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Barry Barish: Gravitational Waves and the Most Precise Device Ever Built | Lex Fridman Podcast #213


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The following is a conversation with Barry Barish, a theoretical physicist at Caltech
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and the winner of the Nobel Prize in Physics for his contributions to the LIGO detector
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and the observation of gravitational waves. LIGO, or the Laser Interferometer Gravitational Wave
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Observatory, is probably the most precise measurement device ever built by humans.
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It consists of two detectors with four kilometer long vacuum chambers situated three thousand
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kilometers apart, operating in unison to measure a motion that is ten thousand times smaller than
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the width of a proton. It is the smallest measurement ever attempted by science,
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a measurement of gravitational waves caused by the most violent and cataclysmic events
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in the universe, occurring over tens of millions of light years away.
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To support this podcast, please check out our sponsors in the description.
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This is the Lex Friedman Podcast and here is my conversation with Barry Barish.
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Yeah, that memory is kind of something I use to illustrate something I think is common in science,
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that people that do science somehow have maintained something that kids always have.
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A small kid, eight years old or so, asks you so many questions usually, typically, that you
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consider them pests. You tell them to stop asking so many questions. And somehow our system manages
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to kill that in most people. So in school, we make people study and do their things,
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but not to pester them by asking too many questions. And I think, not just myself,
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but I think it's typical of scientists like myself that have somehow escaped that. Maybe
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we're still children or maybe we somehow didn't get it beaten out of us. But I teach it in college
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level and it's, to me, one of the biggest deficits is the lack of curiosity, if you want,
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that we've beaten out of them because I think it's an innate human quality.
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Is there some advice or insights you can give to how to keep that flame of curiosity going?
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I think it's a problem of both parents and that parents should realize that's a great quality we
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have. That you're curious and that's good. Instead, we have expressions like curiosity
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killed the cat and more. But basically, it's not thought to be a good thing. Curiosity
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killed the cat means if you're too curious, you get in trouble.
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I don't like cats anyway, so maybe it's a good thing.
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Yeah. That, to me, needs to be solved, really, in education and in homes. It's a realization
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that there's certain human qualities that we should try to build on and not destroy. One of
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them is curiosity. Anyway, back to me and curiosity. I was a pest and asked a lot of
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questions. My father generally could answer them at that age. And the first one I remember that he
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couldn't answer was not a very original question, but basically that ice is made out of water,
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and so why does it float on water? He couldn't answer it. It may not have been the first
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question. It's the first one that I remember. And that was the first time that I realized that
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to learn and answer your own curiosity or questions, there's various mechanisms. In
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this case, it was going to the library or asking people who know more and so forth. But
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eventually, you do it by what we call research. But it's driven by, hopefully, you ask good
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questions. If you ask good questions and you have the mechanism to solve them, then you do what I
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do in life, basically, not necessarily physics. And it's a great quality in humans, and we should
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nurture it. Do you remember any other kind of in high school, maybe early college, more basic
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physics ideas that sparked your curiosity or mathematics or science in general?
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I wasn't really into science until I got to college, to be honest with you. But
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just staying with water for a minute, I remember that I was curious what happens to water. It rains
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and there's water in a wet pavement, and then the pavement dries out. What happened to this
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water that came down? And I didn't know that much. And then eventually, I learned in chemistry or
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something, water is made out of hydrogen and oxygen. Those are both gases. So how the heck
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does it make this substance? It's liquid. Yeah, so that has to do with states of matter.
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I know perhaps LIGO and the thing for which you've gotten the Nobel Prize and the things
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much of your life work perhaps was a happy accident in some sense in the early days. But
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is there a moment where you looked up to the stars and also, the same way you wondered about water,
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wondered about some of the things that are out there in the universe?
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Oh, yeah, I think everybody looks and is in awe and is curious about what it is out there. And
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as I learned more, I learned, of course, that we don't know very much about what's there. And the
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more we learn, the more we know we don't know. I mean, we don't know what the majority of anything
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is out there. It's all what we call dark matter and dark energy. And that's one of the big
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questions. When I was a student, those weren't questions. So we even know less, in a sense,
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the more we look. So of course, I think that's one of the areas that almost it's universal.
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People see the sky, they see the stars and they're beautiful and see it looks different
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on different nights. And it's a curiosity that we all have.
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What are some questions about the universe that in the same way that you felt about the ice
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that today? You mentioned to me offline, you're teaching a course on the frontiers of science,
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frontiers of physics. What are some questions outside the ones we'll probably talk about that
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kind of, yeah, fill you with the, get your flame of curiosity up and firing up, you know,
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fill you with awe? Well, first, I'm a physicist, not an astronomer. So I'm interested in the
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physical phenomenon, really. So the question of dark matter and dark energy, which we probably
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won't talk about, our recent last 20, 30 years, certainly dark energy. Dark energy is a complete
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puzzle. It goes against what you will ask me about, which is general relativity and Einstein's
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general relativity. It basically takes something that he thought was what he called a constant,
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which isn't. And if that's even the right theory, and it represents most of the universe. And then
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we have something called dark matter, and there's good reason to believe it might be an exotic form
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of particles. And that is something I've always worked on, on particle accelerators and so forth.
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And it's a big puzzle, what it is. It's a bit of a cottage industry in that there's lots and lots
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of searches, but it may be a little bit like, you know, looking for a treasure under rocks or
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something. You don't, it's hard to, we don't have really good guidance, except that we have very,
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very good information that is pervasive and it's there. And that it's probably particles, small,
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that the evidence is all of those things. But then the most logical solution doesn't seem to work,
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something called supersymmetry. And do you think the answer could be something very complicated?
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You know, I like to hope that, think that most things that appear complicated are actually
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simple if you really understand them. I think we just don't know at the present time, and it isn't
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something that affects us. It does affect, it affects how the stars go around each other and so
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forth, because we detect that there's missing gravity, but it doesn't affect everyday life at
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all. I tend to think and expect maybe, and that the answers will be simple. We just haven't found
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it yet. Do you think those answers might change the way we see other sources of gravity, black holes,
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the way we see the parts of the universe that we do study? It's conceivable. The black holes that
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we've found in our experiment, we're trying now to understand the origin of those. It's conceivable,
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but doesn't seem the most likely that they were primordial, that is, they were made at the
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beginning. And in that sense, they could represent at least part of the dark matter.
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So there can be connections, dark black holes or how many there are, how much of the mass they
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encompass is still pretty primitive. We don't know. So before I talk to you more about black holes,
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let me take a step back to, I actually went to high school in Chicago and would go to
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take classes at Fermilab, watch the buffalo and so on. So let me ask about, you mentioned that Enrico
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for me was somebody who was inspiring to you in a certain kind of way. Why is that? Can you speak
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to that? Sure. He was amazing, actually. He's the last, I'll come to the reason in a minute, but
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he had a big influence on me at a young age. But he was the last physicist of note that was both
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an experimental physicist and a theorist at the same time. And he did two amazing things within
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months in 1933. We didn't really know what the nucleus was, what radioactive decay was,
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what beta decay was when electrons come out of a nucleus. And near the end of 1933, the neutron had
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just been discovered. And that meant that we knew a little bit more about what the nucleus is, that
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it's made out of neutrons and protons. The neutron wasn't discovered till 1932. And then once we
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discovered that there was a neutron and proton and they made the nucleus and then their electrons
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that go around, the basic ingredients were there. And he wrote down not only just the theory,
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a theory, but a theory that lasted decades and has only been improved on of beta decay, that is,
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the radiation. He did this, came out of nowhere, and it was a fantastic theory. He submitted it
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to Nature magazine, which was the primary best place to publish even then. And it got rejected
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as being too speculative. And so he went back to his drawing board in Rome where he was,
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added some to it, made it even longer, because it's really a classic article, and then published
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it in the local Italian journal for physics and the German one. At the same time, in January of
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1932, Giulio and Curie, for the first time, saw artificial radioactivity. This was an important
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discovery because radioactivity had been discovered much earlier. They had x rays and you
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shouldn't be using them, but there was radioactivity. People knew it was useful for medicine.
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But radioactive materials are hard to find, and so it wasn't prevalent. But if you could make them,
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they had great use. And Giulio and Curie were able to bombard aluminum or something with alpha
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particles and find that they excited something that decayed and had some half life and so forth,
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meaning it was artificial version, or let's call it not a natural version, an induced version of
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radioactive materials. And Fermi somehow had the insight, and I still can't see where he got it,
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that the right way to follow that up was not using charged particles like alphas and so forth,
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but use these newly discovered neutrons as the bombarding particle. It seemed impossible
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they barely had been seen. It was hard to get very many of them. But it had the advantage that
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they're not charged, so they go right into the nucleus. And that turned out to be the experimental
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work that he did that won him the Nobel Prize. And it was the first step in fission, discovery
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of fission. And he did this two completely different things, an experiment that was a great
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idea and a tremendous implementation, because how do you get enough neutrons? And then he learned
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quickly that not only do you want neutrons, but you want really slow ones. He learned that
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experimentally, and he learned how to make slow ones, and then they were able to go through the
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go through the periodic table and make lots of particles. He missed on fission at the moment,
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but he had the basic information, and then fission follows soon after that.
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Forgive me for not knowing, but is the birth of the idea of bombarding with neutrons,
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is that an experimental idea? Was it born out of an experiment? Did he just observe something,
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or is this an Einstein style idea where you come up from basic intuition?
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I think it took a combination, because he realized that neutrons had a characteristic
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that would allow them to go all the way into the nucleus when we didn't really understand
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what the structure was of all this. So that took an understanding or recognition of the physics
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itself of how a neutron interacts compared to, say, an alpha particle that Julio and Curie had
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used. And then he had to invent a way to have enough neutrons, and he had a team of associates,
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and he pulled it off quite quickly. So it was pretty astounding.
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And probably, maybe you can speak to it, his ability to put together the engineering aspects
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of great experiments and doing the theory, they probably fed each other. I wonder,
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can you speak to why we don't see more of that? Is that just really difficult to do?
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It's difficult to do. Yeah, I think in both theory and experiment in physics anyway,
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it was conceivable if you had the right person to do it, and no one's been able to do it since. So
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I had the dream that that was what I was going to be like, Fermi.
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But you love both sides of it, the theory. Yeah, I never liked the idea that you did
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experiments without really understanding the theory, or the theory should be related
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very closely to experiments. And so I've always done experimental work that was closely related
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to the theoretical ideas. I think I told you I'm Russian,
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so I'm going to ask some romantic questions. But is it tragic to you that he's seen as the
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architect of the nuclear age, that some of his creations led to potentially, some of his work
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has led to potentially still the destruction of the human species, some of the most destructive
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weapons? Yeah, I think even more general than him, I gave you all the virtues of curiosity a few
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minutes ago. There's an interesting book called The Ratchet of Curiosity. A ratchet is something
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that goes in one direction. And that is written by a guy who's probably a sociologist or philosopher
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or something. And he picks on this particular problem, but other ones. And that is the danger
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of knowledge, basically. You're curious, you learn something. So it's a little bit like
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curiosity killed the cat. You have to be worried about whether you can handle new information that
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you get. So in this case, the new information had to do with really understanding nuclear physics.
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And that information, maybe we didn't have the sophistication to know how to keep it under
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control. And Fermi himself was a very apolitical person. So he wasn't very driven by, or at least
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he appears in all of his writing, the writing of his wife, the interactions that others had with
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him. Either he avoided it all or he was pretty apolitical. I mean, he just saw the world through
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kind of the lens of a scientist. But he asked if it's tragic. The bomb was tragic, certainly on
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Japan. And he had a role in that. So I wouldn't want it as my legacy, for example. But brought
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it to the human species that it's the ratchet of curiosity that we do stuff just to see what
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happens. That curiosity, that in sort of my area of artificial intelligence, that's been a concern.
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On a small scale, on a silly scale, perhaps currently, there's constantly unintended
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consequences. You create a system and you put it out there and you have intuitions about how
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it will work. You have hopes how it will work, but you put it out there just to see what happens.
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And in most cases, because artificial intelligence is currently not super powerful,
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it doesn't create a large scale negative effects, but that same curiosity as it progresses might
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lead to something that destroys the human species. And the same may be true for bioengineering.
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There's people that engineer viruses to protect us from viruses to see how close is this to
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mutating so it can jump to humans or engineering defenses against those. And it seems exciting and
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the application, the positive applications are really exciting at this time, but we don't think
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about how that runs away in decades to come. Yeah. And I think it's the same idea as this
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little book, The Ratchet of Science, The Ratchet of Curiosity. I mean, whether you pursue,
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take curiosity and let artificial intelligence or machine learning run away with having its
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solutions to whatever you want, or we do it, it's, I think, a similar consequence.
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I think from what I've read about Enrico Fermi, he became a little bit cynical about the human
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species towards the end of his life, both having observed what he observed.
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Well, he didn't write much. I mean, he died young. He died soon after the World War. There was
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already, you know, the work by Teller to develop the hydrogen bomb. And I think he was a little
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cynical of that, you know, pushing it even further and rising tensions between the Soviet Union and
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the U.S. and looked like an endless thing. So, but he didn't say very much, but a little bit,
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as you said. Yeah, there's a few clips to sort of maybe picked on a bad mood, but in a sense that
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almost like a sadness, a melancholy sadness to a hope that waned a little bit about that perhaps we
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can do, like this curious species can find the way out. Well, especially, I think, people who
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worked like he did at Los Alamos and spent years of their life somehow had to convince themselves
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that dropping these bombs would bring lasting peace and that it didn't. Yeah. As a small,
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interesting aside, it'd be interesting to hear if you have opinions on this. His name is also
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attached to the Fermi Paradox, which asks if there is a, you know, it's a very interesting question,
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which is if it does seem if you sort of reason basically that there should be a lot of alien
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civilizations out there. If the human species, if Earth is not that unique by basic, no matter the
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values you pick, it's likely that there's a lot of alien civilizations out there. And if that's the
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case, why have they not at least obviously visited us or sent us loud signals that everybody can
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hear? Fermi's quoted as saying, sitting down at lunch, I think it was with Teller and Herb York,
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who was kind of one of the fathers of the atomic bomb. And he sat down and he said something like,
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where are they? Which meant, where are these other? And then he did some numerology where he
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calculated, you know, how many, what they knew about how many galaxies there are and how many
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stars and how many planets then are like the Earth and blah, blah, blah. That's been done much
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better by somebody named Drake. And so, people usually refer to the, I don't know whether it's
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called the Drake formula or something, but it has the same conclusion. The conclusion is it would
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be a miracle if there weren't other, you know, the statistics are so high that how can we be
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singular and separate? So, probably there is, but there's almost certainly life somewhere. Maybe
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there was even life on Mars a while back, but intelligent life, probably. So, you know, the
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statistics say that communicating with us, I think that it's harder than people think. We might not
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know the right way to expect the communication, but all the communication that we know about
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travels at the speed of light. And we don't think anything can go faster than the speed of light.
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That limits the problem quite a bit. And it makes it difficult to have any back and forth
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communication. You could send signals like we try to or look for, but to have any communication,
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it's pretty hard when it has to be close enough that the speed of light would mean we could
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communicate with each other. And I think, and we didn't even understand that. I mean, we're
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an advanced civilization, but we didn't even understand that a little more than a hundred
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years ago. So, are we just not advanced enough? Maybe to know something about that's the speed
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of light. Maybe there's some other way to communicate that isn't based on electromagnetism.
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I don't know. Gravity seems to be also have the same speed. That was a principle that Einstein
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had and something we've measured actually. So is it possible? I mean, so we'll talk about
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gravitational waves and in some sense, there's a brainstorming going on, which is like,
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how do we detect the signal? Like what would a signal look like and how would we detect it? And
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that's true for gravitational waves. That's true for basically any physics phenomena. You have to
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predict that that signal should exist. You have to have some kind of theory and model why that signal
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should exist. I mean, is it possible that aliens are communicating with us via gravity? Like why
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not? Well, yeah, it's true. Why not? For us, it's very hard to detect these gravitational effects.
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They have to come from something pretty that has a lot of gravity like black holes, but we're
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pretty primitive at this stage. There's very reputable physicists that look for a fifth force,
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one that we haven't found yet. Maybe it's the key. What would a fifth force of physics look
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like exactly? Well, usually they think it's probably a longer range force than we have now.
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But there are reputable colleagues of mine that spend their life looking for a fifth force.
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So longer range than gravity? Yeah. Super long? It doesn't fall off like one over r squared,
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but maybe separately. Gravity, Newton taught us, goes like inversely one over the square of the
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distance apart you are. So it falls pretty fast. That's okay. So now we have a theory of what
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consciousness is. It's just the fifth force of physics. Yeah. There we go. That's a good hypothesis.
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Speaking of gravity, what are gravitational waves? Let's maybe start from the basics.
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We learned gravity from Newton, right? When you were young, you were told that if you jumped up,
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the earth pulls you down. And when the apple falls out of the tree, the earth pulls it down.
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And maybe you even asked your teacher why, but most of us accepted that. That was Newton's
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picture, the apple falling out of the tree. But Newton's theory never told you why the apple
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00:28:00.400
was attracted to the earth. That was a missing in Newton's theory. Newton's theory also
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Newton recognized at least one of the two problems. I'll tell you one of them is there's more than
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those, but one is why does the earth, what's the mechanism by which the earth pulls the apple or
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00:28:20.080
holds the moon when it goes around, whatever it is. That's not explained by Newton, even though he
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has the most successful theory of physics ever went 200 and some years with nobody ever seeing
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00:28:31.040
a violation. But he accurately describes the movement of an object falling down to earth,
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but he's not answering why that what's yeah, because it's a distance. He gives a formula,
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00:28:45.120
which it's a product of the earth's mass, the apple's mass inversely proportional to the square
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of the distance between and then the strength he called capital G, the strength he couldn't
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00:28:57.280
determine, but it was determined 100 years later. But no one ever saw a violation of this until a
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possible violation, which Einstein fixed, which was very small that has to do with
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mercury going around the sun, the orbit being slightly wrong if you calculate it by Newton's
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00:29:16.400
theory. But so like most theories then in physics, you can have a wonderful one like Newton's theory.
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It isn't wrong. But you have to have an improvement on it to answer things that it can't answer. And
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in this case, Einstein's theory is the next step. We don't know if it's anything like a final theory
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or even the only way to formulate it either. But he formulated this theory, which he released in 1915.
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He took 10 years to develop it, even though in 1905, he solved three or four of the most important
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problems in physics in a matter of months. And then he spent 10 years on this problem before he
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let it out. And this is called general relativity. It's a new theory of gravity.
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00:30:07.120
1915. In 1916, Einstein wrote a little paper where he did not do some fancy derivation.
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Instead, he did what I would call he used his intuition, which he was very good at too. And that
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is he noticed that if he wrote the formulas for general relativity in a particular way,
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they looked a lot like the formulas for electricity and magnetism.
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Being Einstein, he then took the leap that electricity and magnetism, we discovered only
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20 years before that in the 1880s, have waves. Of course, that's light and electromagnetic waves,
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radio waves, everything else. So he said, if the formulas look similar, then gravity probably has
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waves too. That's such a big leap, by the way. I mean, maybe you could go back to the 1880s,
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maybe you can correct me, but that just seems like a heck of a leap.
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Yeah. And it was considered to be a heck of a leap. So first that paper was, except for this
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intuition, was poorly written, had a serious mistake. It had a factor of two wrong in the
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00:31:30.320
strength of gravity, which meant if we use those formulas, we would... And two years later,
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00:31:37.200
he wrote a second paper. And in that paper, it turns out to be important for us because in that
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paper, he not only fixed his factor of two mistake, which he never admitted, he just wrote it,
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fixed it like he always did. And then he told us how you make gravitational waves, what makes
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00:31:58.640
gravitational waves. And you might recall in electromagnetism, we make electromagnetic waves
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00:32:05.200
in a simple way. You take a plus charge and minus charge, you oscillate like this, and that makes
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the electromagnetic waves. And a physicist named Hertz made a receiver that could detect the waves
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00:32:16.320
and put it in the next room. He saw them and moved forward and backward and saw that it was wave like.
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00:32:22.160
So Einstein said, it won't be a dipole like that, it'll be a four pole thing. And that's what it's
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00:32:30.400
called, it's called a quadrupole moment that gives the gravitational wave. So that again, by insight,
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not by derivation. That set the table for what you needed to do to do it. At the same time,
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in the same year, Schwarzschild, not Einstein, said there were things called black holes. So
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it's interesting that that came the same. So what year was that? 1915. It was in parallel...
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00:32:56.640
Well, I should probably know this, but did Einstein not have an intuition that there
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should be such things as black holes? That came from Schwarzschild. Oh, interesting.
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00:33:07.200
Yeah. So Schwarzschild, who was a German theoretical physicist, he got killed in the war,
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I think, in the First World War, two years later or so. He's the one that proposed black holes,
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00:33:21.520
that there were black holes. That feels like a natural conclusion of general relativity, no? Or
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00:33:27.120
is that not? Well, it may seem like it, but I don't know about a natural conclusion. It's a result
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00:33:34.560
of curved space time though. Right. But it's such a weird result that you might have to...
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00:33:40.560
It's a special... Yeah, it's a special case. Yeah. So I don't know. Anyway, Einstein then,
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an interesting part of the story is that Einstein then left the problem. Most physicists,
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because it really wasn't derived, he just made this, didn't pick up on it or general relativity
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00:34:01.120
much because quantum mechanics became the thing in physics. And Einstein only picked up this
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00:34:10.080
problem again after he immigrated to the US. So he came to the US in 1932. And I think in 1934 or
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00:34:18.000
1935, he was working with another physicist called Rosen, who he did several important works with,
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00:34:24.400
and they revisited the question. And they had a problem that most of us as students always had,
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00:34:32.880
that study general relativity. General relativity is really hard because it's four dimensional
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00:34:37.680
instead of three dimensional. And if you don't set it up right, you get infinities,
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00:34:42.800
which don't belong there. We call them coordinate singularities as a name. But if you get these
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00:34:49.520
infinities, you don't get the answers you want. And he was trying to derive now general relativity
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00:34:57.440
from general relativity, gravitational waves. And in doing it, he kept getting these infinities.
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00:35:04.240
And so he wrote a paper with Rosen that he submitted to our most important journal,
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00:35:10.880
Physical Review Letters. And that when it was submitted to Physical Review Letters,
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00:35:17.840
it was entitled, Do Gravitational Waves Exist? A very funny title to write 20 years after he
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00:35:24.400
proposed they exist. But it's because he had found these singularities, these infinities. And so
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00:35:32.240
the editor at that time, and the part of it that I don't know, is peer review. We live and die by
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00:35:43.440
peer review as scientists send our stuff out. We don't know when peer review actually started
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00:35:49.520
or what peer review Einstein ever experienced before this time. But the editor of Physical
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00:35:55.520
Review sent this out for review. He had a choice. He could take any article and just accept it.
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00:36:02.000
He could reject it, or he could send it for review. I believe the editors used to have much
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00:36:07.760
more power. Yeah, yeah. And he was a young man. His name was Tate. And he ended up being editor
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00:36:13.360
for years. So he sent this for review to a theoretical physicist named Robertson, who was
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00:36:22.320
also in this field of general relativity, who happened to be on sabbatical at that moment at
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00:36:27.840
Caltech. Otherwise, his institution was Princeton, where Einstein was. And he saw that the way they
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00:36:37.280
set up the problem, the infinities were like I make it as a student, because if you don't
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00:36:42.320
set it up right in general relativity, you get these infinities. And so he reviewed the article
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00:36:48.320
and gave an illustration that if they set it up in what are called cylindrical coordinates, these
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00:36:54.640
infinities went away. The editor of Physical Review was obviously intimidated by Einstein.
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00:37:03.280
He wrote this really not a letter back like I would get saying, you're screwed up in your paper
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00:37:08.800
instead. It was kind of, what do you think of the comments of our referee? Einstein wrote back,
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00:37:17.840
and it's a well documented letter, wrote back a letter to Physical Review saying, I didn't send
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00:37:24.640
you the paper to send it to one of your so called experts. I sent it to you to publish. I withdraw
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00:37:31.600
the paper. And he never published again in that journal. That was 1936. Instead, he rewrote it
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00:37:42.000
with the fixes that were made, changed the title and published it in what was called the Franklin
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00:37:49.920
Review, which is the Franklin Institute in Philadelphia, which is Benjamin Franklin
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00:37:56.960
Institute, which doesn't have a journal now, but did at that time. So the article is published.
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00:38:01.920
It's the last time he ever wrote about it. It remained controversial. So it wasn't until
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00:38:08.080
close to 1960, 1958, where there was a conference that brought together the experts in general
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00:38:19.760
relativity to try to sort out whether it was true that there were gravitational waves or not.
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00:38:29.360
And there was a very nice derivation by a British theorist from the heart of the theory that gets
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00:38:40.240
gravitational waves. And that was number one. The second thing that happened at that meeting is
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00:38:46.160
Richard Feynman was there. And Feynman said, well, if there's typical Feynman, if there's
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00:38:53.200
gravitational waves, they need to be able to do something, otherwise they don't exist. So they
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00:38:58.320
have to be able to transfer energy. So he made an idea of a gedankenexperiment that is just a bar
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00:39:05.920
with a couple of rings on it. And then if a gravitational wave goes through, it distorts the
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00:39:11.120
bar and that creates friction on these little rings and that's heat and that's energy. So that
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meant... Is that a good idea? That sounds like a good idea. Yeah. It means that he showed that
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that with the distortion of space time, you could transfer energy just by this little idea.
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And it was shown theoretically. So at that point, it was believed theoretically then
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00:39:39.360
by people that gravitational waves should exist. No, we should be able to detect them.
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00:39:45.440
We should be able to detect them, except that they're very, very small.
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00:39:49.200
And so what kind of, there's a bunch of questions here, but what kind of events
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00:39:55.280
would generate gravitational waves? You have to have this, what I call quadrupole moment.
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00:40:01.200
That comes about if I have, for example, two objects that go around each other like this,
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00:40:08.400
like the earth around the sun or the moon around the earth, or in our case, it turns out to be two
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00:40:14.960
black holes going around each other like this. So how's that different than basic oscillation
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00:40:19.680
back and forth? Is it just more common in nature to have... Oscillation is a dipole moment. So it
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00:40:24.080
has to be in three dimensional space kind of oscillation. So you have to have something
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00:40:27.600
that's three dimensional that'll give what I called a quadrupole moment. That's just built
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00:40:32.160
into this. And luckily in nature you have stuff... And luckily things exist. And it is luckily
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00:40:38.400
because the effect is so small that you could say, look, I could take a barbell
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00:40:43.120
and spin it, right? And detect the gravitational waves. But unfortunately, no matter how much I
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00:40:50.640
spin it, how fast I spin it, so I know how to make gravitational waves, but they're so weak,
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I can't detect them. So we have to take something that's stronger than I can make. Otherwise we
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00:41:01.520
would do what Hertz did for electromagnetic waves. Go in our lab, take a barbell, put it on
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00:41:07.040
something, spin it. Can I ask a dumb question? So a single object that's weirdly shaped,
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00:41:13.120
does that generate gravitational waves? So if it's rotating? Sure. But it's just a much weaker signal.
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00:41:20.480
It's weaker. Well, we didn't know what the strongest signal would be that we would see.
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00:41:26.880
We targeted seeing something called neutron stars actually, because black holes we don't
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00:41:31.040
know very much about. It turned out we were a little bit lucky. There was a stronger source,
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00:41:35.680
which was the black holes. Well, another ridiculous question. So you say waves. What does a wave mean?
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00:41:43.680
Like the most ridiculous version of that question is, what does it feel like to ride a wave as you
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00:41:52.320
get closer to the source? Or experience it? Well, if you experience a wave, imagine that this is
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00:42:00.320
what happens to you. I don't know what you mean about getting close. It comes to you. So it's like
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00:42:06.320
this light wave or something that comes through you. So when a light hits you, it makes your eyes
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00:42:12.400
detect it. I flashed it. What does this do? It's like going to the amusement park, and they have
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00:42:20.560
these mirrors. You look in this mirror and you look short and fat, and the one next to you makes
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00:42:25.040
you tall and thin. Imagine that you went back and forth between those two mirrors once a second.
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00:42:32.560
That would be a gravitational wave with a period of once a second. If you did it 60 times a second,
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00:42:38.480
go back and forth. And then that's all that happens. It makes you taller and shorter and
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00:42:43.520
fatter back and forth as it goes through you at the frequency of the gravitational wave. So the
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00:42:50.320
frequencies that we detect are higher than one a second, but that's the idea. And the amount is
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00:42:57.520
small. Amount is small, but if you're closer to the source of the wave, is it the same amount?
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00:43:07.200
Yeah, it doesn't dissipate. It doesn't dissipate. Okay, so it's not that fun of an amusement ride.
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00:43:14.880
Well, it does dissipate, but it's proportional to the distance.
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00:43:22.400
Right. It's not a big power.
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00:43:24.720
Right. Gotcha. But it would be a fun ride if you get a little bit closer or a lot closer.
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00:43:31.840
I mean, I wonder what the... Okay, this is a ridiculous question, but I have you here.
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00:43:36.320
I mean, the getting fatter and taller, I mean, that experience, for some reason,
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00:43:44.640
that's mind blowing to me because it brings the distortion of space time to you. I mean,
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00:43:51.520
space time is being morphed, right? Like this is a wave.
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00:43:56.000
That's right.
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00:43:57.200
That's so weird.
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00:43:59.760
And we're in space, so we're affected by it.
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00:44:01.200
Yeah, we're in space and now it's moving.
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00:44:03.520
It's moving. I don't know what to do with it. I mean, does it... Okay.
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00:44:08.480
How much do you think about the philosophical implications of
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00:44:13.440
general relativity? Like that we're in space time and it can be bent by gravity.
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00:44:21.280
Like, is that just what it is? Are we supposed to be okay with this? Because like Newton,
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00:44:27.840
even Newton is a little weird, right? But that at least like makes sense.
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00:44:31.120
That's our physical world. When an apple falls, it makes sense. But the fact that
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00:44:37.680
entirety of the space time we're in can bend, that's really mind blowing.
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00:44:47.840
Let me make another analogy.
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00:44:49.360
This is a therapy session for me at this point.
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00:44:50.880
Yeah, right. Another analogy.
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00:44:52.880
Thank you.
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00:44:53.520
So imagine you have a trampoline.
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00:44:56.000
Yes.
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00:44:56.240
Okay. What happens if you put a marble on a trampoline? It doesn't do anything, right?
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00:45:02.240
No. Just a little bit, but not much.
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00:45:04.720
Yeah. I mean, just if I drop it, it's not going to go anywhere.
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00:45:08.320
Now imagine I put a bowling ball at the center of the trampoline.
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00:45:12.640
Now I come up to the trampoline and I put a marble on, what happens?
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00:45:18.000
It'll roll towards the bowling ball.
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00:45:20.560
Okay. All right. So what's happened is the presence of this massive object distorted the space
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00:45:28.880
that the trampoline did. This is the same thing that happens to the presence of the earth,
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00:45:36.080
the earth and the apple. The presence of the earth affects the space around it,
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00:45:40.160
just like the bowling ball on the trampoline.
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00:45:43.840
Yeah. This doesn't make me feel better. I'm referring from the perspective of an
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00:45:47.280
ant walking around on that trampoline. Then some guy just dropped a ball and then not only dropped
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00:45:55.760
the ball, right? It's not just dropping a bowling ball. It's making the ball go up and down or doing
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00:46:02.640
some kind of oscillation thing where it's like waves. And that's so fundamentally different from
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00:46:08.480
the experience on being on flatland and walking around and just finding delicious, sweet things
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00:46:13.360
as ant does. And it just feels like to me from a human experience perspective, completely,
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00:46:20.000
it's humbling. It's truly humbling.
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00:46:22.800
It's humbling, but we see that kind of phenomenon all the time.
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00:46:26.800
Let me give you another example. Imagine that you walk up to a still pond.
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00:46:32.880
Yes.
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00:46:33.440
Okay. Now I throw, you throw a rock in it, what happens? The rock goes in, sinks to the bottom,
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00:46:41.360
fine. And these little ripples go out and they travel out. That's exactly what happens. I mean,
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00:46:48.400
there's a disturbance, which is these, say, the bowling ball or black holes. And then the ripples
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00:46:55.440
that go out in the water, they're not, they don't have any, they don't have the rock, any part,
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00:47:01.520
pieces of the rock.
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00:47:02.480
See, the thing is, I guess what's not disturbing about that is it's a, I mean, I guess a flat
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00:47:10.000
two dimensional surface that's being disturbed. Like for a three dimensional surface, a three
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00:47:16.640
dimensional space to be disturbed feels weird.
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00:47:19.840
It's even worse. It's four dimensional because it's space and time.
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00:47:23.120
Time, yeah.
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00:47:24.880
So that's why you need Einstein is to make it four dimensional.
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00:47:28.080
To make it okay?
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00:47:29.440
No, to make it.
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00:47:30.640
To make it four dimensional?
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00:47:31.680
Yeah.
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00:47:32.320
Yeah, to take the same phenomenon and look at it in all of space and time. Anyway,
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00:47:39.120
luckily for you and I and all of us, the amount of distortion is incredibly small.
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00:47:47.600
So it turns out that if you think of space itself, now this is going to blow your mind too,
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00:47:54.240
if you think of space as being like a material, like this table, it's very stiff. You know,
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00:48:00.000
we have materials that are very pliable, materials that are very stiff. So space itself is very stiff.
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00:48:06.480
So when gravitational waves come through it, luckily for us,
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00:48:09.520
it doesn't distort it so much that it affects our ordinary life very much.
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00:48:16.240
No, I mean, that's great. That's great. I thought there was something bad coming.
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00:48:19.920
No, this is great. That's great news. So I mean, that, I mean, perhaps we evolved
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00:48:24.160
as life on Earth to be such that for us, this particular set of effects of gravitational waves
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00:48:32.800
is not that significant. Maybe that's why.
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00:48:36.160
It is. You probably used this effect today or yesterday.
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00:48:41.760
Did what?
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00:48:42.960
So it's pervasive. Well, because...
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00:48:45.440
You mean gravity or the way, or external? Because I only...
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00:48:49.440
Curvature of space and time.
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00:48:50.720
Curvature of space. How? I only care, a person is a human, right? The gravity of Earth.
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00:48:56.000
But you use it every day, almost.
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00:48:59.360
Oh, it's curving.
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00:49:00.240
Uh huh.
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00:49:00.720
No, no, no.
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00:49:01.760
No, no, no. It's in this thing. Every time it tells you where you are,
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00:49:07.840
how does it tell you where you are? It tells you where you are because we have
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00:49:11.520
24 satellites or some number that are going around in space and it asks how long it takes
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00:49:18.240
the beam to go to the satellite and come back, the signal, to different ones.
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00:49:24.320
And then it triangulates and tells you where you are. And then if you go down the road,
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00:49:28.560
it tells you where you are. Do you know that if you did that with the satellites and you
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00:49:32.880
didn't use Einstein's equations?
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00:49:34.800
Oh no.
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00:49:36.560
You won't get the right answer. That's right. And in fact, if you take a road that's, say,
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00:49:42.400
10 meters wide, I've done these numbers, and you ask how long you'd stay on the road if
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00:49:46.640
you didn't make the correction for general relativity, this thing you're poo pooing,
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00:49:52.160
because you're using every day, you'd go off the road in about a minute.
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00:49:56.400
Well, actually, that might be my problem.
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00:49:57.200
So you use it. So don't poo poo it.
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00:50:00.480
Well, I think I'm using an Android, so maybe, and the GPS doesn't work that well, so maybe
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00:50:04.320
I'm using Newton's physics. So I need to upgrade to general relativity. So gravitational waves
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00:50:11.280
and Einstein had, wait, Feynman really does have a part in the story?
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00:50:16.720
Yeah.
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00:50:17.280
Was that one of the first kind of experimental proposed to detect gravitational waves?
link |
00:50:22.080
Well, he did what we call a Godonkin experiment. That's a thought experiment.
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00:50:25.360
Yes.
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00:50:25.680
Okay. Not a real experiment. But then after that, then people believe gravitational waves
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00:50:31.760
must exist. You can kind of calculate how big they are. They're tiny. And so people
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00:50:37.280
started searching. The first idea that was used was Feynman's idea, and the very end of it.
link |
00:50:44.080
And it was to take a great big, huge bar of aluminum and then put around, and it's made
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00:50:51.360
like a cylinder, and then put around it some very, very sensitive detectors so that if a
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gravitational wave happened to go through it, it would go, and you'd detect this extra strain
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that was there. And that was this method that was used until we came along. It wasn't a very
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good method to use.
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And what was the, so we're talking about a pretty weak signal here.
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Yeah, that's why that method didn't work.
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So what, can you tell the story of figuring out what kind of method would be able to detect
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this very weak signal of gravitational waves?
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00:51:30.080
So remembering what happens when you go to the amusement park, that it's going to do something
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00:51:38.320
like stretch this way and squash that way, squash this way and stretch this way. We do
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have an instrument that can detect that kind of thing. It's called an interferometer.
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And what it does is it just basically takes, usually light, and the two directions that
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we're talking about, you send light down one direction and the perpendicular direction.
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And if nothing changes, it takes the same, and the arms are the same length, it just
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goes down, bounces back. And if you invert one compared to the other, they cancel so
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that nothing happens.
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But if it's like the amusement park and one of the arms got shorter and fatter, so it
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took longer to go horizontally than it did to go vertically, then when the light comes
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00:52:30.480
back, that comes back somewhat out of time. And that basically is the scheme. The only
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problem is that that's not done very accurately in general, and we had to do it extremely
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accurately.
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So what's the difficulty of doing so accurately?
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Okay. So the measurement that we have to do is a distortion in time. How big is it? It's
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a distortion that's one part in 10 to the 21. That's 21 zeros and a one. Okay.
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So this is like a delay in the thing coming back?
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00:53:13.520
One of them coming back after the other one, but the difference is just one part in 10
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00:53:17.920
to the 21. So for that reason, we make it big, let the arms be long. Okay, so one part
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in 10 to the 21. In our case, it's kilometers long. So we have an instrument that's kilometers
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in one direction, kilometers in the other.
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How many kilometers are we talking about? Four kilometers.
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Four kilometers in each direction. If you take then one part in 10 to the 21, we're
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talking about measuring something to 10 to the minus 18 meters.
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Okay.
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Now, to tell you how small that is, the proton thing we're made of, which you can't go
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and grab so easily, is 10 to the minus 15 meters. So this is one one thousandth the
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size of a proton. That's the size of the effect. Einstein himself didn't think this
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could be measured. We've never seen, actually, he said that. But that's because he didn't
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anticipate modern lasers and techniques that we developed.
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Okay. So maybe can you tell me a little bit what you're referring to as LIGO, the Laser
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Interferometer Gravitational Wave Observatory. What is LIGO? Can you just elaborate kind
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of the big picture view here before I ask you specific questions about it?
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Yeah. So in the same idea that I just said, we have two long vacuum pipes, four kilometers
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long. We start with a laser beam and we divide the beam going down the two arms. And we have
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a mirror at the other end, reflects it back. It's more subtle, but we bring it back. If
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there's no distortion in space time and the lengths are exactly the same, which we calibrate
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them to be, then when it comes back, if we just invert one signal compared to the other,
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they'll just cancel. So we see nothing. Okay. But if one arm got a little bit longer than
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the other, then they don't come back at exactly the same time. They don't exactly cancel.
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That's what we measure. So to give a number to it, we have the change of length to be
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able to do this 10 to the minus 18 meters to one part in 10 to the 12th. And that was
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the big experimental challenge that required a lot of innovation to be able to do.
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You gave a lot of credit to, I think, Caltech and MIT for some of the technical developments
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within this project. Is there some interesting things you can speak to at the low level of
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some cool stuff that had to be solved? I'm a software engineer, so I have so much more
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respect for everything done here than anything I've ever done. So I'll give you an example
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of doing mechanical engineering at a better, basically mechanical engineering and geology
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and maybe at a level. So what's the problem? The problem is the following, that I've given
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you this picture of an instrument that by some magic, I can make good enough to measure
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this very short distance. But then I put it down here, it won't work. And the reason it
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doesn't work is that the Earth itself is moving all over the place all the time. You don't
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realize it, it seems pretty good to you, but it's moving all the time. So somehow it's
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moving so much that we can't deal with it. We happen to be trying to do the experiment
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00:57:10.320
here on Earth, but we can't deal with it. So we have to make the instrument isolated
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from the Earth at the frequencies we're at. We've got to float it. That's an engineering
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00:57:23.040
problem, not a physics problem.
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00:57:24.720
So we're having a conversation on a podcast right now, and people who record music work
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00:57:32.160
with this, how to create an isolated room. And they usually build a room within a room,
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00:57:39.040
but that's still not isolated. In fact, they say it's impossible to truly isolate from
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00:57:43.200
sound, from noise and stuff like that. But that's like one step of millions that you
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00:57:51.760
took is building a room inside a room, because you basically have to isolate all.
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00:57:56.800
No, this is actually an easier problem. You just have to do it really well. So making
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a clean room is really a tough problem because you have to put a room inside a room. This
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is really simple engineering or physics. Okay, so what do you have to do? How do you isolate
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yourself from the Earth? First, we work at, we're not looking at all frequencies for
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00:58:21.600
gravitational waves. We're looking at particular frequencies that you can deal with here on
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Earth. So what are frequencies would those be? You were just talking about frequencies.
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We know by evolution, our bodies know, it's the audio band. Okay, the reason our ears
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00:58:40.800
work where they work is that's where the Earth isn't going, making too much noise.
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Okay, so the reason our ears work the way they work is because this is where it's quiet.
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That's right. So if you go to one Hertz instead of 10 Hertz, the Earth is really moving around.
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So somehow we live in what we call the audio band. It's tens of Hertz to thousands of Hertz.
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That's where we live, okay? If we're going to do an experiment on the Earth, it's the
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same frequency. That's where the Earth is the quietest. So we have to work in that frequency.
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So we're not looking at all frequencies, okay? So the solution for the shaking of the Earth
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to get rid of it is pretty mundane if we do the same thing that you do to make your car drive
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smoothly down the road. So what happens when your car goes over a bump? Early cars did that,
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they bounced. Right.
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Okay, but you don't feel that in your car. So what happened to that energy? You can't just
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disappear energy. So we have these things called shock absorbers in the car. What they do is they
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take the thing that went like that, and they basically can't get rid of the energy, but they
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move it to very, very low frequency. So what you feel isn't, you feel it go smoothly, okay? All
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01:00:08.560
right. So we also work at this frequency. So we basically, why don't we have to do anything other
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01:00:18.080
than shock absorbers? So we made the world's fanciest shock absorbers, okay? Not just like in
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01:00:26.400
your car where there's one layer of them. They're just the right squishiness and so forth. They're
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01:00:30.480
better than what's in the cars. And we have four layers of it. So whatever shakes and gets through
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01:00:35.760
the first layer, we treat it in a second, third, fourth layer. So it's a mechanical engineering
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01:00:40.880
problem. Yeah, that's what I said. So it's not, there's no weird tricks to it, like a chemistry
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01:00:46.640
type thing. No, no. Just, well, the right squishiness, you need the right material inside.
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01:00:51.840
And ours look like little springs, but they're. Springs? They're springs? So like legitimately,
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01:00:58.720
like shock absorbers. Yeah. What? Okay. Okay. And this is now experimental physics at the,
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01:01:06.640
at its limit. Okay. So you do this and we make the world's fanciest shock absorbers,
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01:01:11.120
just mechanical engineering. Just mechanical engineering, this is hilarious. But we didn't,
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01:01:16.800
we weren't good enough to discover gravitational waves. So we did another, we added another
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01:01:25.360
feature and it's something else that you're aware of, probably have one. And that is to get rid of
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01:01:33.920
noise. You've probably noise, which is, you don't like. And that's the same principle that's in
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01:01:40.160
these little Bose earphones. Noise canceling? Noise canceling. So how do they work? They
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01:01:48.240
basically, you go on an airplane and they sense the ambient noise from the engines
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01:01:53.600
and cancel it. Cause it's just the same over and over again. They cancel it. And when the stewardess
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01:01:59.360
comes and asks you whether you want coffee or tea or a drink or something, you hear, you're fine
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01:02:03.760
because she's not ambient. She's the signal. So. Are we talking about active canceling? Like where
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01:02:09.040
are the. Active canceling. So. This is, okay. So another. Don't tell me you have active canceling
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01:02:16.160
on this. Yeah. Besides the shock absorbers. So we had this, so inside this array of shock absorbers.
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01:02:22.480
Yeah. We, you asked for some interesting. This is awesome. So inside this, it's harder than the,
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01:02:29.600
the earphone problem, but it's just engineering. We have to see measure, not just that the
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01:02:36.320
engine still made noise, but the earth is shaking. It's moving in some direction. So we have to
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01:02:42.880
actually tell not only that there's noise and cancel it, but what direction it's from. So we
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01:02:48.240
put this array of seismometers inside this array of shock absorbers and measure the residual motion
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01:02:58.320
and its direction. And we put little actuators that push back against it and cancel it.
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01:03:07.040
This is awesome. So you have the actuators and you have the thing that is sensing the,
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01:03:11.920
the vibrations and then you have the actual actuators that adjust for that and do so in
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01:03:16.080
perfect synchrony. Yeah. What if it all works right. And so how much do we reduce the shaking
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01:03:22.080
of the earth? I mean, one part in 10 to the 12th. One part in 10. So what gets through us is one
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01:03:31.440
part in 10 to the 12th. That's pretty big reduction. You don't need that in your car,
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01:03:39.040
but that's what we do. And so that's how isolated we are from the earth. And that was the biggest,
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01:03:43.200
and that was the biggest, I'd say technical problem outside of the physics instrument,
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01:03:49.040
the interferometer. Can I ask you a weird question here? You make it very poetically
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01:03:54.480
and humorously is saying it's just a mechanical engineering problem, but is this one of the
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01:04:01.360
biggest precision mechanical engineering efforts ever? I mean, this seems exceptionally difficult.
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01:04:09.760
It is. And so it took a long time. And I think nobody seems to challenge the statement that
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01:04:16.960
this is the most precision, precise instrument it's ever been built, LIGO.
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01:04:22.640
I wonder what like listening to Led Zeppelin sounds on this thing,
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01:04:25.680
because it's so isolated. I mean, this is like, I don't know.
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01:04:30.080
No background. No, no back. It's wow. Wow. Wow. So when you were first
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01:04:37.520
conceiving this, I would probably, if I was knowledgeable enough,
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01:04:44.240
kind of laugh off the possibility that this is even possible.
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01:04:48.080
I'm sure, like how many people believe that this is possible? Did you believe this is possible?
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01:04:54.880
I did. I didn't know that we needed, for sure that we needed active. When we started,
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01:05:00.320
we did dispassive, but we were doing the tests to develop the active to add as a second stage,
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01:05:08.320
which we ended up needing. But there was a lot of, you know, now there was a lot of skepticism.
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01:05:15.680
A lot of us, especially astronomers, felt that money was being wasted,
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01:05:20.400
because we were also expensive. Doing what I told you is not cheap. So it was kind of
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01:05:26.160
controversial. It was funded by the National Science Foundation. Can you just linger on this
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01:05:32.240
just for a little longer? The actuator thing, the act of canceling. Do you remember like little
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01:05:41.280
experiments that were done along the way to prove to the team themselves that this is even possible?
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01:05:49.120
Because I work with quite a bit of robots, and to me, the idea that you could do it this precisely
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01:05:54.080
is humbling and embarrassing, frankly. Because like, this is another level of precision that I
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01:06:01.520
can't even, because robots are a mess. And this is basically one of the most precise robots ever.
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01:06:12.800
Right. So like, is there, do you have any like small scale experiments that were done that just
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01:06:18.240
be like, this is possible? Yeah, and larger scale. We made a test, that also has to be in vacuum too,
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01:06:27.040
but we made test chambers that had this system in it, our first mock of this system, so we could test
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01:06:33.280
it and optimize it and make it work. But it's just a mechanical engineering problem. Okay.
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01:06:41.040
And humans are just ape descendants. I gotcha. I gotcha. Is there any video of this? Like some kind
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01:06:49.280
of educational purpose visualizations of this act of canceling? I don't think so.
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01:06:58.160
I mean, does this live on? Well, we work for parts of it, for the active canceling,
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01:07:04.560
we worked with, for the instruments, for the sensor and instruments, we worked with a small
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01:07:11.680
company near where you are, because it was our MIT people that got them that were, you know,
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01:07:17.600
interested in the problem because they thought they might be able to commercialize it for
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01:07:22.240
making stable tables to make microelectronics, for example, which are limited by how stable the table
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01:07:28.400
is. I mean, at this point, it's a little expensive. So you never know, never know where this leads.
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01:07:36.400
So maybe on the, let me ask you, just sticking it a little longer, this silly old mechanical
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01:07:45.200
engineering problem. What was to you kind of the darkest moment of what was the hardest
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01:07:53.520
stumbling block to get over on the engineer side? Like, was there any time where there's a doubt,
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01:07:58.320
where it's like, I'm not sure we would be able to do this, a kind of engineering challenge that was
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01:08:03.920
hit? Do you remember anything like that? I think the one that my colleague at MIT,
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01:08:11.680
Ray Weiss, worked on so hard and was much more of a worry than this. This is only a question if you're
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01:08:18.720
not doing well enough, you have to keep making it better somehow. But this whole huge instrument has
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01:08:26.400
to be in vacuum. And the vacuum tanks are, you know, this big around. And so it's the world's
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01:08:34.720
biggest high vacuum system. And how do you make it? First of all, how do you make this four meter
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01:08:42.720
long sealed vacuum system? It has to be made out of four kilometers, four kilometers long. Would I
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01:08:48.640
say something else? Meters. Four kilometers long. Big difference. Yeah. And so, but to make it,
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01:08:55.360
yeah, we started with a roll of stainless steel, and then we roll it out like a spiral so that
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01:09:04.480
there's a spiral weld on it. Okay, so the engineering was fine. We did that. We worked through
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01:09:14.160
very good companies and so forth to build it. But the big worry was, what if you develop a leak?
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01:09:25.280
This is a high vacuum, not just vacuum system. Typically, in a laboratory, if there's a leak,
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01:09:31.200
you put helium around the thing you have, and then you detect where the helium is coming in.
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01:09:40.000
But if you have something as big as this, you can't surround it with helium. So you might not
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01:09:44.080
actually even know that there's a leak and it will be affecting it. Well, we can measure how
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01:09:51.280
good the vacuum is so we can know that, but a leak can develop and then we don't, how do we fix it
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01:09:58.080
or how do we find it? And so that was, you asked about a worry. That was always a really big worry.
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01:10:04.880
What's the difference, you know, high vacuum and a vacuum? What is high vacuum? That's like some
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delta close to vacuum? Is it some threshold? Well, there's a unit. High vacuum is when the vacuum
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01:10:20.640
and the units that are used, which are tors, there's 10 to the minus nine. And there's high
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01:10:27.040
vacuum is usually used in small places. The biggest vacuum system period is at CERN in this
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01:10:35.600
big particle accelerator, but the high vacuum where they need really good vacuum so particles
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01:10:40.080
don't scatter in it is smaller than ours. So ours is a really large high vacuum system.
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01:10:47.520
I don't know. This is so cool. I mean, this is basically by far the greatest listening device
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01:10:53.600
ever built by human. The fact that like descendants of apes could do this, that evolution started with
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01:10:59.680
single cell organisms. I mean, is there any more, I'm a huge theory is like, yeah, yeah. But like
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01:11:07.200
bridges, when I look at bridges from a civil engineering perspective, it's one of the most
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01:11:11.360
beautiful creations by human beings. It's physics. You're using physics to construct objects that
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01:11:17.200
can support huge amount of mass and it's like structural, but it's also beautiful.
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01:11:21.760
And that humans can collaborate to create that throughout history. And then you take this
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on another level. This is, this is like, it's exciting to me beyond measure that humans can
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01:11:35.040
create something so precise. But another concept lost in this, you just said, you started talking
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01:11:41.600
about single cell. Yeah. Okay. You have to realize this discovery that we made that everybody's
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01:11:47.120
bought off on happened 1.3 billion years ago, somewhere. And then the signal came to us 1.3
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01:11:55.360
billion years ago, we were just converting on the earth from single cell to multi cell life.
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01:12:01.440
So when this actually happened, this collision of two black holes, we weren't here. We weren't
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01:12:07.360
even close to developing single. Yeah, we were had, we're going from single cell to multi cell
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01:12:14.000
life at that point. All to meet up at this, at this point. Yeah. Wow. That's like, that's almost
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01:12:20.720
romantic. It is. Okay. So on the human side of things, it's kind of fascinating because you're
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01:12:32.560
talking about over a thousand people team for LIGO. Yeah. They started out with, you know,
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01:12:39.040
around a hundred and you've for parts of the time at least led this team. What does it take to lead
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01:12:48.400
a team like this of incredibly brilliant theoreticians and engineers and just a lot of
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01:12:56.160
different parties involved? A lot of egos, a lot of ideas. You had this fun, funny example,
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01:13:03.200
I forget where, where in publishing a paper, you have to all agree on like, you know, the phrasing
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01:13:10.720
of a certain sentence or the title of the paper and so on. That's a very interesting, simple
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01:13:15.040
example. I'd love you to speak to that, but just in general, how, what does it take to lead this
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01:13:20.080
kind of team? Okay. I think that the general idea is one we all know. You want to, you want to,
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01:13:28.800
you want to get where the, the sum of something is more than the individual parts is what we say,
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01:13:37.040
right? Yeah. So that's what you're trying to achieve. Yes. Okay. How do you do that? Actually,
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01:13:42.640
mostly if we take multiple objects or people, I mean, you put them together, the sum is less.
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01:13:49.280
Yes. Why? Because they overlap. So you don't have individual things that, you know, this
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01:13:56.400
person does that, this person does that, then you get exactly the sum. But what you want is to
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01:14:02.320
develop where you get more than what the individual contributions are. We know that's
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01:14:07.120
very common. People use that expression everywhere. And it's the expression that has to be kind of
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01:14:14.160
built into how people feel it's working. Because if you're part of a team, and you realize that
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01:14:21.440
somehow the team is able to do more than the individuals could do themselves, then they buy on
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01:14:27.440
kind of in terms of the process. So that's the, that's the goal that you have to have is to, to
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01:14:36.000
achieve that. And that means that you have to realize parts of what you're trying to do that
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01:14:45.840
require not that one person couldn't do it, it requires the combined talents to be able to do
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01:14:52.240
something that neither of them could do themselves. And we have a lot of that kind of thing. And I
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01:14:57.200
think, I mean, build into the some of the examples that I gave you. And so, how do you then, so, so
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01:15:06.320
the key almost in anything you do is the people themselves, right? So in our case,
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01:15:12.400
the first and most important was to attract to spend years of their life on this. And the best
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01:15:20.880
possible people in the world to do it. So the only way to convince them is that somehow it's
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01:15:28.800
better and more interesting for them than what they could do themselves. And so that's part of
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01:15:34.080
this idea. Yeah, that's powerful. But nevertheless, there's best people in the world, there's egos. Is
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01:15:42.240
there something to be said about managing egos? Oh, that's the human problem is always the hardest.
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01:15:47.840
And so there's, that's an art, not a science, I think. I think the fact here that combined,
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01:15:56.080
there's a was a romantic goal that we had to, you know, do something that people hadn't done before,
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01:16:06.240
which was important scientifically and, and a huge challenge, enabled us to say, take and get, I mean,
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01:16:19.600
what we did just to take an example, we use the light to go in this thing comes from lasers.
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01:16:24.320
We need a certain kind of laser. So the kind of laser that we use, there were three different
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01:16:32.560
institutions in the world that had the experts that do this, maybe in competition with each other.
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01:16:38.240
So we got all three to join together and work with us to work on this as an example. So that
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01:16:45.040
you had, and they had the thing that they were working together on a kind of object that they
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01:16:51.680
wouldn't have otherwise. And we're part of a bigger team where they could discover something
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01:16:57.280
that isn't even engineers. These are engineers that do laser. So, and they're part of our laser
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01:17:03.520
physicists. So could you describe the moment or the period of time when finally this incredible
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01:17:14.480
creation of human beings led to a detection of gravitational waves? It's a long story. Unfortunately,
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01:17:22.160
this is a part that we started failures along the way kind of thing or all failures. That's all
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01:17:28.560
that's built into it. If you're not, if you're not mechanical engineering, you build on your failures,
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01:17:36.080
that's expected. So we're trying things that no one's done before. So it's technically not just
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01:17:41.360
gravitational waves. And so it's built on failures. But anyway, we did before me, even
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01:17:48.480
there, the people did R&D on the concepts. But starting in 1994, we got money from the National
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01:17:57.920
Science Foundation to build this thing. It took about five years to build it. So by 1999, we had
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01:18:06.240
built the basic unit. It did not have active seismic isolation at that stage, didn't have some
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01:18:13.920
other things that we have now. What we did at the beginning was stick to technologies that we had
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01:18:27.360
at least enough knowledge that we could make work or had tested in our own laboratories. And so then
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01:18:33.840
we put together the instrument. We made it work. It didn't work very well, but it worked. And we
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01:18:41.040
didn't see any gravitational waves. Then we figured out what limited us. And we went through this
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01:18:45.600
every year for almost 10 years, never seeing gravitational waves. We would run it, looking for
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01:18:55.520
gravitational waves for months, learn what limited us, fix it for months, and then run it again.
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01:19:06.320
Eventually, we knew we had to take another big step. And that's when we made several changes,
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01:19:13.280
including adding these active seismic isolation, which turned out to be a key. And we
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01:19:21.600
fortunately got the National Science Foundation to give us another couple hundred million dollars,
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01:19:27.520
100 million more. And we rebuild it or fixed or improved it. And then in 2015, we turned it on.
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01:19:42.080
And we almost instantly saw this first collision of two black holes.
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01:19:53.600
And then we went through a process of, do we believe what we've seen?
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01:19:58.560
Yeah, I think you're one of the people that went through that process. It sounds like some people
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01:20:02.400
immediately believed it. And then you're like...
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01:20:05.600
So as human beings, we all have different reactions to almost anything. And so
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01:20:10.080
quite a few of my colleagues had a eureka moment immediately. I mean, the figure that we put in our
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01:20:20.160
paper, first is just data. We didn't have to go through fancy computer programs to do anything.
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01:20:27.840
And we show next to it the calculations of Einstein's equations. It looks just like what
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01:20:36.080
we detected. And we did it in two different detectors halfway across the US. So it was
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01:20:42.000
pretty convincing, but you don't want to fool yourself. So being a scientist, for me, we had
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01:20:53.920
to go through and try to understand that the instrument itself, which was new, I said we had
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01:20:58.000
rebuild it, couldn't somehow generate things that look like this. That took some tests. And then the
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01:21:06.240
second, you'll appreciate more, we had to somehow convince ourselves we weren't hacked in some
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01:21:12.080
clever way.
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01:21:12.800
Cybersecurity question.
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01:21:14.320
Yeah. Even though we're not on the internet, but...
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01:21:18.000
Yeah. No, it can be physical access too. Yeah. That's fascinating. It's fascinating that you
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01:21:23.520
would think about that. I mean, not enough. I mean, because it matches prediction. So the chances
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01:21:34.560
of it actually being manipulated is very, very low. But nevertheless...
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01:21:38.320
We still could have disgruntled all the graduate students who had worked with us earlier that...
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01:21:43.520
Who want you to... I don't know how that's supposed to embarrass you. I suppose, yeah. I suppose I
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01:21:48.880
see. But about what I think you said, within a month, you kind of convinced yourself officially.
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01:21:55.360
Within a month, we convinced ourselves. We kept a thousand collaborators quiet during that time.
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01:22:01.520
Then we spent another month or so trying to understand what we'd seen so that we could do the
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01:22:10.080
science with it instead of just putting it out to the world and let somebody else understand that it
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01:22:14.480
was two black holes and what it was. The fact that a thousand collaborators were quiet
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01:22:20.480
is a really strong indication that this is a really close knit team. Yeah. And they're around
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01:22:25.600
the world. Either strong knit or tight knit or had a strong dictatorship or something. Yeah.
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01:22:35.200
Either fear or love. You can rule by fear or love. Yeah, right. You can go back to Machiavelli.
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01:22:39.120
Yeah. All right. Well, this is really exciting that that's a success story because it didn't
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01:22:51.760
have to be a success story, right? I mean, eventually, perhaps you could say it'll be an
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01:22:56.720
event, but it could have taken over a century to get there. Oh, yeah. Yeah. And it's only downhill
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01:23:06.160
now. What do you mean? You mean with gravitational waves? Yeah. Well, now we're off because of the
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01:23:18.240
pandemic, but when we turned off, we were seeing some sort of gravitational wave event each week.
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01:23:26.880
Now we're fixing, we're adding features where it'll probably be when we turn back on next year,
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01:23:32.560
it'll probably be one every couple days. And they're not all the same. So it's
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01:23:38.160
learning about what's out there in gravity instead of just optics. So it's all great.
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01:23:45.840
We're only limited by the fantastic thing other than that this is a great field and it's all new
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01:23:54.880
and so forth is that experimentally, the great thing is that we're limited by technology and
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01:24:04.000
technical limitations, not by science. So another really important discovery that was made before
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01:24:16.400
ours was what's called the Higgs boson made on the big accelerator at CERN. This huge accelerator,
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01:24:23.200
they discovered a really important thing. We have Einstein's equation, E equals MC squared.
link |
01:24:29.920
So energy makes mass or mass can make energy and that's the bomb. But the mechanism by which that
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01:24:37.040
happens, not vision, but how do you create mass from energy was never understood until there was
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01:24:48.560
a theory of it about 70 years ago now. And so they discovered it's named after a man named Higgs.
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01:24:58.400
It's called the Higgs boson. And so it was discovered, but since that time, and I worked
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01:25:05.120
on those experiments since that time, they haven't been able to progress very much further,
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01:25:09.920
a little bit, but not a lot further. And the difference is that we're really lucky
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01:25:14.240
we're in what we're doing in that there you see this Higgs boson, but there's tremendous amount
link |
01:25:22.880
of other physics that goes on and you have to pick out the needle in the haystack of physics.
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01:25:28.080
You can't make the physics go away, it's there. In our case, we have a very weak signal, but once we
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01:25:34.480
get good enough to see it, it's weak compared to where we've reduced the background, but the
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01:25:40.080
background is not physics, it's just technology. It's getting ourselves better isolated from the
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01:25:47.600
Earth or getting a more powerful laser. And so since 2015, when we saw the first one,
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01:25:56.160
we continually can make improvements that are enabling us to turn this into a real science
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01:26:03.040
to do astronomy, a new kind of astronomy. It's a little like astronomy. Galileo started the field.
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01:26:12.560
He basically took lenses that were made for classes and he didn't invent the first telescope,
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01:26:20.080
but made a telescope, looked at Neptune and saw that it had four moons. That was the birth of
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01:26:28.880
not just using your eyes to understand what's out there. And since that time, we've made better and
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01:26:34.880
better telescopes, obviously, and astronomy thrives. And in a similar way, we're starting to
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01:26:41.920
be able to crawl, but we're starting to be able to do that with gravitational waves. And it's
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01:26:49.920
going to be more and more that we can do as we can make better and better instruments because,
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01:26:55.600
as I say, it's not limited by picking it out of others. Yeah, it's not limited by the physics.
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01:27:02.400
So you have an optimism about engineering that as human progress marches on,
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01:27:11.040
engineering will always find a way to build a large enough device,
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01:27:17.280
accurate enough device to detect the same thing. As long as it's not limited by physics,
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01:27:21.360
yeah, they'll do it. So you, two other folks and the entire team won the Nobel prize for this big
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01:27:34.720
effort. There's a million questions I can ask for, but looking back, where does the Nobel prize
link |
01:27:49.680
fit into all of this? If you think hundreds of years from now, I venture to say that people
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01:27:57.920
will not remember the winners of a prize, but they'll remember creations like these.
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01:28:03.360
Maybe I'm romanticizing engineering, but I guess I want to ask how important is the Nobel prize in
link |
01:28:10.880
all of this? Well, that's a complicated question. As a physicist, it's something if you're trying
link |
01:28:22.240
to win a Nobel prize, forget it because they give one a year. So there's been 200 physicists
link |
01:28:30.960
who have won the Nobel prize since 1900. And so things just have to fall right. So your goal cannot
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01:28:40.240
be to win a Nobel prize. It wasn't my dream. It's tremendous for science. Why the Nobel prize for a
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01:28:51.600
guy that made dynamite and stuff is what it is. It's a long story, but it's the one day a year
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01:28:58.400
where actually the science that people have done is all over the world and so forth. Forget about
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01:29:04.720
the people again. It is really good for science. It celebrates science for several days, different
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01:29:14.080
fields, chemistry, medicine and so forth. And everybody doesn't understand everything about
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01:29:21.280
these. They're generally fairly abstract, but then it's on the front page of newspapers around
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01:29:27.760
the world. So it's really good for science. It's not easy to get science on the front page of the
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01:29:32.080
New York Times. It's not there. Should be, but it's not. And so the Nobel prize is important in that
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01:29:41.760
way. Otherwise, I have a certain celebrity that I didn't have before. And now you get to be a
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01:29:53.520
celebrity that advertises science. It's a mechanism to remind us how incredible, how much credit
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01:30:01.280
science deserves and everything. Well, it has a little bit more. One thing I didn't expect,
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01:30:06.240
which is good, is that we have a government. I'm not picking on ours necessarily, but it's true of
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01:30:16.720
all governments are not run by scientists. In our case, it's run by lawyers and businessmen.
link |
01:30:23.040
Yep. Okay. And at best they may have an aide or something that knows a little science. So
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01:30:33.120
in all countries hardly take into account science in making decisions.
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01:30:42.640
Yes. Okay. And
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01:30:44.320
having a Nobel prize, the people in those positions actually listen. So you have more
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01:30:53.200
influence. I don't care whether it's about global warming or what the issue is. There's some
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01:30:58.160
influence, which is lacking otherwise. And people pay attention to what I say. If I talk about
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01:31:05.120
global warming, they wouldn't have before I had the Nobel prize. Yeah, this is very true. You're
link |
01:31:12.160
like the celebrities who talk. Celebrity has power. Celebrity has power. And that's a good
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01:31:20.000
thing. That's a good thing. Singling out people, I mean, on the other side of it, singling out
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01:31:24.880
people has all kinds of, whether it's for Academy Awards or for this, have unfairness and
link |
01:31:32.320
arbitrariness and so forth and so on. So that's the other side of the coin. Just like you said,
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01:31:39.920
especially with the huge experimental projects like this, you know, it's a large team and it
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01:31:45.280
does the nature of the Nobel prizes. It singles out a few individuals to represent the team.
link |
01:31:49.760
Yeah. Nevertheless, it's a beautiful thing. What are ways to improve LIGO in the future,
link |
01:31:57.440
increase the sensitivity? I've seen a few ideas that are kind of fascinating. Are you interested
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01:32:03.520
in them? I'm not speaking about five years. Perhaps you could speak to the next five years,
link |
01:32:09.680
but also the next hundred years. Yeah. So let me talk to both the instrument and the science.
link |
01:32:16.080
Sure. So they go hand in hand. I mean, the thing that I said is if we make it better,
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01:32:21.920
we see more kinds of weaker objects and we do astronomy. Okay. We're very motivated to make
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01:32:29.760
a new instrument, which will be a big step, the next step, like making a new kind of telescope or
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01:32:36.240
something. And the ideas of what that instrument should be haven't converged yet. There's different
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01:32:44.400
ideas in Europe. They've done more work to kind of develop the ideas, but they're different from
link |
01:32:52.480
ours and we have ideas. But I think over the next few years, we'll develop those. The idea is to make
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01:32:59.840
an instrument that's at least 10 times better than what we can do with this instrument, 10 times
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01:33:06.240
better than that. 10 times better means you can look 10 times further out. 10 times further out
link |
01:33:13.600
is a thousand times more volume. So you're seeing much, much more of the universe. The best way to
link |
01:33:21.680
look at it is to look further out. The big change is that if you can see far out, you see further
link |
01:33:29.280
back in history. Yeah, you're traveling back in time. Yeah. And so we can start to do what we
link |
01:33:36.080
call cosmology instead of astronomy or astrophysics. Cosmology is really the study of the evolution of
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01:33:44.160
the universe. And so then you can start to hope to get to the important problems having to do with
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01:33:53.920
how the universe began, how it evolved and so forth, which we really only study now with
link |
01:34:02.160
optical instruments or electromagnetic waves. And early in the universe, those were blocked because
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01:34:12.320
it was, basically it wasn't transparent. So the photons couldn't get out when everything was too
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01:34:18.960
dense. What do you think, sorry on this tangent, what do you think an understanding of gravitational
link |
01:34:24.240
waves from earlier in the universe can help us understand about the Big Bang and all that kind
link |
01:34:28.560
of stuff? Yeah. But it's a non, it's another perspective on the thing. Is there some insights
link |
01:34:37.120
you think could be revealed just to help a layman understand? Sure. First, we don't understand. We
link |
01:34:43.040
use the word Big Bang. We don't understand the physics of what the Big Bang itself was.
link |
01:34:50.320
So I think, and in the early stage, there were particles and there was a huge amount of gravity
link |
01:34:58.160
and mass being made. So I'll say two things. One is, how did it all start? How did it happen? I'll
link |
01:35:10.240
give you at least one example that we don't understand what we should understand. We don't
link |
01:35:16.000
know why we're here. Yes. No, we do not. I don't mean it philosophically. I mean it in terms of
link |
01:35:24.000
physics. Now, what do I mean by that? If I go into my laboratory at CERN or somewhere and I
link |
01:35:30.720
collide particles together or put energy together, I make as much anti matter as matter. Anti matter
link |
01:35:38.480
then annihilates matter and makes energy. So in the early universe, you made somehow a lot of
link |
01:35:49.120
matter and anti matter, but there was an asymmetry. Somehow there was more matter and anti matter.
link |
01:35:55.520
The matter and anti matter annihilated each other. At least that's what we think.
link |
01:35:59.520
And there was only matter leftover. And we live in a universe that we see this all matter.
link |
01:36:05.840
We don't have any idea. We have ideas, but we don't have any way to understand that at the
link |
01:36:12.640
present time with the physics that we know. Can I ask a dumb question? Does anti matter have
link |
01:36:19.600
anything like a gravitational field to send signals? So how does this asymmetry of matter
link |
01:36:29.040
and anti matter could be investigated or further understood by observing gravitational fields or
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01:36:35.520
weirdnesses in gravitational fields? I think that in principle, if there were anti neutron stars,
link |
01:36:45.360
instead of just neutron stars, we would see different kinds of signals, but it didn't get
link |
01:36:51.280
to that. We live in a universe that we've done enough looking because we don't see anti matter,
link |
01:36:56.960
anti protons anywhere, no matter what we look at, that it's all made out of matter.
link |
01:37:01.280
Hmm. There is no anti matter except when we go in our laboratories.
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01:37:06.400
So, but when we go in our laboratories, we make as much anti matter as matter.
link |
01:37:11.280
So there's something about the early universe that made this asymmetry. So we can't even
link |
01:37:16.320
explain why we're here. That's what I meant. Physics wise, not in terms of how we evolved
link |
01:37:25.360
and all that kind of stuff. So there might be inklings of some of the physics that gravitational
link |
01:37:36.080
So gravitational waves don't get obstructed like light. So I said light only goes to 300,000 years.
link |
01:37:42.720
So it goes back to the beginning. So if you could study the early universe with gravitational waves,
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01:37:47.520
we can't do that yet. Then it took 400 years to be able to do that with optical, but
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01:37:54.240
but then you can really understand the very, maybe understand the very early universe.
link |
01:38:00.400
So in terms of questions like why we're here or what the big bang was, we should be, we can,
link |
01:38:10.400
in principle, study that with gravitational waves. So to keep moving in this direction,
link |
01:38:15.360
it's a unique kind of way to understand our universe.
link |
01:38:20.400
So you think there's more Nobel prize level ideas to be discovered in relation to
link |
01:38:25.200
I'd be shocked if there, if there isn't, not even going to that, which is a very long range problem.
link |
01:38:31.680
But I think that we only see with electromagnetic waves, 4% of what's out there.
link |
01:38:39.280
There must be, we looked for things that we knew should be there. There should be,
link |
01:38:48.240
I would be shocked if there wasn't physics, objects, science, and with gravity that doesn't
link |
01:38:58.960
show up in everything we do with telescopes. So I think we're just limited by not having
link |
01:39:06.480
powerful enough instruments yet to do this.
link |
01:39:10.400
Do you have a preference? I keep seeing this E. Lisa idea.
link |
01:39:17.200
Yeah.
link |
01:39:18.240
Is it, do you have a preference for earthbound or space faring mechanisms for?
link |
01:39:26.960
They're complimentary. It's a little bit like, it's completely analogous to what's been done
link |
01:39:32.880
in astronomy. So astronomy from the time of Galileo was done with visible light.
link |
01:39:42.000
The big advances in astronomy in the last 50 years are because we have instruments that look
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01:39:46.560
at the infrared, microwave, ultraviolet and so forth. So looking at different wavelengths
link |
01:39:54.160
has been important. Basically going into space means that we'll look at instead of the audio
link |
01:40:00.240
band, which we look at, as we said on the Earth's surface, we'll look at lower frequencies.
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01:40:05.680
So it's completely complimentary and it starts to be looking at different frequencies just
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01:40:10.960
like we do with astronomy.
link |
01:40:14.320
It seems almost incredible to me, engineering wise, just like on earth to send something
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01:40:18.960
that's kilometers across into space. Is that harder to engineer?
link |
01:40:25.360
It actually is a little different. It's three satellites separated by hundreds of thousands
link |
01:40:32.880
of kilometers and they send a laser beam from one to the other. And if the triangle changes
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01:40:42.960
shape a little bit, they detect that from a graph.
link |
01:40:45.360
Did you say hundreds of thousands of kilometers? Yeah. Sending lasers to each other. Okay.
link |
01:40:56.160
It's just engineering.
link |
01:40:59.920
Is it possible though? Is it doable?
link |
01:41:02.160
Yes.
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01:41:03.520
Okay. That's just incredible because they have to maintain, I mean, the precision here
link |
01:41:11.040
is probably, there might be some more, what is it? Maybe noise is a smaller problem. I
link |
01:41:16.800
guess there's no vibration to worry about like seismic stuff. So getting away from earth,
link |
01:41:22.880
maybe you get away from seismic stuff.
link |
01:41:23.680
Yeah. Those parts are easier. They don't have to measure it as accurately at low frequencies.
link |
01:41:29.200
But they have a lot of tough engineering problems.
link |
01:41:33.200
In order to detect that the gravitational waves affect things, the sensors have to be
link |
01:41:44.000
what we call free masses, just like ours, are isolated from the earth. They have to
link |
01:41:48.400
isolate it from the satellite. And that's a hard problem. They have to do that pretty,
link |
01:41:54.080
not as well as we have to do it, but very well. And they've done a test mission and
link |
01:42:00.080
the engineering seems to be at least in principle in hand. This will be in the 2030s.
link |
01:42:06.880
2030s?
link |
01:42:07.920
Yeah.
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01:42:09.600
This is incredible. This is incredible. Let me ask about black holes.
link |
01:42:17.200
So what we're talking about is observing orbiting black holes. I saw the terminology of like
link |
01:42:27.440
binary black hole systems.
link |
01:42:28.880
Binary black holes.
link |
01:42:29.680
Is that the one that's when they're dancing? Okay.
link |
01:42:33.040
They're both going around each other, just like the earth around the sun.
link |
01:42:36.080
Okay. Is that weird that there's black holes going around each other?
link |
01:42:40.080
So the finding binary systems of stars is similar to finding binary systems of...
link |
01:42:45.840
Of black holes.
link |
01:42:46.560
Well, they were once stars. So we haven't said what a black hole is physically yet.
link |
01:42:55.760
Yeah. What's a black hole?
link |
01:42:56.880
So black hole is first, it's a mathematical concept or a physical concept. And that is
link |
01:43:03.840
a region of space. So it's simply a region of space where the curvature of space time,
link |
01:43:10.640
meaning the gravitational field is so strong that nothing can get out, including light.
link |
01:43:19.040
And there's light gets bent if the space time is warped enough.
link |
01:43:26.320
And so even light gets bent around and stays in it. So that's the concept of a black hole.
link |
01:43:33.200
And maybe you can make... So that's a concept that didn't say how they come about.
link |
01:43:40.400
And there could be different ways they come about. The ones that we are seeing,
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01:43:48.480
we're not sure. That's what we're trying to learn now is what they...
link |
01:43:52.480
But the general expectation is that they come... These black holes happen when a star dies.
link |
01:44:02.000
So what does that mean that a star dies? What happens? A star like our sun
link |
01:44:08.880
basically makes heat and light by fusion. It's made up. And as it burns, it burns up the hydrogen
link |
01:44:17.600
and then the helium and slowly works its way up to the heavier and heavier elements that are
link |
01:44:24.240
in the star. And when it gets up to iron, the fusion process doesn't work anymore.
link |
01:44:30.560
And so the stars die and that happens to stars. And then they do what's called a supernova.
link |
01:44:37.200
What happens then is that a star is a delicate balance between an outward pressure from fusion
link |
01:44:43.760
and light and burning and an inward pressure of gravity trying to pull the
link |
01:44:51.120
masses together. Once it burns itself out, it goes and it collapses and that's a supernova.
link |
01:44:57.760
When it collapses, all the mass that was there is in a very much smaller space. And if a star,
link |
01:45:05.440
if you do the calculations, if a star is big enough, that can create a strong enough
link |
01:45:11.680
gravitational field to make a black hole. Our sun won't. It's too small.
link |
01:45:17.920
Too small.
link |
01:45:19.200
And we don't know exactly what, but it's usually thought that a star has to be at least three
link |
01:45:26.400
times as big as our sun to make a black hole. But that's the physical way there.
link |
01:45:32.160
You can make black holes. That's the first
link |
01:45:34.800
explanation that one would give for what we see,
link |
01:45:41.840
but it's not necessarily true. We're not sure yet.
link |
01:45:45.440
What we see in terms of, for the origins of black holes?
link |
01:45:48.560
No, the black holes that we see in gravitational waves.
link |
01:45:52.320
So the, but you're also looking for the ones who are binary solar systems.
link |
01:45:56.720
So they're binary systems, but they could have been made from binary stars. So there's binary
link |
01:46:01.760
stars around. So that's, so that's the first explanation is that that's what they are.
link |
01:46:07.520
Gotcha.
link |
01:46:09.760
Other explanations, but what we see has some puzzles. This is kind of the way science works,
link |
01:46:16.800
I guess. We see heavier ones than up to, we've seen one system that was 140 times the mass of
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01:46:29.280
our own sun. That's not believed to be possible with the parent being a big star because big
link |
01:46:39.760
stars can only be so big or they are unstable. It's just the fact that they live in an environment
link |
01:46:49.120
that makes them unstable. So the fact that we see bigger ones, they may be come from something else.
link |
01:46:55.920
It's possible that they were made in a different way by little ones eating each other up or maybe
link |
01:47:04.800
they were made or maybe they came with the big bang. The prime, what we call primordial, which
link |
01:47:11.600
means they're really different. They came from that. We don't know at this point if they came
link |
01:47:16.160
with a big bang, then maybe they account for what we call dark matter or some of it.
link |
01:47:21.040
Hmm. Like there was a lot of them if they came with it because there's a lot of dark matter.
link |
01:47:26.080
Yeah.
link |
01:47:27.360
But will gravitational waves give you any kind of intuition about the origin of these oscillating?
link |
01:47:34.240
We think that if we see the distributions enough of them, the distributions of their
link |
01:47:40.320
masses, the distributions of how they're spinning, so we can actually measure when they're going
link |
01:47:45.760
around each other, whether they're spinning like this or whether the whole system has any wobbles.
link |
01:47:55.680
What? So this is now. Okay.
link |
01:48:00.400
We're doing that.
link |
01:48:01.280
And then you're constantly kind of crawling back and back in time.
link |
01:48:04.400
And we're crawling back in time and seeing how many there are as we go back. And so do they
link |
01:48:09.920
point back.
link |
01:48:10.480
So you're like, what is that discipline called, cartography or something? You're like mapping
link |
01:48:15.920
this, the early universe via the lens of gravitational waves.
link |
01:48:21.920
Not yet the early universe, but at least back in time.
link |
01:48:24.080
Earlier.
link |
01:48:24.720
Yeah. So black holes are this mathematical phenomenon, but they come about in different
link |
01:48:32.960
ways. We have a huge black hole at the center of our galaxy and other galaxies. Those probably
link |
01:48:39.600
were made some other way. We don't know when the galaxies themselves had to do with the
link |
01:48:44.160
formation of galaxies. We don't really know. So the fact that we use the word black hole,
link |
01:48:50.240
the origin of black holes might be quite different depending on how they happen. They just have
link |
01:48:56.480
to in the end have a gravitational field that will bend everything in.
link |
01:49:01.200
How do you feel about black holes as a human being? There's this thing that's nearly
link |
01:49:06.720
infinitely dense, doesn't let light escape. Isn't that kind of terrifying? It feels like
link |
01:49:13.680
the stuff in nightmares.
link |
01:49:14.960
I think it's an opportunity.
link |
01:49:19.040
To do what exactly?
link |
01:49:21.360
So like the early universe is an opportunity. If we can study the early universe, we can
link |
01:49:26.800
learn things like I told you. And here again, we have an embarrassing situation in physics.
link |
01:49:32.720
We have two wonderful theories of physics, one based on quantum mechanics, quantum field
link |
01:49:39.920
theory. And we can go to a big accelerator like at CERN and smash particles together
link |
01:49:46.000
and almost explain anything that happens beautifully using quantum field theory and
link |
01:49:51.840
quantum mechanics. Then we have another theory of physics called general relativity, which
link |
01:49:57.200
is what we've been talking about most of the time, which is fantastic at describing the
link |
01:50:02.160
things at high velocities, long distances, and so forth. So that's not the way it's
link |
01:50:12.000
supposed to be. We're trying to create a theory of physics, not two theories of physics.
link |
01:50:18.480
So we have an embarrassment that we have two different theories of physics. People have
link |
01:50:22.960
tried to make a unified theory, what they call a unified theory. You've heard those
link |
01:50:28.080
words for decades. They still haven't. That's been primarily done theoretically or tried.
link |
01:50:36.560
People actively do that. My personal belief is that like much of physics, we need some
link |
01:50:44.640
clues. So we need some experimental evidence. So where is there a place? If we go to CERN
link |
01:50:51.280
and do those experiments, gravitational waves or general relativity don't matter. If we
link |
01:50:56.160
go to study our black holes, elementary particle physics doesn't matter. We're studying these
link |
01:51:02.560
huge objects. So where might we have a place where both phenomena have to be satisfied?
link |
01:51:09.120
An example is black holes. Inside black holes. Yeah. So we can't do that today. But when
link |
01:51:15.920
I think of black hole, it's a potential treasure chest of understanding the fundamental problems
link |
01:51:24.160
of physics and maybe can give us clues to how we bring to the embarrassment of having
link |
01:51:32.800
two theories of physics together. That's my own romantic idea. What's the worst that could
link |
01:51:38.960
happen? It's so enticing. Just go in and look. Do you think, how far are we away from
link |
01:51:45.040
figuring out the unified theory of physics, the theory of everything? What's your sense?
link |
01:51:50.880
Who will solve it? Like what discipline will solve it? Yeah. I think so little progress
link |
01:52:02.080
has been made without more experimental clues, as I said, that we're just not able to say
link |
01:52:16.080
that we're close without some clues. The most popular theory these days that might lead
link |
01:52:26.320
to that is called string theory. The problem with string theory is it solves a lot of beautiful
link |
01:52:34.440
mathematical problems we have in physics. It's very satisfying theoretically, but it
link |
01:52:46.720
has almost no predictive, maybe no predictive ability because it is a theory that works
link |
01:52:53.840
in 11 dimensions. We live in a physical world of three space and one time dimension. In
link |
01:53:02.080
order to make predictions in our world with string theory, you have to somehow get rid
link |
01:53:08.720
of these other seven dimensions. That's done mathematically by saying they curl up on each
link |
01:53:15.280
other on scales that are too small to affect anything here. That's an okay argument, but
link |
01:53:23.400
how you do that is not unique. That means if I start with that theory and I go to our
link |
01:53:30.320
world here, I can't uniquely go to it. And if I can't, it's not predictive. And that's
link |
01:53:37.280
actually a killer. That's a killer. And string theory is, it seems like from my outsider's
link |
01:53:42.480
perspective has lost favor over the years, perhaps because of this very idea. It's a
link |
01:53:46.920
lack of predictive power. I mean, that science has to connect to something where you make
link |
01:53:52.440
predictions as beautiful as it might be. So I don't think we're close. I think we need
link |
01:53:59.960
some experimental clues. It may be that information on something we don't understand presently
link |
01:54:07.520
at all, like dark energy or probably not dark matter, but dark energy or something might
link |
01:54:12.680
give us some ideas. But I can't envision right now in the short term, meaning the horizon
link |
01:54:26.160
that we can see how we're going to bring these two theories together.
link |
01:54:31.760
A kind of a two part question, maybe just asking the same thing in two different ways.
link |
01:54:38.560
One question is, do you have hope that humans will colonize the galaxy? So expand out, become
link |
01:54:47.760
a multi planetary species. Another way of asking that from a gravitational and a propulsion
link |
01:54:53.080
perspective, do you think we'll come up with ways to travel closer to the speed of light
link |
01:54:57.160
or maybe faster than the speed of light, which would make it a whole heck of a lot easier
link |
01:55:02.280
to expand out into the universe?
link |
01:55:06.120
Yeah. Well, I think that's very futuristic. I think we're not that far from being able
link |
01:55:17.800
to make a one way trip to Mars. That's then a question of whether people are willing to
link |
01:55:29.720
send somebody on a one way trip.
link |
01:55:31.640
Oh, I think they are. There's a lot of the explorers burned bright within our hearts.
link |
01:55:36.840
Yeah, exactly.
link |
01:55:37.840
There's a lot of people willing to die for the opportunity to explore new territory.
link |
01:55:42.920
So this recent landing on Mars is pretty impressive. They have a little helicopter. They're going
link |
01:55:51.280
to fly around. You can imagine in the not too distant future that you could have, I
link |
01:55:57.920
don't think civilizations colonizing, I can envision, but I can envision something more
link |
01:56:04.520
like the South Pole. We haven't colonized Antarctica because it's all ice and cold and
link |
01:56:12.000
so forth. But we have stations. So we have a station that's self sustaining at the South
link |
01:56:19.000
Pole. I've been there. It has.
link |
01:56:22.000
Wow, really?
link |
01:56:23.000
Yeah.
link |
01:56:24.000
What's that like? Because there's parallels there to go to Mars.
link |
01:56:30.080
It's fantastic.
link |
01:56:31.080
What's the journey like?
link |
01:56:33.480
The journey involves going. The South Pole station is run in the US by the National Science
link |
01:56:41.640
Foundation. I went because I was on the National Science Board that runs the National Science
link |
01:56:48.160
Foundation. And so you get a VIP trip if you're healthy enough to the South Pole to see it,
link |
01:56:56.120
which I took. You fly from the US to Australia to Christchurch in Southern Australia. And
link |
01:57:08.840
from there you fly to McMurdo Station, which is on the coast. And it's the station with
link |
01:57:13.840
about a thousand people right on the coast of Antarctica. It's about a seven or eight
link |
01:57:20.600
hour flight and they can't predict the weather. So when I flew from Christchurch to McMurdo
link |
01:57:28.040
Station, they tell you in advance, you do it in a military aircraft, they tell you in
link |
01:57:32.980
advance that they can't predict whether they can land because they have to land on ice.
link |
01:57:37.840
And reassuring.
link |
01:57:38.840
Yeah. And so about halfway the pilot got on and said, sorry, this is a, they call it a
link |
01:57:46.760
boomerang flight. You know, boomerang goes out and goes back. So we had to stay a little
link |
01:57:52.360
while in Christchurch, but then we eventually went to McMurdo Station and then flew to the
link |
01:57:59.560
South Pole. The South Pole itself is, when I was there, it was minus 51 degrees. That
link |
01:58:07.920
was summer. Zero humidity. And it's about 11,000 feet altitude because it's never warm
link |
01:58:26.840
enough for anything to melt. So it doesn't snow very much, but it's about 11,000 feet
link |
01:58:32.040
of snowpack. So you land in a place that's high altitude, cold as could be, and incredibly
link |
01:58:41.480
dry, which means you have a physical adjustment. The place itself is fantastic. They have this
link |
01:58:52.360
great station there. They do astronomy at the South Pole. Nature wise, is it beautiful?
link |
01:59:00.320
What's the experience like? Or is it like visiting any town? No, it's very small. There's
link |
01:59:05.160
only less than a hundred people there. Even when I was there, there were about 50 or 60
link |
01:59:13.120
there. And in the winter, there's less, half of that. Their winter. Yeah. It gets real
link |
01:59:18.800
cold. It gets really cold, yeah. But it's a station. And I think, and that's, I mean,
link |
01:59:28.640
we haven't gone beyond that. On the coast of Antarctica, they have greenhouses and they're
link |
01:59:33.920
self sustaining in McMurdo Station, but we haven't really settled more than that kind
link |
01:59:40.840
of thing in Antarctica, which is a big country or a big plot, a big piece of land. So I don't,
link |
01:59:55.440
I can't envision kind of colonizing at people living so much, as much as I can see the equivalent
link |
02:00:04.640
of the South Pole Station. Well, in the computing world, there's an idea of backing up your
link |
02:00:10.400
data and then you want to do offsite backup, to make sure that if the whole thing burns,
link |
02:00:16.520
if your whole house burns down, that you can have a backup offsite of the data. I think
link |
02:00:21.520
the difference between Antarctica and Mars is Mars is an offsite backup. That if we have
link |
02:00:28.260
nuclear war, whatever the heck might happen here on earth, it'd be nice to have a backup
link |
02:00:32.800
elsewhere. And it'd be nice to have a large enough colony where we sent a variety of people
link |
02:00:38.000
except a few silly astronauts in suits, have an actual vibrant, get a few musicians and
link |
02:00:48.160
artists up there, get a few, maybe like one or two computer scientists, those are essential.
link |
02:00:53.920
Maybe even a physicist, but I'm not sure.
link |
02:00:56.320
Yeah, maybe not. So that comes back to something you talked about earlier, which is the paradox,
link |
02:01:02.200
Fermi's paradox, because you talked about having to escape. And so one number you don't
link |
02:01:10.360
know how to use in Fermi's calculation or Drake, who's done it better, is how long do
link |
02:01:15.760
civilizations last? We've barely gotten to where we can communicate with electricity
link |
02:01:24.320
and magnetism and maybe we'll wipe ourselves out pretty soon.
link |
02:01:28.040
Are you hopeful in general? Like you think we've got another couple of hundred years
link |
02:01:32.480
at least? Or are you worried?
link |
02:01:35.680
Well, no, I'm hopeful, but I don't know if I'm hopeful in the longterm. If you say, are
link |
02:01:47.480
we able to go for another couple of thousand years? I'm not sure. I think we have where
link |
02:01:55.720
we started, the fact that we can do things that don't allow us to kind of keep going
link |
02:02:00.760
or there can be, whether it ends up being a virus that we create or ends up being the
link |
02:02:06.560
equivalent of nuclear war or something else. It's not clear that we can control things
link |
02:02:11.480
well enough.
link |
02:02:13.120
So speaking of really cold conditions and not being hopeful and eventual suffering and
link |
02:02:20.520
destruction of the human species, let me ask you about Russian literature. You mentioned,
link |
02:02:26.120
how's that for transition? I'm doing my best here. You mentioned that you used to love
link |
02:02:30.960
literature when you were younger and you even were hoping to be a writer yourself. That
link |
02:02:36.760
was the motivation. And some of the books I've seen that you listed that were inspiring
link |
02:02:43.760
to you was from Russian literature, like Tolstoy, Dostoevsky, Solzhenitsyn. Maybe in general
link |
02:02:52.960
you can speak to your fascination with Russian literature or in general what you picked up
link |
02:02:57.840
from those.
link |
02:02:58.840
I'm not surprised you picked up on the Russian literature, your background, but that's okay.
link |
02:03:08.320
You should be surprised I didn't make the entire conversation about this. That's the
link |
02:03:12.040
real surprise.
link |
02:03:13.040
Yeah. When I didn't really become a physicist or want to go in science until I started college.
link |
02:03:24.280
So when I was younger, I was good at math and that kind of stuff, but I didn't really,
link |
02:03:29.680
I came from a family, nobody went to college and I didn't have any mentors. But I liked
link |
02:03:36.400
to read when I was really young. And so when I was very young, I always carried around
link |
02:03:42.440
a pocket book and read it. And my mother read these mystery stories and I got bored by those
link |
02:03:49.280
eventually. And then I discovered real literature. I don't know what age, but about 12 or 13.
link |
02:03:55.500
And so then I started reading good literature and there's nothing better than Russian literature,
link |
02:04:00.640
of course.
link |
02:04:01.640
Thank you.
link |
02:04:02.640
Reading good literature. So I read quite a bit of Russian literature at that time. And
link |
02:04:16.240
so you asked me about, well, I don't know, I'll say a few words, Dostoevsky. So what
link |
02:04:22.840
about Dostoevsky? For me, Dostoevsky was important in two, I mean, I've read a lot of literature
link |
02:04:33.200
because it's kind of the other thing I do with my life. And he made two incredible,
link |
02:04:39.160
in addition to his own literature, he influenced literature tremendously by having, I don't
link |
02:04:46.960
know how to pronounce polyphony. So he's the first real serious author that had multiple
link |
02:04:53.720
narrators. And he absolutely is the first. And he also was the first, he began existential
link |
02:05:05.440
literature. So the most important book that I've read in the last year when I've been
link |
02:05:12.440
forced to be isolated was existential literature. I decided to reread Camus, The Plague.
link |
02:05:20.960
Oh, yeah. That's a great book.
link |
02:05:23.880
It's a great book and it's right now to read it. It's fantastic.
link |
02:05:26.400
I think that book is about love, actually. Love for humanity.
link |
02:05:30.960
It is, but it has all the, if you haven't read it in recent years, I had read it before,
link |
02:05:37.080
of course, but to read it during this, because it's about a plague. So it's really fantastic
link |
02:05:43.080
to read down. But that reminds me of, he was a great existentialist, but the beginning
link |
02:05:48.000
of existential literature was Dostoevsky.
link |
02:05:50.800
Dostoevsky, yeah.
link |
02:05:51.940
So in addition to his own great novels, he had a tremendous impact on literature.
link |
02:06:00.280
And there's also for Dostoevsky, unlike most other existentialists, he was at least in
link |
02:06:06.300
part religious. I mean, religiosity permeated his idea. I mean, one of my favorite books
link |
02:06:12.360
of his is The Idiot, which is a Christlike figure in there.
link |
02:06:16.720
Well, there's Prince Mishkin, is that his name?
link |
02:06:19.280
Prince Mishkin, yeah.
link |
02:06:20.280
Yeah, Mishkin.
link |
02:06:21.280
Yeah, Mishkin.
link |
02:06:22.280
Yeah.
link |
02:06:23.280
That's one thing about, you read it in English, I presume.
link |
02:06:25.960
Yeah, yeah.
link |
02:06:26.960
Yeah. So the names, that's what gets a lot of people. There's so many names, so hard
link |
02:06:30.500
to pronounce. You have to remember all of them. It's like you have the same problem.
link |
02:06:35.700
But he was a great character.
link |
02:06:38.320
I kind of have a connection with him, because I often, the title of the book, The Idiot,
link |
02:06:47.240
is I kind of, I often call myself an idiot, because that's how I feel. I feel so naive
link |
02:06:52.620
about this world. And I'm not sure, I'm not sure why that is. Maybe it's genetic or so
link |
02:06:59.600
on. But I have a connection, a spiritual connection to that character.
link |
02:07:05.160
To Mishkin.
link |
02:07:06.160
To Mishkin, yeah.
link |
02:07:07.160
But he was far from an idiot.
link |
02:07:10.160
No, in some sense, in some sense. But in another sense, maybe not of this world.
link |
02:07:17.400
In another sense he was. I mean, he was a bumbler, a bunker.
link |
02:07:23.020
But you also mentioned Solzhenitsyn, very interesting.
link |
02:07:28.160
And he always confused me. Of course, he was really, really important in writing about
link |
02:07:36.800
Stalin, and first getting in trouble, and then later he wrote about Stalin in a way,
link |
02:07:48.480
I forget what the book was, in a way that was very critical of Lenin.
link |
02:07:55.640
Yeah, he's evolved through the years, and he actually showed support for Putin eventually.
link |
02:08:00.640
It was a very interesting transition he took, no, journey he took through thinking about
link |
02:08:08.480
Russia and the Soviet Union. But I think what I get from him is basic, it's like Viktor
link |
02:08:17.920
has this man's search for meaning. I have a similar kind of sense of the cruelty of
link |
02:08:25.640
human nature, cruelty of indifference, but also the ability to find happiness in the
link |
02:08:31.520
small joys of life. That's something, there's nothing like a prison camp that makes you
link |
02:08:37.720
realize you could still be happy with a very, very little.
link |
02:08:41.760
Yeah, his description of how to go through a day and actually enjoy it in a prison camp
link |
02:08:50.160
is pretty amazing. And some prison camp, it's the worst of the worst.
link |
02:08:56.760
And also, I do think about the role of authoritarian states in hopeful idealistic systems somehow
link |
02:09:09.440
leading to the suffering of millions. And this might be arguable, but I think a lot
link |
02:09:16.760
of people believe that Stalin, I think, genuinely believed that he's doing good for the world.
link |
02:09:24.240
And he wasn't. It's a very valuable lesson that even evil people think they're doing
link |
02:09:32.280
good. Otherwise, it's too difficult to do the evil. The best way to do evil is to believe
link |
02:09:38.360
about framing it in a way like you're doing good. And then this is a very clear picture
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02:09:44.000
of that, which is the gulags. And Solzhenitsyn is one of the best people to reveal that.
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The most recent thing I read, it isn't actually fiction, was the woman, I can't remember
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her name, who got the Nobel Prize about within the last five years. I don't know whether
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she's Ukrainian or Russian, but there are interviews. Have you read that?
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Interview of Ukrainian survivors of...
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Well, I think she may be originally Ukrainian. The book's written in Russian and translated
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in English, and many of the interviews are in Moscow and places. But she won the Nobel
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Prize within the last five years or so. But what's interesting is that these are people
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of all different ages, all different occupations and so forth, and they're reflecting on their
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reaction to basically the present Soviet system, the system they lived with before.
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There's a lot of looking back by a lot of them with, well, it being much better before.
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02:10:57.400
Yeah. I don't know what... In America, we think we know the right answer, what it means
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to be, to build a better world. I'm not so sure. I think we're all just trying to figure
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it out.
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02:11:12.440
Yeah, there's...
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We're doing our best.
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I think you're right.
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Is there advice you can give to young people today, besides reading Russian literature
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at a young age, about how to find their way in life, how to find success in Korea or just
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life in general?
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My own belief, it may not be very deep, but I believe it. I think you should follow your
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dreams and you should have dreams and follow your dreams if you can, to the extent that
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you can. And we spend a lot of our time doing something with ourselves. In my case, physics,
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in your case, I don't know, whatever it is, machine learning and this. Yeah, you should
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have fun.
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02:12:05.720
What was... Wait, wait, wait. Follow your dreams. What dream did you have? Because there's...
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02:12:12.120
Well, originally, I was...
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02:12:14.720
Because you didn't follow your dream. I thought you were supposed to be a writer.
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I changed along the way. I was gonna be, but I changed.
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What happened?
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That was... What happened? Oh, I read... I decided to take the most serious literature
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course in my high school, which was a mistake. I'd probably be a second rate writer now.
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And...
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Could be a Nobel Prize winning writer.
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02:12:37.520
And the book that we read, even though I had read Russian novels, I was 15, I think, cured
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me from being a novelist.
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Destroyed your dream?
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02:12:54.080
Yes.
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Cured you. Okay. What was the book?
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Moby Dick.
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Okay.
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02:12:58.800
So, why Moby Dick?
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02:13:00.360
Yeah, why?
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So, I've read it since, and it's a great novel. Maybe it's as good as the Russian novels.
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02:13:07.680
I've never made it through. It was too boring. It was too long.
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Okay. Your words are gonna mesh with what I say.
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Excellent.
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And you may have the same problem at older ages.
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That's why I'm not a writer.
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02:13:19.520
It may be. So, the problem is, Moby Dick is... What I remember was there was a chapter that
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was maybe 100 pages long, all describing this, why there was Ahab and the white whale, and
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it was the battle between Ahab with his wooden peg leg and the white whale.
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02:13:39.520
And there was a chapter that was 100 pages long in my memory, I don't know how long it
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really was, that described in detail, though, great white whale and what he was doing and
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what his fins were like and this and that.
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02:13:52.360
And it was so incredibly boring, the word you used, that I thought, if this is great
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literature, screw it.
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02:14:00.280
Fascinating.
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02:14:01.280
Okay. And now, why did I have a problem? I know now in reflection, because I still read
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a lot, and I read that novel after I was 30 or 40 years old, and the problem was simple.
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I diagnosed what the problem was. That novel, in contrast to the Russian novels, which are
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very realistic and point of view, is one huge metaphor.
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02:14:32.960
At 15 years old, I probably didn't know the word, and I certainly didn't know the meaning
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of metaphor.
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02:14:38.200
Yeah, like, why do I care about a fish? Why are you telling me all about this fish?
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02:14:42.160
Exactly. It's one big metaphor. So, reading it later as a metaphor, I could really enjoy
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it. But the teacher gave me the wrong book, or maybe it was the right book because I went
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into physics. But it was truly, I think, I may oversimplify, but it was really that I
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was too young to read that book. Not too young to read the Russian novels, interestingly,
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but too young to read that because I probably didn't even know the word, and I certainly
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didn't understand it as a metaphor.
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02:15:10.800
Well, in terms of fish, I recommend people read Old Man and the Sea, much shorter, much
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better. It's still a metaphor, though. But you can read it just as a story about a guy
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catching a fish, and it's still fun to read. I had the same experience as you, not with
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02:15:29.560
Moby Dick, but later in college, I took a course on James Joyce. Don't ask me why. I
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was majoring in computer science, I took a course on James Joyce. And I was kept being
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told that he is widely considered, by many considered, to be the greatest literary writer
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02:15:46.640
of the 20th century. And I kept reading, I think, so his short story is The Dead, I think
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02:15:52.520
it's called. It was very good. Well, not very good, but pretty good. And then Ulysses.
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It's actually very good.
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02:15:58.360
It is very good. Only The Dead, the final story, it still rings with me today. But then
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02:16:02.640
Ulysses was, I got through Ulysses with the help of some Cliff Notes and so on. And so
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02:16:09.400
I did Ulysses and then Finnegan's Wake. The moment I started Finnegan's Wake, I said,
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this is stupid. That's when I went full into like, I don't know, that's when I went full
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02:16:22.440
Kafka, Bukowski, like people who just talk about the darkness of the human condition
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in the fewest words possible and without any of the music of language. So it was a turning
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point as well. I wonder when is the right time to appreciate the beauty of language.
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02:16:45.200
Like even Shakespeare. I was very much off put by Shakespeare in high school and only
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later I started to appreciate its value in the same way. Let me ask you a ridiculous
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question. Okay. I mean, because you've read Russian literature, let me ask this one last
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question. I might be lying. There might be a couple more, but what do you think is the
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meaning of this whole thing? You got a Nobel prize for looking out into the, trying to
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reach back into the beginning of the universe, listening to the gravitational waves, but
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02:17:24.800
that still doesn't answer the why. Why are we here? Beyond just the matter and anti matter,
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the philosophical question.
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The philosophical question about the meaning of life, I'm probably not really good at.
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I think that the individual meaning, I would say it rather simplistically is whether you've
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made a difference, a positive difference, I'd say for anything besides yourself. Meaning
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you could have been important to other people or you could have discovered gravitational
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02:18:11.340
waves that matters to other people or something, but something beyond just existing on the
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earth as an individual. So your life has meaning if you have affected either knowledge or people
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02:18:27.440
or something beyond yourself. It's a simplistic statement, but it's about as good as I can
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say. In all of its simplicity, it may be very true. Does it make you sad that this ride
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ends? Do you think about your mortality? Are you afraid of it?
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02:18:55.360
Not exactly afraid of it, but saddened by it. I'm old enough to know that I've lived
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most of my life and I enjoy being alive. I can imagine being sick and not wanting to
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be alive, but I'm not.
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It's been a good ride.
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I'm not happy to see it come to an end. I'd like to see it prolong, but I don't fear the
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dying itself or that kind of thing. It's more, I'd like to prolong what is I think a good
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life that I'm living and still living.
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02:19:51.240
It's sad to think that the finiteness of it is the thing that makes it special. And also
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02:20:01.600
sad to me, at least it's kind of, I don't think I'm using too strong of a word, but
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02:20:08.520
it's kind of terrifying the uncertainty of it. The mystery of it, the mystery of death.
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02:20:15.960
The mystery of it, yeah, of death. When we're talking about the mystery of black holes that's
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02:20:20.120
somehow distant, that's somehow out there and the mystery of our own.
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02:20:25.120
But even life, the mystery of consciousness, I find so hard to deal with too. I mean, it's
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not as painful. I mean, we're conscious, but the whole magic of life we can understand,
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02:20:37.640
but consciousness where we can actually think and so forth. It's pretty.
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02:20:43.560
It seems like such a beautiful gift that it really sucks that we get to let go of it.
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02:20:48.520
We have to let go of it. What do you hope your legacy is? As I'm sure they will. Aliens
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02:20:54.080
when they visit and humans have destroyed all of human civilization. Aliens read about
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02:20:59.320
you in an encyclopedia that we'll leave behind. What do you hope it says?
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02:21:03.520
Well, I would hope they, to the extent that they evaluated me, felt that I helped move
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science forward as a tangible contribution and that I served as a good role model for
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02:21:22.520
how humans should live their lives.
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02:21:25.680
And we're part of creating one of the most incredible things humans have ever created.
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02:21:31.840
So yes, there's the science. That's the Fermi thing, right?
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02:21:36.920
And the instrument, I guess.
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02:21:38.240
And the instrument. The instrument is a magical creation, not just by a human, by a collection
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02:21:43.960
of humans. The collaboration is, that's humanity at its best. I do hope we last quite a bit
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longer, but if we don't, this is a good thing to remember humans by. At least they built
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02:22:05.560
that thing. That's pretty impressive. Barry, this is an amazing conversation. Thank you
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02:22:10.320
so much for wasting your time and explaining so many things so well. I appreciate your
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time today.
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02:22:15.840
Thank you.
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02:22:17.960
Thanks for listening to this conversation with Barry Barish. To support this podcast,
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02:22:22.760
please check out our sponsors in the description. And now let me leave you with some words from
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02:22:28.280
Werner Heisenberg, a theoretical physicist and one of the key pioneers of quantum mechanics.
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02:22:35.840
Not only is the universe stranger than we think, it is stranger than we can think. Thank
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02:22:43.500
you for listening and hope to see you next time.