Transcript
00:00:00 The following is a conversation with Barry Barish, a theoretical physicist at Caltech
00:00:05 and the winner of the Nobel Prize in Physics for his contributions to the LIGO detector
00:00:11 and the observation of gravitational waves. LIGO, or the Laser Interferometer Gravitational Wave
00:00:18 Observatory, is probably the most precise measurement device ever built by humans.
00:00:24 It consists of two detectors with four kilometer long vacuum chambers situated three thousand
00:00:31 kilometers apart, operating in unison to measure a motion that is ten thousand times smaller than
00:00:38 the width of a proton. It is the smallest measurement ever attempted by science,
00:00:44 a measurement of gravitational waves caused by the most violent and cataclysmic events
00:00:50 in the universe, occurring over tens of millions of light years away.
00:00:55 To support this podcast, please check out our sponsors in the description.
00:00:59 This is the Lex Friedman Podcast and here is my conversation with Barry Barish.
00:01:31 Yeah, that memory is kind of something I use to illustrate something I think is common in science,
00:01:42 that people that do science somehow have maintained something that kids always have.
00:01:49 A small kid, eight years old or so, asks you so many questions usually, typically, that you
00:01:57 consider them pests. You tell them to stop asking so many questions. And somehow our system manages
00:02:05 to kill that in most people. So in school, we make people study and do their things,
00:02:13 but not to pester them by asking too many questions. And I think, not just myself,
00:02:21 but I think it’s typical of scientists like myself that have somehow escaped that. Maybe
00:02:28 we’re still children or maybe we somehow didn’t get it beaten out of us. But I teach it in college
00:02:36 level and it’s, to me, one of the biggest deficits is the lack of curiosity, if you want,
00:02:42 that we’ve beaten out of them because I think it’s an innate human quality.
00:02:46 Is there some advice or insights you can give to how to keep that flame of curiosity going?
00:02:50 I think it’s a problem of both parents and that parents should realize that’s a great quality we
00:02:57 have. That you’re curious and that’s good. Instead, we have expressions like curiosity
00:03:03 killed the cat and more. But basically, it’s not thought to be a good thing. Curiosity
00:03:14 killed the cat means if you’re too curious, you get in trouble.
00:03:16 I don’t like cats anyway, so maybe it’s a good thing.
00:03:21 Yeah. That, to me, needs to be solved, really, in education and in homes. It’s a realization
00:03:28 that there’s certain human qualities that we should try to build on and not destroy. One of
00:03:34 them is curiosity. Anyway, back to me and curiosity. I was a pest and asked a lot of
00:03:40 questions. My father generally could answer them at that age. And the first one I remember that he
00:03:46 couldn’t answer was not a very original question, but basically that ice is made out of water,
00:03:56 and so why does it float on water? He couldn’t answer it. It may not have been the first
00:04:05 question. It’s the first one that I remember. And that was the first time that I realized that
00:04:11 to learn and answer your own curiosity or questions, there’s various mechanisms. In
00:04:17 this case, it was going to the library or asking people who know more and so forth. But
00:04:23 eventually, you do it by what we call research. But it’s driven by, hopefully, you ask good
00:04:33 questions. If you ask good questions and you have the mechanism to solve them, then you do what I
00:04:37 do in life, basically, not necessarily physics. And it’s a great quality in humans, and we should
00:04:45 nurture it. Do you remember any other kind of in high school, maybe early college, more basic
00:04:52 physics ideas that sparked your curiosity or mathematics or science in general?
00:04:57 I wasn’t really into science until I got to college, to be honest with you. But
00:05:02 just staying with water for a minute, I remember that I was curious what happens to water. It rains
00:05:14 and there’s water in a wet pavement, and then the pavement dries out. What happened to this
00:05:19 water that came down? And I didn’t know that much. And then eventually, I learned in chemistry or
00:05:24 something, water is made out of hydrogen and oxygen. Those are both gases. So how the heck
00:05:29 does it make this substance? It’s liquid. Yeah, so that has to do with states of matter.
00:05:39 I know perhaps LIGO and the thing for which you’ve gotten the Nobel Prize and the things
00:05:46 much of your life work perhaps was a happy accident in some sense in the early days. But
00:05:53 is there a moment where you looked up to the stars and also, the same way you wondered about water,
00:05:57 wondered about some of the things that are out there in the universe?
00:06:01 Oh, yeah, I think everybody looks and is in awe and is curious about what it is out there. And
00:06:10 as I learned more, I learned, of course, that we don’t know very much about what’s there. And the
00:06:17 more we learn, the more we know we don’t know. I mean, we don’t know what the majority of anything
00:06:22 is out there. It’s all what we call dark matter and dark energy. And that’s one of the big
00:06:27 questions. When I was a student, those weren’t questions. So we even know less, in a sense,
00:06:33 the more we look. So of course, I think that’s one of the areas that almost it’s universal.
00:06:43 People see the sky, they see the stars and they’re beautiful and see it looks different
00:06:49 on different nights. And it’s a curiosity that we all have.
00:06:54 What are some questions about the universe that in the same way that you felt about the ice
00:07:01 that today? You mentioned to me offline, you’re teaching a course on the frontiers of science,
00:07:07 frontiers of physics. What are some questions outside the ones we’ll probably talk about that
00:07:12 kind of, yeah, fill you with the, get your flame of curiosity up and firing up, you know,
00:07:23 fill you with awe? Well, first, I’m a physicist, not an astronomer. So I’m interested in the
00:07:29 physical phenomenon, really. So the question of dark matter and dark energy, which we probably
00:07:36 won’t talk about, our recent last 20, 30 years, certainly dark energy. Dark energy is a complete
00:07:45 puzzle. It goes against what you will ask me about, which is general relativity and Einstein’s
00:07:53 general relativity. It basically takes something that he thought was what he called a constant,
00:08:00 which isn’t. And if that’s even the right theory, and it represents most of the universe. And then
00:08:09 we have something called dark matter, and there’s good reason to believe it might be an exotic form
00:08:14 of particles. And that is something I’ve always worked on, on particle accelerators and so forth.
00:08:22 And it’s a big puzzle, what it is. It’s a bit of a cottage industry in that there’s lots and lots
00:08:28 of searches, but it may be a little bit like, you know, looking for a treasure under rocks or
00:08:34 something. You don’t, it’s hard to, we don’t have really good guidance, except that we have very,
00:08:40 very good information that is pervasive and it’s there. And that it’s probably particles, small,
00:08:49 that the evidence is all of those things. But then the most logical solution doesn’t seem to work,
00:08:57 something called supersymmetry. And do you think the answer could be something very complicated?
00:09:06 You know, I like to hope that, think that most things that appear complicated are actually
00:09:12 simple if you really understand them. I think we just don’t know at the present time, and it isn’t
00:09:19 something that affects us. It does affect, it affects how the stars go around each other and so
00:09:26 forth, because we detect that there’s missing gravity, but it doesn’t affect everyday life at
00:09:32 all. I tend to think and expect maybe, and that the answers will be simple. We just haven’t found
00:09:42 it yet. Do you think those answers might change the way we see other sources of gravity, black holes,
00:09:49 the way we see the parts of the universe that we do study? It’s conceivable. The black holes that
00:09:57 we’ve found in our experiment, we’re trying now to understand the origin of those. It’s conceivable,
00:10:06 but doesn’t seem the most likely that they were primordial, that is, they were made at the
00:10:11 beginning. And in that sense, they could represent at least part of the dark matter.
00:10:16 So there can be connections, dark black holes or how many there are, how much of the mass they
00:10:23 encompass is still pretty primitive. We don’t know. So before I talk to you more about black holes,
00:10:28 let me take a step back to, I actually went to high school in Chicago and would go to
00:10:34 take classes at Fermilab, watch the buffalo and so on. So let me ask about, you mentioned that Enrico
00:10:43 for me was somebody who was inspiring to you in a certain kind of way. Why is that? Can you speak
00:10:50 to that? Sure. He was amazing, actually. He’s the last, I’ll come to the reason in a minute, but
00:11:00 he had a big influence on me at a young age. But he was the last physicist of note that was both
00:11:11 an experimental physicist and a theorist at the same time. And he did two amazing things within
00:11:17 months in 1933. We didn’t really know what the nucleus was, what radioactive decay was,
00:11:29 what beta decay was when electrons come out of a nucleus. And near the end of 1933, the neutron had
00:11:42 just been discovered. And that meant that we knew a little bit more about what the nucleus is, that
00:11:47 it’s made out of neutrons and protons. The neutron wasn’t discovered till 1932. And then once we
00:11:54 discovered that there was a neutron and proton and they made the nucleus and then their electrons
00:12:00 that go around, the basic ingredients were there. And he wrote down not only just the theory,
00:12:08 a theory, but a theory that lasted decades and has only been improved on of beta decay, that is,
00:12:16 the radiation. He did this, came out of nowhere, and it was a fantastic theory. He submitted it
00:12:24 to Nature magazine, which was the primary best place to publish even then. And it got rejected
00:12:33 as being too speculative. And so he went back to his drawing board in Rome where he was,
00:12:42 added some to it, made it even longer, because it’s really a classic article, and then published
00:12:48 it in the local Italian journal for physics and the German one. At the same time, in January of
00:12:58 1932, Giulio and Curie, for the first time, saw artificial radioactivity. This was an important
00:13:07 discovery because radioactivity had been discovered much earlier. They had x rays and you
00:13:14 shouldn’t be using them, but there was radioactivity. People knew it was useful for medicine.
00:13:21 But radioactive materials are hard to find, and so it wasn’t prevalent. But if you could make them,
00:13:26 they had great use. And Giulio and Curie were able to bombard aluminum or something with alpha
00:13:35 particles and find that they excited something that decayed and had some half life and so forth,
00:13:44 meaning it was artificial version, or let’s call it not a natural version, an induced version of
00:13:51 radioactive materials. And Fermi somehow had the insight, and I still can’t see where he got it,
00:14:05 that the right way to follow that up was not using charged particles like alphas and so forth,
00:14:12 but use these newly discovered neutrons as the bombarding particle. It seemed impossible
00:14:19 they barely had been seen. It was hard to get very many of them. But it had the advantage that
00:14:26 they’re not charged, so they go right into the nucleus. And that turned out to be the experimental
00:14:35 work that he did that won him the Nobel Prize. And it was the first step in fission, discovery
00:14:42 of fission. And he did this two completely different things, an experiment that was a great
00:14:50 idea and a tremendous implementation, because how do you get enough neutrons? And then he learned
00:14:58 quickly that not only do you want neutrons, but you want really slow ones. He learned that
00:15:04 experimentally, and he learned how to make slow ones, and then they were able to go through the
00:15:09 go through the periodic table and make lots of particles. He missed on fission at the moment,
00:15:16 but he had the basic information, and then fission follows soon after that.
00:15:21 Forgive me for not knowing, but is the birth of the idea of bombarding with neutrons,
00:15:29 is that an experimental idea? Was it born out of an experiment? Did he just observe something,
00:15:35 or is this an Einstein style idea where you come up from basic intuition?
00:15:40 I think it took a combination, because he realized that neutrons had a characteristic
00:15:46 that would allow them to go all the way into the nucleus when we didn’t really understand
00:15:53 what the structure was of all this. So that took an understanding or recognition of the physics
00:16:00 itself of how a neutron interacts compared to, say, an alpha particle that Julio and Curie had
00:16:06 used. And then he had to invent a way to have enough neutrons, and he had a team of associates,
00:16:16 and he pulled it off quite quickly. So it was pretty astounding.
00:16:21 And probably, maybe you can speak to it, his ability to put together the engineering aspects
00:16:28 of great experiments and doing the theory, they probably fed each other. I wonder,
00:16:33 can you speak to why we don’t see more of that? Is that just really difficult to do?
00:16:38 It’s difficult to do. Yeah, I think in both theory and experiment in physics anyway,
00:16:47 it was conceivable if you had the right person to do it, and no one’s been able to do it since. So
00:16:52 I had the dream that that was what I was going to be like, Fermi.
00:16:56 But you love both sides of it, the theory. Yeah, I never liked the idea that you did
00:17:01 experiments without really understanding the theory, or the theory should be related
00:17:05 very closely to experiments. And so I’ve always done experimental work that was closely related
00:17:11 to the theoretical ideas. I think I told you I’m Russian,
00:17:16 so I’m going to ask some romantic questions. But is it tragic to you that he’s seen as the
00:17:23 architect of the nuclear age, that some of his creations led to potentially, some of his work
00:17:30 has led to potentially still the destruction of the human species, some of the most destructive
00:17:38 weapons? Yeah, I think even more general than him, I gave you all the virtues of curiosity a few
00:17:47 minutes ago. There’s an interesting book called The Ratchet of Curiosity. A ratchet is something
00:17:52 that goes in one direction. And that is written by a guy who’s probably a sociologist or philosopher
00:17:59 or something. And he picks on this particular problem, but other ones. And that is the danger
00:18:06 of knowledge, basically. You’re curious, you learn something. So it’s a little bit like
00:18:11 curiosity killed the cat. You have to be worried about whether you can handle new information that
00:18:16 you get. So in this case, the new information had to do with really understanding nuclear physics.
00:18:22 And that information, maybe we didn’t have the sophistication to know how to keep it under
00:18:30 control. And Fermi himself was a very apolitical person. So he wasn’t very driven by, or at least
00:18:41 he appears in all of his writing, the writing of his wife, the interactions that others had with
00:18:46 him. Either he avoided it all or he was pretty apolitical. I mean, he just saw the world through
00:18:52 kind of the lens of a scientist. But he asked if it’s tragic. The bomb was tragic, certainly on
00:19:01 Japan. And he had a role in that. So I wouldn’t want it as my legacy, for example. But brought
00:19:08 it to the human species that it’s the ratchet of curiosity that we do stuff just to see what
00:19:19 happens. That curiosity, that in sort of my area of artificial intelligence, that’s been a concern.
00:19:27 On a small scale, on a silly scale, perhaps currently, there’s constantly unintended
00:19:33 consequences. You create a system and you put it out there and you have intuitions about how
00:19:40 it will work. You have hopes how it will work, but you put it out there just to see what happens.
00:19:44 And in most cases, because artificial intelligence is currently not super powerful,
00:19:49 it doesn’t create a large scale negative effects, but that same curiosity as it progresses might
00:19:58 lead to something that destroys the human species. And the same may be true for bioengineering.
00:20:04 There’s people that engineer viruses to protect us from viruses to see how close is this to
00:20:15 mutating so it can jump to humans or engineering defenses against those. And it seems exciting and
00:20:25 the application, the positive applications are really exciting at this time, but we don’t think
00:20:30 about how that runs away in decades to come. Yeah. And I think it’s the same idea as this
00:20:36 little book, The Ratchet of Science, The Ratchet of Curiosity. I mean, whether you pursue,
00:20:46 take curiosity and let artificial intelligence or machine learning run away with having its
00:20:53 solutions to whatever you want, or we do it, it’s, I think, a similar consequence.
00:20:59 I think from what I’ve read about Enrico Fermi, he became a little bit cynical about the human
00:21:07 species towards the end of his life, both having observed what he observed.
00:21:12 Well, he didn’t write much. I mean, he died young. He died soon after the World War. There was
00:21:20 already, you know, the work by Teller to develop the hydrogen bomb. And I think he was a little
00:21:26 cynical of that, you know, pushing it even further and rising tensions between the Soviet Union and
00:21:32 the U.S. and looked like an endless thing. So, but he didn’t say very much, but a little bit,
00:21:38 as you said. Yeah, there’s a few clips to sort of maybe picked on a bad mood, but in a sense that
00:21:45 almost like a sadness, a melancholy sadness to a hope that waned a little bit about that perhaps we
00:21:55 can do, like this curious species can find the way out. Well, especially, I think, people who
00:22:02 worked like he did at Los Alamos and spent years of their life somehow had to convince themselves
00:22:08 that dropping these bombs would bring lasting peace and that it didn’t. Yeah. As a small,
00:22:18 interesting aside, it’d be interesting to hear if you have opinions on this. His name is also
00:22:23 attached to the Fermi Paradox, which asks if there is a, you know, it’s a very interesting question,
00:22:30 which is if it does seem if you sort of reason basically that there should be a lot of alien
00:22:37 civilizations out there. If the human species, if Earth is not that unique by basic, no matter the
00:22:46 values you pick, it’s likely that there’s a lot of alien civilizations out there. And if that’s the
00:22:52 case, why have they not at least obviously visited us or sent us loud signals that everybody can
00:22:59 hear? Fermi’s quoted as saying, sitting down at lunch, I think it was with Teller and Herb York,
00:23:09 who was kind of one of the fathers of the atomic bomb. And he sat down and he said something like,
00:23:15 where are they? Which meant, where are these other? And then he did some numerology where he
00:23:25 calculated, you know, how many, what they knew about how many galaxies there are and how many
00:23:31 stars and how many planets then are like the Earth and blah, blah, blah. That’s been done much
00:23:37 better by somebody named Drake. And so, people usually refer to the, I don’t know whether it’s
00:23:42 called the Drake formula or something, but it has the same conclusion. The conclusion is it would
00:23:47 be a miracle if there weren’t other, you know, the statistics are so high that how can we be
00:23:53 singular and separate? So, probably there is, but there’s almost certainly life somewhere. Maybe
00:24:04 there was even life on Mars a while back, but intelligent life, probably. So, you know, the
00:24:13 statistics say that communicating with us, I think that it’s harder than people think. We might not
00:24:25 know the right way to expect the communication, but all the communication that we know about
00:24:34 travels at the speed of light. And we don’t think anything can go faster than the speed of light.
00:24:41 That limits the problem quite a bit. And it makes it difficult to have any back and forth
00:24:48 communication. You could send signals like we try to or look for, but to have any communication,
00:24:54 it’s pretty hard when it has to be close enough that the speed of light would mean we could
00:25:00 communicate with each other. And I think, and we didn’t even understand that. I mean, we’re
00:25:06 an advanced civilization, but we didn’t even understand that a little more than a hundred
00:25:11 years ago. So, are we just not advanced enough? Maybe to know something about that’s the speed
00:25:22 of light. Maybe there’s some other way to communicate that isn’t based on electromagnetism.
00:25:26 I don’t know. Gravity seems to be also have the same speed. That was a principle that Einstein
00:25:33 had and something we’ve measured actually. So is it possible? I mean, so we’ll talk about
00:25:39 gravitational waves and in some sense, there’s a brainstorming going on, which is like,
00:25:48 how do we detect the signal? Like what would a signal look like and how would we detect it? And
00:25:52 that’s true for gravitational waves. That’s true for basically any physics phenomena. You have to
00:25:57 predict that that signal should exist. You have to have some kind of theory and model why that signal
00:26:02 should exist. I mean, is it possible that aliens are communicating with us via gravity? Like why
00:26:09 not? Well, yeah, it’s true. Why not? For us, it’s very hard to detect these gravitational effects.
00:26:18 They have to come from something pretty that has a lot of gravity like black holes, but we’re
00:26:24 pretty primitive at this stage. There’s very reputable physicists that look for a fifth force,
00:26:36 one that we haven’t found yet. Maybe it’s the key. What would a fifth force of physics look
00:26:44 like exactly? Well, usually they think it’s probably a longer range force than we have now.
00:26:50 But there are reputable colleagues of mine that spend their life looking for a fifth force.
00:26:56 So longer range than gravity? Yeah. Super long? It doesn’t fall off like one over r squared,
00:27:02 but maybe separately. Gravity, Newton taught us, goes like inversely one over the square of the
00:27:10 distance apart you are. So it falls pretty fast. That’s okay. So now we have a theory of what
00:27:14 consciousness is. It’s just the fifth force of physics. Yeah. There we go. That’s a good hypothesis.
00:27:24 Speaking of gravity, what are gravitational waves? Let’s maybe start from the basics.
00:27:32 We learned gravity from Newton, right? When you were young, you were told that if you jumped up,
00:27:39 the earth pulls you down. And when the apple falls out of the tree, the earth pulls it down.
00:27:47 And maybe you even asked your teacher why, but most of us accepted that. That was Newton’s
00:27:55 picture, the apple falling out of the tree. But Newton’s theory never told you why the apple
00:28:00 was attracted to the earth. That was a missing in Newton’s theory. Newton’s theory also
00:28:07 Newton recognized at least one of the two problems. I’ll tell you one of them is there’s more than
00:28:12 those, but one is why does the earth, what’s the mechanism by which the earth pulls the apple or
00:28:20 holds the moon when it goes around, whatever it is. That’s not explained by Newton, even though he
00:28:25 has the most successful theory of physics ever went 200 and some years with nobody ever seeing
00:28:31 a violation. But he accurately describes the movement of an object falling down to earth,
00:28:38 but he’s not answering why that what’s yeah, because it’s a distance. He gives a formula,
00:28:45 which it’s a product of the earth’s mass, the apple’s mass inversely proportional to the square
00:28:51 of the distance between and then the strength he called capital G, the strength he couldn’t
00:28:57 determine, but it was determined 100 years later. But no one ever saw a violation of this until a
00:29:03 possible violation, which Einstein fixed, which was very small that has to do with
00:29:08 mercury going around the sun, the orbit being slightly wrong if you calculate it by Newton’s
00:29:16 theory. But so like most theories then in physics, you can have a wonderful one like Newton’s theory.
00:29:25 It isn’t wrong. But you have to have an improvement on it to answer things that it can’t answer. And
00:29:34 in this case, Einstein’s theory is the next step. We don’t know if it’s anything like a final theory
00:29:41 or even the only way to formulate it either. But he formulated this theory, which he released in 1915.
00:29:51 He took 10 years to develop it, even though in 1905, he solved three or four of the most important
00:29:56 problems in physics in a matter of months. And then he spent 10 years on this problem before he
00:30:02 let it out. And this is called general relativity. It’s a new theory of gravity.
00:30:07 1915. In 1916, Einstein wrote a little paper where he did not do some fancy derivation.
00:30:18 Instead, he did what I would call he used his intuition, which he was very good at too. And that
00:30:30 is he noticed that if he wrote the formulas for general relativity in a particular way,
00:30:37 they looked a lot like the formulas for electricity and magnetism.
00:30:40 Being Einstein, he then took the leap that electricity and magnetism, we discovered only
00:30:46 20 years before that in the 1880s, have waves. Of course, that’s light and electromagnetic waves,
00:30:54 radio waves, everything else. So he said, if the formulas look similar, then gravity probably has
00:31:01 waves too. That’s such a big leap, by the way. I mean, maybe you could go back to the 1880s,
00:31:10 maybe you can correct me, but that just seems like a heck of a leap.
00:31:15 Yeah. And it was considered to be a heck of a leap. So first that paper was, except for this
00:31:22 intuition, was poorly written, had a serious mistake. It had a factor of two wrong in the
00:31:30 strength of gravity, which meant if we use those formulas, we would… And two years later,
00:31:37 he wrote a second paper. And in that paper, it turns out to be important for us because in that
00:31:43 paper, he not only fixed his factor of two mistake, which he never admitted, he just wrote it,
00:31:50 fixed it like he always did. And then he told us how you make gravitational waves, what makes
00:31:58 gravitational waves. And you might recall in electromagnetism, we make electromagnetic waves
00:32:05 in a simple way. You take a plus charge and minus charge, you oscillate like this, and that makes
00:32:10 the electromagnetic waves. And a physicist named Hertz made a receiver that could detect the waves
00:32:16 and put it in the next room. He saw them and moved forward and backward and saw that it was wave like.
00:32:22 So Einstein said, it won’t be a dipole like that, it’ll be a four pole thing. And that’s what it’s
00:32:30 called, it’s called a quadrupole moment that gives the gravitational wave. So that again, by insight,
00:32:36 not by derivation. That set the table for what you needed to do to do it. At the same time,
00:32:43 in the same year, Schwarzschild, not Einstein, said there were things called black holes. So
00:32:49 it’s interesting that that came the same. So what year was that? 1915. It was in parallel…
00:32:56 Well, I should probably know this, but did Einstein not have an intuition that there
00:33:01 should be such things as black holes? That came from Schwarzschild. Oh, interesting.
00:33:07 Yeah. So Schwarzschild, who was a German theoretical physicist, he got killed in the war,
00:33:14 I think, in the First World War, two years later or so. He’s the one that proposed black holes,
00:33:21 that there were black holes. That feels like a natural conclusion of general relativity, no? Or
00:33:27 is that not? Well, it may seem like it, but I don’t know about a natural conclusion. It’s a result
00:33:34 of curved space time though. Right. But it’s such a weird result that you might have to…
00:33:40 It’s a special… Yeah, it’s a special case. Yeah. So I don’t know. Anyway, Einstein then,
00:33:48 an interesting part of the story is that Einstein then left the problem. Most physicists,
00:33:54 because it really wasn’t derived, he just made this, didn’t pick up on it or general relativity
00:34:01 much because quantum mechanics became the thing in physics. And Einstein only picked up this
00:34:10 problem again after he immigrated to the US. So he came to the US in 1932. And I think in 1934 or
00:34:18 1935, he was working with another physicist called Rosen, who he did several important works with,
00:34:24 and they revisited the question. And they had a problem that most of us as students always had,
00:34:32 that study general relativity. General relativity is really hard because it’s four dimensional
00:34:37 instead of three dimensional. And if you don’t set it up right, you get infinities,
00:34:42 which don’t belong there. We call them coordinate singularities as a name. But if you get these
00:34:49 infinities, you don’t get the answers you want. And he was trying to derive now general relativity
00:34:57 from general relativity, gravitational waves. And in doing it, he kept getting these infinities.
00:35:04 And so he wrote a paper with Rosen that he submitted to our most important journal,
00:35:10 Physical Review Letters. And that when it was submitted to Physical Review Letters,
00:35:17 it was entitled, Do Gravitational Waves Exist? A very funny title to write 20 years after he
00:35:24 proposed they exist. But it’s because he had found these singularities, these infinities. And so
00:35:32 the editor at that time, and the part of it that I don’t know, is peer review. We live and die by
00:35:43 peer review as scientists send our stuff out. We don’t know when peer review actually started
00:35:49 or what peer review Einstein ever experienced before this time. But the editor of Physical
00:35:55 Review sent this out for review. He had a choice. He could take any article and just accept it.
00:36:02 He could reject it, or he could send it for review. I believe the editors used to have much
00:36:07 more power. Yeah, yeah. And he was a young man. His name was Tate. And he ended up being editor
00:36:13 for years. So he sent this for review to a theoretical physicist named Robertson, who was
00:36:22 also in this field of general relativity, who happened to be on sabbatical at that moment at
00:36:27 Caltech. Otherwise, his institution was Princeton, where Einstein was. And he saw that the way they
00:36:37 set up the problem, the infinities were like I make it as a student, because if you don’t
00:36:42 set it up right in general relativity, you get these infinities. And so he reviewed the article
00:36:48 and gave an illustration that if they set it up in what are called cylindrical coordinates, these
00:36:54 infinities went away. The editor of Physical Review was obviously intimidated by Einstein.
00:37:03 He wrote this really not a letter back like I would get saying, you’re screwed up in your paper
00:37:08 instead. It was kind of, what do you think of the comments of our referee? Einstein wrote back,
00:37:17 and it’s a well documented letter, wrote back a letter to Physical Review saying, I didn’t send
00:37:24 you the paper to send it to one of your so called experts. I sent it to you to publish. I withdraw
00:37:31 the paper. And he never published again in that journal. That was 1936. Instead, he rewrote it
00:37:42 with the fixes that were made, changed the title and published it in what was called the Franklin
00:37:49 Review, which is the Franklin Institute in Philadelphia, which is Benjamin Franklin
00:37:56 Institute, which doesn’t have a journal now, but did at that time. So the article is published.
00:38:01 It’s the last time he ever wrote about it. It remained controversial. So it wasn’t until
00:38:08 close to 1960, 1958, where there was a conference that brought together the experts in general
00:38:19 relativity to try to sort out whether it was true that there were gravitational waves or not.
00:38:29 And there was a very nice derivation by a British theorist from the heart of the theory that gets
00:38:40 gravitational waves. And that was number one. The second thing that happened at that meeting is
00:38:46 Richard Feynman was there. And Feynman said, well, if there’s typical Feynman, if there’s
00:38:53 gravitational waves, they need to be able to do something, otherwise they don’t exist. So they
00:38:58 have to be able to transfer energy. So he made an idea of a gedankenexperiment that is just a bar
00:39:05 with a couple of rings on it. And then if a gravitational wave goes through, it distorts the
00:39:11 bar and that creates friction on these little rings and that’s heat and that’s energy. So that
00:39:19 meant… Is that a good idea? That sounds like a good idea. Yeah. It means that he showed that
00:39:24 that with the distortion of space time, you could transfer energy just by this little idea.
00:39:31 And it was shown theoretically. So at that point, it was believed theoretically then
00:39:39 by people that gravitational waves should exist. No, we should be able to detect them.
00:39:45 We should be able to detect them, except that they’re very, very small.
00:39:49 And so what kind of, there’s a bunch of questions here, but what kind of events
00:39:55 would generate gravitational waves? You have to have this, what I call quadrupole moment.
00:40:01 That comes about if I have, for example, two objects that go around each other like this,
00:40:08 like the earth around the sun or the moon around the earth, or in our case, it turns out to be two
00:40:14 black holes going around each other like this. So how’s that different than basic oscillation
00:40:19 back and forth? Is it just more common in nature to have… Oscillation is a dipole moment. So it
00:40:24 has to be in three dimensional space kind of oscillation. So you have to have something
00:40:27 that’s three dimensional that’ll give what I called a quadrupole moment. That’s just built
00:40:32 into this. And luckily in nature you have stuff… And luckily things exist. And it is luckily
00:40:38 because the effect is so small that you could say, look, I could take a barbell
00:40:43 and spin it, right? And detect the gravitational waves. But unfortunately, no matter how much I
00:40:50 spin it, how fast I spin it, so I know how to make gravitational waves, but they’re so weak,
00:40:56 I can’t detect them. So we have to take something that’s stronger than I can make. Otherwise we
00:41:01 would do what Hertz did for electromagnetic waves. Go in our lab, take a barbell, put it on
00:41:07 something, spin it. Can I ask a dumb question? So a single object that’s weirdly shaped,
00:41:13 does that generate gravitational waves? So if it’s rotating? Sure. But it’s just a much weaker signal.
00:41:20 It’s weaker. Well, we didn’t know what the strongest signal would be that we would see.
00:41:26 We targeted seeing something called neutron stars actually, because black holes we don’t
00:41:31 know very much about. It turned out we were a little bit lucky. There was a stronger source,
00:41:35 which was the black holes. Well, another ridiculous question. So you say waves. What does a wave mean?
00:41:43 Like the most ridiculous version of that question is, what does it feel like to ride a wave as you
00:41:52 get closer to the source? Or experience it? Well, if you experience a wave, imagine that this is
00:42:00 what happens to you. I don’t know what you mean about getting close. It comes to you. So it’s like
00:42:06 this light wave or something that comes through you. So when a light hits you, it makes your eyes
00:42:12 detect it. I flashed it. What does this do? It’s like going to the amusement park, and they have
00:42:20 these mirrors. You look in this mirror and you look short and fat, and the one next to you makes
00:42:25 you tall and thin. Imagine that you went back and forth between those two mirrors once a second.
00:42:32 That would be a gravitational wave with a period of once a second. If you did it 60 times a second,
00:42:38 go back and forth. And then that’s all that happens. It makes you taller and shorter and
00:42:43 fatter back and forth as it goes through you at the frequency of the gravitational wave. So the
00:42:50 frequencies that we detect are higher than one a second, but that’s the idea. And the amount is
00:42:57 small. Amount is small, but if you’re closer to the source of the wave, is it the same amount?
00:43:07 Yeah, it doesn’t dissipate. It doesn’t dissipate. Okay, so it’s not that fun of an amusement ride.
00:43:14 Well, it does dissipate, but it’s proportional to the distance.
00:43:22 Right. It’s not a big power.
00:43:24 Right. Gotcha. But it would be a fun ride if you get a little bit closer or a lot closer.
00:43:31 I mean, I wonder what the… Okay, this is a ridiculous question, but I have you here.
00:43:36 I mean, the getting fatter and taller, I mean, that experience, for some reason,
00:43:44 that’s mind blowing to me because it brings the distortion of space time to you. I mean,
00:43:51 space time is being morphed, right? Like this is a wave.
00:43:56 That’s right.
00:43:57 That’s so weird.
00:43:59 And we’re in space, so we’re affected by it.
00:44:01 Yeah, we’re in space and now it’s moving.
00:44:03 It’s moving. I don’t know what to do with it. I mean, does it… Okay.
00:44:08 How much do you think about the philosophical implications of
00:44:13 general relativity? Like that we’re in space time and it can be bent by gravity.
00:44:21 Like, is that just what it is? Are we supposed to be okay with this? Because like Newton,
00:44:27 even Newton is a little weird, right? But that at least like makes sense.
00:44:31 That’s our physical world. When an apple falls, it makes sense. But the fact that
00:44:37 entirety of the space time we’re in can bend, that’s really mind blowing.
00:44:47 Let me make another analogy.
00:44:49 This is a therapy session for me at this point.
00:44:50 Yeah, right. Another analogy.
00:44:52 Thank you.
00:44:53 So imagine you have a trampoline.
00:44:56 Yes.
00:44:56 Okay. What happens if you put a marble on a trampoline? It doesn’t do anything, right?
00:45:02 No. Just a little bit, but not much.
00:45:04 Yeah. I mean, just if I drop it, it’s not going to go anywhere.
00:45:08 Now imagine I put a bowling ball at the center of the trampoline.
00:45:12 Now I come up to the trampoline and I put a marble on, what happens?
00:45:18 It’ll roll towards the bowling ball.
00:45:20 Okay. All right. So what’s happened is the presence of this massive object distorted the space
00:45:28 that the trampoline did. This is the same thing that happens to the presence of the earth,
00:45:36 the earth and the apple. The presence of the earth affects the space around it,
00:45:40 just like the bowling ball on the trampoline.
00:45:43 Yeah. This doesn’t make me feel better. I’m referring from the perspective of an
00:45:47 ant walking around on that trampoline. Then some guy just dropped a ball and then not only dropped
00:45:55 the ball, right? It’s not just dropping a bowling ball. It’s making the ball go up and down or doing
00:46:02 some kind of oscillation thing where it’s like waves. And that’s so fundamentally different from
00:46:08 the experience on being on flatland and walking around and just finding delicious, sweet things
00:46:13 as ant does. And it just feels like to me from a human experience perspective, completely,
00:46:20 it’s humbling. It’s truly humbling.
00:46:22 It’s humbling, but we see that kind of phenomenon all the time.
00:46:26 Let me give you another example. Imagine that you walk up to a still pond.
00:46:32 Yes.
00:46:33 Okay. Now I throw, you throw a rock in it, what happens? The rock goes in, sinks to the bottom,
00:46:41 fine. And these little ripples go out and they travel out. That’s exactly what happens. I mean,
00:46:48 there’s a disturbance, which is these, say, the bowling ball or black holes. And then the ripples
00:46:55 that go out in the water, they’re not, they don’t have any, they don’t have the rock, any part,
00:47:01 pieces of the rock.
00:47:02 See, the thing is, I guess what’s not disturbing about that is it’s a, I mean, I guess a flat
00:47:10 two dimensional surface that’s being disturbed. Like for a three dimensional surface, a three
00:47:16 dimensional space to be disturbed feels weird.
00:47:19 It’s even worse. It’s four dimensional because it’s space and time.
00:47:23 Time, yeah.
00:47:24 So that’s why you need Einstein is to make it four dimensional.
00:47:28 To make it okay?
00:47:29 No, to make it.
00:47:30 To make it four dimensional?
00:47:31 Yeah.
00:47:32 Yeah, to take the same phenomenon and look at it in all of space and time. Anyway,
00:47:39 luckily for you and I and all of us, the amount of distortion is incredibly small.
00:47:47 So it turns out that if you think of space itself, now this is going to blow your mind too,
00:47:54 if you think of space as being like a material, like this table, it’s very stiff. You know,
00:48:00 we have materials that are very pliable, materials that are very stiff. So space itself is very stiff.
00:48:06 So when gravitational waves come through it, luckily for us,
00:48:09 it doesn’t distort it so much that it affects our ordinary life very much.
00:48:16 No, I mean, that’s great. That’s great. I thought there was something bad coming.
00:48:19 No, this is great. That’s great news. So I mean, that, I mean, perhaps we evolved
00:48:24 as life on Earth to be such that for us, this particular set of effects of gravitational waves
00:48:32 is not that significant. Maybe that’s why.
00:48:36 It is. You probably used this effect today or yesterday.
00:48:41 Did what?
00:48:42 So it’s pervasive. Well, because…
00:48:45 You mean gravity or the way, or external? Because I only…
00:48:49 Curvature of space and time.
00:48:50 Curvature of space. How? I only care, a person is a human, right? The gravity of Earth.
00:48:56 But you use it every day, almost.
00:48:59 Oh, it’s curving.
00:49:00 Uh huh.
00:49:00 No, no, no.
00:49:01 No, no, no. It’s in this thing. Every time it tells you where you are,
00:49:07 how does it tell you where you are? It tells you where you are because we have
00:49:11 24 satellites or some number that are going around in space and it asks how long it takes
00:49:18 the beam to go to the satellite and come back, the signal, to different ones.
00:49:24 And then it triangulates and tells you where you are. And then if you go down the road,
00:49:28 it tells you where you are. Do you know that if you did that with the satellites and you
00:49:32 didn’t use Einstein’s equations?
00:49:34 Oh no.
00:49:36 You won’t get the right answer. That’s right. And in fact, if you take a road that’s, say,
00:49:42 10 meters wide, I’ve done these numbers, and you ask how long you’d stay on the road if
00:49:46 you didn’t make the correction for general relativity, this thing you’re poo pooing,
00:49:52 because you’re using every day, you’d go off the road in about a minute.
00:49:56 Well, actually, that might be my problem.
00:49:57 So you use it. So don’t poo poo it.
00:50:00 Well, I think I’m using an Android, so maybe, and the GPS doesn’t work that well, so maybe
00:50:04 I’m using Newton’s physics. So I need to upgrade to general relativity. So gravitational waves
00:50:11 and Einstein had, wait, Feynman really does have a part in the story?
00:50:16 Yeah.
00:50:17 Was that one of the first kind of experimental proposed to detect gravitational waves?
00:50:22 Well, he did what we call a Godonkin experiment. That’s a thought experiment.
00:50:25 Yes.
00:50:25 Okay. Not a real experiment. But then after that, then people believe gravitational waves
00:50:31 must exist. You can kind of calculate how big they are. They’re tiny. And so people
00:50:37 started searching. The first idea that was used was Feynman’s idea, and the very end of it.
00:50:44 And it was to take a great big, huge bar of aluminum and then put around, and it’s made
00:50:51 like a cylinder, and then put around it some very, very sensitive detectors so that if a
00:50:57 gravitational wave happened to go through it, it would go, and you’d detect this extra strain
00:51:03 that was there. And that was this method that was used until we came along. It wasn’t a very
00:51:10 good method to use.
00:51:12 And what was the, so we’re talking about a pretty weak signal here.
00:51:16 Yeah, that’s why that method didn’t work.
00:51:19 So what, can you tell the story of figuring out what kind of method would be able to detect
00:51:26 this very weak signal of gravitational waves?
00:51:30 So remembering what happens when you go to the amusement park, that it’s going to do something
00:51:38 like stretch this way and squash that way, squash this way and stretch this way. We do
00:51:44 have an instrument that can detect that kind of thing. It’s called an interferometer.
00:51:50 And what it does is it just basically takes, usually light, and the two directions that
00:51:58 we’re talking about, you send light down one direction and the perpendicular direction.
00:52:04 And if nothing changes, it takes the same, and the arms are the same length, it just
00:52:10 goes down, bounces back. And if you invert one compared to the other, they cancel so
00:52:16 that nothing happens.
00:52:17 But if it’s like the amusement park and one of the arms got shorter and fatter, so it
00:52:24 took longer to go horizontally than it did to go vertically, then when the light comes
00:52:30 back, that comes back somewhat out of time. And that basically is the scheme. The only
00:52:37 problem is that that’s not done very accurately in general, and we had to do it extremely
00:52:44 accurately.
00:52:45 So what’s the difficulty of doing so accurately?
00:52:52 Okay. So the measurement that we have to do is a distortion in time. How big is it? It’s
00:53:00 a distortion that’s one part in 10 to the 21. That’s 21 zeros and a one. Okay.
00:53:08 So this is like a delay in the thing coming back?
00:53:13 One of them coming back after the other one, but the difference is just one part in 10
00:53:17 to the 21. So for that reason, we make it big, let the arms be long. Okay, so one part
00:53:26 in 10 to the 21. In our case, it’s kilometers long. So we have an instrument that’s kilometers
00:53:33 in one direction, kilometers in the other.
00:53:34 How many kilometers are we talking about? Four kilometers.
00:53:37 Four kilometers in each direction. If you take then one part in 10 to the 21, we’re
00:53:44 talking about measuring something to 10 to the minus 18 meters.
00:53:54 Okay.
00:53:55 Now, to tell you how small that is, the proton thing we’re made of, which you can’t go
00:54:01 and grab so easily, is 10 to the minus 15 meters. So this is one one thousandth the
00:54:07 size of a proton. That’s the size of the effect. Einstein himself didn’t think this
00:54:13 could be measured. We’ve never seen, actually, he said that. But that’s because he didn’t
00:54:19 anticipate modern lasers and techniques that we developed.
00:54:27 Okay. So maybe can you tell me a little bit what you’re referring to as LIGO, the Laser
00:54:34 Interferometer Gravitational Wave Observatory. What is LIGO? Can you just elaborate kind
00:54:40 of the big picture view here before I ask you specific questions about it?
00:54:44 Yeah. So in the same idea that I just said, we have two long vacuum pipes, four kilometers
00:54:54 long. We start with a laser beam and we divide the beam going down the two arms. And we have
00:55:03 a mirror at the other end, reflects it back. It’s more subtle, but we bring it back. If
00:55:09 there’s no distortion in space time and the lengths are exactly the same, which we calibrate
00:55:14 them to be, then when it comes back, if we just invert one signal compared to the other,
00:55:20 they’ll just cancel. So we see nothing. Okay. But if one arm got a little bit longer than
00:55:26 the other, then they don’t come back at exactly the same time. They don’t exactly cancel.
00:55:31 That’s what we measure. So to give a number to it, we have the change of length to be
00:55:42 able to do this 10 to the minus 18 meters to one part in 10 to the 12th. And that was
00:55:48 the big experimental challenge that required a lot of innovation to be able to do.
00:55:55 You gave a lot of credit to, I think, Caltech and MIT for some of the technical developments
00:56:02 within this project. Is there some interesting things you can speak to at the low level of
00:56:10 some cool stuff that had to be solved? I’m a software engineer, so I have so much more
00:56:17 respect for everything done here than anything I’ve ever done. So I’ll give you an example
00:56:25 of doing mechanical engineering at a better, basically mechanical engineering and geology
00:56:35 and maybe at a level. So what’s the problem? The problem is the following, that I’ve given
00:56:42 you this picture of an instrument that by some magic, I can make good enough to measure
00:56:47 this very short distance. But then I put it down here, it won’t work. And the reason it
00:56:54 doesn’t work is that the Earth itself is moving all over the place all the time. You don’t
00:56:59 realize it, it seems pretty good to you, but it’s moving all the time. So somehow it’s
00:57:05 moving so much that we can’t deal with it. We happen to be trying to do the experiment
00:57:10 here on Earth, but we can’t deal with it. So we have to make the instrument isolated
00:57:16 from the Earth at the frequencies we’re at. We’ve got to float it. That’s an engineering
00:57:23 problem, not a physics problem.
00:57:24 So we’re having a conversation on a podcast right now, and people who record music work
00:57:32 with this, how to create an isolated room. And they usually build a room within a room,
00:57:39 but that’s still not isolated. In fact, they say it’s impossible to truly isolate from
00:57:43 sound, from noise and stuff like that. But that’s like one step of millions that you
00:57:51 took is building a room inside a room, because you basically have to isolate all.
00:57:56 No, this is actually an easier problem. You just have to do it really well. So making
00:58:02 a clean room is really a tough problem because you have to put a room inside a room. This
00:58:07 is really simple engineering or physics. Okay, so what do you have to do? How do you isolate
00:58:14 yourself from the Earth? First, we work at, we’re not looking at all frequencies for
00:58:21 gravitational waves. We’re looking at particular frequencies that you can deal with here on
00:58:26 Earth. So what are frequencies would those be? You were just talking about frequencies.
00:58:34 We know by evolution, our bodies know, it’s the audio band. Okay, the reason our ears
00:58:40 work where they work is that’s where the Earth isn’t going, making too much noise.
00:58:45 Okay, so the reason our ears work the way they work is because this is where it’s quiet.
00:58:48 That’s right. So if you go to one Hertz instead of 10 Hertz, the Earth is really moving around.
00:58:59 So somehow we live in what we call the audio band. It’s tens of Hertz to thousands of Hertz.
00:59:06 That’s where we live, okay? If we’re going to do an experiment on the Earth, it’s the
00:59:14 same frequency. That’s where the Earth is the quietest. So we have to work in that frequency.
00:59:18 So we’re not looking at all frequencies, okay? So the solution for the shaking of the Earth
00:59:25 to get rid of it is pretty mundane if we do the same thing that you do to make your car drive
00:59:33 smoothly down the road. So what happens when your car goes over a bump? Early cars did that,
00:59:39 they bounced. Right.
00:59:41 Okay, but you don’t feel that in your car. So what happened to that energy? You can’t just
00:59:47 disappear energy. So we have these things called shock absorbers in the car. What they do is they
00:59:53 take the thing that went like that, and they basically can’t get rid of the energy, but they
00:59:58 move it to very, very low frequency. So what you feel isn’t, you feel it go smoothly, okay? All
01:00:08 right. So we also work at this frequency. So we basically, why don’t we have to do anything other
01:00:18 than shock absorbers? So we made the world’s fanciest shock absorbers, okay? Not just like in
01:00:26 your car where there’s one layer of them. They’re just the right squishiness and so forth. They’re
01:00:30 better than what’s in the cars. And we have four layers of it. So whatever shakes and gets through
01:00:35 the first layer, we treat it in a second, third, fourth layer. So it’s a mechanical engineering
01:00:40 problem. Yeah, that’s what I said. So it’s not, there’s no weird tricks to it, like a chemistry
01:00:46 type thing. No, no. Just, well, the right squishiness, you need the right material inside.
01:00:51 And ours look like little springs, but they’re. Springs? They’re springs? So like legitimately,
01:00:58 like shock absorbers. Yeah. What? Okay. Okay. And this is now experimental physics at the,
01:01:06 at its limit. Okay. So you do this and we make the world’s fanciest shock absorbers,
01:01:11 just mechanical engineering. Just mechanical engineering, this is hilarious. But we didn’t,
01:01:16 we weren’t good enough to discover gravitational waves. So we did another, we added another
01:01:25 feature and it’s something else that you’re aware of, probably have one. And that is to get rid of
01:01:33 noise. You’ve probably noise, which is, you don’t like. And that’s the same principle that’s in
01:01:40 these little Bose earphones. Noise canceling? Noise canceling. So how do they work? They
01:01:48 basically, you go on an airplane and they sense the ambient noise from the engines
01:01:53 and cancel it. Cause it’s just the same over and over again. They cancel it. And when the stewardess
01:01:59 comes and asks you whether you want coffee or tea or a drink or something, you hear, you’re fine
01:02:03 because she’s not ambient. She’s the signal. So. Are we talking about active canceling? Like where
01:02:09 are the. Active canceling. So. This is, okay. So another. Don’t tell me you have active canceling
01:02:16 on this. Yeah. Besides the shock absorbers. So we had this, so inside this array of shock absorbers.
01:02:22 Yeah. We, you asked for some interesting. This is awesome. So inside this, it’s harder than the,
01:02:29 the earphone problem, but it’s just engineering. We have to see measure, not just that the
01:02:36 engine still made noise, but the earth is shaking. It’s moving in some direction. So we have to
01:02:42 actually tell not only that there’s noise and cancel it, but what direction it’s from. So we
01:02:48 put this array of seismometers inside this array of shock absorbers and measure the residual motion
01:02:58 and its direction. And we put little actuators that push back against it and cancel it.
01:03:07 This is awesome. So you have the actuators and you have the thing that is sensing the,
01:03:11 the vibrations and then you have the actual actuators that adjust for that and do so in
01:03:16 perfect synchrony. Yeah. What if it all works right. And so how much do we reduce the shaking
01:03:22 of the earth? I mean, one part in 10 to the 12th. One part in 10. So what gets through us is one
01:03:31 part in 10 to the 12th. That’s pretty big reduction. You don’t need that in your car,
01:03:39 but that’s what we do. And so that’s how isolated we are from the earth. And that was the biggest,
01:03:43 and that was the biggest, I’d say technical problem outside of the physics instrument,
01:03:49 the interferometer. Can I ask you a weird question here? You make it very poetically
01:03:54 and humorously is saying it’s just a mechanical engineering problem, but is this one of the
01:04:01 biggest precision mechanical engineering efforts ever? I mean, this seems exceptionally difficult.
01:04:09 It is. And so it took a long time. And I think nobody seems to challenge the statement that
01:04:16 this is the most precision, precise instrument it’s ever been built, LIGO.
01:04:22 I wonder what like listening to Led Zeppelin sounds on this thing,
01:04:25 because it’s so isolated. I mean, this is like, I don’t know.
01:04:30 No background. No, no back. It’s wow. Wow. Wow. So when you were first
01:04:37 conceiving this, I would probably, if I was knowledgeable enough,
01:04:44 kind of laugh off the possibility that this is even possible.
01:04:48 I’m sure, like how many people believe that this is possible? Did you believe this is possible?
01:04:54 I did. I didn’t know that we needed, for sure that we needed active. When we started,
01:05:00 we did dispassive, but we were doing the tests to develop the active to add as a second stage,
01:05:08 which we ended up needing. But there was a lot of, you know, now there was a lot of skepticism.
01:05:15 A lot of us, especially astronomers, felt that money was being wasted,
01:05:20 because we were also expensive. Doing what I told you is not cheap. So it was kind of
01:05:26 controversial. It was funded by the National Science Foundation. Can you just linger on this
01:05:32 just for a little longer? The actuator thing, the act of canceling. Do you remember like little
01:05:41 experiments that were done along the way to prove to the team themselves that this is even possible?
01:05:49 Because I work with quite a bit of robots, and to me, the idea that you could do it this precisely
01:05:54 is humbling and embarrassing, frankly. Because like, this is another level of precision that I
01:06:01 can’t even, because robots are a mess. And this is basically one of the most precise robots ever.
01:06:12 Right. So like, is there, do you have any like small scale experiments that were done that just
01:06:18 be like, this is possible? Yeah, and larger scale. We made a test, that also has to be in vacuum too,
01:06:27 but we made test chambers that had this system in it, our first mock of this system, so we could test
01:06:33 it and optimize it and make it work. But it’s just a mechanical engineering problem. Okay.
01:06:41 And humans are just ape descendants. I gotcha. I gotcha. Is there any video of this? Like some kind
01:06:49 of educational purpose visualizations of this act of canceling? I don’t think so.
01:06:58 I mean, does this live on? Well, we work for parts of it, for the active canceling,
01:07:04 we worked with, for the instruments, for the sensor and instruments, we worked with a small
01:07:11 company near where you are, because it was our MIT people that got them that were, you know,
01:07:17 interested in the problem because they thought they might be able to commercialize it for
01:07:22 making stable tables to make microelectronics, for example, which are limited by how stable the table
01:07:28 is. I mean, at this point, it’s a little expensive. So you never know, never know where this leads.
01:07:36 So maybe on the, let me ask you, just sticking it a little longer, this silly old mechanical
01:07:45 engineering problem. What was to you kind of the darkest moment of what was the hardest
01:07:53 stumbling block to get over on the engineer side? Like, was there any time where there’s a doubt,
01:07:58 where it’s like, I’m not sure we would be able to do this, a kind of engineering challenge that was
01:08:03 hit? Do you remember anything like that? I think the one that my colleague at MIT,
01:08:11 Ray Weiss, worked on so hard and was much more of a worry than this. This is only a question if you’re
01:08:18 not doing well enough, you have to keep making it better somehow. But this whole huge instrument has
01:08:26 to be in vacuum. And the vacuum tanks are, you know, this big around. And so it’s the world’s
01:08:34 biggest high vacuum system. And how do you make it? First of all, how do you make this four meter
01:08:42 long sealed vacuum system? It has to be made out of four kilometers, four kilometers long. Would I
01:08:48 say something else? Meters. Four kilometers long. Big difference. Yeah. And so, but to make it,
01:08:55 yeah, we started with a roll of stainless steel, and then we roll it out like a spiral so that
01:09:04 there’s a spiral weld on it. Okay, so the engineering was fine. We did that. We worked through
01:09:14 very good companies and so forth to build it. But the big worry was, what if you develop a leak?
01:09:25 This is a high vacuum, not just vacuum system. Typically, in a laboratory, if there’s a leak,
01:09:31 you put helium around the thing you have, and then you detect where the helium is coming in.
01:09:40 But if you have something as big as this, you can’t surround it with helium. So you might not
01:09:44 actually even know that there’s a leak and it will be affecting it. Well, we can measure how
01:09:51 good the vacuum is so we can know that, but a leak can develop and then we don’t, how do we fix it
01:09:58 or how do we find it? And so that was, you asked about a worry. That was always a really big worry.
01:10:04 What’s the difference, you know, high vacuum and a vacuum? What is high vacuum? That’s like some
01:10:11 delta close to vacuum? Is it some threshold? Well, there’s a unit. High vacuum is when the vacuum
01:10:20 and the units that are used, which are tors, there’s 10 to the minus nine. And there’s high
01:10:27 vacuum is usually used in small places. The biggest vacuum system period is at CERN in this
01:10:35 big particle accelerator, but the high vacuum where they need really good vacuum so particles
01:10:40 don’t scatter in it is smaller than ours. So ours is a really large high vacuum system.
01:10:47 I don’t know. This is so cool. I mean, this is basically by far the greatest listening device
01:10:53 ever built by human. The fact that like descendants of apes could do this, that evolution started with
01:10:59 single cell organisms. I mean, is there any more, I’m a huge theory is like, yeah, yeah. But like
01:11:07 bridges, when I look at bridges from a civil engineering perspective, it’s one of the most
01:11:11 beautiful creations by human beings. It’s physics. You’re using physics to construct objects that
01:11:17 can support huge amount of mass and it’s like structural, but it’s also beautiful.
01:11:21 And that humans can collaborate to create that throughout history. And then you take this
01:11:26 on another level. This is, this is like, it’s exciting to me beyond measure that humans can
01:11:35 create something so precise. But another concept lost in this, you just said, you started talking
01:11:41 about single cell. Yeah. Okay. You have to realize this discovery that we made that everybody’s
01:11:47 bought off on happened 1.3 billion years ago, somewhere. And then the signal came to us 1.3
01:11:55 billion years ago, we were just converting on the earth from single cell to multi cell life.
01:12:01 So when this actually happened, this collision of two black holes, we weren’t here. We weren’t
01:12:07 even close to developing single. Yeah, we were had, we’re going from single cell to multi cell
01:12:14 life at that point. All to meet up at this, at this point. Yeah. Wow. That’s like, that’s almost
01:12:20 romantic. It is. Okay. So on the human side of things, it’s kind of fascinating because you’re
01:12:32 talking about over a thousand people team for LIGO. Yeah. They started out with, you know,
01:12:39 around a hundred and you’ve for parts of the time at least led this team. What does it take to lead
01:12:48 a team like this of incredibly brilliant theoreticians and engineers and just a lot of
01:12:56 different parties involved? A lot of egos, a lot of ideas. You had this fun, funny example,
01:13:03 I forget where, where in publishing a paper, you have to all agree on like, you know, the phrasing
01:13:10 of a certain sentence or the title of the paper and so on. That’s a very interesting, simple
01:13:15 example. I’d love you to speak to that, but just in general, how, what does it take to lead this
01:13:20 kind of team? Okay. I think that the general idea is one we all know. You want to, you want to,
01:13:28 you want to get where the, the sum of something is more than the individual parts is what we say,
01:13:37 right? Yeah. So that’s what you’re trying to achieve. Yes. Okay. How do you do that? Actually,
01:13:42 mostly if we take multiple objects or people, I mean, you put them together, the sum is less.
01:13:49 Yes. Why? Because they overlap. So you don’t have individual things that, you know, this
01:13:56 person does that, this person does that, then you get exactly the sum. But what you want is to
01:14:02 develop where you get more than what the individual contributions are. We know that’s
01:14:07 very common. People use that expression everywhere. And it’s the expression that has to be kind of
01:14:14 built into how people feel it’s working. Because if you’re part of a team, and you realize that
01:14:21 somehow the team is able to do more than the individuals could do themselves, then they buy on
01:14:27 kind of in terms of the process. So that’s the, that’s the goal that you have to have is to, to
01:14:36 achieve that. And that means that you have to realize parts of what you’re trying to do that
01:14:45 require not that one person couldn’t do it, it requires the combined talents to be able to do
01:14:52 something that neither of them could do themselves. And we have a lot of that kind of thing. And I
01:14:57 think, I mean, build into the some of the examples that I gave you. And so, how do you then, so, so
01:15:06 the key almost in anything you do is the people themselves, right? So in our case,
01:15:12 the first and most important was to attract to spend years of their life on this. And the best
01:15:20 possible people in the world to do it. So the only way to convince them is that somehow it’s
01:15:28 better and more interesting for them than what they could do themselves. And so that’s part of
01:15:34 this idea. Yeah, that’s powerful. But nevertheless, there’s best people in the world, there’s egos. Is
01:15:42 there something to be said about managing egos? Oh, that’s the human problem is always the hardest.
01:15:47 And so there’s, that’s an art, not a science, I think. I think the fact here that combined,
01:15:56 there’s a was a romantic goal that we had to, you know, do something that people hadn’t done before,
01:16:06 which was important scientifically and, and a huge challenge, enabled us to say, take and get, I mean,
01:16:19 what we did just to take an example, we use the light to go in this thing comes from lasers.
01:16:24 We need a certain kind of laser. So the kind of laser that we use, there were three different
01:16:32 institutions in the world that had the experts that do this, maybe in competition with each other.
01:16:38 So we got all three to join together and work with us to work on this as an example. So that
01:16:45 you had, and they had the thing that they were working together on a kind of object that they
01:16:51 wouldn’t have otherwise. And we’re part of a bigger team where they could discover something
01:16:57 that isn’t even engineers. These are engineers that do laser. So, and they’re part of our laser
01:17:03 physicists. So could you describe the moment or the period of time when finally this incredible
01:17:14 creation of human beings led to a detection of gravitational waves? It’s a long story. Unfortunately,
01:17:22 this is a part that we started failures along the way kind of thing or all failures. That’s all
01:17:28 that’s built into it. If you’re not, if you’re not mechanical engineering, you build on your failures,
01:17:36 that’s expected. So we’re trying things that no one’s done before. So it’s technically not just
01:17:41 gravitational waves. And so it’s built on failures. But anyway, we did before me, even
01:17:48 there, the people did R&D on the concepts. But starting in 1994, we got money from the National
01:17:57 Science Foundation to build this thing. It took about five years to build it. So by 1999, we had
01:18:06 built the basic unit. It did not have active seismic isolation at that stage, didn’t have some
01:18:13 other things that we have now. What we did at the beginning was stick to technologies that we had
01:18:27 at least enough knowledge that we could make work or had tested in our own laboratories. And so then
01:18:33 we put together the instrument. We made it work. It didn’t work very well, but it worked. And we
01:18:41 didn’t see any gravitational waves. Then we figured out what limited us. And we went through this
01:18:45 every year for almost 10 years, never seeing gravitational waves. We would run it, looking for
01:18:55 gravitational waves for months, learn what limited us, fix it for months, and then run it again.
01:19:06 Eventually, we knew we had to take another big step. And that’s when we made several changes,
01:19:13 including adding these active seismic isolation, which turned out to be a key. And we
01:19:21 fortunately got the National Science Foundation to give us another couple hundred million dollars,
01:19:27 100 million more. And we rebuild it or fixed or improved it. And then in 2015, we turned it on.
01:19:42 And we almost instantly saw this first collision of two black holes.
01:19:53 And then we went through a process of, do we believe what we’ve seen?
01:19:58 Yeah, I think you’re one of the people that went through that process. It sounds like some people
01:20:02 immediately believed it. And then you’re like…
01:20:05 So as human beings, we all have different reactions to almost anything. And so
01:20:10 quite a few of my colleagues had a eureka moment immediately. I mean, the figure that we put in our
01:20:20 paper, first is just data. We didn’t have to go through fancy computer programs to do anything.
01:20:27 And we show next to it the calculations of Einstein’s equations. It looks just like what
01:20:36 we detected. And we did it in two different detectors halfway across the US. So it was
01:20:42 pretty convincing, but you don’t want to fool yourself. So being a scientist, for me, we had
01:20:53 to go through and try to understand that the instrument itself, which was new, I said we had
01:20:58 rebuild it, couldn’t somehow generate things that look like this. That took some tests. And then the
01:21:06 second, you’ll appreciate more, we had to somehow convince ourselves we weren’t hacked in some
01:21:12 clever way.
01:21:12 Cybersecurity question.
01:21:14 Yeah. Even though we’re not on the internet, but…
01:21:18 Yeah. No, it can be physical access too. Yeah. That’s fascinating. It’s fascinating that you
01:21:23 would think about that. I mean, not enough. I mean, because it matches prediction. So the chances
01:21:34 of it actually being manipulated is very, very low. But nevertheless…
01:21:38 We still could have disgruntled all the graduate students who had worked with us earlier that…
01:21:43 Who want you to… I don’t know how that’s supposed to embarrass you. I suppose, yeah. I suppose I
01:21:48 see. But about what I think you said, within a month, you kind of convinced yourself officially.
01:21:55 Within a month, we convinced ourselves. We kept a thousand collaborators quiet during that time.
01:22:01 Then we spent another month or so trying to understand what we’d seen so that we could do the
01:22:10 science with it instead of just putting it out to the world and let somebody else understand that it
01:22:14 was two black holes and what it was. The fact that a thousand collaborators were quiet
01:22:20 is a really strong indication that this is a really close knit team. Yeah. And they’re around
01:22:25 the world. Either strong knit or tight knit or had a strong dictatorship or something. Yeah.
01:22:35 Either fear or love. You can rule by fear or love. Yeah, right. You can go back to Machiavelli.
01:22:39 Yeah. All right. Well, this is really exciting that that’s a success story because it didn’t
01:22:51 have to be a success story, right? I mean, eventually, perhaps you could say it’ll be an
01:22:56 event, but it could have taken over a century to get there. Oh, yeah. Yeah. And it’s only downhill
01:23:06 now. What do you mean? You mean with gravitational waves? Yeah. Well, now we’re off because of the
01:23:18 pandemic, but when we turned off, we were seeing some sort of gravitational wave event each week.
01:23:26 Now we’re fixing, we’re adding features where it’ll probably be when we turn back on next year,
01:23:32 it’ll probably be one every couple days. And they’re not all the same. So it’s
01:23:38 learning about what’s out there in gravity instead of just optics. So it’s all great.
01:23:45 We’re only limited by the fantastic thing other than that this is a great field and it’s all new
01:23:54 and so forth is that experimentally, the great thing is that we’re limited by technology and
01:24:04 technical limitations, not by science. So another really important discovery that was made before
01:24:16 ours was what’s called the Higgs boson made on the big accelerator at CERN. This huge accelerator,
01:24:23 they discovered a really important thing. We have Einstein’s equation, E equals MC squared.
01:24:29 So energy makes mass or mass can make energy and that’s the bomb. But the mechanism by which that
01:24:37 happens, not vision, but how do you create mass from energy was never understood until there was
01:24:48 a theory of it about 70 years ago now. And so they discovered it’s named after a man named Higgs.
01:24:58 It’s called the Higgs boson. And so it was discovered, but since that time, and I worked
01:25:05 on those experiments since that time, they haven’t been able to progress very much further,
01:25:09 a little bit, but not a lot further. And the difference is that we’re really lucky
01:25:14 we’re in what we’re doing in that there you see this Higgs boson, but there’s tremendous amount
01:25:22 of other physics that goes on and you have to pick out the needle in the haystack of physics.
01:25:28 You can’t make the physics go away, it’s there. In our case, we have a very weak signal, but once we
01:25:34 get good enough to see it, it’s weak compared to where we’ve reduced the background, but the
01:25:40 background is not physics, it’s just technology. It’s getting ourselves better isolated from the
01:25:47 Earth or getting a more powerful laser. And so since 2015, when we saw the first one,
01:25:56 we continually can make improvements that are enabling us to turn this into a real science
01:26:03 to do astronomy, a new kind of astronomy. It’s a little like astronomy. Galileo started the field.
01:26:12 He basically took lenses that were made for classes and he didn’t invent the first telescope,
01:26:20 but made a telescope, looked at Neptune and saw that it had four moons. That was the birth of
01:26:28 not just using your eyes to understand what’s out there. And since that time, we’ve made better and
01:26:34 better telescopes, obviously, and astronomy thrives. And in a similar way, we’re starting to
01:26:41 be able to crawl, but we’re starting to be able to do that with gravitational waves. And it’s
01:26:49 going to be more and more that we can do as we can make better and better instruments because,
01:26:55 as I say, it’s not limited by picking it out of others. Yeah, it’s not limited by the physics.
01:27:02 So you have an optimism about engineering that as human progress marches on,
01:27:11 engineering will always find a way to build a large enough device,
01:27:17 accurate enough device to detect the same thing. As long as it’s not limited by physics,
01:27:21 yeah, they’ll do it. So you, two other folks and the entire team won the Nobel prize for this big
01:27:34 effort. There’s a million questions I can ask for, but looking back, where does the Nobel prize
01:27:49 fit into all of this? If you think hundreds of years from now, I venture to say that people
01:27:57 will not remember the winners of a prize, but they’ll remember creations like these.
01:28:03 Maybe I’m romanticizing engineering, but I guess I want to ask how important is the Nobel prize in
01:28:10 all of this? Well, that’s a complicated question. As a physicist, it’s something if you’re trying
01:28:22 to win a Nobel prize, forget it because they give one a year. So there’s been 200 physicists
01:28:30 who have won the Nobel prize since 1900. And so things just have to fall right. So your goal cannot
01:28:40 be to win a Nobel prize. It wasn’t my dream. It’s tremendous for science. Why the Nobel prize for a
01:28:51 guy that made dynamite and stuff is what it is. It’s a long story, but it’s the one day a year
01:28:58 where actually the science that people have done is all over the world and so forth. Forget about
01:29:04 the people again. It is really good for science. It celebrates science for several days, different
01:29:14 fields, chemistry, medicine and so forth. And everybody doesn’t understand everything about
01:29:21 these. They’re generally fairly abstract, but then it’s on the front page of newspapers around
01:29:27 the world. So it’s really good for science. It’s not easy to get science on the front page of the
01:29:32 New York Times. It’s not there. Should be, but it’s not. And so the Nobel prize is important in that
01:29:41 way. Otherwise, I have a certain celebrity that I didn’t have before. And now you get to be a
01:29:53 celebrity that advertises science. It’s a mechanism to remind us how incredible, how much credit
01:30:01 science deserves and everything. Well, it has a little bit more. One thing I didn’t expect,
01:30:06 which is good, is that we have a government. I’m not picking on ours necessarily, but it’s true of
01:30:16 all governments are not run by scientists. In our case, it’s run by lawyers and businessmen.
01:30:23 Yep. Okay. And at best they may have an aide or something that knows a little science. So
01:30:33 in all countries hardly take into account science in making decisions.
01:30:42 Yes. Okay. And
01:30:44 having a Nobel prize, the people in those positions actually listen. So you have more
01:30:53 influence. I don’t care whether it’s about global warming or what the issue is. There’s some
01:30:58 influence, which is lacking otherwise. And people pay attention to what I say. If I talk about
01:31:05 global warming, they wouldn’t have before I had the Nobel prize. Yeah, this is very true. You’re
01:31:12 like the celebrities who talk. Celebrity has power. Celebrity has power. And that’s a good
01:31:20 thing. That’s a good thing. Singling out people, I mean, on the other side of it, singling out
01:31:24 people has all kinds of, whether it’s for Academy Awards or for this, have unfairness and
01:31:32 arbitrariness and so forth and so on. So that’s the other side of the coin. Just like you said,
01:31:39 especially with the huge experimental projects like this, you know, it’s a large team and it
01:31:45 does the nature of the Nobel prizes. It singles out a few individuals to represent the team.
01:31:49 Yeah. Nevertheless, it’s a beautiful thing. What are ways to improve LIGO in the future,
01:31:57 increase the sensitivity? I’ve seen a few ideas that are kind of fascinating. Are you interested
01:32:03 in them? I’m not speaking about five years. Perhaps you could speak to the next five years,
01:32:09 but also the next hundred years. Yeah. So let me talk to both the instrument and the science.
01:32:16 Sure. So they go hand in hand. I mean, the thing that I said is if we make it better,
01:32:21 we see more kinds of weaker objects and we do astronomy. Okay. We’re very motivated to make
01:32:29 a new instrument, which will be a big step, the next step, like making a new kind of telescope or
01:32:36 something. And the ideas of what that instrument should be haven’t converged yet. There’s different
01:32:44 ideas in Europe. They’ve done more work to kind of develop the ideas, but they’re different from
01:32:52 ours and we have ideas. But I think over the next few years, we’ll develop those. The idea is to make
01:32:59 an instrument that’s at least 10 times better than what we can do with this instrument, 10 times
01:33:06 better than that. 10 times better means you can look 10 times further out. 10 times further out
01:33:13 is a thousand times more volume. So you’re seeing much, much more of the universe. The best way to
01:33:21 look at it is to look further out. The big change is that if you can see far out, you see further
01:33:29 back in history. Yeah, you’re traveling back in time. Yeah. And so we can start to do what we
01:33:36 call cosmology instead of astronomy or astrophysics. Cosmology is really the study of the evolution of
01:33:44 the universe. And so then you can start to hope to get to the important problems having to do with
01:33:53 how the universe began, how it evolved and so forth, which we really only study now with
01:34:02 optical instruments or electromagnetic waves. And early in the universe, those were blocked because
01:34:12 it was, basically it wasn’t transparent. So the photons couldn’t get out when everything was too
01:34:18 dense. What do you think, sorry on this tangent, what do you think an understanding of gravitational
01:34:24 waves from earlier in the universe can help us understand about the Big Bang and all that kind
01:34:28 of stuff? Yeah. But it’s a non, it’s another perspective on the thing. Is there some insights
01:34:37 you think could be revealed just to help a layman understand? Sure. First, we don’t understand. We
01:34:43 use the word Big Bang. We don’t understand the physics of what the Big Bang itself was.
01:34:50 So I think, and in the early stage, there were particles and there was a huge amount of gravity
01:34:58 and mass being made. So I’ll say two things. One is, how did it all start? How did it happen? I’ll
01:35:10 give you at least one example that we don’t understand what we should understand. We don’t
01:35:16 know why we’re here. Yes. No, we do not. I don’t mean it philosophically. I mean it in terms of
01:35:24 physics. Now, what do I mean by that? If I go into my laboratory at CERN or somewhere and I
01:35:30 collide particles together or put energy together, I make as much anti matter as matter. Anti matter
01:35:38 then annihilates matter and makes energy. So in the early universe, you made somehow a lot of
01:35:49 matter and anti matter, but there was an asymmetry. Somehow there was more matter and anti matter.
01:35:55 The matter and anti matter annihilated each other. At least that’s what we think.
01:35:59 And there was only matter leftover. And we live in a universe that we see this all matter.
01:36:05 We don’t have any idea. We have ideas, but we don’t have any way to understand that at the
01:36:12 present time with the physics that we know. Can I ask a dumb question? Does anti matter have
01:36:19 anything like a gravitational field to send signals? So how does this asymmetry of matter
01:36:29 and anti matter could be investigated or further understood by observing gravitational fields or
01:36:35 weirdnesses in gravitational fields? I think that in principle, if there were anti neutron stars,
01:36:45 instead of just neutron stars, we would see different kinds of signals, but it didn’t get
01:36:51 to that. We live in a universe that we’ve done enough looking because we don’t see anti matter,
01:36:56 anti protons anywhere, no matter what we look at, that it’s all made out of matter.
01:37:01 Hmm. There is no anti matter except when we go in our laboratories.
01:37:06 So, but when we go in our laboratories, we make as much anti matter as matter.
01:37:11 So there’s something about the early universe that made this asymmetry. So we can’t even
01:37:16 explain why we’re here. That’s what I meant. Physics wise, not in terms of how we evolved
01:37:25 and all that kind of stuff. So there might be inklings of some of the physics that gravitational
01:37:36 So gravitational waves don’t get obstructed like light. So I said light only goes to 300,000 years.
01:37:42 So it goes back to the beginning. So if you could study the early universe with gravitational waves,
01:37:47 we can’t do that yet. Then it took 400 years to be able to do that with optical, but
01:37:54 but then you can really understand the very, maybe understand the very early universe.
01:38:00 So in terms of questions like why we’re here or what the big bang was, we should be, we can,
01:38:10 in principle, study that with gravitational waves. So to keep moving in this direction,
01:38:15 it’s a unique kind of way to understand our universe.
01:38:20 So you think there’s more Nobel prize level ideas to be discovered in relation to
01:38:25 I’d be shocked if there, if there isn’t, not even going to that, which is a very long range problem.
01:38:31 But I think that we only see with electromagnetic waves, 4% of what’s out there.
01:38:39 There must be, we looked for things that we knew should be there. There should be,
01:38:48 I would be shocked if there wasn’t physics, objects, science, and with gravity that doesn’t
01:38:58 show up in everything we do with telescopes. So I think we’re just limited by not having
01:39:06 powerful enough instruments yet to do this.
01:39:10 Do you have a preference? I keep seeing this E. Lisa idea.
01:39:17 Yeah.
01:39:18 Is it, do you have a preference for earthbound or space faring mechanisms for?
01:39:26 They’re complimentary. It’s a little bit like, it’s completely analogous to what’s been done
01:39:32 in astronomy. So astronomy from the time of Galileo was done with visible light.
01:39:42 The big advances in astronomy in the last 50 years are because we have instruments that look
01:39:46 at the infrared, microwave, ultraviolet and so forth. So looking at different wavelengths
01:39:54 has been important. Basically going into space means that we’ll look at instead of the audio
01:40:00 band, which we look at, as we said on the Earth’s surface, we’ll look at lower frequencies.
01:40:05 So it’s completely complimentary and it starts to be looking at different frequencies just
01:40:10 like we do with astronomy.
01:40:14 It seems almost incredible to me, engineering wise, just like on earth to send something
01:40:18 that’s kilometers across into space. Is that harder to engineer?
01:40:25 It actually is a little different. It’s three satellites separated by hundreds of thousands
01:40:32 of kilometers and they send a laser beam from one to the other. And if the triangle changes
01:40:42 shape a little bit, they detect that from a graph.
01:40:45 Did you say hundreds of thousands of kilometers? Yeah. Sending lasers to each other. Okay.
01:40:56 It’s just engineering.
01:40:59 Is it possible though? Is it doable?
01:41:02 Yes.
01:41:03 Okay. That’s just incredible because they have to maintain, I mean, the precision here
01:41:11 is probably, there might be some more, what is it? Maybe noise is a smaller problem. I
01:41:16 guess there’s no vibration to worry about like seismic stuff. So getting away from earth,
01:41:22 maybe you get away from seismic stuff.
01:41:23 Yeah. Those parts are easier. They don’t have to measure it as accurately at low frequencies.
01:41:29 But they have a lot of tough engineering problems.
01:41:33 In order to detect that the gravitational waves affect things, the sensors have to be
01:41:44 what we call free masses, just like ours, are isolated from the earth. They have to
01:41:48 isolate it from the satellite. And that’s a hard problem. They have to do that pretty,
01:41:54 not as well as we have to do it, but very well. And they’ve done a test mission and
01:42:00 the engineering seems to be at least in principle in hand. This will be in the 2030s.
01:42:06 2030s?
01:42:07 Yeah.
01:42:09 This is incredible. This is incredible. Let me ask about black holes.
01:42:17 So what we’re talking about is observing orbiting black holes. I saw the terminology of like
01:42:27 binary black hole systems.
01:42:28 Binary black holes.
01:42:29 Is that the one that’s when they’re dancing? Okay.
01:42:33 They’re both going around each other, just like the earth around the sun.
01:42:36 Okay. Is that weird that there’s black holes going around each other?
01:42:40 So the finding binary systems of stars is similar to finding binary systems of…
01:42:45 Of black holes.
01:42:46 Well, they were once stars. So we haven’t said what a black hole is physically yet.
01:42:55 Yeah. What’s a black hole?
01:42:56 So black hole is first, it’s a mathematical concept or a physical concept. And that is
01:43:03 a region of space. So it’s simply a region of space where the curvature of space time,
01:43:10 meaning the gravitational field is so strong that nothing can get out, including light.
01:43:19 And there’s light gets bent if the space time is warped enough.
01:43:26 And so even light gets bent around and stays in it. So that’s the concept of a black hole.
01:43:33 And maybe you can make… So that’s a concept that didn’t say how they come about.
01:43:40 And there could be different ways they come about. The ones that we are seeing,
01:43:48 we’re not sure. That’s what we’re trying to learn now is what they…
01:43:52 But the general expectation is that they come… These black holes happen when a star dies.
01:44:02 So what does that mean that a star dies? What happens? A star like our sun
01:44:08 basically makes heat and light by fusion. It’s made up. And as it burns, it burns up the hydrogen
01:44:17 and then the helium and slowly works its way up to the heavier and heavier elements that are
01:44:24 in the star. And when it gets up to iron, the fusion process doesn’t work anymore.
01:44:30 And so the stars die and that happens to stars. And then they do what’s called a supernova.
01:44:37 What happens then is that a star is a delicate balance between an outward pressure from fusion
01:44:43 and light and burning and an inward pressure of gravity trying to pull the
01:44:51 masses together. Once it burns itself out, it goes and it collapses and that’s a supernova.
01:44:57 When it collapses, all the mass that was there is in a very much smaller space. And if a star,
01:45:05 if you do the calculations, if a star is big enough, that can create a strong enough
01:45:11 gravitational field to make a black hole. Our sun won’t. It’s too small.
01:45:17 Too small.
01:45:19 And we don’t know exactly what, but it’s usually thought that a star has to be at least three
01:45:26 times as big as our sun to make a black hole. But that’s the physical way there.
01:45:32 You can make black holes. That’s the first
01:45:34 explanation that one would give for what we see,
01:45:41 but it’s not necessarily true. We’re not sure yet.
01:45:45 What we see in terms of, for the origins of black holes?
01:45:48 No, the black holes that we see in gravitational waves.
01:45:52 So the, but you’re also looking for the ones who are binary solar systems.
01:45:56 So they’re binary systems, but they could have been made from binary stars. So there’s binary
01:46:01 stars around. So that’s, so that’s the first explanation is that that’s what they are.
01:46:07 Gotcha.
01:46:09 Other explanations, but what we see has some puzzles. This is kind of the way science works,
01:46:16 I guess. We see heavier ones than up to, we’ve seen one system that was 140 times the mass of
01:46:29 our own sun. That’s not believed to be possible with the parent being a big star because big
01:46:39 stars can only be so big or they are unstable. It’s just the fact that they live in an environment
01:46:49 that makes them unstable. So the fact that we see bigger ones, they may be come from something else.
01:46:55 It’s possible that they were made in a different way by little ones eating each other up or maybe
01:47:04 they were made or maybe they came with the big bang. The prime, what we call primordial, which
01:47:11 means they’re really different. They came from that. We don’t know at this point if they came
01:47:16 with a big bang, then maybe they account for what we call dark matter or some of it.
01:47:21 Hmm. Like there was a lot of them if they came with it because there’s a lot of dark matter.
01:47:26 Yeah.
01:47:27 But will gravitational waves give you any kind of intuition about the origin of these oscillating?
01:47:34 We think that if we see the distributions enough of them, the distributions of their
01:47:40 masses, the distributions of how they’re spinning, so we can actually measure when they’re going
01:47:45 around each other, whether they’re spinning like this or whether the whole system has any wobbles.
01:47:55 What? So this is now. Okay.
01:48:00 We’re doing that.
01:48:01 And then you’re constantly kind of crawling back and back in time.
01:48:04 And we’re crawling back in time and seeing how many there are as we go back. And so do they
01:48:09 point back.
01:48:10 So you’re like, what is that discipline called, cartography or something? You’re like mapping
01:48:15 this, the early universe via the lens of gravitational waves.
01:48:21 Not yet the early universe, but at least back in time.
01:48:24 Earlier.
01:48:24 Yeah. So black holes are this mathematical phenomenon, but they come about in different
01:48:32 ways. We have a huge black hole at the center of our galaxy and other galaxies. Those probably
01:48:39 were made some other way. We don’t know when the galaxies themselves had to do with the
01:48:44 formation of galaxies. We don’t really know. So the fact that we use the word black hole,
01:48:50 the origin of black holes might be quite different depending on how they happen. They just have
01:48:56 to in the end have a gravitational field that will bend everything in.
01:49:01 How do you feel about black holes as a human being? There’s this thing that’s nearly
01:49:06 infinitely dense, doesn’t let light escape. Isn’t that kind of terrifying? It feels like
01:49:13 the stuff in nightmares.
01:49:14 I think it’s an opportunity.
01:49:19 To do what exactly?
01:49:21 So like the early universe is an opportunity. If we can study the early universe, we can
01:49:26 learn things like I told you. And here again, we have an embarrassing situation in physics.
01:49:32 We have two wonderful theories of physics, one based on quantum mechanics, quantum field
01:49:39 theory. And we can go to a big accelerator like at CERN and smash particles together
01:49:46 and almost explain anything that happens beautifully using quantum field theory and
01:49:51 quantum mechanics. Then we have another theory of physics called general relativity, which
01:49:57 is what we’ve been talking about most of the time, which is fantastic at describing the
01:50:02 things at high velocities, long distances, and so forth. So that’s not the way it’s
01:50:12 supposed to be. We’re trying to create a theory of physics, not two theories of physics.
01:50:18 So we have an embarrassment that we have two different theories of physics. People have
01:50:22 tried to make a unified theory, what they call a unified theory. You’ve heard those
01:50:28 words for decades. They still haven’t. That’s been primarily done theoretically or tried.
01:50:36 People actively do that. My personal belief is that like much of physics, we need some
01:50:44 clues. So we need some experimental evidence. So where is there a place? If we go to CERN
01:50:51 and do those experiments, gravitational waves or general relativity don’t matter. If we
01:50:56 go to study our black holes, elementary particle physics doesn’t matter. We’re studying these
01:51:02 huge objects. So where might we have a place where both phenomena have to be satisfied?
01:51:09 An example is black holes. Inside black holes. Yeah. So we can’t do that today. But when
01:51:15 I think of black hole, it’s a potential treasure chest of understanding the fundamental problems
01:51:24 of physics and maybe can give us clues to how we bring to the embarrassment of having
01:51:32 two theories of physics together. That’s my own romantic idea. What’s the worst that could
01:51:38 happen? It’s so enticing. Just go in and look. Do you think, how far are we away from
01:51:45 figuring out the unified theory of physics, the theory of everything? What’s your sense?
01:51:50 Who will solve it? Like what discipline will solve it? Yeah. I think so little progress
01:52:02 has been made without more experimental clues, as I said, that we’re just not able to say
01:52:16 that we’re close without some clues. The most popular theory these days that might lead
01:52:26 to that is called string theory. The problem with string theory is it solves a lot of beautiful
01:52:34 mathematical problems we have in physics. It’s very satisfying theoretically, but it
01:52:46 has almost no predictive, maybe no predictive ability because it is a theory that works
01:52:53 in 11 dimensions. We live in a physical world of three space and one time dimension. In
01:53:02 order to make predictions in our world with string theory, you have to somehow get rid
01:53:08 of these other seven dimensions. That’s done mathematically by saying they curl up on each
01:53:15 other on scales that are too small to affect anything here. That’s an okay argument, but
01:53:23 how you do that is not unique. That means if I start with that theory and I go to our
01:53:30 world here, I can’t uniquely go to it. And if I can’t, it’s not predictive. And that’s
01:53:37 actually a killer. That’s a killer. And string theory is, it seems like from my outsider’s
01:53:42 perspective has lost favor over the years, perhaps because of this very idea. It’s a
01:53:46 lack of predictive power. I mean, that science has to connect to something where you make
01:53:52 predictions as beautiful as it might be. So I don’t think we’re close. I think we need
01:53:59 some experimental clues. It may be that information on something we don’t understand presently
01:54:07 at all, like dark energy or probably not dark matter, but dark energy or something might
01:54:12 give us some ideas. But I can’t envision right now in the short term, meaning the horizon
01:54:26 that we can see how we’re going to bring these two theories together.
01:54:31 A kind of a two part question, maybe just asking the same thing in two different ways.
01:54:38 One question is, do you have hope that humans will colonize the galaxy? So expand out, become
01:54:47 a multi planetary species. Another way of asking that from a gravitational and a propulsion
01:54:53 perspective, do you think we’ll come up with ways to travel closer to the speed of light
01:54:57 or maybe faster than the speed of light, which would make it a whole heck of a lot easier
01:55:02 to expand out into the universe?
01:55:06 Yeah. Well, I think that’s very futuristic. I think we’re not that far from being able
01:55:17 to make a one way trip to Mars. That’s then a question of whether people are willing to
01:55:29 send somebody on a one way trip.
01:55:31 Oh, I think they are. There’s a lot of the explorers burned bright within our hearts.
01:55:36 Yeah, exactly.
01:55:37 There’s a lot of people willing to die for the opportunity to explore new territory.
01:55:42 So this recent landing on Mars is pretty impressive. They have a little helicopter. They’re going
01:55:51 to fly around. You can imagine in the not too distant future that you could have, I
01:55:57 don’t think civilizations colonizing, I can envision, but I can envision something more
01:56:04 like the South Pole. We haven’t colonized Antarctica because it’s all ice and cold and
01:56:12 so forth. But we have stations. So we have a station that’s self sustaining at the South
01:56:19 Pole. I’ve been there. It has.
01:56:22 Wow, really?
01:56:23 Yeah.
01:56:24 What’s that like? Because there’s parallels there to go to Mars.
01:56:30 It’s fantastic.
01:56:31 What’s the journey like?
01:56:33 The journey involves going. The South Pole station is run in the US by the National Science
01:56:41 Foundation. I went because I was on the National Science Board that runs the National Science
01:56:48 Foundation. And so you get a VIP trip if you’re healthy enough to the South Pole to see it,
01:56:56 which I took. You fly from the US to Australia to Christchurch in Southern Australia. And
01:57:08 from there you fly to McMurdo Station, which is on the coast. And it’s the station with
01:57:13 about a thousand people right on the coast of Antarctica. It’s about a seven or eight
01:57:20 hour flight and they can’t predict the weather. So when I flew from Christchurch to McMurdo
01:57:28 Station, they tell you in advance, you do it in a military aircraft, they tell you in
01:57:32 advance that they can’t predict whether they can land because they have to land on ice.
01:57:37 And reassuring.
01:57:38 Yeah. And so about halfway the pilot got on and said, sorry, this is a, they call it a
01:57:46 boomerang flight. You know, boomerang goes out and goes back. So we had to stay a little
01:57:52 while in Christchurch, but then we eventually went to McMurdo Station and then flew to the
01:57:59 South Pole. The South Pole itself is, when I was there, it was minus 51 degrees. That
01:58:07 was summer. Zero humidity. And it’s about 11,000 feet altitude because it’s never warm
01:58:26 enough for anything to melt. So it doesn’t snow very much, but it’s about 11,000 feet
01:58:32 of snowpack. So you land in a place that’s high altitude, cold as could be, and incredibly
01:58:41 dry, which means you have a physical adjustment. The place itself is fantastic. They have this
01:58:52 great station there. They do astronomy at the South Pole. Nature wise, is it beautiful?
01:59:00 What’s the experience like? Or is it like visiting any town? No, it’s very small. There’s
01:59:05 only less than a hundred people there. Even when I was there, there were about 50 or 60
01:59:13 there. And in the winter, there’s less, half of that. Their winter. Yeah. It gets real
01:59:18 cold. It gets really cold, yeah. But it’s a station. And I think, and that’s, I mean,
01:59:28 we haven’t gone beyond that. On the coast of Antarctica, they have greenhouses and they’re
01:59:33 self sustaining in McMurdo Station, but we haven’t really settled more than that kind
01:59:40 of thing in Antarctica, which is a big country or a big plot, a big piece of land. So I don’t,
01:59:55 I can’t envision kind of colonizing at people living so much, as much as I can see the equivalent
02:00:04 of the South Pole Station. Well, in the computing world, there’s an idea of backing up your
02:00:10 data and then you want to do offsite backup, to make sure that if the whole thing burns,
02:00:16 if your whole house burns down, that you can have a backup offsite of the data. I think
02:00:21 the difference between Antarctica and Mars is Mars is an offsite backup. That if we have
02:00:28 nuclear war, whatever the heck might happen here on earth, it’d be nice to have a backup
02:00:32 elsewhere. And it’d be nice to have a large enough colony where we sent a variety of people
02:00:38 except a few silly astronauts in suits, have an actual vibrant, get a few musicians and
02:00:48 artists up there, get a few, maybe like one or two computer scientists, those are essential.
02:00:53 Maybe even a physicist, but I’m not sure.
02:00:56 Yeah, maybe not. So that comes back to something you talked about earlier, which is the paradox,
02:01:02 Fermi’s paradox, because you talked about having to escape. And so one number you don’t
02:01:10 know how to use in Fermi’s calculation or Drake, who’s done it better, is how long do
02:01:15 civilizations last? We’ve barely gotten to where we can communicate with electricity
02:01:24 and magnetism and maybe we’ll wipe ourselves out pretty soon.
02:01:28 Are you hopeful in general? Like you think we’ve got another couple of hundred years
02:01:32 at least? Or are you worried?
02:01:35 Well, no, I’m hopeful, but I don’t know if I’m hopeful in the longterm. If you say, are
02:01:47 we able to go for another couple of thousand years? I’m not sure. I think we have where
02:01:55 we started, the fact that we can do things that don’t allow us to kind of keep going
02:02:00 or there can be, whether it ends up being a virus that we create or ends up being the
02:02:06 equivalent of nuclear war or something else. It’s not clear that we can control things
02:02:11 well enough.
02:02:13 So speaking of really cold conditions and not being hopeful and eventual suffering and
02:02:20 destruction of the human species, let me ask you about Russian literature. You mentioned,
02:02:26 how’s that for transition? I’m doing my best here. You mentioned that you used to love
02:02:30 literature when you were younger and you even were hoping to be a writer yourself. That
02:02:36 was the motivation. And some of the books I’ve seen that you listed that were inspiring
02:02:43 to you was from Russian literature, like Tolstoy, Dostoevsky, Solzhenitsyn. Maybe in general
02:02:52 you can speak to your fascination with Russian literature or in general what you picked up
02:02:57 from those.
02:02:58 I’m not surprised you picked up on the Russian literature, your background, but that’s okay.
02:03:08 You should be surprised I didn’t make the entire conversation about this. That’s the
02:03:12 real surprise.
02:03:13 Yeah. When I didn’t really become a physicist or want to go in science until I started college.
02:03:24 So when I was younger, I was good at math and that kind of stuff, but I didn’t really,
02:03:29 I came from a family, nobody went to college and I didn’t have any mentors. But I liked
02:03:36 to read when I was really young. And so when I was very young, I always carried around
02:03:42 a pocket book and read it. And my mother read these mystery stories and I got bored by those
02:03:49 eventually. And then I discovered real literature. I don’t know what age, but about 12 or 13.
02:03:55 And so then I started reading good literature and there’s nothing better than Russian literature,
02:04:00 of course.
02:04:01 Thank you.
02:04:02 Reading good literature. So I read quite a bit of Russian literature at that time. And
02:04:16 so you asked me about, well, I don’t know, I’ll say a few words, Dostoevsky. So what
02:04:22 about Dostoevsky? For me, Dostoevsky was important in two, I mean, I’ve read a lot of literature
02:04:33 because it’s kind of the other thing I do with my life. And he made two incredible,
02:04:39 in addition to his own literature, he influenced literature tremendously by having, I don’t
02:04:46 know how to pronounce polyphony. So he’s the first real serious author that had multiple
02:04:53 narrators. And he absolutely is the first. And he also was the first, he began existential
02:05:05 literature. So the most important book that I’ve read in the last year when I’ve been
02:05:12 forced to be isolated was existential literature. I decided to reread Camus, The Plague.
02:05:20 Oh, yeah. That’s a great book.
02:05:23 It’s a great book and it’s right now to read it. It’s fantastic.
02:05:26 I think that book is about love, actually. Love for humanity.
02:05:30 It is, but it has all the, if you haven’t read it in recent years, I had read it before,
02:05:37 of course, but to read it during this, because it’s about a plague. So it’s really fantastic
02:05:43 to read down. But that reminds me of, he was a great existentialist, but the beginning
02:05:48 of existential literature was Dostoevsky.
02:05:50 Dostoevsky, yeah.
02:05:51 So in addition to his own great novels, he had a tremendous impact on literature.
02:06:00 And there’s also for Dostoevsky, unlike most other existentialists, he was at least in
02:06:06 part religious. I mean, religiosity permeated his idea. I mean, one of my favorite books
02:06:12 of his is The Idiot, which is a Christlike figure in there.
02:06:16 Well, there’s Prince Mishkin, is that his name?
02:06:19 Prince Mishkin, yeah.
02:06:20 Yeah, Mishkin.
02:06:21 Yeah, Mishkin.
02:06:22 Yeah.
02:06:23 That’s one thing about, you read it in English, I presume.
02:06:25 Yeah, yeah.
02:06:26 Yeah. So the names, that’s what gets a lot of people. There’s so many names, so hard
02:06:30 to pronounce. You have to remember all of them. It’s like you have the same problem.
02:06:35 But he was a great character.
02:06:38 I kind of have a connection with him, because I often, the title of the book, The Idiot,
02:06:47 is I kind of, I often call myself an idiot, because that’s how I feel. I feel so naive
02:06:52 about this world. And I’m not sure, I’m not sure why that is. Maybe it’s genetic or so
02:06:59 on. But I have a connection, a spiritual connection to that character.
02:07:05 To Mishkin.
02:07:06 To Mishkin, yeah.
02:07:07 But he was far from an idiot.
02:07:10 No, in some sense, in some sense. But in another sense, maybe not of this world.
02:07:17 In another sense he was. I mean, he was a bumbler, a bunker.
02:07:23 But you also mentioned Solzhenitsyn, very interesting.
02:07:28 And he always confused me. Of course, he was really, really important in writing about
02:07:36 Stalin, and first getting in trouble, and then later he wrote about Stalin in a way,
02:07:48 I forget what the book was, in a way that was very critical of Lenin.
02:07:55 Yeah, he’s evolved through the years, and he actually showed support for Putin eventually.
02:08:00 It was a very interesting transition he took, no, journey he took through thinking about
02:08:08 Russia and the Soviet Union. But I think what I get from him is basic, it’s like Viktor
02:08:17 has this man’s search for meaning. I have a similar kind of sense of the cruelty of
02:08:25 human nature, cruelty of indifference, but also the ability to find happiness in the
02:08:31 small joys of life. That’s something, there’s nothing like a prison camp that makes you
02:08:37 realize you could still be happy with a very, very little.
02:08:41 Yeah, his description of how to go through a day and actually enjoy it in a prison camp
02:08:50 is pretty amazing. And some prison camp, it’s the worst of the worst.
02:08:56 And also, I do think about the role of authoritarian states in hopeful idealistic systems somehow
02:09:09 leading to the suffering of millions. And this might be arguable, but I think a lot
02:09:16 of people believe that Stalin, I think, genuinely believed that he’s doing good for the world.
02:09:24 And he wasn’t. It’s a very valuable lesson that even evil people think they’re doing
02:09:32 good. Otherwise, it’s too difficult to do the evil. The best way to do evil is to believe
02:09:38 about framing it in a way like you’re doing good. And then this is a very clear picture
02:09:44 of that, which is the gulags. And Solzhenitsyn is one of the best people to reveal that.
02:09:53 The most recent thing I read, it isn’t actually fiction, was the woman, I can’t remember
02:09:58 her name, who got the Nobel Prize about within the last five years. I don’t know whether
02:10:04 she’s Ukrainian or Russian, but there are interviews. Have you read that?
02:10:09 Interview of Ukrainian survivors of…
02:10:12 Well, I think she may be originally Ukrainian. The book’s written in Russian and translated
02:10:18 in English, and many of the interviews are in Moscow and places. But she won the Nobel
02:10:23 Prize within the last five years or so. But what’s interesting is that these are people
02:10:31 of all different ages, all different occupations and so forth, and they’re reflecting on their
02:10:39 reaction to basically the present Soviet system, the system they lived with before.
02:10:45 There’s a lot of looking back by a lot of them with, well, it being much better before.
02:10:57 Yeah. I don’t know what… In America, we think we know the right answer, what it means
02:11:05 to be, to build a better world. I’m not so sure. I think we’re all just trying to figure
02:11:11 it out.
02:11:12 Yeah, there’s…
02:11:13 We’re doing our best.
02:11:14 I think you’re right.
02:11:17 Is there advice you can give to young people today, besides reading Russian literature
02:11:23 at a young age, about how to find their way in life, how to find success in Korea or just
02:11:29 life in general?
02:11:37 My own belief, it may not be very deep, but I believe it. I think you should follow your
02:11:43 dreams and you should have dreams and follow your dreams if you can, to the extent that
02:11:48 you can. And we spend a lot of our time doing something with ourselves. In my case, physics,
02:11:55 in your case, I don’t know, whatever it is, machine learning and this. Yeah, you should
02:12:04 have fun.
02:12:05 What was… Wait, wait, wait. Follow your dreams. What dream did you have? Because there’s…
02:12:12 Well, originally, I was…
02:12:14 Because you didn’t follow your dream. I thought you were supposed to be a writer.
02:12:16 I changed along the way. I was gonna be, but I changed.
02:12:20 What happened?
02:12:21 That was… What happened? Oh, I read… I decided to take the most serious literature
02:12:28 course in my high school, which was a mistake. I’d probably be a second rate writer now.
02:12:34 And…
02:12:35 Could be a Nobel Prize winning writer.
02:12:37 And the book that we read, even though I had read Russian novels, I was 15, I think, cured
02:12:50 me from being a novelist.
02:12:53 Destroyed your dream?
02:12:54 Yes.
02:12:55 Cured you. Okay. What was the book?
02:12:56 Moby Dick.
02:12:57 Okay.
02:12:58 So, why Moby Dick?
02:13:00 Yeah, why?
02:13:01 So, I’ve read it since, and it’s a great novel. Maybe it’s as good as the Russian novels.
02:13:07 I’ve never made it through. It was too boring. It was too long.
02:13:11 Okay. Your words are gonna mesh with what I say.
02:13:14 Excellent.
02:13:15 And you may have the same problem at older ages.
02:13:17 That’s why I’m not a writer.
02:13:19 It may be. So, the problem is, Moby Dick is… What I remember was there was a chapter that
02:13:27 was maybe 100 pages long, all describing this, why there was Ahab and the white whale, and
02:13:34 it was the battle between Ahab with his wooden peg leg and the white whale.
02:13:39 And there was a chapter that was 100 pages long in my memory, I don’t know how long it
02:13:43 really was, that described in detail, though, great white whale and what he was doing and
02:13:49 what his fins were like and this and that.
02:13:52 And it was so incredibly boring, the word you used, that I thought, if this is great
02:13:58 literature, screw it.
02:14:00 Fascinating.
02:14:01 Okay. And now, why did I have a problem? I know now in reflection, because I still read
02:14:06 a lot, and I read that novel after I was 30 or 40 years old, and the problem was simple.
02:14:18 I diagnosed what the problem was. That novel, in contrast to the Russian novels, which are
02:14:25 very realistic and point of view, is one huge metaphor.
02:14:32 At 15 years old, I probably didn’t know the word, and I certainly didn’t know the meaning
02:14:37 of metaphor.
02:14:38 Yeah, like, why do I care about a fish? Why are you telling me all about this fish?
02:14:42 Exactly. It’s one big metaphor. So, reading it later as a metaphor, I could really enjoy
02:14:47 it. But the teacher gave me the wrong book, or maybe it was the right book because I went
02:14:51 into physics. But it was truly, I think, I may oversimplify, but it was really that I
02:14:59 was too young to read that book. Not too young to read the Russian novels, interestingly,
02:15:04 but too young to read that because I probably didn’t even know the word, and I certainly
02:15:08 didn’t understand it as a metaphor.
02:15:10 Well, in terms of fish, I recommend people read Old Man and the Sea, much shorter, much
02:15:15 better. It’s still a metaphor, though. But you can read it just as a story about a guy
02:15:21 catching a fish, and it’s still fun to read. I had the same experience as you, not with
02:15:29 Moby Dick, but later in college, I took a course on James Joyce. Don’t ask me why. I
02:15:34 was majoring in computer science, I took a course on James Joyce. And I was kept being
02:15:38 told that he is widely considered, by many considered, to be the greatest literary writer
02:15:46 of the 20th century. And I kept reading, I think, so his short story is The Dead, I think
02:15:52 it’s called. It was very good. Well, not very good, but pretty good. And then Ulysses.
02:15:57 It’s actually very good.
02:15:58 It is very good. Only The Dead, the final story, it still rings with me today. But then
02:16:02 Ulysses was, I got through Ulysses with the help of some Cliff Notes and so on. And so
02:16:09 I did Ulysses and then Finnegan’s Wake. The moment I started Finnegan’s Wake, I said,
02:16:14 this is stupid. That’s when I went full into like, I don’t know, that’s when I went full
02:16:22 Kafka, Bukowski, like people who just talk about the darkness of the human condition
02:16:28 in the fewest words possible and without any of the music of language. So it was a turning
02:16:36 point as well. I wonder when is the right time to appreciate the beauty of language.
02:16:45 Like even Shakespeare. I was very much off put by Shakespeare in high school and only
02:16:49 later I started to appreciate its value in the same way. Let me ask you a ridiculous
02:16:55 question. Okay. I mean, because you’ve read Russian literature, let me ask this one last
02:17:04 question. I might be lying. There might be a couple more, but what do you think is the
02:17:10 meaning of this whole thing? You got a Nobel prize for looking out into the, trying to
02:17:17 reach back into the beginning of the universe, listening to the gravitational waves, but
02:17:24 that still doesn’t answer the why. Why are we here? Beyond just the matter and anti matter,
02:17:33 the philosophical question.
02:17:35 The philosophical question about the meaning of life, I’m probably not really good at.
02:17:42 I think that the individual meaning, I would say it rather simplistically is whether you’ve
02:17:56 made a difference, a positive difference, I’d say for anything besides yourself. Meaning
02:18:05 you could have been important to other people or you could have discovered gravitational
02:18:11 waves that matters to other people or something, but something beyond just existing on the
02:18:16 earth as an individual. So your life has meaning if you have affected either knowledge or people
02:18:27 or something beyond yourself. It’s a simplistic statement, but it’s about as good as I can
02:18:35 say. In all of its simplicity, it may be very true. Does it make you sad that this ride
02:18:46 ends? Do you think about your mortality? Are you afraid of it?
02:18:55 Not exactly afraid of it, but saddened by it. I’m old enough to know that I’ve lived
02:19:06 most of my life and I enjoy being alive. I can imagine being sick and not wanting to
02:19:14 be alive, but I’m not.
02:19:17 It’s been a good ride.
02:19:23 I’m not happy to see it come to an end. I’d like to see it prolong, but I don’t fear the
02:19:35 dying itself or that kind of thing. It’s more, I’d like to prolong what is I think a good
02:19:44 life that I’m living and still living.
02:19:51 It’s sad to think that the finiteness of it is the thing that makes it special. And also
02:20:01 sad to me, at least it’s kind of, I don’t think I’m using too strong of a word, but
02:20:08 it’s kind of terrifying the uncertainty of it. The mystery of it, the mystery of death.
02:20:15 The mystery of it, yeah, of death. When we’re talking about the mystery of black holes that’s
02:20:20 somehow distant, that’s somehow out there and the mystery of our own.
02:20:25 But even life, the mystery of consciousness, I find so hard to deal with too. I mean, it’s
02:20:31 not as painful. I mean, we’re conscious, but the whole magic of life we can understand,
02:20:37 but consciousness where we can actually think and so forth. It’s pretty.
02:20:43 It seems like such a beautiful gift that it really sucks that we get to let go of it.
02:20:48 We have to let go of it. What do you hope your legacy is? As I’m sure they will. Aliens
02:20:54 when they visit and humans have destroyed all of human civilization. Aliens read about
02:20:59 you in an encyclopedia that we’ll leave behind. What do you hope it says?
02:21:03 Well, I would hope they, to the extent that they evaluated me, felt that I helped move
02:21:12 science forward as a tangible contribution and that I served as a good role model for
02:21:22 how humans should live their lives.
02:21:25 And we’re part of creating one of the most incredible things humans have ever created.
02:21:31 So yes, there’s the science. That’s the Fermi thing, right?
02:21:36 And the instrument, I guess.
02:21:38 And the instrument. The instrument is a magical creation, not just by a human, by a collection
02:21:43 of humans. The collaboration is, that’s humanity at its best. I do hope we last quite a bit
02:21:58 longer, but if we don’t, this is a good thing to remember humans by. At least they built
02:22:05 that thing. That’s pretty impressive. Barry, this is an amazing conversation. Thank you
02:22:10 so much for wasting your time and explaining so many things so well. I appreciate your
02:22:14 time today.
02:22:15 Thank you.
02:22:17 Thanks for listening to this conversation with Barry Barish. To support this podcast,
02:22:22 please check out our sponsors in the description. And now let me leave you with some words from
02:22:28 Werner Heisenberg, a theoretical physicist and one of the key pioneers of quantum mechanics.
02:22:35 Not only is the universe stranger than we think, it is stranger than we can think. Thank
02:22:43 you for listening and hope to see you next time.