Transcript
00:00:00 The following is a conversation with S. James Gates, Jr.
00:00:03 He’s a theoretical physicist and professor at Brown University,
00:00:07 working on supersymmetry, supergravity, and superstring theory.
00:00:11 He served on former President Obama’s Council of Advisors on Science and Technology,
00:00:16 and he’s now the coauthor of a new book titled Proving Einstein Right,
00:00:21 about the scientists who set out to prove Einstein’s theory of relativity.
00:00:26 You may have noticed that I’ve been speaking with not just computer scientists,
00:00:30 but philosophers, mathematicians, physicists, economists, and soon, much more.
00:00:35 To me, AI is much bigger than deep learning, bigger than computing.
00:00:39 It is our civilization’s journey into understanding the human mind
00:00:43 and creating echoes of it in the machine.
00:00:45 That journey includes, of course, the world of theoretical physics
00:00:50 and its practice of first principles mathematical thinking
00:00:53 and exploring the fundamental nature of our reality.
00:00:57 This is the Artificial Intelligence Podcast.
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00:03:08 And now, here’s my conversation with S. James Gates Jr.
00:03:13 You tell a story when you were eight.
00:03:15 You had a profound realization that the stars in the sky
00:03:18 are actually places that we could travel to one day.
00:03:22 Do you think human beings will ever venture outside our solar system?
00:03:27 Wow, the question of whether humanity gets outside of the solar system.
00:03:30 It’s going to be a challenge,
00:03:31 and as long as the laws of physics that we have today are accurate and valid,
00:03:38 it’s going to be extraordinarily difficult.
00:03:40 I’m a science fiction fan, as you probably know,
00:03:43 so I love to dream of starships and traveling to other solar systems,
00:03:48 but the barriers are just formidable.
00:03:52 If we just kind of venture a little bit into science fiction,
00:03:55 do you think the spaceships, if we are successful,
00:03:58 that take us outside the solar system,
00:04:00 will look like the ones we have today,
00:04:03 or are fundamental breakthroughs necessary?
00:04:07 In order to have genuine starships,
00:04:10 probably some really radical views about the way the universe works
00:04:14 are going to have to take place in our science.
00:04:17 We could, with our current technology,
00:04:22 think about constructing multigenerational starships
00:04:25 where the people who get on them are not the people who get off at the other end.
00:04:31 But even if we do that, the formidable problem is actually our bodies,
00:04:36 which doesn’t seem to be conscious for a lot of people.
00:04:41 Even getting to Mars is going to present this challenge,
00:04:44 because we live in this wonderful home,
00:04:47 has a protective magnetic magnetosphere around it,
00:04:50 and so we’re shielded from cosmic radiation.
00:04:54 Once you leave this shield, there are some estimates that,
00:04:58 for example, if you sent someone to Mars,
00:05:02 with our technology, probably about two years out there without the shield,
00:05:05 they’re going to be bombarded.
00:05:07 That means radiation, probably means cancer.
00:05:10 So that’s one of the most formidable challenges,
00:05:12 even if we could get over the technology.
00:05:16 Do you think, so Mars is a harsh place.
00:05:19 Elon Musk, SpaceX and other folks,
00:05:22 NASA are really pushing to put a human being on Mars.
00:05:25 Do you think, again, let’s forgive me
00:05:28 for lingering in science fiction land for a little bit.
00:05:31 Do you think one day we may be able to colonize Mars?
00:05:34 First, do you think we’ll put a human on Mars,
00:05:37 and then do you think we’ll put many humans on Mars?
00:05:40 So first of all, I am extraordinarily convinced
00:05:45 we will not put a human on Mars by 2030,
00:05:48 which is a date that you often hear in the public debate.
00:05:52 What’s the challenge there?
00:05:53 What do you think?
00:05:54 So there are a couple of ways that I could slice this,
00:05:56 but the one that I think is simplest for people to understand involves money.
00:06:01 So you look at how we got to the moon in the 1960s.
00:06:05 It was about 10 year duration
00:06:07 between the challenge that President Kennedy laid out
00:06:10 and our successfully landing a moon.
00:06:12 I was actually here at MIT
00:06:14 when that first moon landing occurred,
00:06:16 so I remember watching it on TV.
00:06:18 But how did we get there?
00:06:19 Well, we had this extraordinarily technical agency
00:06:24 of the United States government, NASA.
00:06:26 It consumed about 5% of the country’s economic output.
00:06:32 And so you say 5% of the economic output
00:06:35 over about a 10 year period gets us 250,000 miles in space.
00:06:40 Mars is about a hundred times farther.
00:06:43 So you have at least a hundred times the challenge
00:06:45 and we’re spending about one tenth of the funds
00:06:48 that we spent then as a government.
00:06:50 So my claim is that it’s at least a thousand times harder
00:06:54 for me to imagine us getting to Mars by 2030.
00:06:58 And he had that part that you mentioned in the speech
00:07:00 that I just have to throw in there of JFK,
00:07:03 of we do these things not because they’re easy,
00:07:06 but because they’re hard.
00:07:07 That’s such a beautiful line
00:07:09 that I would love to hear a modern president say
00:07:11 about a scientific endeavor.
00:07:13 Well, one day we live and hope
00:07:16 that such a president will arise for our nation.
00:07:19 But even if, like I said,
00:07:21 even if you fix the technical problems,
00:07:24 the biological engineering that I worry most about,
00:07:28 however, I’m gonna go out on a limb here.
00:07:31 I think that by 2090 or so,
00:07:35 or 2100, should I say 120,
00:07:41 I suspect we’re gonna have a human on Mars.
00:07:44 Wow, so you think that many years out,
00:07:46 first a few tangents.
00:07:48 You said bioengineering is a challenge.
00:07:50 What’s the challenge there?
00:07:52 So as I said, the real problem with interstellar travel,
00:07:57 aside from the technology challenges,
00:08:00 the real problem is radiation.
00:08:03 And how do you engineer either an environment or a body,
00:08:08 because we see rapid advances going on in bioengineering,
00:08:12 how do you engineer either a ship or a body
00:08:16 so that something, some person
00:08:18 that’s recognizably human will survive
00:08:22 the rigors of interplanetary space travel?
00:08:24 It’s much more difficult than most people
00:08:26 seem to take into account.
00:08:29 So if we could linger on the 2090, 2100, 2120,
00:08:36 sort of thinking of that kind of,
00:08:40 you know, and let’s linger on money.
00:08:42 Okay.
00:08:43 So Elon Musk and Jeff Bezos are pushing the cost,
00:08:48 trying to push the cost down.
00:08:50 I mean, this is, so do you have hope
00:08:52 as this actually sort of a brilliant big picture scientist,
00:08:56 do you think a business entrepreneur can take science
00:09:02 and make it cheaper and get it out there faster?
00:09:04 So bending the cost curve is,
00:09:06 you’ll notice that has been an anchor.
00:09:08 This is the simplest way for me to discuss this with people
00:09:10 about what the challenge is.
00:09:12 So yes, bending the cost curve is certainly critical
00:09:16 if we’re going to be successful.
00:09:18 Now, you asked about the endeavors that are out there now
00:09:22 sponsored by two very prominent American citizens,
00:09:25 Jeff Bezos and Elon Musk.
00:09:28 I’m disappointed actually in what I see
00:09:31 in terms of the routes that are being pursued.
00:09:35 So let me give you one example there.
00:09:36 And this one is going to be a little bit more technical.
00:09:39 So if you look at the kinds of rockets
00:09:41 that both these organizations are creating,
00:09:45 yes, it’s wonderful, reusable technology
00:09:47 to see a rocket go up and land on its fins
00:09:50 just like it did in science fiction movies
00:09:51 when I was a kid, that’s astounding.
00:09:54 But the real problem is those rockets,
00:09:58 the technology that we’re doing now
00:10:00 is not really that different
00:10:02 than what was used to go to the moon.
00:10:04 And there are alternatives it turns out.
00:10:06 There’s an engine called a flare engine,
00:10:09 which so a traditional rocket,
00:10:11 if you look at the engine, it looks like a bell, right?
00:10:13 And then the flame comes out the bottom.
00:10:14 But there is a kind of engine called a flare engine,
00:10:17 which is essentially, when you look at it,
00:10:20 it looks like an exhaust pipe
00:10:23 on like a fancy car that’s long and elongated.
00:10:27 And it’s a type of rocket engine
00:10:29 that we know there’ve been preliminary testing,
00:10:32 we know it works.
00:10:34 And it also is actually much more economical
00:10:36 because what it does is allow you
00:10:38 to vary the amount of thrust as you go up.
00:10:40 In a way that you cannot do
00:10:42 with one of these bell shaped engines.
00:10:44 So you would think that an entrepreneur
00:10:48 might try to have the breakthrough to use flare nozzles,
00:10:53 as they’re called, as a way to bend the cost curve.
00:10:56 Because as we keep coming back,
00:10:57 that’s gonna be a big factor.
00:10:59 But that’s not happening.
00:11:00 In fact, what we see is what I think of as incremental change
00:11:04 in terms of our technology.
00:11:06 So I’m not really very encouraged by what I personally see.
00:11:10 So incremental change won’t bend the cost curve.
00:11:12 I don’t see it.
00:11:14 Just linger on the sci fi for one more question.
00:11:17 Sure.
00:11:18 Do you think we’re alone in the universe?
00:11:20 Are we the only intelligent form of life?
00:11:23 So there is a quote by Carl Sagan,
00:11:27 which I really love when I hear this question.
00:11:30 And I recall the quote,
00:11:32 and it goes something like,
00:11:34 if we’re the only conscious life in the universe,
00:11:38 it’s in a terrible waste of space
00:11:40 because the universe is an incredibly big place.
00:11:45 And when Carl made that statement,
00:11:47 we didn’t know about the profusion of planets
00:11:50 that are out there.
00:11:51 In the last decade,
00:11:53 we’ve discovered over a thousand planets
00:11:56 and a substantial number of those planets are Earth like
00:11:59 in terms of being in the Goldilocks zone as it’s called.
00:12:04 So in my mind, it’s practically inconceivable
00:12:09 that we’re the only conscious form of life in the universe.
00:12:13 But that doesn’t mean they’ve come to visit us.
00:12:15 Do you think they would look,
00:12:17 do you think we’ll recognize alien life if we saw it?
00:12:21 Do you think it’d look anything like the carbon base,
00:12:24 the biological system we have on Earth today?
00:12:27 It would depend on that life’s native environment
00:12:31 in which it arose.
00:12:32 If that environment was sufficiently like our environment,
00:12:36 there’s a principle in biology and nature called convergence,
00:12:39 which is that even if you have two biological systems
00:12:42 that are totally separated from each other,
00:12:44 if they face similar conditions,
00:12:46 nature tends to converge on solutions.
00:12:49 And so there might be similarities
00:12:52 if this alien life form was born in a place
00:12:55 that’s kind of like this place.
00:12:57 Physics appears to be quite similar,
00:13:00 the laws of physics across the entirety of the universe.
00:13:03 Do you think weirder things than we see on Earth
00:13:06 can spring up out of the same kinds of laws of physics?
00:13:10 From the laws of physics, I would say yes.
00:13:12 First of all, if you look at carbon based life,
00:13:14 why are we carbon based?
00:13:15 Well, it turns out it’s because of the way
00:13:18 that carbon interacts with elements,
00:13:20 which in fact is also a reflection
00:13:22 on the electronic structure of the carbon nucleus.
00:13:26 So you can look down the table of elements and say,
00:13:28 well, gee, do we see similar elements?
00:13:30 The answer is yes.
00:13:31 And one that one often hears about
00:13:34 in science fiction is silicon.
00:13:36 So maybe there’s a silicon based life form out there
00:13:38 if the conditions are right.
00:13:40 But I think it’s presumptuous of us
00:13:41 to think that we are the template
00:13:44 by which all life has to appear.
00:13:50 Before we dive into beautiful details,
00:13:52 let me ask a big question.
00:13:55 What to you is the most beautiful idea,
00:13:58 maybe the most surprising, mysterious idea in physics?
00:14:02 The most surprising idea to me
00:14:03 is that we can actually do physics.
00:14:05 The universe did not have to be constructed
00:14:08 in such a way with our limited intellectual capacity
00:14:13 that is actually put together in such a way
00:14:17 and that we are put together in such a way
00:14:20 that we can, with our mind’s eye,
00:14:24 delve incredibly deeply into the structure of the universe.
00:14:27 That to me is pretty close to a miracle.
00:14:30 So there are simple equations, relatively simple,
00:14:34 that can describe things, the fundamental functions.
00:14:40 They can describe everything about our reality.
00:14:42 That’s not, can you imagine universes
00:14:46 where everything is a lot more complicated?
00:14:50 Do you think there’s something inherent about universes
00:14:54 that simple laws are…
00:14:57 Well, first of all, let me,
00:14:58 this is a question that I encounter in a number of guides.
00:15:02 A lot of people will raise the question
00:15:04 about whether mathematics is the language of the universe.
00:15:08 And my response is mathematics is the language
00:15:11 that we humans are capable of using in describing the universe.
00:15:14 It may have little to do with the universe,
00:15:17 but in terms of our capacity, it’s the microscope,
00:15:20 it’s the telescope through which we,
00:15:22 it’s the lens through which we are able to view the universe
00:15:26 with the precision that no other human language allows.
00:15:31 So could there be other universes?
00:15:32 Well, I don’t even know if this one looks like I think it does.
00:15:36 But the beautiful surprising thing is that physics,
00:15:43 there are laws of physics, very few laws of physics
00:15:46 that can effectively compress down
00:15:48 the functioning of the universe.
00:15:50 Yes, that’s extraordinarily surprising.
00:15:52 I like to use the analogy
00:15:54 with computers and information technology.
00:15:56 If you worry about transmitting large bundles of data,
00:16:01 one of the things that computer scientists do for us
00:16:03 is they allow for processes that are called compression,
00:16:06 where you take big packets of data
00:16:07 and you press them down into much smaller packets,
00:16:10 and then you transmit those
00:16:11 and then unpack them at the other end.
00:16:13 And so it looks a little bit to me
00:16:16 like the universe has kind of done us a favor.
00:16:18 It’s constructed our minds in such a way
00:16:20 that we have this thing called mathematics,
00:16:23 which then as we look at the universe,
00:16:24 teaches us how to carry out the compression process.
00:16:29 A quick question about compression.
00:16:31 Do you think the human mind can be compressed?
00:16:35 The biology can be compressed?
00:16:38 We talked about space travel.
00:16:40 To be able to compress the information
00:16:42 that captures some large percent of what it means
00:16:46 to be me or you,
00:16:48 and then be able to send that at the speed of light.
00:16:52 Wow, that’s a big question.
00:16:54 And let me try to take it apart,
00:16:56 unpack it into several pieces.
00:16:58 I don’t believe that wetware biology such as we are
00:17:02 has an exclusive patent on intellectual consciousness.
00:17:08 I suspect that other structures in the universe
00:17:11 are perfectly capable of producing the data streams
00:17:14 that we use to process, first of all,
00:17:17 our observations of the universe
00:17:18 and an awareness of ourself.
00:17:20 I can imagine other structures can do that also.
00:17:23 So that’s part of what you were talking about,
00:17:26 which I would have some disagreement with.
00:17:30 Consciousness.
00:17:31 What’s the most interesting part of us humans?
00:17:36 Is consciousness the thing?
00:17:38 I think that’s the most interesting thing about humans.
00:17:39 And then you’re saying that there’s other entities
00:17:43 throughout the universe.
00:17:45 I can well imagine that the architecture
00:17:48 that supports our consciousness, again,
00:17:50 has no patent on consciousness.
00:17:53 Just in case you have an interesting thought here,
00:17:57 there’s folks perhaps in philosophy called panpsychists
00:18:01 that believe consciousness underlies everything.
00:18:04 It is one of the fundamental laws of the universe.
00:18:07 Do you have a sense that that could possibly fit into…
00:18:09 I don’t know the answer to that question.
00:18:12 One part of that belief system is giya,
00:18:15 which is that there’s a kind of conscious life force
00:18:18 about our planet.
00:18:20 And I’ve encountered these things before.
00:18:22 I don’t quite know what to make of them.
00:18:25 My own life experience, and I’ll be 69 in about two months,
00:18:30 and I have spent all my adulthood thinking about
00:18:33 the way that mathematics interacts with nature
00:18:37 and with us to try to understand nature.
00:18:39 And all I can tell you from all of my integrated experience
00:18:43 is that there is something extraordinarily mysterious
00:18:47 to me about our universe.
00:18:48 This is something that Einstein said
00:18:51 from his life experience as a scientist.
00:18:53 And this mysteriousness almost feels
00:18:59 like the universe is our parent.
00:19:03 It’s a very strange thing perhaps to hear scientists say,
00:19:07 but there are just so many strange coincidences
00:19:10 that you just get a sense that something is going on.
00:19:14 Well, I interrupted you.
00:19:16 In terms of compressing what we’re down to,
00:19:19 we can send it at the speed of light.
00:19:21 Yes.
00:19:23 So the first thing is I would argue that it’s probably
00:19:26 very likely that artificial intelligence
00:19:30 ultimately will develop something like consciousness,
00:19:32 something that for us will probably be indistinguishable
00:19:35 from consciousness.
00:19:36 So that’s what I meant by our biological processing equipment
00:19:41 that we carry up here probably does not hold a patent
00:19:44 on consciousness, because it’s really
00:19:46 about the data streams.
00:19:48 As far as I can tell, that’s what we are.
00:19:49 We are self actuating, self learning data streams.
00:19:53 That to me is most accurate way I can tell you
00:19:56 what I’ve seen in my lifetime about what humans are
00:19:59 at the level of consciousness.
00:20:01 So if that’s the case, then you just need to have
00:20:03 an architecture that supports that information processing.
00:20:06 So let’s assume that that’s true,
00:20:09 that in fact what we call consciousness is really about
00:20:13 a very peculiar kind of data stream.
00:20:17 If that’s the case, then if you can export that
00:20:21 to a piece of hardware, something metal,
00:20:25 electronic, what have you, then you certainly will,
00:20:29 ultimately that kind of consciousness could get to Mars
00:20:32 very quickly, it doesn’t have our problems.
00:20:35 You can engineer the body, as I said,
00:20:36 it’s a ship or a body, you engineer one or both.
00:20:41 Send it at a speed of light, well,
00:20:44 that one is a more difficult one because that now
00:20:47 goes beyond just a matter of having a data stream.
00:20:49 It’s now the preservation of the information
00:20:51 in the data stream.
00:20:53 And so unless you can build something that’s like
00:20:56 a super, super, super version of the way the internet works
00:20:59 because most people aren’t aware that the internet itself
00:21:02 is actually a miracle, it’s based on a technology
00:21:04 called message packaging.
00:21:06 So if you could exponentiate message packaging
00:21:10 in some way to preserve the information
00:21:11 that’s in the data stream, then maybe
00:21:13 your dream becomes true.
00:21:16 You mentioned with artificial intelligence,
00:21:18 sort of us human beings not having
00:21:21 a monopoly on consciousness.
00:21:24 Does the idea of artificial intelligence systems,
00:21:29 computational systems, being able to basically
00:21:33 replacing us humans scare you, excite you?
00:21:37 What do you think about that?
00:21:38 So I’m gonna tell you about a conversation
00:21:40 I once had with Eric Schmidt.
00:21:41 I was sitting at a meeting with him
00:21:43 and he was a few feet away and he turned to me
00:21:46 and he said something like, you know, Jim,
00:21:49 in maybe a decade or so, we’re gonna have computers
00:21:51 that do what you do.
00:21:53 And my response was not unless they can dream
00:21:55 because there’s something about,
00:21:57 the way that we humans actually generate creativity.
00:22:01 It’s somehow, I get this sense of my lived experience
00:22:04 in watching creative people that it’s somehow
00:22:07 connected to the irrational parts of what goes on
00:22:09 in our head and dreaming is part of that irrational.
00:22:12 So unless you can build a piece of artificial intelligence
00:22:15 that dreams, I have a strong suspicion
00:22:17 that you will not get something that will fully be conscious
00:22:21 by a definition that I would accept, for example.
00:22:24 So you mentioned dreaming.
00:22:25 You’ve played around with some out there fascinating ideas.
00:22:31 How do you think, and we’ll start diving into
00:22:35 the world of the very small ideas of super symmetry
00:22:38 and all that in terms of visualization,
00:22:41 in terms of how do you think about it?
00:22:43 How do you dream of it?
00:22:44 How do you come up with ideas
00:22:46 in that fascinating, mysterious space?
00:22:49 So in my workspace, which is basically
00:22:52 where I am charged with coming up on a mathematical palette
00:22:59 with new ideas that will help me understand
00:23:02 the structure of nature and hopefully help all of us
00:23:04 understand the structure of nature.
00:23:06 I’ve observed several different ways
00:23:08 in which my creativity expresses itself.
00:23:10 There’s one mode which looks pretty normal,
00:23:12 which I sort of think of as the Chinese water torture method.
00:23:16 Drop, drop, drop, you get more and more information
00:23:19 and suddenly it all congeals and you get a clear picture.
00:23:23 And so that’s kind of a standard way of working.
00:23:25 And I think that’s how most people think about
00:23:28 the way technical people solve problems.
00:23:30 That is kind of you accumulate this body of information
00:23:34 and at a certain point you synthesize it
00:23:37 and then boom, there’s something new.
00:23:39 But I’ve also observed in myself and other scientists
00:23:41 that there are other ways that we are creative.
00:23:44 And these other ways to me are actually far more powerful.
00:23:48 I first personally experienced this
00:23:50 when I was a freshman at MIT over in Baker House
00:23:53 right across the campus.
00:23:55 And I was in a calculus course, 1801 is called at MIT.
00:24:00 And calculus comes in two different flavors.
00:24:03 One of them is called differential calculus.
00:24:05 The other is called integral calculus.
00:24:07 Differential calculus is the calculus
00:24:09 that Newton invented to describe motion.
00:24:13 It turns out integral calculus was probably invented
00:24:15 about 1700 years earlier by Archimedes.
00:24:18 But we didn’t know that when I was a freshman.
00:24:20 But so that’s what you study as a student.
00:24:24 And the differential calculus part of the course was,
00:24:26 to me, I wouldn’t, how do I say this?
00:24:30 It was something that by the drip, drip, drip method
00:24:32 you could sort of figure it out.
00:24:35 Now, the integral part of calculus,
00:24:37 I could memorize the formula.
00:24:38 That was not the formulae, that was not the problem.
00:24:42 The problem was why, in my own mind,
00:24:44 why do these formulae work?
00:24:47 And because of that, when I was in the part
00:24:52 of the calculus course where we had to do
00:24:53 multiple substitutions to solve integrals,
00:24:56 I had a lot of difficulty.
00:24:59 I was emotionally involved in my education
00:25:01 because this is where I think the passion of motion comes to.
00:25:05 And it caused an emotional crisis
00:25:07 that I was having these difficulties
00:25:09 understanding the integral part of calculus.
00:25:10 The why.
00:25:11 The why, that’s right, the why of it.
00:25:12 Not the rote memorization of fact,
00:25:15 but the why of it.
00:25:16 Why does this work?
00:25:18 And so one night I was over in my dormitory room
00:25:21 in Baker House.
00:25:23 I was trying to do a calculus problem set.
00:25:25 I was getting nowhere.
00:25:28 I got a terrific headache.
00:25:30 I went to sleep and had this very strange dream.
00:25:33 And when I woke, awakened,
00:25:36 I could do three and four substitutions
00:25:38 and integrals with relative ease.
00:25:41 Now, this to me was an astounding experience
00:25:44 because I had never before in my life understood
00:25:48 that one subconscious is actually capable
00:25:51 of being harnessed to do mathematics.
00:25:54 I experienced it, this.
00:25:55 And I’ve experienced this more than once.
00:25:56 So this was just the first time why I remember it so.
00:25:59 So that’s why when it comes to like
00:26:02 really wickedly tough problems,
00:26:04 I think that the kind of creativity
00:26:06 that you need to solve them
00:26:08 is probably this second variety
00:26:10 which comes somehow from dreaming.
00:26:15 Do you think, again, I told you I’m Russian.
00:26:18 So we romanticize suffering.
00:26:20 But do you think part of that equation
00:26:22 is the suffering leading up to that dreaming?
00:26:25 So the suffering is,
00:26:28 I am convinced that this kind of creative,
00:26:31 this second mode of creativity as I like to call it,
00:26:34 I’m convinced that this second mode of creativity
00:26:37 is in fact that suffering is a kind of crucible
00:26:43 that triggers it.
00:26:44 Because the mind I think is struggling to get out of this.
00:26:47 And the only way to actually solve the problem.
00:26:51 And even though you’re not consciously solving problems,
00:26:54 something is going on.
00:26:55 And I’ve talked about to a few other people
00:26:57 and I’ve heard other similar stories.
00:27:00 And so I guess what I think about it is
00:27:03 it’s a little bit by like the way
00:27:04 that thermonuclear weapons work.
00:27:07 I don’t know if you know how they work.
00:27:09 But a thermonuclear weapon is actually two bombs.
00:27:11 It’s an atomic bomb which sort of does a compression.
00:27:14 And then you have a fusion bomb that goes off.
00:27:16 And somehow that emotional pressure
00:27:18 I think acts like the first stage of a thermonuclear weapon.
00:27:22 That’s when we get really big thoughts.
00:27:25 The analogy between thermonuclear weapons
00:27:27 and the subconscious, the connection there is,
00:27:30 at least visually, is kind of interesting.
00:27:34 There may be, Freud would have a few things to say.
00:27:39 Well, part of it is probably based
00:27:41 on my own trajectory through life.
00:27:43 My father was in the US Army for 27 years.
00:27:46 And so I started my life out on a military basis.
00:27:50 And so a lot of probably the things that wander around
00:27:53 in my subconscious are connected to that experience.
00:27:56 I apologize for all the tangents, but.
00:27:58 Well, you’re doing it.
00:27:59 You’re doing it.
00:28:01 But you’re encouraging by answering the stupid questions.
00:28:07 No, they’re not stupid.
00:28:08 You know, your father was in the Army.
00:28:14 What do you think about, Neil deGrasse Tyson recently wrote
00:28:20 a book on interlinking the progress of science
00:28:25 to sort of the aspirations of our military endeavors
00:28:31 and DARPA funding and so on.
00:28:33 What do you think about war in general?
00:28:35 Do you think we’ll always have war?
00:28:37 Do you think we’ll always have conflict in the world?
00:28:42 I’m not sure that we’re going to be able
00:28:43 to afford to have war always, because if.
00:28:47 Strictly financially speaking?
00:28:49 No, not in terms of finance, but in terms of consequences.
00:28:53 So if you look at technology today,
00:28:56 you can have non state actors acquire technology,
00:29:00 for example, bioterrorism, whose impact is roughly speaking
00:29:05 equivalent to what it used to take nations
00:29:07 to impart on a population.
00:29:10 I think the cost of war is ultimately,
00:29:13 it’s going to be a little, I think
00:29:14 it’s going to work a little bit like the Cold War.
00:29:16 You know, we survived 50, 60 years as a species
00:29:21 with these weapons that are so terrible that they could have
00:29:25 actually ended our form of life on this planet, but it didn’t.
00:29:29 Why didn’t it?
00:29:30 Well, it’s a very bizarre and interesting thing,
00:29:32 but it was called mutually assured destruction.
00:29:34 And so the cost was so great that people eventually
00:29:37 figured out that you can’t really
00:29:39 use these things, which is kind of interesting,
00:29:41 because if you read the history about the development
00:29:43 of nuclear weapons, physicists actually
00:29:45 realized this pretty quickly.
00:29:46 I think it was maybe Schrodinger who
00:29:49 said that these things are not really weapons.
00:29:51 They’re political implements.
00:29:52 They’re not weapons, because the cost is so high.
00:29:55 And if you take that example and spread it out
00:30:00 to the kind of technological development
00:30:01 we’re seeing now outside of nuclear physics,
00:30:04 but I picked the example of biology,
00:30:06 I could well imagine that there would be material science
00:30:10 sorts of equivalents across a broad front of technology.
00:30:14 You take that experience from nuclear weapons,
00:30:17 and the picture that I see is that it would be possible
00:30:20 to develop technologies that are so terrible that you couldn’t
00:30:24 use them, because the costs are too high.
00:30:27 And that might cure us.
00:30:29 And many people have argued that actually it prevented,
00:30:33 nuclear weapons have prevented more military conflict than.
00:30:36 It certainly froze the conflict domain.
00:30:41 It’s interesting that nowadays it
00:30:44 was with the removal of the threat of mutually assured
00:30:46 destruction that other forces took over in our geopolitics.
00:30:52 Do you have worries of existential threats
00:30:57 of nuclear weapons or other technologies
00:31:00 like artificial intelligence?
00:31:01 Do you think we humans will tend to figure out
00:31:05 how to not blow ourselves up?
00:31:06 I don’t know, quite frankly.
00:31:10 This is something I’ve thought about.
00:31:11 And I’m not, I mean, so I’m a spectator in the sense
00:31:16 that as a scientist, I collect and collate data.
00:31:21 So I’ve been doing that all my life
00:31:23 and looking at my species.
00:31:25 And it’s not clear to me that we are
00:31:27 going to avoid a catastrophic, self induced ending.
00:31:34 Are you optimistic?
00:31:37 Not as a scientist, but as a single element speaker?
00:31:40 I would say I wouldn’t bet against us.
00:31:45 Beautifully put.
00:31:47 Let’s dive into the world of the very small,
00:31:50 if we could for a bit.
00:31:52 What are the basic particles, either experimentally observed
00:31:56 or hypothesized by physicists?
00:31:59 So as we physicists look at the universe,
00:32:02 you can, first of all, there are two big buckets of particles.
00:32:05 That is the smallest objects that we
00:32:07 are able to currently mathematically conceive
00:32:11 and then experimentally verify that these ideas have
00:32:15 a sense of accuracy to them.
00:32:17 So one of those buckets we call matter.
00:32:20 These are things like electrons, things
00:32:23 that are like quarks, which are particles that
00:32:25 exist inside of protons.
00:32:27 And there’s a whole family of these things.
00:32:30 There are, in fact, 18 quarks and apparently six
00:32:34 electron like objects that we call leptons.
00:32:37 So that’s one bucket.
00:32:39 The other bucket that we see both in our mathematics
00:32:41 as well as in our experimental equipment
00:32:43 are a set of particles that you can call force carriers.
00:32:47 The most familiar force carrier is the photon, the particle
00:32:50 of light that allows you to see me.
00:32:52 In fact, it’s the same object that
00:32:54 carries electric repulsion between like charges.
00:32:58 From science fiction, we have the object
00:33:00 called the graviton, which is talked about a lot in science
00:33:03 fiction and Star Trek.
00:33:05 But the graviton is also a mathematical object
00:33:07 that we physicists have known about essentially
00:33:09 since Einstein wrote his theory of general relativity.
00:33:13 There are four forces in nature, the fundamental forces.
00:33:17 There is the gravitational force.
00:33:19 Its carrier is the graviton.
00:33:21 There are three other forces in nature,
00:33:23 the electromagnetic force, the strong nuclear force,
00:33:25 and the weak nuclear force.
00:33:27 And each one of these forces has one or more carriers.
00:33:30 The photon is the carrier of the electromagnetic force.
00:33:33 The strong nuclear force actually has eight carriers.
00:33:35 They’re called gluons.
00:33:37 And then the weak nuclear force has three carriers.
00:33:39 They’re called the W plus, W minus, and Z bosons.
00:33:44 So those are the things that both in mathematics
00:33:46 and in experiments, by the way, the most precise experiments
00:33:49 we’re ever as a species able to conduct
00:33:53 is about measuring the accuracy of these ideas.
00:33:55 And we know that at least to one part in a billion,
00:33:57 these ideas are right.
00:33:59 So first of all, you’ve made it sound both elegant and simple.
00:34:05 But is it crazy to you that there is force carriers?
00:34:11 Like, is that supposed to be a trivial idea to think about?
00:34:14 If we think about photons, gluons,
00:34:17 that there’s four fundamental forces of physics,
00:34:21 and then those forces are expressed.
00:34:24 There’s carriers of those forces.
00:34:26 Like, is that a kind of trivial thing?
00:34:29 It’s not a trivial thing at all.
00:34:31 In fact, it was a puzzle for Sir Isaac Newton,
00:34:33 because he’s the first person to give us basically physics.
00:34:37 Before Isaac Newton, physics didn’t exist.
00:34:39 What did exist was called natural philosophy,
00:34:41 so discussions about using the methods of classical philosophy
00:34:45 to understand nature, natural philosophy.
00:34:48 So the Greeks, we call them scientists,
00:34:50 but they were natural philosophers.
00:34:52 Physics doesn’t get born until Newton writes the Principia.
00:34:56 One of the things that puzzled him was how gravity works,
00:35:00 because if you read very carefully what he writes,
00:35:04 he basically says, and I’m paraphrasing badly,
00:35:07 but he basically says that someone who thinks deeply
00:35:10 about this subject would find it inconceivable
00:35:13 that an object in one place or location
00:35:17 can magically reach out and affect another object
00:35:19 with nothing intervening.
00:35:21 And so it puzzled him.
00:35:23 There’s a puzzle of you, action at a distance.
00:35:25 I mean, not as a physicist.
00:35:27 It would, it would, except that I am a physicist,
00:35:29 and we have long ago resolved this issue,
00:35:32 and the resolution came about
00:35:33 through a second great physicist.
00:35:36 Most people have heard of Newton.
00:35:38 Most people have heard of Einstein.
00:35:40 But between the two of them,
00:35:41 there was another extraordinarily great physicist,
00:35:43 a man named James Clark Maxwell.
00:35:45 And Maxwell, between these two other giants,
00:35:49 taught us about electric and magnetic forces,
00:35:52 and it’s from his equations that one can figure out
00:35:55 that there’s a carrier called the photon.
00:35:58 So this was resolved for physicists around 1860 or so.
00:36:04 So what are bosons and fermions and hadrons,
00:36:08 elementary and composites?
00:36:09 Sure, so earlier I said.
00:36:12 Two buckets.
00:36:13 You have got two buckets
00:36:14 if you wanna try to build the universe.
00:36:15 You gotta start off with things on these two buckets.
00:36:18 So you gotta have things, that’s a matter,
00:36:21 and then you have to have other objects that act on them
00:36:23 to cause those things to cohere to fixed finite patterns,
00:36:28 because you need those fixed finite patterns
00:36:30 as building blocks.
00:36:31 So that’s the way our universe looks to people like me.
00:36:34 Now, the building blocks do different things.
00:36:37 So let’s go back to these two buckets again.
00:36:39 Let me start with a bucket containing the particle of light.
00:36:42 Let me imagine I’m in a dusty room with two flashlights,
00:36:46 and I have one flashlight, which I direct directly
00:36:49 in front of me, and then I have you stand over to say my left
00:36:52 and then we both take our flashlights and turn them on
00:36:54 and make sure the beams go right through each other.
00:36:56 And the beams do just that.
00:36:57 They go right through each other.
00:36:58 They don’t bounce off of each other.
00:37:00 The reason the room has to be dusty
00:37:01 is because we wanna see the light.
00:37:03 The room dust wasn’t there.
00:37:04 We wouldn’t actually see the light
00:37:05 until it got to the other wall, right?
00:37:07 So you see the beam because it’s the dust in the air.
00:37:09 But the two beams actually pass right through each other.
00:37:12 They literally pass right through.
00:37:13 They don’t affect each other at all.
00:37:15 One acts like the other’s not there.
00:37:20 The particle of light is the simplest example
00:37:23 that shows that behavior.
00:37:24 That’s a boson.
00:37:26 Now let’s imagine that we’re in the same dusty room
00:37:30 and this time you have a bucket of balls
00:37:31 and I have a bucket of balls.
00:37:33 And we try to throw them so that we get something
00:37:36 like a beam, throwing them fast, right?
00:37:39 If they collide, they don’t just pass through each other.
00:37:41 They bounce off of each other.
00:37:43 Now that’s mostly because they have electric charge
00:37:45 and electric charges, light charges repel.
00:37:48 But mathematically, I know how to turn off
00:37:50 the electric charge.
00:37:51 And if you do that, you’ll find these still repel.
00:37:53 And it’s because they are these things we call fermions.
00:37:57 So this is how you distinguish the things
00:37:59 that are in the two buckets.
00:38:00 They are either bosons or fermions.
00:38:04 Which of them, and maybe you can mention
00:38:06 the most popular of the bosons.
00:38:09 The most recently discovered.
00:38:12 It’s like when I was in high school
00:38:15 and there was a really popular majorette.
00:38:18 Her name is the Higgs particle these days.
00:38:21 Can you describe which of the bosons
00:38:26 and the fermions have been discovered,
00:38:28 hypothesized, which have been experimentally validated,
00:38:31 what’s still out there?
00:38:32 Right, so the two buckets that I’ve actually described
00:38:37 to you have all been first hypothesized
00:38:40 and then verified by observation.
00:38:43 With the Higgs boson being the most recent
00:38:45 one of these things.
00:38:47 We haven’t actually verified the graviton
00:38:49 interestingly enough.
00:38:51 Mathematically, we have an expectation
00:38:54 that gravitons exist.
00:38:55 But we’ve not performed an experiment
00:38:56 to show that this is an accurate idea that nature uses.
00:38:59 So something has to be a carrier.
00:39:02 For the force of gravity, exactly.
00:39:04 Can it be something way more mysterious than we,
00:39:08 so when you say the graviton, is it,
00:39:11 would it be like the other particles, force carriers,
00:39:15 or can it be something much more mysterious?
00:39:16 In some ways, yes, but in other ways, no.
00:39:18 It turns out that the graviton is also,
00:39:21 if you look at Einstein’s theory,
00:39:24 he taught us about this thing he calls space time,
00:39:26 which is, if you try to imagine it,
00:39:29 you can sort of think of it as kind of a rubber surface.
00:39:32 That’s one popular depiction of space time.
00:39:34 It’s not an accurate depiction
00:39:36 because the only accuracy is actually in the calculus
00:39:38 that he uses, but that’s close enough.
00:39:41 So if you have a sheet of rubber, you can wave it.
00:39:43 You can actually form a wave on it.
00:39:46 Space time is enough like that
00:39:47 so that when space time oscillates, you create these waves.
00:39:51 These waves carry energy.
00:39:53 We expect them to carry energy in quanta.
00:39:55 That’s what a graviton is.
00:39:56 It’s a wave in space time.
00:39:57 And so the fact that we have seen the waves
00:40:00 with LIGO over the course of the last three years,
00:40:03 and we’ve recently used gravitational wave observatories
00:40:07 to watch colliding black holes and neutron stars
00:40:09 and all sorts of really cool stuff out there.
00:40:12 So we know the waves exist,
00:40:14 but in order to know that gravitons exist,
00:40:16 you have to prove that these waves carry energy
00:40:18 in energy packets.
00:40:20 And that’s what we don’t have the technology to do yet.
00:40:25 And perhaps briefly jumping to a philosophical question,
00:40:28 does it make sense to you that gravity
00:40:30 is so much weaker than the other forces?
00:40:32 No.
00:40:34 You see, now you’ve touched on a very deep mystery
00:40:40 about physics.
00:40:42 There are a lot of such questions in physics
00:40:44 about why things are as they are.
00:40:47 And as someone who believes that there are some things
00:40:50 that certainly are coincidences,
00:40:53 like you could ask the same question about,
00:40:54 well, why are the planets at the orbits
00:40:57 that they are around the sun?
00:40:58 The answer turns out there is no good reason.
00:41:00 It’s just an accident.
00:41:01 So there are things in nature that have that character.
00:41:03 And perhaps the strength of the various forces is like that.
00:41:08 On the other hand, we don’t know that that’s the case.
00:41:10 And there may be some deep reasons
00:41:12 about why the forces are ordered as they are,
00:41:15 where the weakest force is gravity,
00:41:17 the next weakest force is the weak interaction,
00:41:19 the weak nuclear force, then there’s electromagnetism,
00:41:22 there’s a strong force.
00:41:23 We don’t really have a good understanding
00:41:24 of why this is the ordering of the forces.
00:41:27 So some of the fascinating work you’ve done
00:41:30 is in the space of supersymmetry, symmetry in general.
00:41:36 Can you describe, first of all, what is supersymmetry?
00:41:39 Yes, so you remember the two buckets
00:41:41 I told you about perhaps earlier?
00:41:43 So there are two buckets in our universe.
00:41:46 So now I want you to think about drawing a pie
00:41:51 that has four quadrants.
00:41:53 So I want you to cut the piece of pie in fourths.
00:41:56 So in one quadrant, I’m gonna put all the buckets
00:41:58 that we talked about that are like the electron and quarks.
00:42:01 In a different quadrant,
00:42:02 I’m going to put all the force carriers.
00:42:04 The other two quadrants are empty.
00:42:06 Now, I showed you a picture of that.
00:42:08 You’d see a circle.
00:42:10 There would be a bunch of stuff in one upper quadrant
00:42:12 and stuff in others.
00:42:13 And then I would ask you a question.
00:42:15 Does that look symmetrical to you?
00:42:19 No. No.
00:42:20 And that’s exactly right
00:42:22 because we humans actually have a very deeply programmed
00:42:26 sense of symmetry.
00:42:28 It’s something that is part of that mystery of the universe.
00:42:32 So how would you make it symmetrical?
00:42:34 Or one way you could is by saying
00:42:35 those two empty quadrants had things in them also.
00:42:38 And if you do that, that’s supersymmetry.
00:42:42 So that’s what I understood
00:42:43 when I was a graduate student here at MIT in 1975
00:42:47 when the mathematics of this was first being born.
00:42:52 Supersymmetry was actually born in the Ukraine
00:42:55 in the late 60s, but we had this thing
00:42:56 called the Iron Curtain.
00:42:57 So we Westerners didn’t know about it.
00:43:00 But by the early 70s, independently,
00:43:02 there were scientists in the West
00:43:04 who had rediscovered supersymmetry.
00:43:07 Bruno Zemeno and Julius Wess were their names.
00:43:10 So this was around 71 or 72 when this happened.
00:43:14 I started graduate school in 73.
00:43:16 So around 74, 75, I was trying to figure out
00:43:19 how to write a thesis so that I could become a physicist
00:43:21 the rest of my life.
00:43:23 I did a, I had a great advisor, Professor James Young
00:43:27 who had taught me a number of things about electrons
00:43:31 and weak forces and those sorts of things.
00:43:33 But I decided that if I was going to have a really
00:43:40 an opportunity to maximize my chances of being successful,
00:43:45 I should strike it out in a direction
00:43:46 that other people were not studying.
00:43:48 And so as a consequence, I surveyed ideas
00:43:52 that were going, that were being developed.
00:43:54 And I came across the idea of supersymmetry.
00:43:57 And it was so, the mathematics was so remarkable
00:44:00 that I just, it bowled me over.
00:44:03 I actually have two undergraduate degrees.
00:44:05 My first undergraduate degree is actually mathematics.
00:44:07 And my second is physics,
00:44:09 even though I always wanted to be a physicist.
00:44:12 Plan A, which involved getting good grades was mathematics.
00:44:17 I was a mathematics major thinking about graduate school,
00:44:20 but my heart was in physics.
00:44:22 If we could take a small digression,
00:44:26 what’s to you the most beautiful idea in mathematics
00:44:29 that you’ve encountered in this interplay
00:44:31 between math and physics?
00:44:33 It’s the idea of symmetry.
00:44:35 The fact that our innate sense of symmetry
00:44:39 winds up aligning with just incredible mathematics,
00:44:44 to me is the most beautiful thing.
00:44:47 It’s very strange, but true
00:44:50 that if symmetries were perfect, we would not exist.
00:44:53 And so even though we have these very powerful ideas
00:44:55 about balance in the universe in some sense,
00:44:57 it’s only when you break those balances
00:44:59 that you get creatures like humans
00:45:01 and objects like planets and stars.
00:45:03 So although they are a scaffold for reality,
00:45:07 they cannot be the entirety of reality.
00:45:09 So I’m kind of naturally attracted
00:45:15 to parts of science and technology
00:45:18 where symmetry plays a dominant role.
00:45:21 And not just, I guess, symmetry as you said,
00:45:23 but the magic happens when you break the symmetry.
00:45:26 The magic happens when you break the symmetry.
00:45:29 Okay, so diving right back in,
00:45:31 you mentioned four quadrants.
00:45:33 Yes.
00:45:34 Two are filled with stuff we can, two buckets.
00:45:37 And then there’s crazy mathematical thing,
00:45:39 ideas fulfilling the other two.
00:45:41 What are those things?
00:45:43 So earlier, the way I described these two buckets
00:45:46 is I gave you a story that started out
00:45:48 by putting us in a dusty room with two flashlights.
00:45:52 And I said, turn on your flashlight, I’ll turn on mine,
00:45:55 the beams will go through each other.
00:45:56 And the beams are composed of force carriers called photons.
00:46:00 They carry the electromagnetic force
00:46:03 and they pass right through each other.
00:46:04 So imagine looking at the mathematics of such an object,
00:46:07 which you don’t have to imagine people like me do that.
00:46:11 So you take that mathematics
00:46:12 and then you ask yourself a question.
00:46:15 You see, mathematics is a palette.
00:46:16 It’s just like a musical composer
00:46:20 is able to construct variations on a theme.
00:46:24 Well, a piece of mathematics in the hand of a physicist
00:46:26 is something that we can construct variations on.
00:46:29 So even though the mathematics that Maxwell gave us
00:46:33 about light, we know how to construct variations on that.
00:46:38 And one of the variations you can construct is to say,
00:46:41 suppose you have a force carrier for electromagnetism
00:46:45 that behaves like an electron
00:46:47 in that it would bounce off of another one.
00:46:49 That’s changing a mathematical term in an equation.
00:46:53 So if you did that, you would have a force carrier.
00:46:56 So you would say first it belongs
00:46:58 in this force carrying bucket,
00:46:59 but it’s got this property of bouncing off like electrons.
00:47:01 So you say, well, gee, wait, no,
00:47:03 that’s not the right bucket.
00:47:04 So you’re forced to actually put it
00:47:05 in one of these empty quadrants.
00:47:07 So those sorts of things, basically we give them…
00:47:12 So the photon mathematically
00:47:14 can be accompanied by a photino.
00:47:15 It’s the thing that carries a force
00:47:18 but has the rule of bouncing off.
00:47:20 In a similar manner, you could start with an electron
00:47:24 and you say, okay, so write down the mathematical electron.
00:47:27 I know how to do that.
00:47:28 A physicist named Dirac first told us how to do that
00:47:30 back in the late 20s, early 30s.
00:47:33 So take that mathematics.
00:47:34 And then you say, let me look at that mathematics
00:47:37 and find out what in the mathematics
00:47:39 causes two electrons to bounce off of each other,
00:47:42 even if I turn off the electrical charge.
00:47:44 So I could do that.
00:47:45 And now let me change that mathematical term.
00:47:48 So now I have something that carries electrical charge,
00:47:50 but if you take two of them,
00:47:52 I’m sorry, if you turn their charges off,
00:47:53 they’ll pass through each other.
00:47:55 So that puts things in the other quadrant.
00:47:57 And those things we tend to call,
00:48:00 we put the S in front of their name.
00:48:02 So in the lower quadrant here, we have electrons
00:48:04 and this now newly filled quadrant, we have selectors.
00:48:08 And the quadrant over here, we had quarks.
00:48:12 Over here, we have squarks.
00:48:13 So now we’ve got this balanced pie.
00:48:15 And that’s basically what I understood
00:48:17 as a graduate student in 1975
00:48:20 about this idea of supersymmetry,
00:48:22 that it was going to fill up these two quadrants
00:48:24 of the pie in a way that no one
00:48:25 had ever thought about before.
00:48:27 So I was amazed that no one else at MIT
00:48:30 found this an interesting idea.
00:48:32 So it led to my becoming the first person in MIT
00:48:37 to really study supersymmetry.
00:48:39 This is 1975, 76, 77.
00:48:42 And in 77, I wrote the first PhD thesis
00:48:44 in the physics department on this idea
00:48:47 because I was drawn to the balance.
00:48:50 Drawn to the symmetry.
00:48:51 So what does that, first of all,
00:48:56 is this fundamentally a mathematical idea?
00:49:01 So how much experimental, and we’ll have this theme.
00:49:04 It’s a really interesting one.
00:49:05 When you explore the world of the small
00:49:08 and in your new book talking about
00:49:11 Approving Einstein, right, that we’ll also talk about,
00:49:14 there’s this theme of kind of starting it,
00:49:16 exploring crazy ideas first in the mathematics
00:49:19 and then seeking for ways to experimentally validate them.
00:49:23 Where do you put supersymmetry in that?
00:49:25 It’s closer than string theory.
00:49:28 It has not yet been validated.
00:49:30 In some sense, you mentioned Einstein,
00:49:33 so let’s go there for a moment.
00:49:35 In our book, Approving Einstein Right,
00:49:37 we actually do talk about the fact
00:49:38 that Albert Einstein in 1915 wrote a set of equations
00:49:42 which were very different from Newton’s equations
00:49:45 in describing gravity.
00:49:46 These equations made some predictions
00:49:48 that were different from Newton’s predictions.
00:49:51 It actually made three different predictions.
00:49:53 One of them was not actually a prediction,
00:49:55 but a postdiction, because it was known
00:49:57 that Mercury was not orbiting the sun
00:49:59 in the way that Newton would have told you.
00:50:01 And so Einstein’s theory actually describes Mercury
00:50:05 orbiting in a way that was observed
00:50:08 as opposed to what Newton would have told you.
00:50:09 So that was one prediction.
00:50:11 The second prediction that came out of
00:50:13 the theory of general relativity,
00:50:14 which Einstein wrote in 1915,
00:50:17 was that if you,
00:50:21 so let me describe an experiment and come back to it.
00:50:23 Suppose I had a glass of water,
00:50:25 and I filled the glass up,
00:50:28 and then I moved the glass slowly back and forth
00:50:31 between our two faces.
00:50:33 It would appear to me like your face was moving,
00:50:36 even though you weren’t moving.
00:50:38 I mean, it’s actually, and what’s causing it
00:50:40 is because the light gets bent through the glass
00:50:42 as it passes from your face to my eye.
00:50:45 So Einstein in his 1915 theory of general relativity
00:50:50 found out that gravity has the same effect on light
00:50:54 as that glass of water.
00:50:55 It would cause beams of light to bend.
00:50:58 Now, Newton also knew this,
00:51:01 but Einstein’s prediction was that light
00:51:02 would bend twice as much.
00:51:04 And so here’s a mathematical idea.
00:51:07 Now, how do you actually prove it?
00:51:09 Well, you’ve got to watch.
00:51:11 Just a quick pause on that, just the language you’re using.
00:51:15 He found out.
00:51:17 I can say he did a calculation.
00:51:19 It’s a really interesting notion
00:51:21 that one of the beautiful things about this universe
00:51:25 is you can do a calculation
00:51:28 and combine with some of that magical intuition
00:51:30 that physicists have, actually predict what would be,
00:51:35 what’s possible to experimentally validate.
00:51:37 That’s correct.
00:51:38 So he found out in the sense
00:51:40 that there seems to be something here
00:51:43 and mathematically it should bend,
00:51:46 gravity should bend light this amount.
00:51:48 And so therefore that’s something that could be potentially,
00:51:51 and then come up with an experiment that could be validated.
00:51:53 Right.
00:51:54 And that’s the way that actually modern physics,
00:51:57 deeply fundamental modern physics, this is how it works.
00:52:02 Earlier we spoke about the Higgs boson.
00:52:04 So why did we go looking for it?
00:52:06 The answer is that back in the late 60s and early 70s,
00:52:10 some people wrote some equations
00:52:12 and the equations predicted this.
00:52:15 So then we went looking for it.
00:52:18 So on supersymmetry for a second,
00:52:21 there’s these things called idynchrous symbols,
00:52:25 these strange little graphs.
00:52:26 Yes.
00:52:27 You refer to them as revealing something
00:52:29 like binary code underlying reality.
00:52:32 First of all, can you describe these graphs?
00:52:34 Describe these graphs, what are they?
00:52:38 What are these beautiful little strange graphs?
00:52:40 Well, first of all, idynchrous are an invention of mine,
00:52:44 together with a colleague named Michael Fox.
00:52:46 In 2005, we were looking at equations.
00:52:50 Well, the story’s a little bit more complicated
00:52:51 and it’ll take too long to explain all the details,
00:52:54 but the Reader’s Digest version
00:52:55 is that we were looking at these equations
00:52:58 and we figured out that all the data
00:53:01 in a certain class of equations could be put in pictures.
00:53:04 And the pictures, what do they look like?
00:53:06 Well, they’re just little balls.
00:53:09 You have black balls and white balls.
00:53:12 Those stand for those two buckets, by the way,
00:53:14 that we talked about in reality.
00:53:15 The white balls are things that are like particles of light.
00:53:18 The black balls are like electrons.
00:53:20 And then you can draw lines connecting these balls.
00:53:24 And these lines are deeply mathematical objects
00:53:27 and there’s no way for me to,
00:53:29 I have no physical model for telling you what the lines are.
00:53:33 But if you were a mathematician,
00:53:36 I would do a technical phrase saying,
00:53:37 this is the orbit of the representation
00:53:39 and the action of the symmetry generators.
00:53:41 Mathematicians wouldn’t understand that.
00:53:43 Nobody else in their right mind would,
00:53:45 so let’s not go there.
00:53:47 So, but we figured out that the data
00:53:49 that was in the equations was in these funny pictures
00:53:52 that we could draw.
00:53:53 And so that was stunning,
00:53:56 but it also was encouraging
00:53:59 because there are problems with the equations,
00:54:02 which I had first learned about in 1979
00:54:06 when I was down at Harvard
00:54:07 and I went out to Caltech for the first time
00:54:09 and working with a great scientist
00:54:11 by the name of John Schwartz.
00:54:12 There are problems in the equations we don’t know how to solve.
00:54:16 And so one of the things about solving problems
00:54:18 that you don’t know how to solve
00:54:20 is that beating your head against a brick wall
00:54:22 is probably not a good philosophy about how to solve it.
00:54:25 So what do you need to do?
00:54:26 You need to change your sense of reference,
00:54:29 your frame of reference, your perspective.
00:54:31 So when I saw these funny pictures,
00:54:35 I thought, gee, that might be a way
00:54:37 to solve these problems with equations
00:54:39 that we don’t know how to do.
00:54:41 So that was for me one of the first attractions
00:54:44 is that I now had an alternative language
00:54:46 to try to attack a set of mathematical problems.
00:54:50 But I quickly realized that A,
00:54:54 this mathematical language was not known by mathematicians,
00:54:58 which makes it pretty interesting
00:54:59 because now you have to actually teach mathematicians
00:55:02 about a piece of mathematics
00:55:04 because that’s how they make their living.
00:55:05 And the great thing about working with mathematicians,
00:55:08 of course, is the rigor with which they examine ideas.
00:55:11 So they make your ideas better than they start out.
00:55:14 So I start working with a group of mathematicians
00:55:16 and it was in that collaboration that we figured out
00:55:18 that these funny pictures had error correcting codes
00:55:20 buried in them.
00:55:23 Can you talk about what are error correcting codes?
00:55:25 Ah, sure.
00:55:26 So the simplest way to talk about error correcting codes
00:55:32 is first of all, to talk about digital information.
00:55:36 Digital information is basically strings of ones and zeros.
00:55:39 They’re called bits.
00:55:41 So now let’s imagine that I want to send you some bits.
00:55:46 Well, maybe I could show you pictures,
00:55:50 but maybe it’s a rainy day
00:55:52 or maybe the windows in your house are foggy.
00:55:56 So sometimes when I show you a zero,
00:55:59 you might interpret it as a one.
00:56:01 Or other times when I show you a one,
00:56:03 you might interpret it as a zero.
00:56:05 So if that’s the case,
00:56:07 that means when I try to send you this data,
00:56:08 it comes to you in corrupted form.
00:56:11 And so the challenge is how do you get it to be uncorrupted?
00:56:15 In the 1940s, a computer scientist named Hamming
00:56:21 addressed the problem of how do you reliably transmit
00:56:24 digital information?
00:56:26 And what he came up with was a brilliant idea.
00:56:29 Now, the way that you solve it
00:56:31 is that you take the data that you want to send,
00:56:33 the ones in your strings of ones and zeros,
00:56:34 your favorite string,
00:56:36 and then you dump more ones and zeros in,
00:56:38 but you dump them in in a particular pattern.
00:56:41 And this particular pattern
00:56:42 is what a Hamming code is all about.
00:56:45 So it’s an error correcting code
00:56:46 because if the person at the other end
00:56:48 knows what the pattern’s supposed to be,
00:56:49 they can figure out when one’s got changed to zeros,
00:56:52 zero’s got changed to one.
00:56:53 So it turned out that our strange little objects
00:56:57 that came from looking at the equations
00:56:59 that we couldn’t solve,
00:57:00 it turns out that when you look at them deeply enough,
00:57:02 you find out that they have ones and zeros
00:57:06 buried in them.
00:57:07 But even more astoundingly,
00:57:08 the ones and zeros are not there randomly.
00:57:10 They are in the pattern of error correcting codes.
00:57:14 So this was an astounding thing
00:57:16 that when we first got this result
00:57:19 and tried to publish it,
00:57:20 it took us three years to convince other physicists
00:57:22 that we weren’t crazy.
00:57:23 Eventually we were able to publish it,
00:57:25 I and this collaboration of mathematicians
00:57:27 and other physicists.
00:57:29 And so ever since then,
00:57:31 I have actually been looking at the mathematics
00:57:34 of these objects,
00:57:35 trying to still understand properties of the equations.
00:57:39 And I want to understand the properties of equations
00:57:40 because I want to be able to try things like electrons.
00:57:43 So as you can see,
00:57:44 it’s just like a two step removed process
00:57:46 of trying to get back to reality.
00:57:48 So what would you say is the most beautiful property
00:57:50 of these Adinkra graphs, objects?
00:57:56 What do you think, by the way, the word symbols,
00:57:58 what do you think of them, these simple graphs?
00:58:01 Are they objects or?
00:58:04 How should we think about that?
00:58:06 For people who work with mathematics like me,
00:58:08 our mathematical concepts are,
00:58:11 we often refer to them as objects
00:58:13 because they feel like real things.
00:58:15 Even though you can’t see them or touch them,
00:58:17 they’re so much part of your interior life
00:58:21 that it is as if you could.
00:58:23 So we often refer to these things as objects,
00:58:26 even though there’s nothing objective about them.
00:58:28 And what does a single graph represent in space?
00:58:31 Okay, so the simplest of these graphs
00:58:34 has to have one white ball and one black ball.
00:58:36 That’s that balance that we talked about earlier.
00:58:38 Remember, we want to balance out the quadrants?
00:58:40 Well, you can’t do it unless you have
00:58:42 a black ball and white ball.
00:58:43 So the simplest of these objects looks like two little balls,
00:58:46 one black, one white, connected by a single line.
00:58:49 And what it’s talking about is, as I said,
00:58:51 a deep mathematical property related to symmetry.
00:58:54 You’ve mentioned the error correcting codes,
00:58:56 but is there a particular beautiful property
00:58:58 that stands out to you about these objects
00:59:00 that you just find?
00:59:01 Yes, yes, there is.
00:59:03 Early on in the development of it.
00:59:04 Yes, there is.
00:59:05 The craziest thing about these to me
00:59:10 is that when you look at physics
00:59:14 and try to write equations where information
00:59:17 gets transmitted reliably,
00:59:20 if you’re in one of these super symmetrical systems
00:59:22 with this extra symmetry,
00:59:23 that doesn’t happen unless there’s
00:59:24 an error correcting code present.
00:59:26 So it’s as if the universe says,
00:59:29 you don’t retransmit information
00:59:31 unless there’s something about an error correcting code.
00:59:33 This to me is the craziest thing
00:59:35 that I’ve ever personally encountered in my research.
00:59:38 And it’s actually got me to wondering
00:59:41 how this could come about,
00:59:42 because the only place in nature
00:59:44 that we know about error correcting codes is genetics.
00:59:47 And in genetics, we think it was evolution
00:59:50 that causes error correcting codes to be in genomes.
00:59:53 And so does that mean that there was
00:59:54 some kind of form of evolution
00:59:55 acting on the mathematical laws of the physics
00:59:58 of our universe?
00:59:59 This is a very bizarre and strange idea.
01:00:01 And it’s something I’ve wondered about
01:00:02 from time to time since making these discoveries.
01:00:05 Do you think such an idea could be fundamental,
01:00:08 or is it emergent throughout
01:00:09 all the different kinds of systems?
01:00:12 I don’t know whether it’s fundamental.
01:00:15 I probably will not live to find out.
01:00:18 This is gonna be the work of probably some future
01:00:20 either mathematician or physicist
01:00:22 to figure out what these things actually mean.
01:00:24 We have to talk a bit about the magical,
01:00:27 the mysterious string theory, super string theory.
01:00:31 Sure.
01:00:32 There’s still maybe this aspect of it,
01:00:35 which is there’s still for me
01:00:37 from an outsider’s perspective,
01:00:39 this fascinating heated debate.
01:00:42 On the status of string theory.
01:00:44 Can you clarify this debate,
01:00:46 perhaps articulating the various views
01:00:48 and say where you land on it?
01:00:50 So first of all, I doubt that I will be able
01:00:53 to say anything to clarify the debate
01:00:55 around string theory for a general audience.
01:01:01 Part of the reason is because string theory
01:01:05 has done something I’ve never seen the erectal physics do.
01:01:08 It has broken out into consciousness
01:01:10 of the general public before we’re finished.
01:01:13 You see, string theory doesn’t actually exist
01:01:15 because when we use the word theory,
01:01:17 we mean a particular set of attributes.
01:01:20 In particular, it means that you have
01:01:21 an overarching paradigm that explains
01:01:23 what it is that you’re doing.
01:01:25 No such overarching paradigm exists for string theory.
01:01:29 What string theory is currently
01:01:31 is an enormously large mutually reinforcing collection
01:01:35 of mathematical facts in which we can find no contradictions.
01:01:39 We don’t know why it’s there,
01:01:41 but we can certainly say that without challenge.
01:01:44 Now, just because you find a piece of mathematics
01:01:46 doesn’t mean that this applies to nature.
01:01:49 And in fact, there has been a very heated debate
01:01:53 about whether string theory is some sort of hysteria
01:01:57 among the community of theoretical physicists,
01:02:00 or whether it has something fundamental
01:02:01 to say about our universe.
01:02:04 We don’t yet know the answer to that question.
01:02:07 What those of us who study string theory
01:02:09 will tell you are things like,
01:02:12 string theory has been extraordinarily productive
01:02:14 in getting us to think more deeply,
01:02:16 even about mathematics that’s not string theory,
01:02:19 but the kind of mathematics
01:02:20 that we’ve used to describe elementary particles.
01:02:23 There have been spin offs from string theory,
01:02:25 and this has been going on now for two decades almost,
01:02:28 that have allowed us, for example,
01:02:31 to more accurately calculate the force between electrons
01:02:34 with the presence of quantum mechanics.
01:02:36 This is not something you hear about in the public.
01:02:39 There are other similar things.
01:02:42 That kind of property I just told you about
01:02:44 is what’s called weak strong duality,
01:02:46 and it comes directly from string theory.
01:02:48 There are other things such as
01:02:53 a property called holography,
01:02:55 which allows one to take equations
01:02:59 and look at them on the boundary of a space,
01:03:01 and then to know information about inside a space
01:03:04 without actually doing calculations there.
01:03:06 This has come directly from string theory.
01:03:08 So there are a number of direct mathematical effects
01:03:12 that we learn as string theory,
01:03:14 but we take these ideas and look at math
01:03:16 that we already know and we find suddenly
01:03:18 we’re more powerful.
01:03:19 This is a pretty good indication
01:03:20 there’s something interesting going on
01:03:22 with string theory itself.
01:03:23 So it’s the early days
01:03:24 of a powerful mathematical framework.
01:03:25 That’s what we have right now.
01:03:27 What are the big, first of all,
01:03:30 most people will probably, which as you said,
01:03:33 most general public would know actually
01:03:35 what string theory is, which is at the highest level,
01:03:38 which is a fascinating fact.
01:03:41 Well, string theory is what they do
01:03:43 on the Big Bang Theory, right?
01:03:44 One, can you maybe describe what is string theory,
01:03:51 and two, what are the open challenges?
01:03:55 So what is string theory?
01:03:57 Well, the simplest explanation I can provide
01:04:01 is to go back and ask what are particles,
01:04:05 which is the question you first asked me.
01:04:10 What’s the smallest thing?
01:04:11 Yeah, what’s the smallest thing?
01:04:13 So particles, one way I try to describe particles
01:04:20 to people is start,
01:04:21 I want you to imagine a little ball
01:04:24 and I want you to let the size of that ball shrink
01:04:26 until it has no extent whatsoever,
01:04:28 but it still has the mass of the ball.
01:04:32 That’s actually what Newton was working with
01:04:34 when he first invented physics.
01:04:36 He’s the real inventor of the massive particle,
01:04:39 which is this idea that underlies all of physics.
01:04:43 So that’s where we start.
01:04:44 It’s a mathematical construct
01:04:46 that you get by taking a limit of things that you know.
01:04:51 So what’s a string?
01:04:51 Well, in the same analogy, I would say,
01:04:54 now I want you to start with a piece of spaghetti.
01:04:57 So we all know what that looks like.
01:04:59 And now I want you to let the thickness of the spaghetti
01:05:03 shrink until it has no thickness.
01:05:05 Mathematically, I mean, in words, this makes no sense,
01:05:08 but mathematically, this actually works
01:05:11 and you get this mathematical object out.
01:05:13 It has properties that are like spaghetti.
01:05:15 It can wiggle and jiggle,
01:05:17 but it can also move collectively
01:05:19 like a piece of spaghetti.
01:05:21 It’s the mathematics of those sorts of objects
01:05:24 that constitute string theory.
01:05:25 And does the multidimensional, 11 dimensional,
01:05:30 however many dimensional, more than four dimension,
01:05:34 is that a crazy idea to you?
01:05:36 Is that the stranger aspect of string theory to you?
01:05:40 Not really, and also partly because of my own research.
01:05:45 So earlier we talked about these strange symbols
01:05:49 that we’ve discovered inside the equations.
01:05:51 It turns out that to a very large extent,
01:05:54 a Dinkers don’t really care about the number of dimensions.
01:05:56 They kind of have an internal mathematical consistency
01:05:59 that allows them to be manifested
01:06:00 in many different dimensions.
01:06:02 Since supersymmetry is a part of string theory,
01:06:05 then the same property you would expect
01:06:07 to be inherited by string theory.
01:06:09 However, another little known fact,
01:06:12 which is not in the public debate,
01:06:14 is that there are actually strings
01:06:15 that are only four dimensional.
01:06:17 This is something that was discovered
01:06:19 at the end of the 80s by a scientist,
01:06:23 by three different groups of physicists
01:06:25 working independently.
01:06:27 I and my friend Warren Siegel,
01:06:29 who were at the University of Maryland at the time,
01:06:31 were able to prove that there’s mathematics
01:06:33 that looks totally four dimensional,
01:06:34 and yet it’s a string.
01:06:36 There was a group in Germany
01:06:37 that used slightly different mathematics,
01:06:40 but they found the same result.
01:06:42 And then there was a group at Cornell
01:06:43 who using yet a third piece of mathematics
01:06:46 found the same result.
01:06:46 So the fact that extra dimensions
01:06:49 is so widely talked about in the public
01:06:53 is partly a function of how the public
01:06:55 has come to understand string theory
01:06:57 and how the story has been told to them.
01:06:59 But there are alternatives you don’t know about.
01:07:02 If we could talk about maybe experimental validation,
01:07:06 and you’re the coauthor of a recently published book,
01:07:11 Proving Einstein Right,
01:07:14 the human story of it too,
01:07:16 the daring expeditions that change
01:07:18 how we look at the universe.
01:07:19 Do you see echoes of the early days
01:07:22 of general relativity in the 1910s
01:07:25 to the more stretched out to string theory?
01:07:29 I do, I do.
01:07:31 And that’s one reason why I was happy to focus
01:07:33 on the story of how Einstein became a global superstar.
01:07:43 Earlier in our discussion,
01:07:45 we went over his history where in 1915,
01:07:51 he came up with this piece of mathematics,
01:07:53 used it to do some calculations
01:07:55 and then made a prediction.
01:07:57 Yes.
01:07:58 But making a prediction is not enough.
01:08:00 Someone’s got to go out and measure.
01:08:02 And so string theory is in that in between zone.
01:08:07 Now for Einstein, it was from 1915 to 1919.
01:08:09 1915 he makes the correct prediction.
01:08:14 By the way, he made an incorrect prediction
01:08:16 about the same thing in 1911,
01:08:17 but he corrected himself in 1915.
01:08:20 And by 1919, the first pieces
01:08:22 of experimental observational data became available
01:08:27 to say, yes, he’s not wrong.
01:08:31 And by 1922, the argument that based on observation
01:08:35 was overwhelming that he was not wrong.
01:08:38 Can you describe what special general relativity are
01:08:41 just briefly?
01:08:42 Sure.
01:08:43 And what prediction Einstein made
01:08:45 and maybe some or a memorable moment
01:08:52 from the human journey of trying to prove this thing right,
01:08:56 which is incredible.
01:08:58 Right.
01:08:58 So I’m very fortunate to have worked
01:09:02 with a talented novelist who wanted to write a book
01:09:07 that coincided with a book I wanted to write
01:09:09 about how science kind of feels if you’re a person,
01:09:14 because it’s actually people who do science,
01:09:17 even though that may not be obvious to everyone.
01:09:20 So for me, I wanted to write this book
01:09:22 for a couple of reasons.
01:09:23 I wanted young people to understand
01:09:26 that the seeming alien giants that live before them
01:09:32 were just as human as they are.
01:09:34 They get married, they get divorced.
01:09:35 They get married, they get divorced.
01:09:37 They do terrible things.
01:09:38 They do great things.
01:09:39 They’re people.
01:09:40 They’re just people like you.
01:09:42 And so that part of telling the story allowed me
01:09:44 to get that out there for both young people interested
01:09:47 in the sciences as well as the public.
01:09:49 But the other part of the story is I wanted to open up
01:09:54 sort of what it was like.
01:09:58 Now I’m a scientist.
01:10:00 And so I will not pretend to be a great writer.
01:10:02 I understand a lot about mathematics
01:10:04 and I’ve even created my own mathematics
01:10:07 that is kind of a weird thing to be able to do.
01:10:11 But in order to tell the story,
01:10:13 you really have to have an incredible master
01:10:18 of the narrative.
01:10:19 And that was my coauthor, Kathy Pelletier,
01:10:22 who is a novelist.
01:10:24 So we formed this conjoined brain, I used to call us.
01:10:27 She used to call us Professor Higgins and Eliza Doolittle.
01:10:30 My expression for us is that we were a conjoined brain
01:10:33 to tell this story.
01:10:34 And it allowed, so what are some magical moments?
01:10:39 To me, the first magical moment in telling the story
01:10:43 was looking at Albert Einstein and his struggle
01:10:48 because although we regard him as a genius,
01:10:51 as I said, in 1911, he actually made an incorrect prediction
01:10:54 about bending starlight.
01:10:55 And that’s actually what set the astronomers off.
01:10:59 In 1914, there was an eclipse.
01:11:02 And by various accidents of war and weather
01:11:06 and all sorts of things that we talk about in the book,
01:11:08 no one was able to make the measurement.
01:11:11 If they had made the measurement,
01:11:13 it would have disagreed with his 1911 prediction
01:11:19 because nature only has one answer.
01:11:22 And so then you see how fortunate he was
01:11:26 that wars and bad weather and accidents and transporting
01:11:32 equipment stopped any measurements from being made.
01:11:35 So he corrects himself in 1915,
01:11:38 but the astronomers are already out there
01:11:40 trying to make the measurement.
01:11:41 So now he gives them a different number.
01:11:43 And it turns out that’s the number that nature agrees with.
01:11:46 So it gives you a sense of this is a person struggling
01:11:50 with something deeply.
01:11:52 And although his deep insight led him to this,
01:11:56 it is the circumstance of time, place and accident
01:12:01 but through which we view him.
01:12:03 And the story could have turned out very differently
01:12:06 where first he makes a prediction,
01:12:09 the measurements are made in 1914,
01:12:11 they disagree with his prediction.
01:12:13 And so what would the world view him as?
01:12:15 Well, he’s this professor who made this prediction
01:12:17 that didn’t get it right, yes?
01:12:20 So the fragility of human history
01:12:26 is illustrated by that story.
01:12:27 And it’s one of my favorite things.
01:12:29 You also learn things like in our book,
01:12:32 how eclipses and watching eclipses was a driver
01:12:36 of the development of science in our nation
01:12:37 when it was very young.
01:12:38 In fact, even before we were a nation,
01:12:40 it turns out there were citizens of this would be country
01:12:47 that were going out trying to measure eclipses.
01:12:50 So some fortune, some misfortune affects
01:12:54 the progress of science.
01:12:56 Absolutely.
01:12:57 Especially with ideas as, to me at least,
01:13:01 if I put myself back in those days,
01:13:03 as radical as general relativity is.
01:13:08 First, can you describe, if it’s OK briefly,
01:13:12 what general relativity is?
01:13:14 And yeah, could you just take a moment of, yeah,
01:13:18 put yourself in those shoes in the academic researchers,
01:13:22 scientists of that time, and what is this theory?
01:13:25 What is it trying to describe about our world?
01:13:28 It’s trying to answer the thing that left Isaac Newton puzzled.
01:13:37 Isaac Newton says gravity magically
01:13:39 goes from one place to another.
01:13:41 He doesn’t believe it, by the way.
01:13:43 He knows that’s not right.
01:13:45 But the mathematics is so good that you have to say,
01:13:48 well, I’ll throw my qualms away because I’ll use it.
01:13:52 That’s all we used to get a man from the Earth to the moon
01:13:55 was that mathematics.
01:13:58 So I’m one of those scientists, and I’ve seen this.
01:14:03 And if I thought deeply about it,
01:14:04 maybe I know that Newton himself wasn’t comfortable.
01:14:08 And so the first thing I would hope that I would feel
01:14:11 is, gee, there’s this young kid out there who
01:14:13 has an idea to fill in this hole that was left with us
01:14:17 by Sir Isaac Newton.
01:14:19 That, I hope, would be my reaction.
01:14:23 I have a suspicion.
01:14:24 I’m kind of a mathematical creature.
01:14:29 I was four years old when I first
01:14:30 decided that science was what I wanted to do with my life.
01:14:33 And so if my personality back then was like it is now,
01:14:38 I think it’s probably likely I would
01:14:41 want to have studied his mathematics.
01:14:43 What was a piece of mathematics that he was
01:14:45 using to make this prediction?
01:14:47 Because he didn’t actually create that mathematics.
01:14:50 That mathematics was created roughly 50 years
01:14:52 before he lived.
01:14:53 He’s the person who harnessed it in order
01:14:56 to make a prediction.
01:14:57 In fact, he had to be taught this mathematics by a friend.
01:15:00 So this is in our book.
01:15:03 So putting myself in that time, I would want to, like I said,
01:15:08 I think I would feel excitement.
01:15:09 I would want to know what the mathematics is.
01:15:10 And then I would want to do the calculations myself.
01:15:13 Because one thing that physics is all about
01:15:16 is that you don’t have to take anybody’s word for anything.
01:15:19 You can do it yourself.
01:15:20 It does seem that mathematics is a little bit more
01:15:23 tolerant of radical ideas, or mathematicians,
01:15:25 or people who find beauty in mathematics.
01:15:31 All the white questions have no good answer.
01:15:33 But let me ask, why do you think Einstein never
01:15:35 got the Nobel Prize for general relativity?
01:15:38 He got it for the photoelectric effect.
01:15:40 That is correct.
01:15:41 Well, first of all, that’s something
01:15:42 that is misunderstood about the Nobel Prize in physics.
01:15:46 The Nobel Prize in physics is never
01:15:48 given for purely proposing an idea.
01:15:54 It is always given for proposing an idea that
01:15:57 has observational support.
01:15:59 So he could not get the Nobel Prize
01:16:02 for either special relativity nor general relativity,
01:16:05 because the provisions that Alfred Nobel left for the award
01:16:08 prevent that.
01:16:11 But after it’s been validated, can he not get it then, or no?
01:16:16 Yes, but remember the validation doesn’t really
01:16:19 come until the 1920s.
01:16:21 But that’s why they invented the second Nobel Prize.
01:16:24 I mean, Marie Curie, you can get a second Nobel Prize
01:16:28 for one of the greatest theories in physics.
01:16:31 So let’s be clear on this.
01:16:33 The theory of general relativity had its critics
01:16:39 even up until the 50s.
01:16:43 So if the committee had wanted to give
01:16:47 the prize for general relativity,
01:16:50 there were vociferous critics of general relativity
01:16:54 up until the 50s.
01:16:56 Einstein died in 1955.
01:16:59 What lessons do you draw from the story you tell in the book,
01:17:04 from general relativity, from the radical nature
01:17:07 of the theory, to looking at the future of string theory?
01:17:12 Well, I think that the string theorists are probably
01:17:14 going to retrace this path.
01:17:17 But it’s going to be far longer and more torturous,
01:17:20 in my opinion.
01:17:22 String theory is such a broad and deep development
01:17:29 that, in my opinion, when it becomes acceptable,
01:17:34 it’s going to be because of a confluence of observations.
01:17:38 It’s not going to be a single observation.
01:17:40 And I have to tell you that, so I gave a seminar here
01:17:44 yesterday at MIT.
01:17:46 And it’s on an idea I have about how string theory can
01:17:50 leave signatures in the cosmic microwave background, which
01:17:53 is an astrophysical structure.
01:17:56 And so if those kinds of observations are borne out,
01:18:01 if perhaps other things related to the idea of supersymmetry
01:18:05 are borne out, those are going to be the first powerful
01:18:08 observationally based pieces of evidence that
01:18:12 will begin to do what the Eddington expedition did
01:18:18 in 1919.
01:18:19 But that may take several decades.
01:18:22 Do you think there will be Nobel prizes given
01:18:25 for string theory?
01:18:26 No, because I think it will exceed normal human lifetimes.
01:18:34 But there are other prizes that are given.
01:18:38 I mean, there is something called the Breakthrough Prize.
01:18:42 There’s a Russian immigrant, a Russian American immigrant
01:18:45 named Yuri Milner, I believe his name,
01:18:48 started this wonderful prize called the Breakthrough Prize.
01:18:53 It’s three times as much money as the Nobel Prize.
01:18:56 And it gets awarded every year.
01:18:58 And so something like one of those prizes
01:19:00 is likely to be garnered at some point far earlier
01:19:04 than a Nobel award.
01:19:07 Jumping around a few topics.
01:19:09 While you were at Caltech, you’ve
01:19:11 gotten to interact, I believe, with Richard Feynman,
01:19:15 I have to ask.
01:19:16 Yes, Richard Feynman, indeed.
01:19:19 Do you have any stories that stand out
01:19:20 in your memory of that time?
01:19:21 I have a fair number of stories, but I’m not
01:19:23 prepared to tell them.
01:19:24 They’re not all politically correct.
01:19:26 Let me see.
01:19:28 Let me just say, I’ll say the following.
01:19:31 Richard Feynman, if you’ve ever read
01:19:33 some of the books about him, in particular,
01:19:36 there’s a book called Surely You’re Joking, Mr. Feynman.
01:19:38 There’s a series of books that starts with Surely You’re
01:19:42 Joking, Mr. Feynman.
01:19:43 And I think the second one may be something like What Do You
01:19:45 Care What They Say or something.
01:19:47 I mean, the titles are all, there are three of them.
01:19:49 When I read those books, I was amazed at how accurately
01:19:53 those books portrayed the man that I interacted with.
01:19:57 He was irreverent, he was fun, he was deeply intelligent,
01:20:01 he was deeply human.
01:20:03 And those books tell that story very effectively.
01:20:07 Even just those moments, how did they
01:20:09 affect you as a physicist?
01:20:12 Well, one of the, well, it’s funny because one
01:20:15 of the things that, I didn’t hear Feynman say this,
01:20:20 but one of the things that is reported that he said
01:20:25 is if you’re in a bar stool as a physicist,
01:20:29 and you can’t explain to the guy on the bar stool
01:20:31 next to you what you’re doing, you
01:20:33 don’t understand what you’re doing.
01:20:35 And there’s a lot of that that I think is correct,
01:20:40 that when you truly understand something as complicated
01:20:47 as string theory, when it’s in its fully formed final
01:20:53 development, it should be something
01:20:55 you could tell to the person on the bar stool next to you.
01:20:58 And that’s something that affects the way I do science,
01:21:03 quite frankly.
01:21:04 It also affects the way I talk to the public about science.
01:21:08 It’s one of my mantras that I keep deeply,
01:21:11 and try to keep deeply before me when I appear in public fora
01:21:15 speaking about physics in particular and science
01:21:20 in general.
01:21:21 It’s also something that Einstein
01:21:22 said in a different way.
01:21:23 He said he had these two different formulations.
01:21:27 One of them is when the answer is simple, it’s God speaking.
01:21:31 And the other thing that he said was
01:21:33 that what he did in his work was simply
01:21:37 the distillation of common sense,
01:21:40 that you distill down to something.
01:21:43 And he also said you make things as simple as possible
01:21:45 but no simpler.
01:21:47 So all of those things, and certainly this attitude for me
01:21:50 first seeing this was exemplified
01:21:53 by being around Richard Feynman.
01:21:55 So in all your work, you’re always
01:21:56 searching for the simplicity, for the simple, clear.
01:21:59 I am, ultimately.
01:22:00 Ultimately, I am.
01:22:01 You served President Barack Obama’s Council of Advisors
01:22:05 in Science and Technology.
01:22:07 For seven years, yes.
01:22:08 For seven years with Eric Schmidt
01:22:11 and several other brilliant people?
01:22:13 Met Eric for the first time in 2009
01:22:17 when the council was called together.
01:22:19 Yeah, I’ve seen pictures of you in that room.
01:22:21 I mean, there’s a bunch of brilliant people.
01:22:23 It kind of looks amazing.
01:22:24 What was that experience like, being called
01:22:27 upon that kind of service?
01:22:29 So let me go back to my father, first of all.
01:22:31 I earlier mentioned that my father served 27 years
01:22:34 in the US Army, starting in World War II.
01:22:37 He went off in 1942, 43 to fight against the fascists.
01:22:42 He was part of the supply corps that
01:22:45 supplied General Patton as the tanks rolled
01:22:47 across Western Europe, pushing back the forces of Nazism
01:22:51 to meet up with our Russian comrades
01:22:54 who were pushing the Nazis starting in Stalingrad.
01:22:59 And the Second World War is actually
01:23:02 a very interesting piece of history
01:23:06 to know from both sides.
01:23:08 Here in America, we typically don’t.
01:23:09 But I’ve actually studied history as an adult.
01:23:12 So I actually know sort of the whole story.
01:23:14 And on the Russian side, we don’t know the Americans.
01:23:16 We weren’t taught the American side of the story.
01:23:19 I know.
01:23:20 I have many Russian friends, and we’ve
01:23:22 had this conversation on many occasions.
01:23:24 It’s fascinating.
01:23:25 But you know, like General Zhukov, for example,
01:23:27 was something that you wouldn’t know about,
01:23:28 but you might not know about a Patton.
01:23:30 But you’re right.
01:23:30 So Georgy Zhukov or Rokossovsky, I mean,
01:23:34 there’s a whole list of names that I’ve
01:23:36 learned in the last 15 or 20 years looking
01:23:39 at the Second World War.
01:23:41 So your father was in the midst of that,
01:23:44 probably one of the greatest wars in history.
01:23:46 In the history of our species.
01:23:49 And so the idea of service comes to me essentially
01:23:54 from that example.
01:23:57 So in 2009, when I first got a call from a Nobel laureate
01:24:06 actually in biology, Harold Varmus,
01:24:09 I was on my way to India, and I got this email message,
01:24:13 and he said he needed to talk to me.
01:24:15 And I said, OK, fine, we can talk.
01:24:18 Got back to States I didn’t hear from him.
01:24:20 We went through several cycles of this, sending me a message,
01:24:22 I want to talk to you, and then him never contacting us.
01:24:24 Finally, I was on my way to give a physics presentation
01:24:28 at the University of Florida in Gainesville,
01:24:29 and Jess had stepped off a plane,
01:24:34 and my mobile phone went off, and it was Harold.
01:24:37 And so I said, Harold, why do you keep sending me messages
01:24:40 that you want to talk but you never call?
01:24:43 And he said, well, I’m sorry, things have been hectic
01:24:45 and da, da, da, da, da.
01:24:47 And then he said, if you were offered the opportunity
01:24:51 to serve on the US President’s Council of Advisors
01:24:55 on Science and Technology, what would be your answer?
01:24:59 I was amused at the formulation of the question,
01:25:02 because it’s clear there’s a purpose of why the question is
01:25:06 asked that way.
01:25:07 But then he made it clear to me he wasn’t joking.
01:25:12 And literally, one of the few times in my life,
01:25:15 my knees went weak and I had to hold myself up
01:25:19 against a wall so that I didn’t fall over.
01:25:23 I doubt if most of us who have been the beneficiaries
01:25:28 of the benefits of this country,
01:25:31 when given that kind of opportunity, could say no.
01:25:34 And I know I certainly couldn’t say no.
01:25:37 I was frightened out of my wits because I had never,
01:25:43 although I have, my career in terms of policy recommendations
01:25:50 is actually quite long, it goes back to the 80s,
01:25:52 but I had never been called upon to serve as an advisor
01:25:57 to a president of the United States.
01:26:00 And it was very scary, but I did not feel that I could say no
01:26:06 because I wouldn’t be able to sleep with myself at night
01:26:10 saying that I chickened out or whatever.
01:26:14 And so I took the plunge and we had a pretty good run.
01:26:19 There are things that I did in those seven years
01:26:23 of which I’m extraordinarily proud.
01:26:28 One of the ways I tell people is if you’ve ever seen
01:26:30 that television cartoon called Schoolhouse Rock,
01:26:34 there’s this one story about how a bill becomes a law.
01:26:37 And I’ve kind of lived that.
01:26:38 There are things that I did
01:26:41 that have now been codified in US law.
01:26:44 Not everybody gets a chance to do things like that in life.
01:26:47 What do you think is the, science and technology,
01:26:50 especially in American politics,
01:26:53 we haven’t had a president who’s an engineer or a scientist.
01:26:58 What do you think is the role of a president like President Obama
01:27:01 in understanding the latest ideas in science and tech?
01:27:05 What was that experience like?
01:27:06 Well, first of all, I’ve met other presidents
01:27:09 beside President Obama.
01:27:10 He is the most extraordinary president
01:27:12 that I’ve ever encountered.
01:27:15 Despite the fact that he went to Harvard.
01:27:18 When I think about President Obama,
01:27:21 he is a deep mystery to me.
01:27:23 In the same way perhaps that the universe is a mystery.
01:27:27 I don’t really understand how that constellation
01:27:29 of personality traits could come to fit
01:27:34 within a single individual.
01:27:35 But I saw them for seven years.
01:27:38 So I’m convinced that I wasn’t seeing fake news.
01:27:41 I was seeing real data.
01:27:42 He was just an extraordinary man.
01:27:44 And one of the things that was completely clear
01:27:48 was that he was not afraid and not intimidated
01:27:55 to be in a room of really smart people.
01:27:58 I mean, really smart people.
01:28:00 That he was completely comfortable in asking
01:28:06 some of the world’s greatest experts,
01:28:07 what do I do about this problem?
01:28:09 And it wasn’t that he was going to just take the problem
01:28:12 and it wasn’t that he was going to just take their answer,
01:28:15 but he would listen to the advice.
01:28:18 And that to me was extraordinary.
01:28:21 As I said, I’ve been around other executives
01:28:23 and I’ve never seen one quite like him.
01:28:27 He’s an extraordinary learner, is what I observed.
01:28:30 And not just about science.
01:28:32 He has a way of internalizing information in real time
01:28:36 that I’ve never seen in a politician before.
01:28:39 Even in extraordinarily complicated situations.
01:28:42 Even scientific ideas.
01:28:43 Scientific or non scientific.
01:28:45 Complicated ideas don’t have to be scientific ideas.
01:28:47 But I have, like I said, seen him in real time
01:28:50 process complicated ideas with a speed that was stunning.
01:28:54 In fact, he shocked the entire council.
01:28:56 I mean, we were all stunned at his capacity
01:29:01 to be presented with complicated ideas
01:29:06 and then to wrestle with them and internalize them.
01:29:08 And then come back, more interestingly enough,
01:29:11 come back with really good questions to ask.
01:29:14 I’ve noticed this in an area that I understand more
01:29:17 of artificial intelligence.
01:29:19 I’ve seen him integrate information
01:29:21 about artificial intelligence and then come out
01:29:24 with these kind of Richard Feynman like insights.
01:29:27 That’s exactly right.
01:29:28 And as I said, those of us who have been in that position,
01:29:32 it is stunning to see it happen because you don’t expect it.
01:29:35 Yeah, he takes what, for a lot of sort of graduate students,
01:29:40 takes like four years in a particular topic
01:29:42 and he just does it in a few minutes.
01:29:43 He sees it very naturally.
01:29:46 You’ve mentioned that you would love
01:29:47 to see experimental validation of super strength theory
01:29:51 before you shove.
01:29:53 Before I shuffle off this mortal coil.
01:29:56 Which the poetry of that reference
01:29:58 made me smile when I saw it.
01:30:00 You know, people actually misunderstand it
01:30:02 because it’s not what, it doesn’t mean
01:30:03 what we generally take it to mean colloquially.
01:30:06 But it’s such a beautiful expression.
01:30:08 Yeah, it is.
01:30:09 It’s from the Hamlet, to be or not to be speech.
01:30:13 Which I still don’t understand what that’s about.
01:30:15 But so many interpretations.
01:30:18 Anyway, what are the most exciting problems in physics
01:30:22 that are just within our reach of understanding
01:30:25 and maybe solve the next few decades
01:30:27 that you may be able to see?
01:30:29 So in physics, you limited it to physics.
01:30:32 Physics, mathematics, this kind of space of problems
01:30:36 that fascinate you.
01:30:39 Well, the one that looks on the immediate horizon
01:30:41 like we’re gonna get to is quantum computing.
01:30:45 And that’s gonna, if we actually get there,
01:30:47 that’s gonna be extraordinarily interesting.
01:30:50 Do you think that’s a fundamentally problem of theory
01:30:53 or is it now in the space of engineering?
01:30:55 It’s in the space of engineering.
01:30:57 I was out at a Q station, as you may know,
01:31:01 Microsoft has this research facility in Santa Barbara.
01:31:06 I was out there a couple of months in my capacity
01:31:09 as a vice president of American Physical Society.
01:31:12 And I had some things that were like lectures
01:31:15 and they were telling me what they were doing.
01:31:18 And it sure sounded like they knew what they were doing
01:31:20 and that they were close to major breakthroughs.
01:31:24 Yeah, that’s a really exciting possibility there.
01:31:26 But back to Hamlet, do you ponder mortality,
01:31:31 your own mortality?
01:31:32 Nope, my mother died when I was 11 years old.
01:31:35 And so I immediately knew what the end of the story was
01:31:41 for all of us.
01:31:42 As a consequence, I’ve never spent a lot of time
01:31:45 thinking about death.
01:31:47 It’ll come in its own good time.
01:31:49 And sort of to me, the job of every human
01:31:54 is to make the best and the most of the time
01:31:56 that’s given to us in order not for our own selfish gain,
01:32:02 but to try to make this place a better place
01:32:04 for someone else.
01:32:08 And on the why of life, why do you think we are?
01:32:13 I have no idea and I never even worried about it.
01:32:17 For me, I have an answer, a local answer.
01:32:20 The apparent why for me was
01:32:22 because I’m supposed to do physics.
01:32:25 But it’s funny because there’s so many other
01:32:29 quantum mechanically speaking possibilities in your life,
01:32:33 such as being an astronaut, for example.
01:32:35 So you know about that, I see.
01:32:36 Well, like Einstein and the vicissitudes
01:32:45 that prevented the 1914 measurement of starlight vending,
01:32:50 the universe is constructed in such a way
01:32:53 that I didn’t become an astronaut, which would have,
01:32:56 for me, I would have faced the worst choice in my life,
01:33:00 whether I would try to become an astronaut
01:33:04 or whether I would try to do theoretical physics.
01:33:07 Both of these dreams were born
01:33:09 when I was four years old simultaneously.
01:33:11 And so I can’t imagine how difficult
01:33:14 that decision would have been.
01:33:16 The universe helped you out on that one.
01:33:19 Not only in that one, but in many ones.
01:33:21 It helped me out by allowing me to pick the right dad.
01:33:25 Is there a day in your life you could relive
01:33:27 because it made you truly happy?
01:33:29 What day would that be if you could just look back?
01:33:32 Being a theoretical physicist
01:33:35 is like having Christmas every day.
01:33:39 I have lots of joy in my life.
01:33:43 The moments of invention, the moments of ideas, revelation.
01:33:46 Yes, the only thing that exceed them are
01:33:49 some family experiences like when my kids were born
01:33:53 and that kind of stuff, but they’re pretty high up there.
01:33:57 Well, I don’t see a better way to end it, Jim.
01:34:00 Thank you so much.
01:34:01 It was a huge honor talking to you today.
01:34:03 This worked out better than I thought.
01:34:05 I’m glad to hear it.
01:34:35 And now, let me leave you with some words of wisdom
01:34:38 from the great Albert Einstein for the rebels among us.
01:34:42 Unthinking respect for authority
01:34:45 is the greatest enemy of truth.
01:34:48 Thank you for listening and hope to see you next time.