe focus on that. Certainly on optics. You begin to show him things.
He's a brilliant human being. I think bit by bit, he would begin to see what's going on.
But if you just dumped him in front of Einstein, he'd sit there as eyes would glaze over.
I mean, I guess it's almost a question of how big of a leap, how many leaps have been taken
in science that go from Newton to Einstein? We sometimes in a compressed version of history
think that not much. Oh, that's totally wrong. A lot. Huge amounts in multifarious ways,
involving fundamental conceptions, mathematical structures, the evolution of novel experimentation
and devices, the organization. It's not everything. Everything. I mean, to a point where I wonder,
even if Newton was like, you said 40, but even like 30. So he's very, like if you would be able
to catch up with the conception of everything. I wonder as a scientist, how much you load in
from age five about this world in order to be able to conceive of the world of ideas that push
that science forward. I mean, you mentioned the railroad and all those kinds of things that might
be fundamental to our ability to invent even when it doesn't directly obviously seem relevant.
Well, yes. I mean, the railroad, the steam engine, the watt engine, et cetera. I mean,
that was really the watt engine, you know, was developed pretty, although watt knew Joseph Black,
a chemist, scientist, and so on, did stuff on heat, was developed pretty much independently of
the developing thoughts about heat at the time. But what it's not independent of is the evolution
of practice in the manufacture and construction of devices, which can do things in extraordinarily
novel ways and the premium being gradually placed on calculating how you can make them more efficient.
That is of a piece with a way of thinking about the world in which you're controlling things
and working. It's something that humans have been doing for a long time, but in this more
concerted and structured way, I think you really don't find it in the fullest sense until
well into the 1500s and really not fully until the 17th century later on.
So Newton had this year of miracles. I wonder if I could ask you briefly about Einstein and
his year of miracles. I've been reading, rereading, revisiting the brilliance of
the papers that Einstein published in the year 1905, one of which one of the Nobel Prize,
the photoelectric effect, but also Brownian motion, special theory of relativity, and of
course the old E equals MC squared. Does that make sense to you that these two figures had such
productive years that there's this moment of genius? Maybe if we zoom out, my work is very
much in artificial intelligence, wondering about the nature of intelligence. How did evolution
on earth produce genius that could come up with so much in so little time? To me, that gives me hope
that one person can change the world in such a small amount of time.
Well, of course, there are precedents in both Newton's and Einstein's cases for elements of
what we're finding there and so on. Well, I have no idea. You know, I'm sure you must have read,
it was a kind of a famous story that after Einstein died, he donated his brain and they sliced it up
to see if they could find something unusual there, nothing unusual visibly in there. Clearly,
there are people who for various reasons, maybe both intrinsic and extrinsic in the sense of
experience and so on, are capable of coming up with these extraordinary results. Many years ago,
when I was a student, a friend of mine came in and said, did you read about, did you read this?
I forget what it was. Anyway, there was a story in the paper. It was about, I think it was a young
woman who was, she couldn't speak and she was somewhere on the autism spectrum. She could not
read other people's affect, in any ways, but she could sit down at a piano and having heard it once
and then run variations on the most complex, pianistic works of Chopin and others. Right. Now, how?
Some aspect of our mind is able to tune in some aspect of reality and become a master of it.
And every once in a while, that means coming up with breakthrough ideas in physics. Yep. How
the heck does that happen? Who knows? Jed, I'd like to say thank you so much for spending your
valuable time with me today. It was a really fascinating conversation. I've learned so much
about Isaac Newton, who's one of the most fascinating figures in human history. So thank you so much
for talking to me. A pleasure. I enjoyed it very much. Thanks for listening to this conversation
with Jed Buchwald. To support this podcast, please check out our sponsors in the description.
And now, let me leave you with some words from Thomas Kuhn, a philosopher of science.
The answers you get depend on the questions you ask. Thank you for listening and hope to see you
next time.