What is Real? (Lee Smolin) | AI Podcast Clips

00:00:00.000 | - What is real?

00:00:02.880 | Let's start with an easy question.

00:00:05.080 | Put another way, how do we know what is real

00:00:07.800 | and what is merely a creation

00:00:09.320 | of our human perception and imagination?

00:00:12.860 | - We don't know.

00:00:14.300 | We don't know.

00:00:15.140 | This is science.

00:00:15.960 | I presume we're talking about science.

00:00:18.580 | And we believe, or I believe,

00:00:21.920 | that there is a world that is independent of my existence

00:00:27.160 | and my experience about it and my knowledge of it.

00:00:31.160 | And this I call the real world.

00:00:33.460 | - So you said science, but even bigger than science.

00:00:37.760 | - Sure, sure.

00:00:38.760 | I need not have said this is science.

00:00:41.020 | I just was warming up.

00:00:42.980 | - Warming up.

00:00:45.120 | Okay, now that we're warmed up,

00:00:46.440 | let's take a brief step outside of science.

00:00:49.680 | Is it completely a crazy idea to you

00:00:53.040 | that everything that exists

00:00:55.040 | is merely a creation of our mind?

00:00:57.440 | So there's a few, not many,

00:01:00.520 | this is outside of science now,

00:01:02.840 | people who believe perception is fundamentally

00:01:06.760 | what's in our human perception,

00:01:08.620 | the visual cortex and so on,

00:01:10.240 | the cognitive constructs that's being formed there

00:01:14.880 | is the reality, and that anything outside

00:01:18.320 | is something that we can never really grasp.

00:01:21.120 | Is that a crazy idea to you?

00:01:22.720 | - There's a version of that that is not crazy at all.

00:01:26.400 | What we experience is constructed by our brains

00:01:31.000 | and by our brains in an active mode.

00:01:34.840 | So we don't see the raw world,

00:01:40.560 | we see a very processed world.

00:01:42.460 | We feel something that's very processed through our brains,

00:01:46.120 | and our brains are incredible.

00:01:48.760 | But I still believe that behind that experience,

00:01:53.760 | that mirror, veil, or whatever you wanna call it,

00:01:58.040 | there is a real world, and I'm curious about it.

00:02:01.160 | - Can we truly, how do we get a sense of that real world?

00:02:05.360 | Is it through the tools of physics,

00:02:07.260 | from theory to the experiments?

00:02:10.040 | Or can we actually grasp it in some intuitive way

00:02:13.960 | that's more connected to our ape ancestors?

00:02:18.960 | Or is it still fundamentally the tools of math and physics

00:02:23.800 | that really allow us to grasp it?

00:02:24.640 | - Well, let's talk about what tools they are,

00:02:27.680 | what you say are the tools of math and physics.

00:02:30.680 | I mean, I think we're in the same position

00:02:33.120 | as our ancestors in the caves,

00:02:36.520 | or before the caves, or whatever.

00:02:38.800 | We find ourselves in this world, and we're curious.

00:02:41.960 | We also, it's important to be able to explain

00:02:46.560 | what happens when there are fires,

00:02:48.320 | when there are not fires, what animals and plants

00:02:50.800 | are good to eat, and all that stuff.

00:02:53.660 | But we're also just curious.

00:02:56.320 | We look up in the sky, and we see the sun,

00:02:58.720 | and the moon, and the stars, and we see some of those move,

00:03:02.640 | and we're very curious about that.

00:03:05.840 | I think we're just naturally curious.

00:03:09.480 | So, we make, this is my version of how we work.

00:03:14.480 | We make up stories and explanations.

00:03:17.680 | And there are two things which I think

00:03:23.640 | are just true of being human.

00:03:26.200 | We make judgments fast, because we have to.

00:03:29.680 | We're, to survive, is that a tiger, or is that not a tiger?

00:03:34.680 | And we go. - Act.

00:03:37.060 | - We have to act fast on incomplete information.

00:03:39.800 | So, we judge quickly, and we're often wrong,

00:03:44.680 | or at least sometimes wrong, which is all I need for this.

00:03:47.800 | We're often wrong.

00:03:49.200 | So, we fool ourselves, and we fool other people, readily.

00:03:54.200 | And so, there's lots of stories that get told,

00:03:58.560 | and some of them result in a concrete benefit,

00:04:02.960 | and some of them don't.

00:04:05.680 | - So, you said we're often wrong,

00:04:08.040 | but what does it mean to be right?

00:04:11.100 | - Right, that's an excellent question.

00:04:14.620 | To be right, well, since I believe

00:04:19.020 | that there is a real world, I believe that to be,

00:04:23.640 | you can challenge me on this if you're not a realist.

00:04:26.160 | A realist is somebody who believes

00:04:27.640 | in this real, objective world,

00:04:29.900 | which is independent of our perception.

00:04:31.700 | If I'm a realist, I think that to be right

00:04:36.300 | is to come closer.

00:04:38.860 | I think, first of all, there's a relative scale.

00:04:40.860 | There's not right and wrong.

00:04:42.140 | There's right or more right and less right.

00:04:45.600 | And you're more right if you come closer

00:04:47.740 | to an exact, true description of that real world.

00:04:51.700 | Now, can we know that for sure?

00:04:53.460 | No.

00:04:54.700 | - And the scientific method is ultimately

00:04:57.540 | what allows us to get a sense

00:04:59.300 | of how close we're getting to that real world?

00:05:01.660 | - No on two counts.

00:05:02.780 | First of all, I don't believe there's a scientific method.

00:05:05.620 | I was very influenced when I was in graduate school

00:05:09.340 | by the writings of Paul Feyerabend,

00:05:11.460 | who was an important philosopher of science,

00:05:14.380 | who argued that there isn't a scientific method.

00:05:16.980 | - There is or there isn't?

00:05:17.820 | - There is not.

00:05:18.660 | - There's not.

00:05:19.620 | Can you elaborate?

00:05:20.460 | I'm sorry if you were going to,

00:05:22.460 | but can you elaborate on the,

00:05:24.000 | what does it mean for there not to be a scientific method,

00:05:27.460 | this notion that I think a lot of people believe in?

00:05:31.720 | In this day and age?

00:05:33.480 | - Sure.

00:05:34.720 | Paul Feyerabend, he was a student of Popper,

00:05:38.400 | who taught Karl Popper.

00:05:40.960 | And Feyerabend argued,

00:05:45.520 | both by logic and by historical example,

00:05:48.600 | that you name anything that should be part of

00:05:52.360 | the practice of science,

00:05:53.680 | say you should always make sure that your theories agree

00:05:56.100 | with all the data that's already been taken.

00:05:59.840 | And he'll prove to you that there have to be times

00:06:02.260 | when science contradicts,

00:06:04.040 | when some scientist contradicts that advice

00:06:08.040 | for science to progress overall.

00:06:14.660 | So it's not a simple matter.

00:06:16.920 | I think that,

00:06:18.460 | I think of science as a community.

00:06:23.880 | - Of people.

00:06:24.840 | - Of people, and as a community of people

00:06:27.800 | bound by certain ethical precepts,

00:06:31.760 | percepts, whatever that is.

00:06:33.560 | - So in that community, a set of ideas they operate under,

00:06:39.160 | meaning ethically, of kind of the rules of the game

00:06:43.040 | they operate under.

00:06:44.120 | - Don't lie, report all your results,

00:06:46.660 | whether they agree or don't agree with your hypothesis.

00:06:49.660 | Check, the training of a scientist

00:06:54.680 | mostly consists of methods of checking,

00:06:57.960 | because again, we make lots of mistakes,

00:07:00.100 | we're very error prone,

00:07:02.320 | but there are tools both on the mathematics side

00:07:05.280 | and the experimental side to check

00:07:07.140 | and double check and triple check.

00:07:09.640 | And a scientist goes through a training,

00:07:13.040 | and I think this is part of it.

00:07:15.040 | You can't just walk off the street and say,

00:07:16.840 | "Yo, I'm a scientist."

00:07:19.280 | You have to go through the training,

00:07:20.920 | and the training, the test that lets you be done

00:07:25.920 | with the training is can you form a convincing case

00:07:31.200 | for something that your colleagues

00:07:36.440 | will not be able to shout down,

00:07:39.200 | because they'll ask, "Did you check this,

00:07:41.080 | "and did you check that, and did you check this,

00:07:42.780 | "and what about a seeming contradiction with this?"

00:07:46.320 | And you've gotta have answers to all those things

00:07:50.880 | or you don't get taken seriously.

00:07:52.440 | And when you get to the point where you can produce

00:07:55.180 | that kind of defense and argument,

00:07:57.580 | then they give you a PhD.

00:07:59.120 | And you're kind of licensed.

00:08:02.520 | You're still gonna be questioned,

00:08:04.620 | and you still may propose or publish mistakes,

00:08:09.280 | but the community is gonna have to waste less time

00:08:13.120 | fixing your mistakes.

00:08:14.480 | - Yes, but if you can maybe linger on it a little longer,

00:08:18.880 | what's the gap between the thing that that community does

00:08:23.880 | and the ideal of the scientific method?

00:08:26.280 | The scientific method is you should be able

00:08:30.480 | to repeat an experiment.

00:08:32.480 | There's a lot of elements to what construes

00:08:38.080 | the scientific method, but the final result,

00:08:40.620 | the hope of it is that you should be able to say

00:08:45.360 | with some confidence that a particular thing

00:08:48.800 | is close to the truth.

00:08:51.660 | - Right, but there's not a simple relationship

00:08:54.080 | between experiment and hypothesis or theory.

00:08:57.220 | For example, Galileo did this experiment

00:08:59.720 | of dropping a ball from the top of a tower,

00:09:03.080 | and it falls right at the base of the tower.

00:09:05.500 | And Aristotelian would say, "Wow, of course it falls

00:09:10.120 | "right to the base of the tower.

00:09:11.340 | "That shows that the Earth isn't moving

00:09:13.000 | "while the ball is falling."

00:09:15.400 | And Galileo says no weight is a principle of inertia

00:09:18.440 | and it has an inertia in a direction

00:09:20.960 | with the Earth isn't moving and the tower

00:09:23.040 | and the ball and the Earth all move together.

00:09:25.500 | When the principle of inertia tells you it hits the bottom,

00:09:28.760 | it does look, therefore my principle of inertia is right.

00:09:31.680 | And Aristotelian says no, Aristotle's science is right,

00:09:35.960 | the Earth is stationary.

00:09:38.080 | And so you've got to get an interconnected bunch of cases

00:09:43.080 | and work hard to line up and explain.

00:09:47.840 | It took centuries to make the transition

00:09:50.520 | from Aristotelian physics to the new physics.

00:09:54.560 | It wasn't done till Newton in 1680-something, 1687.

00:09:59.560 | - So what do you think is the nature of the process

00:10:03.640 | that seems to lead to progress?

00:10:06.640 | If we at least look at the long arc of science

00:10:09.800 | of all the community of scientists,

00:10:12.060 | they seem to do a better job of coming up with ideas

00:10:15.640 | that engineers can then take on and build rockets with

00:10:19.800 | or build computers with or build cool stuff with.

00:10:24.800 | - I don't know, a better job than what?

00:10:27.280 | - Than this previous century.

00:10:31.160 | So century by century, we'll talk about string theory

00:10:34.480 | and so on and kind of possible,

00:10:36.680 | what you might think of as dead ends and so on.

00:10:39.680 | - Which is not the way I think of string theory.

00:10:41.280 | We'll straighten it out.

00:10:42.120 | We'll get on string straight.

00:10:44.520 | But there is, nevertheless, in science,

00:10:46.560 | very often at least temporary dead ends.

00:10:50.680 | But if you look through centuries,

00:10:55.680 | the century before Newton and the century after Newton,

00:10:59.760 | it seems like a lot of ideas came closer to the truth

00:11:04.760 | that then could be usable by our civilization

00:11:08.920 | to build the iPhone, right?

00:11:11.560 | To build cool things that improve our quality of life.

00:11:14.540 | That's the progress I'm kind of referring to.

00:11:17.100 | - Let me, can I say that more precisely?

00:11:20.080 | - Yes.

00:11:20.920 | (laughing)

00:11:21.760 | It's a low bar.

00:11:22.580 | - 'Cause I think it's important to get the time places right.

00:11:27.320 | - Yes.

00:11:28.460 | - There was a scientific revolution that partly succeeded

00:11:33.280 | between about 1900 or late 1890s

00:11:38.160 | and into the 1930s, 1940s,

00:11:43.160 | and maybe some, if you stretched it, into the 1970s.

00:11:48.480 | And the technology, this was the discovery of relativity,

00:11:53.160 | and that included a lot of developments

00:11:54.760 | of electromagnetism.

00:11:56.960 | The confirmation, which wasn't really well confirmed

00:12:01.240 | into the 20th century, that matter was made of atoms.

00:12:05.200 | And the whole picture of nuclei

00:12:07.280 | with electrons going around,

00:12:08.480 | and this is early 20th century.

00:12:11.160 | And then quantum mechanics was from 1905,

00:12:16.160 | took a long time to develop,

00:12:17.800 | to the late 1920s, and then it was basically in final form.

00:12:22.800 | And the basis of this partial revolution,

00:12:28.080 | and we can come back to why it's only a partial revolution,

00:12:31.080 | is the basis of the technologies you mentioned.

00:12:35.680 | All of, I mean, electrical technology

00:12:39.480 | was being developed slowly with this,

00:12:41.520 | and in fact, there's a close relation

00:12:44.640 | between the development of electricity

00:12:48.200 | and the electrification of cities in the United States

00:12:52.760 | and Europe and so forth,

00:12:54.240 | and the development of the science.

00:12:57.940 | The fundamental physics,

00:13:04.700 | since the early 1970s,

00:13:07.180 | doesn't have a story like that so far.

00:13:09.860 | There's not a series of triumphs and progresses,

00:13:14.860 | and there's not any practical application.

00:13:18.400 | - So, just to linger briefly on the early 20th century

00:13:24.700 | and the revolutions in science that happened there,

00:13:27.740 | what was the method by which the scientific community

00:13:32.620 | kept each other in check about

00:13:36.580 | when you get something right, when you get something wrong?

00:13:38.780 | Is experimental validation ultimately the final test?

00:13:42.260 | - It's absolutely necessary,

00:13:43.980 | and the key things were all validated,

00:13:46.280 | the key predictions of quantum mechanics

00:13:49.580 | and of the theory of electricity and magnetism.

00:13:51.920 | - So, before we talk about Einstein,

00:13:55.580 | your new book before string theory, quantum mechanics,

00:13:58.860 | so on, let's take a step back at a higher level question.

00:14:02.700 | What is, that you mentioned, what is realism?

00:14:07.020 | What is anti-realism?

00:14:09.260 | And maybe why do you find realism,

00:14:12.500 | as you mentioned, so compelling?

00:14:14.340 | - Realism is the belief in an external world

00:14:20.820 | independent of our existence, our perception,

00:14:27.340 | our belief, our knowledge.

00:14:29.380 | A realist, as a physicist, is somebody who believes

00:14:34.180 | that there should be possible

00:14:36.980 | some completely objective description

00:14:40.880 | of each and every process at the fundamental level,

00:14:45.480 | which describes and explains exactly what happens

00:14:49.680 | and why it happens.

00:14:51.460 | - That kind of implies that that system,

00:14:54.340 | in a realist view, is deterministic,

00:14:56.980 | meaning there's no fuzzy magic going on

00:14:59.780 | that you can never get to the bottom of.

00:15:00.980 | You can get to the bottom of anything

00:15:02.940 | and perfectly describe it.

00:15:04.900 | - Some people would say that I'm not that interested

00:15:09.380 | in determinism, but I could live with the fundamental world,

00:15:14.380 | which had some chance in it.

00:15:17.220 | - So do you, you said you could live with it,

00:15:20.420 | but do you think God plays dice in our universe?

00:15:25.180 | - I think it's probably much worse than that.

00:15:27.420 | - In which direction?

00:15:30.740 | - I think that theories can change

00:15:32.580 | and theories can change without warning.

00:15:34.780 | I think the future is open.

00:15:37.180 | - You mean the fundamental laws of physics can change?

00:15:39.540 | - Yeah.

00:15:40.380 | - Okay, we'll get there.

00:15:42.540 | I thought we would be able to find some solid ground,

00:15:48.340 | but apparently--

00:15:49.380 | - Well, the ground is pretty solid.

00:15:50.220 | - The entirety of it, temporarily so.

00:15:53.780 | Okay, so realism is the idea that

00:15:58.580 | while the ground is solid, you can describe it.

00:16:01.540 | What's the role of the human being,

00:16:03.300 | our beautiful, complex human mind in realism?

00:16:08.300 | Do we have a, are we just another set of molecules

00:16:13.420 | connected together in a clever way,

00:16:15.100 | or does the observer, our human mind,

00:16:20.100 | consciousness have a role in this realism view

00:16:23.400 | of the physical universe?

00:16:25.020 | - There's two ways, there's two questions

00:16:28.100 | you could be asking.

00:16:29.100 | Does our conscious mind, do our perceptions

00:16:34.380 | play a role in making things become,

00:16:37.540 | in making things real or things becoming?

00:16:41.000 | That's question one.

00:16:42.020 | Question two is, does this, we can call it

00:16:46.100 | a naturalist view of the world

00:16:50.240 | that is based on realism, allow a place

00:16:54.760 | to understand the existence of and the nature

00:16:57.480 | of perceptions and consciousness in mind?

00:17:00.480 | And that's question two.

00:17:01.940 | Question two, I do think a lot about,

00:17:05.320 | and my answer, which is not an answer, is I hope so,

00:17:09.840 | but it certainly doesn't yet.

00:17:11.380 | - So what kind-- - Question one,

00:17:13.840 | I don't think so.

00:17:15.720 | But of course, the answer to question one

00:17:17.400 | depends on question two.

00:17:18.840 | - Right.

00:17:20.460 | So I'm not up to question one, yeah.

00:17:22.700 | - So question two is the thing that you can

00:17:24.380 | kind of struggle with at this time.

00:17:26.140 | What about the anti-realists?

00:17:30.740 | So what flavor, what are the different camps

00:17:34.900 | of anti-realists that you've talked about?

00:17:37.080 | I think it would be nice if you could articulate

00:17:39.620 | for the people for whom there is not

00:17:42.780 | a very concrete real world, or there's divisions,

00:17:46.140 | or it's messier than the realist view of the universe.

00:17:50.920 | What are the different camps, what are the different views?

00:17:53.320 | - I'm not sure I'm a good scholar

00:17:56.000 | and can talk about the different camps and analyze it,

00:17:58.640 | but many of the inventors of quantum physics

00:18:03.240 | were not realists, were anti-realists.

00:18:05.480 | And there are scholars, they lived in a very perilous time

00:18:09.680 | between the two world wars.

00:18:12.480 | And there were a lot of trends in culture

00:18:16.180 | which were going that way.

00:18:17.940 | But in any case, they said things like

00:18:20.540 | the purpose of science is not to give an objective

00:18:26.060 | realist description of nature as it would be in our absence.

00:18:29.420 | This might be saying Niels Bohr.

00:18:31.740 | The purpose of science is as an extension

00:18:35.020 | of our conversations with each other

00:18:37.460 | to describe our interactions with nature.

00:18:40.000 | And we're free to invent and use terms like particle,

00:18:44.020 | or wave, or causality, or time, or space

00:18:47.340 | if they're useful to us and they carry

00:18:51.620 | some intuitive implication.

00:18:55.140 | But we shouldn't believe that they actually have to do

00:18:58.020 | with what nature would be like in our absence,

00:19:01.180 | which we have nothing to say about.

00:19:04.100 | - Do you find any aspect of that,

00:19:06.780 | 'cause you kind of said that we human beings tell stories.

00:19:10.140 | Do you find aspects of that kind of anti-realist view

00:19:14.620 | of Niels Bohr compelling?

00:19:17.460 | That we're fundamentally our storytellers

00:19:19.620 | and then we create tools of space and time and causality

00:19:24.620 | and whatever this fun quantum mechanics stuff is

00:19:28.200 | to help us tell the story of our world.

00:19:31.440 | - Sure, I just would like to believe that there's

00:19:34.220 | an aspiration for the other thing.

00:19:37.140 | - The other thing being what?

00:19:40.060 | - The realist point of view.

00:19:42.660 | - Do you hope that the stories will eventually lead us

00:19:45.980 | to discovering the real world as it is?

00:19:50.980 | - Yeah.

00:19:56.180 | - Is perfection possible, by the way?

00:19:57.820 | - No.

00:19:58.660 | You mean will we ever get there and know that we're there?

00:20:03.540 | - Yeah, exactly.

00:20:05.100 | - That's for people 5,000 years in the future.

00:20:08.440 | We're certainly nowhere near there yet.

00:20:10.380 | - Do you think reality that exists outside of our mind,

00:20:17.860 | do you think there's a limit to our cognitive abilities,

00:20:23.300 | as again descendants of apes,

00:20:25.460 | who are just biological systems?

00:20:27.440 | Is there a limit to our mind's capability

00:20:30.420 | to actually understand reality?

00:20:34.380 | There comes a point, even with the help

00:20:39.020 | of the tools of physics, that we just cannot grasp

00:20:43.680 | some fundamental aspects of that reality.

00:20:45.460 | - Again, I think that's a question

00:20:46.840 | for 5,000 years in the future.

00:20:48.460 | - We're not even close to that limit.

00:20:49.780 | - I think there is a universality.

00:20:52.700 | Here, I don't agree with David Deutsch about everything,

00:20:55.520 | but I admire the way he put things in his last book.

00:20:59.880 | And he talked about the role of explanation.

00:21:03.180 | And he talked about the universality of certain languages,

00:21:07.460 | or the universality of mathematics,

00:21:09.660 | or of computing, and so forth.

00:21:14.380 | And he believed that universality,

00:21:17.060 | which is something real, which is somehow comes out

00:21:20.880 | of the fact that a symbolic system,

00:21:22.620 | or a mathematical system, can refer to itself,

00:21:26.220 | and can, I forget what that's called,

00:21:28.780 | can reference back to itself.

00:21:31.340 | And build, in which he argued for a universality

00:21:35.660 | of possibility for our understanding,

00:21:38.140 | whatever is out there.

00:21:40.020 | But I admire that argument.

00:21:43.940 | But it seems to me we're doing okay so far,

00:21:48.940 | but we'll have to see.

00:21:52.500 | - Whether there is a limit or not.

00:21:53.820 | For now, we've got plenty to play with.

00:21:55.900 | - Yeah.

00:21:56.740 | (audience applauding)

00:21:59.900 | (audience cheering)

00:22:02.900 | (audience cheering)

00:22:05.900 | (audience cheering)

00:22:08.900 | (audience cheering)

00:22:11.900 | [BLANK_AUDIO]

What is Real? (Lee Smolin) | AI Podcast Clips

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