Barry Barish: Gravitational Waves and the Most Precise Device Ever Built

00:00:00.000 | The following is a conversation with Barry Barish,

00:00:02.960 | a theoretical physicist at Caltech,

00:00:05.440 | and the winner of the Nobel Prize in Physics

00:00:08.280 | for his contributions to the LIGO detector

00:00:11.360 | and the observation of gravitational waves.

00:00:14.760 | LIGO, or the Laser Interferometer

00:00:17.080 | Gravitational Wave Observatory,

00:00:19.200 | is probably the most precise measurement device

00:00:22.380 | ever built by humans.

00:00:25.240 | It consists of two detectors

00:00:27.120 | with four kilometer long vacuum chambers

00:00:29.520 | situated 3,000 kilometers apart,

00:00:33.240 | operating in unison to measure a motion

00:00:36.360 | that is 10,000 times smaller than the width of a proton.

00:00:41.220 | It is the smallest measurement ever attempted by science,

00:00:44.720 | a measurement of gravitational waves

00:00:46.840 | caused by the most violent and cataclysmic events

00:00:50.260 | in the universe,

00:00:51.560 | occurring over tens of millions of light years away.

00:00:55.080 | To support this podcast,

00:00:57.600 | please check out our sponsors in the description.

00:01:00.760 | This is the Lex Friedman Podcast,

00:01:03.400 | and here is my conversation with Barry Barish.

00:01:07.140 | You've mentioned that you were always curious

00:01:10.080 | about the physical world,

00:01:11.360 | and that an early question you remember stood out

00:01:14.600 | where you asked your dad,

00:01:16.200 | "Why does ice float on water?"

00:01:18.400 | And he couldn't answer.

00:01:19.800 | And this was very surprising to you.

00:01:22.320 | So you went on to learn why.

00:01:25.560 | Maybe you can speak to what are some early questions

00:01:27.920 | in math and physics that really sparked your curiosity?

00:01:31.760 | - Yeah, that memory is

00:01:33.800 | kind of something I use to illustrate

00:01:39.240 | something I think that's common in science,

00:01:42.200 | is that people that do science somehow have maintained,

00:01:45.340 | maintained something that kids always have.

00:01:50.000 | A small kid, eight years old or so,

00:01:55.160 | asks you so many questions usually,

00:01:57.000 | typically that you consider them pests,

00:01:59.760 | tell them to stop asking so many questions.

00:02:02.160 | And somehow our system manages to kill that in most people.

00:02:08.000 | So in school, we make people do study and do their things,

00:02:14.460 | but not to pester them by asking too many questions.

00:02:18.040 | And I think, not just myself,

00:02:22.680 | but I think it's typical of scientists like myself

00:02:25.840 | that have somehow escaped that.

00:02:28.920 | Maybe we're still children,

00:02:30.280 | or maybe we somehow didn't get it beaten out of us.

00:02:34.080 | But I think it's, I teach in college level,

00:02:37.580 | and it's, to me, one of the biggest deficits

00:02:40.640 | is the lack of curiosity, if you want,

00:02:43.340 | that we've beaten out of them,

00:02:44.520 | 'cause I think it's an innate human quality.

00:02:47.520 | - Is there some advice or insights you can give

00:02:49.600 | to how to keep that flame of curiosity going?

00:02:51.240 | - I think it's a problem of both parents,

00:02:53.280 | and the parents should realize

00:02:56.800 | that's a great quality we have,

00:02:58.480 | that you're curious and that's good.

00:03:01.120 | Instead, we have expressions like curiosity killed the cat.

00:03:04.880 | And more, but I mean, basically,

00:03:10.960 | it's not thought to be a good thing.

00:03:13.160 | You get, curiosity killed the cat means

00:03:15.140 | if you're too curious, you get in trouble.

00:03:17.240 | - I don't like cats anyway, so maybe it's a good thing.

00:03:20.560 | - Yeah, yeah, that, to me, needs to be solved,

00:03:25.000 | really, in education and in homes.

00:03:27.520 | That realization that there's certain human qualities

00:03:30.540 | that we should try to build on and not destroy,

00:03:34.320 | one of them is curiosity.

00:03:35.720 | Anyway, back to me and curiosity,

00:03:38.160 | I was a pest and asked a lot of questions.

00:03:40.760 | My father generally could answer them at that age.

00:03:45.000 | And the first one I remember that he couldn't answer

00:03:48.800 | was not a very original question,

00:03:52.600 | but basically that ice is made out of water,

00:03:56.520 | and so why does it float on water?

00:03:58.500 | And he couldn't answer it.

00:04:03.320 | And it may not have been the first question,

00:04:06.160 | it's the first one that I remember.

00:04:07.400 | And that was the first time that I realized

00:04:10.880 | that to learn and answer your own curiosity or questions,

00:04:15.880 | there's various mechanisms.

00:04:17.880 | In this case, it was going to the library

00:04:20.720 | or asking people who know more and so forth,

00:04:23.080 | but eventually you do it by what we call research.

00:04:26.600 | But it's driven by,

00:04:31.280 | if you're, hopefully you ask good questions,

00:04:33.800 | if you ask good questions

00:04:35.000 | and you have the mechanisms to solve them,

00:04:37.360 | then you do what I do in life, basically.

00:04:39.360 | Not necessarily physics,

00:04:40.680 | and it's a great quality in humans and we should nurture it.

00:04:46.560 | - Do you remember any other kind of, in high school,

00:04:49.960 | maybe early college, more basic physics ideas

00:04:54.320 | that sparked your curiosity

00:04:55.880 | or mathematics or science in general?

00:04:57.400 | - I wasn't really into science until I got to college,

00:05:01.400 | to be honest with you.

00:05:02.820 | But just staying with water for a minute,

00:05:06.680 | I remember that I was curious

00:05:11.160 | why, what happens to water?

00:05:15.040 | You know, it rains and there's water in a wet pavement

00:05:17.680 | and then the pavement dries out.

00:05:19.120 | What happened to this water that came down?

00:05:22.240 | And I didn't know that much.

00:05:24.000 | And then eventually I learned in chemistry or something,

00:05:27.000 | water's made out of hydrogen and oxygen.

00:05:29.600 | Those are both gases,

00:05:30.680 | so how the heck does it make this substance, this liquid?

00:05:33.800 | (both laugh)

00:05:37.560 | - Yeah, so that has to do with states of matter.

00:05:41.440 | I know perhaps LIGO and the thing

00:05:45.280 | for which you've gotten the Nobel Prize

00:05:46.760 | and the things much of your life work

00:05:49.400 | perhaps was a happy accident in some sense

00:05:53.000 | in the early days,

00:05:54.040 | but is there a moment where you looked up to the stars

00:05:57.200 | and also the same way you wondered about water,

00:05:59.800 | wondered about some of the things

00:06:01.120 | that are out there in the universe?

00:06:03.480 | - Oh yeah, I think everybody looks and is in awe

00:06:07.600 | and is curious about what it is out there.

00:06:11.600 | And as I learned more, I learned, of course,

00:06:15.560 | that we don't know very much about what's there.

00:06:18.960 | And the more we learn, the more we know we don't know.

00:06:21.400 | I mean, we don't know what the majority

00:06:23.760 | of anything is out there.

00:06:25.360 | It's all what we call dark matter, dark energy.

00:06:28.680 | And that's one of the big questions.

00:06:30.480 | 20 years when I was a student, those weren't questions.

00:06:33.120 | So we even know less in a sense

00:06:35.120 | the more we look.

00:06:38.000 | So of course, I think that's one of the areas

00:06:41.400 | that almost it's universal.

00:06:44.960 | People see the sky, they see the stars

00:06:47.680 | and they're beautiful and see it looks different

00:06:50.840 | on different nights.

00:06:51.920 | And it's a curiosity that we all have.

00:06:54.800 | - What are some questions about the universe

00:06:59.240 | that in the same way that you felt about the ice,

00:07:03.280 | that today, you mentioned to me offline,

00:07:05.760 | you're teaching a course on the frontiers of science,

00:07:08.760 | frontiers of physics.

00:07:10.360 | What are some questions, outside the ones

00:07:12.920 | we'll probably talk about, that kind of,

00:07:15.420 | yeah, fill you with, get your flame of curiosity up

00:07:21.920 | and firing up, fill you with awe?

00:07:26.680 | - Well, first I'm a physicist, not an astronomer.

00:07:29.520 | So I'm interested in the physical phenomenon, really.

00:07:32.480 | So the question of dark matter and dark energy,

00:07:37.480 | which we probably won't talk about,

00:07:39.680 | are recent, they're in the last 20, 30 years,

00:07:43.200 | or certainly dark energy.

00:07:45.420 | Dark energy is a complete puzzle.

00:07:47.880 | It goes against what you will ask me about,

00:07:51.520 | which is general relativity

00:07:53.720 | and Einstein's general relativity.

00:07:55.840 | It basically takes something that he thought was,

00:08:00.440 | what he called a constant, which isn't,

00:08:03.240 | and if that's even the right theory,

00:08:07.160 | and it represents most of the universe.

00:08:10.840 | And then we have something called dark matter,

00:08:12.760 | and there's good reason to believe

00:08:14.280 | it might be an exotic form of particles.

00:08:18.720 | And that is something I've always worked on,

00:08:22.280 | on particle accelerators and so forth.

00:08:24.320 | And it's a big puzzle, what it is.

00:08:26.440 | It's a bit of a cottage industry

00:08:28.040 | in that there's lots and lots of searches.

00:08:30.820 | But it may be a little bit like,

00:08:34.120 | looking for a treasure under rocks or something.

00:08:36.840 | It's hard to, we don't have really good guidance,

00:08:40.320 | except that we have very, very good information

00:08:44.480 | that it's pervasive and it's there.

00:08:48.500 | And that it's probably particles, small,

00:08:51.800 | that evidences all of those things.

00:08:55.220 | But then the most logical solution doesn't seem to work,

00:08:59.440 | something called supersymmetry.

00:09:01.040 | - And do you think the answer could be

00:09:05.560 | something very complicated?

00:09:07.560 | - You know, I like to hope that,

00:09:10.840 | think that most things that appear complicated

00:09:14.420 | are actually simple, if you really understand them.

00:09:17.560 | I think we just don't know at the present time,

00:09:21.360 | and it isn't something that affects us.

00:09:23.680 | It does affect, it affects how the stars

00:09:27.480 | go around each other and so forth,

00:09:29.160 | 'cause we detect that there's missing gravity.

00:09:31.400 | But it doesn't affect everyday life at all.

00:09:35.520 | I tend to think and expect, maybe,

00:09:40.520 | and that the answers will be simple,

00:09:43.600 | we just haven't found it yet.

00:09:45.500 | - Do you think those answers might change

00:09:47.140 | the way we see other sources of gravity, black holes,

00:09:51.240 | the way we see the parts of the universe that we do study?

00:09:56.240 | - It's conceivable.

00:09:58.400 | The black holes that we've found in our experiment,

00:10:01.440 | and we're trying now to understand the origin of those,

00:10:06.040 | it's conceivable, but not, doesn't seem the most likely

00:10:10.500 | that they were primordial,

00:10:12.280 | that is, they were made at the beginning.

00:10:14.280 | And in that sense, they could represent

00:10:16.480 | at least part of the dark matter.

00:10:18.840 | So there can be connections.

00:10:20.280 | Dark black holes, or how many there are,

00:10:23.880 | how much of the mass they encompass

00:10:25.640 | is still pretty primitive, we don't know.

00:10:28.520 | - So before I talk to you more about black holes,

00:10:30.560 | let me take a step back to,

00:10:32.380 | I actually went to high school in Chicago,

00:10:34.800 | and would go to take classes at Fermilab,

00:10:39.800 | watch the buffalo and so on.

00:10:41.320 | - Yeah. (laughing)

00:10:42.960 | - So let me ask about, you mentioned that Enrico, for me,

00:10:45.820 | was somebody who was inspiring to you

00:10:48.400 | in a certain kind of way.

00:10:49.880 | Why is that, can you speak to that?

00:10:52.560 | - Sure.

00:10:53.920 | He was amazing, actually.

00:10:55.680 | He's the last, this is not the,

00:10:59.600 | I'll come to the reason in a minute,

00:11:01.080 | but he had a big influence on me at a young age.

00:11:05.020 | But he was the last physicist of note

00:11:11.480 | that was both an experimental physicist

00:11:14.360 | and a theorist at the same time.

00:11:16.720 | And he did two amazing things within months.

00:11:20.520 | In 1933, we didn't really know what the nucleus was,

00:11:25.520 | what radioactive decay was, what beta decay was,

00:11:32.560 | when electrons come out of a nucleus.

00:11:36.480 | And near the end of 1933,

00:11:40.840 | the neutron had just been discovered,

00:11:45.560 | and that meant that we knew a little bit more

00:11:47.400 | about what the nucleus is,

00:11:49.040 | that it's made out of neutrons and protons.

00:11:51.440 | The neutron wasn't discovered till 1932.

00:11:55.120 | And once we discovered that there was a neutron and proton,

00:11:59.160 | and they made the nucleus,

00:12:00.600 | and then there are electrons that go around,

00:12:02.840 | the basic ingredients were there.

00:12:05.080 | And he wrote down not only just the theory,

00:12:09.600 | a theory, but a theory that lasted decades

00:12:12.600 | and has only been improved on of beta decay,

00:12:17.240 | that is, the radiation.

00:12:19.320 | He did this, came out of nowhere,

00:12:22.320 | and it was a fantastic theory.

00:12:24.360 | He submitted it to "Nature" magazine,

00:12:27.460 | which was the primary best place to publish even then.

00:12:32.460 | And it got rejected as being too speculative.

00:12:37.680 | And so he went back to his drawing board in Rome

00:12:42.400 | where he was, added some to it, made it even longer,

00:12:46.920 | 'cause it's really a classic article,

00:12:48.680 | and then published it in the local Italian journal

00:12:53.680 | for physics and the German one.

00:12:56.720 | At the same time, in January of 1932,

00:13:01.040 | Giulio and Curie, for the first time,

00:13:04.440 | saw artificial radioactivity.

00:13:07.600 | This was an important discovery

00:13:09.160 | because radioactivity had been discovered much earlier.

00:13:12.640 | And they had X-rays, and you shouldn't be using them,

00:13:16.880 | but there was radioactivity.

00:13:19.000 | People knew it was useful for medicine.

00:13:21.040 | But radioactive materials are hard to find,

00:13:25.440 | and so it wasn't prevalent.

00:13:27.040 | But if you could make them, then they had great use.

00:13:29.920 | And Giulio and Curie were able to bombard aluminum

00:13:34.420 | or something with alpha particles

00:13:38.120 | and find that they excited something

00:13:41.560 | that decayed and had some half-life and so forth,

00:13:46.280 | meaning it was the artificial version,

00:13:48.960 | or let's call it not a natural version,

00:13:51.680 | an induced version of radioactive materials.

00:13:54.680 | And Fermi somehow had the insight,

00:14:02.320 | and I still can't see where he got it,

00:14:06.980 | that the right way to follow that up

00:14:09.560 | was not using charged particles like alphas and so forth,

00:14:13.920 | but use these newly discovered neutrons

00:14:17.800 | as the bombarding particle.

00:14:19.440 | Seemed impossible.

00:14:21.440 | They barely had been seen.

00:14:22.980 | It was hard to get very many of them.

00:14:26.480 | But it had the advantage that they don't,

00:14:28.820 | they're not charged, so they go right into the nucleus.

00:14:34.660 | And that turned out to be the experimental work

00:14:37.720 | that he did that won him the Nobel Prize.

00:14:40.700 | And it was the first step in fission,

00:14:43.080 | discovery of fission.

00:14:45.640 | And he did this two completely different things,

00:14:48.840 | an experiment that was a great idea

00:14:52.200 | and a tremendous implementation,

00:14:55.000 | because how do you get enough neutrons?

00:14:57.760 | And then he learned quickly that not only do you want

00:15:01.040 | neutrons, but you want really slow ones.

00:15:04.540 | He learned that experimentally,

00:15:06.000 | and he learned how to make slow ones,

00:15:07.840 | and then they were able to make,

00:15:09.740 | go through the periodic table and make lots of particles.

00:15:14.740 | He missed on fission at the moment,

00:15:17.120 | but he had the basic information,

00:15:18.920 | and then fission followed soon after that.

00:15:21.920 | - Forgive me for not knowing,

00:15:23.040 | but is the birth of the idea of bombarding neutrons,

00:15:27.700 | is that an experimental idea?

00:15:33.360 | Was it born out of an experiment,

00:15:34.840 | he just observed something,

00:15:35.880 | or is this an Einstein-style idea

00:15:38.240 | where you come up from basic intuition?

00:15:40.760 | - I think it took a combination,

00:15:43.120 | because he realized that neutrons had a characteristic

00:15:46.700 | that would allow them to go all the way into the nucleus

00:15:50.160 | when we didn't really understand

00:15:51.720 | what the structure was of all this.

00:15:55.820 | So that took an understanding or recognition

00:16:00.080 | of the physics itself of how a neutron interacts

00:16:03.120 | compared to say an alpha particle

00:16:04.800 | that Giulio and Curie had used.

00:16:07.440 | And then he had to invent a way to have enough neutrons,

00:16:11.960 | and he had a team of associates,

00:16:16.760 | and he pulled it off quite quickly.

00:16:18.960 | So it was pretty astounding.

00:16:20.840 | - And probably, maybe you can speak to it,

00:16:25.020 | his ability to put together the engineering aspects

00:16:28.720 | of great experiments and doing the theory,

00:16:31.280 | they probably fed each other.

00:16:32.760 | I wonder, can you speak to why we don't see more of that?

00:16:36.360 | Is that just really difficult to do?

00:16:38.540 | - It's difficult to do, yeah.

00:16:40.120 | I think in both theory and experiment,

00:16:44.320 | in physics anyway,

00:16:45.540 | it was conceivable if you had the right person to do it,

00:16:51.480 | and no one's been able to do it since.

00:16:52.920 | So I had the dream that that was

00:16:55.020 | what I was gonna be like, Fermi.

00:16:56.880 | - So you love both sides of it, the theory and the experiment.

00:16:59.320 | - Yeah, I never liked the idea that you did experiments

00:17:02.320 | without really understanding the theory,

00:17:04.040 | or the theory should be related very closely to experiments.

00:17:07.920 | And so I've always done experimental work

00:17:10.480 | that was closely related to the theoretical ideas.

00:17:14.140 | - I think I told you I'm Russian,

00:17:16.760 | so I'm gonna ask some romantic questions.

00:17:18.720 | But is it tragic to you that he's seen

00:17:23.260 | as the architect of the nuclear age,

00:17:25.360 | that some of his creations led to potentially,

00:17:28.640 | some of his work has led to potentially still

00:17:33.640 | the destruction of the human species,

00:17:36.000 | some of the most destructive weapons?

00:17:38.920 | - Yeah.

00:17:39.740 | I think even more general than him,

00:17:43.600 | I gave you all the virtues of curiosity a few minutes ago.

00:17:48.320 | There's an interesting book

00:17:49.380 | called "The Ratchet of Curiosity."

00:17:51.280 | You know, a ratchet is something that goes in one direction.

00:17:54.280 | And that is written by a guy who's probably a sociologist

00:17:58.880 | or philosopher or something.

00:18:00.720 | And he picks on this particular problem, but other ones,

00:18:04.440 | and that is the danger of knowledge, basically.

00:18:07.520 | You're curious, you learn something.

00:18:10.200 | So it's a little bit like curiosity killed the cat.

00:18:12.520 | You have to be worried about whether you can handle

00:18:15.400 | new information that you get.

00:18:16.840 | So in this case, the new information had to do

00:18:19.660 | with really understanding nuclear physics.

00:18:23.000 | And that information, maybe we didn't have

00:18:26.200 | the sophistication to know how to keep it under control.

00:18:31.200 | Yeah, and Fermi himself was a very apolitical person.

00:18:36.400 | So he wasn't very driven by,

00:18:40.200 | or at least he appears in all of his writing,

00:18:43.480 | the writing of his wife,

00:18:44.680 | the interactions that others had with him

00:18:46.380 | as either he avoided it all or he was pretty apolitical.

00:18:50.100 | I mean, he just saw the world through

00:18:52.120 | kind of the lens of a scientist.

00:18:55.240 | But he asked if it's tragic.

00:18:57.520 | The bomb was tragic, certainly on Japan,

00:19:01.960 | and he had a role in that.

00:19:03.520 | So I wouldn't want it as my legacy, for example.

00:19:06.660 | - I mean, but brought it to the human species

00:19:10.160 | that it's the ratchet of curiosity that we,

00:19:14.280 | we do stuff just to see what happens.

00:19:21.080 | That curiosity, that in sort of my area

00:19:24.200 | of artificial intelligence, that's been a concern.

00:19:27.440 | There, on a small scale, on a silly scale,

00:19:29.960 | perhaps currently, there's constantly

00:19:33.280 | unintended consequences.

00:19:35.160 | You create a system and you put it out there

00:19:37.920 | and you have intuitions about how it will work.

00:19:41.040 | You have hopes how it will work,

00:19:42.500 | but you put it out there just to see what happens.

00:19:44.520 | - Yeah.

00:19:45.360 | - And in most cases, because artificial intelligence

00:19:47.840 | is currently not super powerful,

00:19:49.780 | it doesn't create large-scale negative effects.

00:19:54.780 | But that same curiosity, as it progresses,

00:19:58.060 | might lead to something that destroys the human species.

00:20:01.560 | And the same may be true for bioengineering.

00:20:04.840 | There's people that engineer viruses

00:20:09.840 | to protect us from viruses, to see how do,

00:20:14.920 | how close is this to mutating so it can jump to humans?

00:20:17.880 | Or going, or engineering defenses against those.

00:20:22.880 | And it seems exciting, and the application,

00:20:26.380 | the positive applications are really exciting at this time,

00:20:28.880 | but we don't think about how that runs away

00:20:33.120 | in decades to come.

00:20:34.580 | - Yeah, and I think it's the same idea

00:20:36.500 | as this little book, "The Ratchet of Science,"

00:20:39.700 | the ratchet of curiosity.

00:20:43.300 | I mean, whether you pursue, take curiosity

00:20:47.420 | and let artificial intelligence or machine learning

00:20:51.300 | run away with having its solutions to whatever you want,

00:20:55.500 | or we do it, is, I think, a similar consequence.

00:20:59.820 | - I think, from what I've read about Enrico Fermi,

00:21:03.700 | he became a little bit cynical about the human species

00:21:08.340 | towards the end of his life,

00:21:09.940 | both having observed what he observed.

00:21:12.080 | - Well, he didn't write much.

00:21:14.860 | I mean, he died young.

00:21:15.860 | He died soon after the World War.

00:21:19.540 | There was already the work by Teller

00:21:24.620 | to develop the hydrogen bomb,

00:21:26.540 | and I think he was a little cynical of that,

00:21:28.900 | pushing it even further, and the rising tensions

00:21:32.220 | between the Soviet Union and the US,

00:21:34.220 | and it looked like an endless thing.

00:21:36.460 | But he didn't say very much, but a little bit,

00:21:38.980 | as you said, that--

00:21:39.820 | - Yeah, there's a few clips to sort of maybe pick

00:21:43.700 | on a bad mood, but in a sense that,

00:21:46.260 | almost like a sadness, a melancholy sadness,

00:21:48.860 | to a hope that waned a little bit about that,

00:21:53.860 | perhaps we can do, like, this curious species

00:21:59.540 | can find the way out.

00:22:01.320 | - Well, especially, I think, people who worked

00:22:03.080 | like he did at Los Alamos and spent years of their life

00:22:07.080 | somehow had to convince themselves

00:22:09.060 | that dropping these bombs would bring lasting peace.

00:22:12.740 | - Yes, and it did.

00:22:13.580 | - And it didn't, yeah.

00:22:14.900 | - As a small interesting aside,

00:22:19.620 | it'd be interesting to hear if you have opinions on this,

00:22:22.500 | his name is also attached to the Fermi Paradox,

00:22:26.060 | which asks if there's, you know,

00:22:29.300 | with, it's a very interesting question,

00:22:31.100 | which is, it does seem, if you sort of reason, basically,

00:22:35.540 | that there should be a lot of alien civilizations out there

00:22:39.300 | if the human species, if Earth is not that unique,

00:22:43.820 | by basic, no matter the values you pick,

00:22:47.400 | it's likely that there's a lot of alien civilizations

00:22:51.200 | out there, and if that's the case,

00:22:53.620 | why have they not at least obviously visited us

00:22:57.220 | or sent us loud signals that everybody can hear?

00:23:00.820 | - Fermi's quoted as saying, sitting down at lunch,

00:23:03.960 | I think it was with Teller and Herb York,

00:23:09.260 | who was kind of one of the fathers of the atomic bomb,

00:23:13.660 | and he sat down and he says something like,

00:23:15.500 | "Where are they?"

00:23:16.860 | - Yeah.

00:23:17.780 | - Which meant, where are these other,

00:23:20.100 | and then he did some numerology where he calculated,

00:23:25.100 | you know, how many, what they knew about how many

00:23:29.660 | galaxies there are and how many stars

00:23:33.220 | and how many planets there are like the Earth

00:23:35.540 | and blah, blah, blah.

00:23:36.780 | That's been done much better by somebody named Drake,

00:23:40.500 | and so people usually refer to the,

00:23:42.460 | I don't know whether it's called the Drake formula

00:23:44.180 | or something, but it has the same conclusion.

00:23:46.660 | The conclusion is it would be a miracle

00:23:49.260 | if there weren't other, you know,

00:23:51.860 | the statistics are so high that how can we be singular

00:23:55.180 | and separate?

00:23:56.020 | That, so probably there is,

00:24:01.700 | well, there's almost certainly life somewhere.

00:24:04.580 | Maybe there was even life on Mars a while back,

00:24:07.300 | but intelligent life, probably white,

00:24:12.300 | or we saw, so, you know, the statistics say that.

00:24:15.340 | Communicating with us, I think that it's harder

00:24:19.060 | than people think.

00:24:20.600 | We might not know the right way to expect the communication,

00:24:27.820 | but all the communication that we know about,

00:24:34.280 | travels at the speed of light,

00:24:35.780 | and we don't think anything can go faster

00:24:40.340 | in the speed of light.

00:24:41.180 | That limits the problem quite a bit,

00:24:44.220 | and it makes it difficult to have any

00:24:47.940 | back and forth communication.

00:24:49.420 | You could send signals like we try to or look for,

00:24:53.140 | but to have any communication, it's pretty hard

00:24:55.500 | when it has to be close enough that the speed of light

00:24:58.700 | would mean we could communicate with each other,

00:25:02.180 | and I think, and we didn't even understand that.

00:25:05.720 | I mean, we're an advanced civilization,

00:25:07.960 | but we didn't even understand that

00:25:09.660 | a little more than 100 years ago.

00:25:12.900 | So, are we just not advanced enough, maybe,

00:25:17.900 | to know something about that's the speed of light?

00:25:22.720 | Maybe there's some other way to communicate

00:25:24.560 | that isn't based on electromagnetism.

00:25:27.000 | I don't know.

00:25:28.760 | Gravity seems to be also have the same speed.

00:25:31.960 | That was a principle that Einstein had,

00:25:34.360 | and something we've measured, actually.

00:25:36.800 | - So, is it possible, I mean,

00:25:38.640 | so we'll talk about gravitational waves,

00:25:40.760 | and in some sense, there's a brainstorming going on,

00:25:45.760 | which is like, how do we detect the signal?

00:25:50.440 | Like, what would a signal look like,

00:25:51.840 | and how would we detect it?

00:25:52.960 | And that's true for gravitational waves.

00:25:54.440 | That's true for basically any physics phenomena.

00:25:57.600 | You have to predict that that signal should exist.

00:25:59.640 | You have to have some kind of theory

00:26:00.980 | and model why that signal should exist.

00:26:03.280 | I mean, is it possible that aliens

00:26:05.360 | are communicating with us via gravity?

00:26:07.400 | Like, why not?

00:26:10.400 | - Well, yeah, it's true, why not?

00:26:15.020 | For us, it's very hard to detect

00:26:17.280 | these gravitational effects.

00:26:19.080 | They have to come from something pretty,

00:26:21.560 | that has a lot of gravity, like black holes.

00:26:24.120 | But we're pretty primitive at this stage.

00:26:29.340 | There's very reputable physicists

00:26:34.200 | that look for a fifth force,

00:26:36.680 | one that we haven't found yet.

00:26:38.120 | Maybe it's the key.

00:26:39.320 | - What would that look like?

00:26:42.440 | What would a fifth force of physics look like, exactly?

00:26:45.200 | - Well, usually, they think it's probably a long-range,

00:26:48.160 | longer-range force than we have now.

00:26:50.400 | But there are reputable colleagues of mine

00:26:55.500 | that spend their life looking for a fifth force.

00:26:58.240 | - So, longer-range than gravity?

00:27:00.140 | Is it like super long?

00:27:01.820 | - It doesn't fall off like one over r-squared,

00:27:04.020 | but maybe separately.

00:27:06.580 | Gravity, Newton taught us, goes like inversely,

00:27:10.740 | one over the square of the distance apart you are.

00:27:13.180 | So, it falls pretty fast.

00:27:14.420 | - That's okay.

00:27:15.240 | So, now we have a theory of what consciousness is.

00:27:16.820 | It's just the fifth force of physics.

00:27:19.940 | - Yeah.

00:27:20.780 | - There we go.

00:27:21.600 | That's a good hypothesis.

00:27:26.260 | Speaking of gravity, what are gravitational waves?

00:27:31.260 | This may be start from the basics.

00:27:33.340 | - We learned gravity from Newton, right?

00:27:37.720 | You and you were young.

00:27:39.640 | You were told that if you jumped up,

00:27:41.620 | the Earth pulled you down.

00:27:42.920 | And when the apple falls out of the tree,

00:27:47.300 | the Earth pulls it down.

00:27:48.720 | And maybe you even asked your teacher why,

00:27:52.420 | but most of us accepted that.

00:27:55.600 | That was Newton's picture,

00:27:57.800 | the apple falling out of the tree.

00:27:59.720 | But Newton's theory never told you

00:28:01.280 | why the apple was attracted to the Earth.

00:28:04.400 | That was missing in Newton's theory.

00:28:06.980 | Newton's theory also,

00:28:10.200 | Newton recognized at least one of the two problems,

00:28:12.900 | I'll tell you.

00:28:13.740 | One of them is, there's more than those,

00:28:15.540 | but one is, why does the Earth,

00:28:18.520 | what's the mechanism by which the Earth pulls the apple

00:28:22.360 | or holds the moon when it goes around, whatever it is?

00:28:25.500 | That's not explained by Newton,

00:28:27.800 | even though he has the most successful theory of physics ever

00:28:30.960 | went 200 and some years with nobody ever seeing a violation.

00:28:35.040 | - But he accurately describes the movement of an object

00:28:38.080 | falling down to Earth, but he's not answering why that,

00:28:41.080 | what's, 'cause it's a distance, right?

00:28:43.120 | - He gives a formula, which it's a product

00:28:46.900 | of the Earth's mass, the apple's mass,

00:28:50.140 | inversely proportional to the square

00:28:51.920 | of the distance between,

00:28:53.440 | and then the strength he called capital G,

00:28:56.400 | the strength he couldn't determine,

00:28:58.480 | but it was determined 100 years later.

00:29:01.080 | But no one ever saw a violation of this

00:29:03.160 | until a possible violation, which Einstein fixed,

00:29:07.120 | which was very small,

00:29:08.240 | that has to do with Mercury going around the sun,

00:29:10.680 | the orbit being slightly wrong,

00:29:14.320 | if you calculate it by Newton's theory.

00:29:17.800 | But so, like most theories then in physics,

00:29:22.800 | you can have a wonderful one like Newton's theory,

00:29:25.480 | it isn't wrong, but you have to have an improvement on it

00:29:30.480 | to answer things that it can't answer.

00:29:33.900 | And in this case, Einstein's theory is the next step.

00:29:37.680 | We don't know if it's anything like a final theory

00:29:41.240 | or even the only way to formulate it either,

00:29:45.520 | but he formulated this theory, which he released in 1915.

00:29:50.520 | He took 10 years to develop it,

00:29:55.320 | even though in 1905, he solved three or four

00:29:58.600 | of the most important problems in physics

00:30:00.320 | in a matter of months,

00:30:01.420 | and then he spent 10 years on this problem

00:30:03.480 | before he let it out, and this is called general relativity,

00:30:07.300 | it's a new theory of gravity, 1915.

00:30:10.520 | In 1916, Einstein wrote a little paper

00:30:15.520 | where he did not do some fancy derivation,

00:30:21.520 | instead he did, what I would call it,

00:30:26.520 | he used his intuition, which he was very good at too,

00:30:31.080 | and that is he noticed that if he wrote the formulas

00:30:37.040 | for general relativity in a particular way,

00:30:40.120 | they looked a lot like the formulas

00:30:42.220 | for electricity and magnetism.

00:30:43.900 | Being Einstein, he then took the leap

00:30:48.680 | that electricity and magnetism,

00:30:50.680 | we discovered only 20 years before that,

00:30:53.200 | in the 1880s, have waves.

00:30:56.360 | Of course, that's light and electromagnetic waves,

00:30:59.600 | radio waves, everything else.

00:31:01.560 | So he said if the formulas look similar,

00:31:04.880 | then gravity probably has waves too.

00:31:07.600 | - That's such a big leap, by the way,

00:31:10.080 | I mean, maybe you can correct me,

00:31:11.440 | but that just seems like a heck of a leap.

00:31:15.080 | - Yeah, and it was considered to be a heck of a leap.

00:31:18.960 | So first, that paper was, except for this intuition,

00:31:22.800 | was poorly written, had a serious mistake,

00:31:27.800 | it had a factor of two wrong in the strength of gravity,

00:31:31.240 | which meant if we used those formulas, we would,

00:31:34.440 | and two years later, he wrote a second paper

00:31:40.200 | and in that paper, it turns out to be important for us

00:31:43.720 | because in that paper, he not only fixed his factor

00:31:47.880 | of two mistake, which he never admitted,

00:31:50.160 | he just wrote it, fixed it like he always did,

00:31:53.840 | and then he told us how you make gravitational waves,

00:31:58.360 | what makes gravitational waves.

00:32:01.080 | And you might recall in electromagnetism,

00:32:04.480 | we make electromagnetic waves in a simple way,

00:32:06.800 | you take a plus charge and minus charge,

00:32:09.160 | you oscillate like this

00:32:10.360 | and that makes electromagnetic waves.

00:32:12.800 | And a physicist named Hertz made a receiver

00:32:15.760 | that could detect the waves and put it in the next room.

00:32:18.960 | He saw them and moved forward and backward

00:32:21.140 | and saw that it was wave-like.

00:32:23.160 | So Einstein said it won't be a dipole like that,

00:32:27.880 | it'll be a four-pole thing,

00:32:29.360 | and that's what, it's called a quadrupole moment

00:32:32.400 | that gives the gravitational wave.

00:32:34.640 | So he saw that again by insight, not by derivation.

00:32:39.080 | That set the table for what you needed to do to do it.

00:32:42.480 | At the same time, in the same year,

00:32:44.640 | Schwarzschild, not Einstein,

00:32:47.080 | said there were things called black holes.

00:32:49.440 | So it's interesting that that came the same.

00:32:51.720 | - So what year was that?

00:32:53.640 | - 1915.

00:32:54.660 | - It was in parallel.

00:32:57.140 | I should probably know this,

00:33:00.160 | but did Einstein not have an intuition

00:33:01.760 | that there should be such things as black holes?

00:33:04.320 | - That came from Schwarzschild.

00:33:05.840 | - Oh, interesting.

00:33:07.320 | - Yeah, so Schwarzschild,

00:33:09.400 | who was a German theoretical physicist,

00:33:13.160 | he got killed in the war, I think,

00:33:15.080 | in the First World War two years later or so.

00:33:19.600 | He's the one that proposed black holes,

00:33:21.760 | that there were black holes.

00:33:22.760 | - That feels like a natural conclusion

00:33:24.380 | of general relativity, no?

00:33:27.200 | Or is that not?

00:33:28.040 | - Well, it may seem like it,

00:33:30.600 | but I don't know about a natural conclusion.

00:33:32.560 | It's a result of curved space-time, though.

00:33:36.760 | - Right, but it's such a weird result

00:33:39.000 | that you might have to, it's a special--

00:33:41.640 | - Yeah, it's a special case.

00:33:43.720 | So I don't know.

00:33:46.920 | Anyway, Einstein then,

00:33:49.120 | an interesting part of the story

00:33:50.640 | is that Einstein then left the problem.

00:33:52.920 | Most physicists, because it really wasn't derived,

00:33:57.360 | he just made this, didn't pick up on it,

00:33:59.920 | or general relativity much,

00:34:01.560 | because quantum mechanics became the thing in physics.

00:34:05.720 | And Einstein only picked up this problem again

00:34:10.720 | after he immigrated to the US.

00:34:12.640 | So he came to the US in 1932,

00:34:15.420 | and I think in 1934 or '35,

00:34:19.160 | he was working with another physicist called Rosen,

00:34:21.980 | who he did several important works with,

00:34:24.520 | and they revisited the question.

00:34:26.840 | And they had a problem that most of us as students

00:34:31.840 | always had, that studied general relativity.

00:34:34.560 | General relativity's really hard

00:34:36.320 | because it's four-dimensional instead of three-dimensional.

00:34:39.620 | And if you don't set it up right,

00:34:41.280 | you get infinities, which don't belong there.

00:34:44.720 | We call them coordinate singularities as a name.

00:34:48.560 | But if you get these infinities,

00:34:50.260 | you don't get the answers you want.

00:34:52.040 | And he was trying to derive now,

00:34:55.960 | general relativity from general relativity,

00:34:59.560 | gravitational waves.

00:35:01.160 | And in doing it, he kept getting these infinities.

00:35:04.320 | And so he wrote a paper with Rosen

00:35:07.560 | that he submitted to our most important journal,

00:35:11.000 | Physical Review Letters.

00:35:13.080 | And that when it was submitted to Physical Review Letters,

00:35:17.960 | it was entitled, "Do Gravitational Waves Exist?"

00:35:21.960 | A very funny title to write

00:35:23.600 | 20 years after he proposed they exist.

00:35:26.600 | But it's because he had found these singularities,

00:35:29.760 | these infinities.

00:35:31.840 | And so the editor at that time,

00:35:36.840 | and part of it that I don't know is peer review.

00:35:41.920 | We live and die by peer review as scientists

00:35:45.200 | send our stuff out.

00:35:46.480 | We don't know when peer review actually started

00:35:49.600 | or what peer review Einstein ever experienced

00:35:53.200 | before this time.

00:35:54.280 | But the editor of Physical Review sent this out for review.

00:35:57.500 | He had a choice.

00:35:59.780 | He could take any article and just accept it.

00:36:02.200 | He could reject it or he could send it for review.

00:36:05.640 | - Right, I believe the editors

00:36:07.120 | used to have much more power.

00:36:08.600 | - Yeah, yeah.

00:36:09.560 | And he was a young man, his name was Tate.

00:36:12.040 | And he ended up being editor for years.

00:36:14.360 | But so he sent this for review

00:36:18.160 | to a theoretical physicist named Robertson

00:36:22.120 | who was also in this field of general relativity

00:36:25.160 | who happened to be on sabbatical at that moment at Caltech.

00:36:29.060 | Otherwise his institution was Princeton

00:36:31.080 | where Einstein was.

00:36:33.740 | And he saw that the way they set up the problem,

00:36:38.320 | the infinities were like I make it as a student

00:36:41.800 | 'cause if you don't set it up right in general relativity,

00:36:44.160 | you get these infinities.

00:36:46.480 | And so he reviewed the article and gave an illustration

00:36:51.040 | that if they set it up

00:36:52.000 | on what are called cylindrical coordinates,

00:36:54.000 | these infinities went away.

00:36:57.600 | The editor of Physical Review

00:37:00.900 | was obviously intimidated by Einstein.

00:37:03.420 | He wrote this really not a letter back

00:37:05.540 | like I would get saying,

00:37:07.180 | you're screwed up in your paper.

00:37:08.900 | Instead, it was kind of,

00:37:11.620 | what do you think of the comments of our referee?

00:37:16.540 | Einstein wrote back, it's a well-documented letter,

00:37:20.620 | wrote back a letter to Physical Review

00:37:22.940 | saying I didn't send you the paper

00:37:26.220 | to send it to one of your so-called experts,

00:37:28.440 | I sent it to you to publish.

00:37:30.360 | I withdraw the paper.

00:37:32.640 | And he never published again in that journal.

00:37:37.360 | That was 1936.

00:37:38.560 | Instead, he rewrote it

00:37:42.320 | with the fixes that were made,

00:37:45.120 | changed the title and published it

00:37:47.840 | in what was called the Franklin Review

00:37:50.520 | which is the Franklin Institute in Philadelphia

00:37:55.160 | which is Benjamin Franklin Institute

00:37:57.540 | which doesn't have a journal now but did at that time.

00:38:00.480 | So the article is published.

00:38:02.020 | It's the last time he ever wrote about it.

00:38:04.700 | It remained controversial.

00:38:06.740 | So it wasn't until close to 1960, 1958

00:38:11.740 | where there was a conference

00:38:13.940 | that brought together the experts in general relativity

00:38:20.500 | to try to sort out whether there was

00:38:23.380 | whether it was true

00:38:27.780 | that there were gravitational waves or not.

00:38:30.180 | And there was a very nice derivation

00:38:34.180 | by a British theorist from the heart of the theory

00:38:39.180 | that gets gravitational waves.

00:38:42.460 | And that was number one.

00:38:44.780 | The second thing that happened at that meeting

00:38:46.500 | is Richard Feynman was there.

00:38:49.020 | And Feynman said, well, if there's typical Feynman,

00:38:53.260 | if there's gravitational waves,

00:38:54.980 | they need to be able to do something.

00:38:57.020 | Otherwise, they don't exist.

00:38:58.700 | So they have to be able to transfer energy.

00:39:00.540 | So he made a idea of a Gedanken experiment

00:39:04.180 | that is just a bar with a couple of rings on it.

00:39:08.460 | And then if a gravitational wave goes through it,

00:39:11.060 | distorts the bar.

00:39:12.320 | And that creates friction on these little rings.

00:39:17.180 | And that's heat and that's energy.

00:39:19.180 | So that meant--

00:39:20.580 | - Is that a good idea?

00:39:21.660 | It sounds like a good idea.

00:39:22.820 | - Yeah, it means that he showed

00:39:25.300 | that with the distortion of space-time,

00:39:28.260 | you could transfer energy just by this little idea.

00:39:31.620 | And it was shown theoretically.

00:39:33.620 | So at that point, it was believed theoretically

00:39:38.620 | then by people that gravitational waves should exist.

00:39:43.340 | - No, we should be able to detect them.

00:39:45.620 | - We should be able to detect them,

00:39:47.100 | except that they're very, very small.

00:39:50.660 | - So what kind of, there's a bunch of questions here,

00:39:53.140 | but what kind of events would generate gravitational waves?

00:39:58.140 | - You have to have this, what I call quadrupole moment.

00:40:01.340 | That comes about if I have, for example,

00:40:06.220 | two objects that go around each other like this,

00:40:08.580 | like the Earth around the Sun or the Moon around the Earth.

00:40:13.300 | Or in our case, it turns out to be two black holes

00:40:15.680 | going around each other like this.

00:40:17.660 | - So how's that different

00:40:18.700 | than basic oscillation back and forth?

00:40:20.780 | Is it just more common in nature to have--

00:40:22.300 | - Oscillation is a dipole moment.

00:40:24.100 | - So it has to be in three-dimensional space

00:40:25.620 | and kind of oscillation.

00:40:26.740 | - So you have to have something that's three-dimensional

00:40:28.940 | that'll give what I call a quadrupole moment

00:40:31.580 | that's just built into this.

00:40:33.140 | - And luckily in nature, you have stuff--

00:40:35.380 | - And luckily, things exist.

00:40:37.460 | And it is luckily because the effect is so small

00:40:40.340 | that you could say, look, I can take a barbell

00:40:44.420 | and spin it, right, and detect the gravitational waves.

00:40:49.060 | But unfortunately, no matter how much I spin it,

00:40:52.300 | how fast I spin it-- - Oh, interesting.

00:40:54.220 | - So I know how to make gravitational waves,

00:40:56.900 | but they're so weak, I can't detect them.

00:40:58.700 | So we have to take something that's stronger

00:41:01.060 | than I can make.

00:41:02.120 | Otherwise, we would do what Hertz did

00:41:03.980 | for electromagnetic waves, go in our lab,

00:41:06.580 | take a barbell, put it on something, spin it.

00:41:09.060 | - Can I ask a dumb question?

00:41:10.100 | So a single object that's weirdly shaped,

00:41:14.140 | does that generate gravitational waves?

00:41:15.660 | So if it's rotating?

00:41:18.900 | - Sure, it-- - But it's just

00:41:20.580 | much weaker signal. - It's weaker.

00:41:23.020 | Well, we didn't know what the strongest signal would be

00:41:25.380 | that we would see.

00:41:27.840 | We targeted seeing something called neutron stars,

00:41:30.380 | actually, because black holes,

00:41:31.700 | we don't know very much about.

00:41:32.980 | It turned out we were a little bit lucky.

00:41:34.740 | There was a stronger source, which was the black holes.

00:41:37.900 | - Well, another ridiculous question.

00:41:39.840 | So you say waves.

00:41:42.920 | What does a wave mean?

00:41:44.600 | Like the most ridiculous version of that question is,

00:41:48.880 | what does it feel like to ride a wave

00:41:53.000 | as you get closer to the source?

00:41:54.960 | Or experience it?

00:41:57.920 | - Well, if you experience a wave,

00:41:59.880 | imagine that this is what happens to you.

00:42:02.180 | I don't know what you mean by getting close.

00:42:04.960 | It comes to you.

00:42:06.280 | So it's like this light wave or something

00:42:09.760 | that comes through you.

00:42:10.600 | So when the light hits you, it makes your eyes detect it.

00:42:14.880 | I flashed it.

00:42:16.240 | What does this do?

00:42:17.120 | It's like going to the amusement park,

00:42:20.960 | and they have these mirrors.

00:42:22.440 | You look in this mirror, and you look short and fat,

00:42:24.800 | and the one next to you makes you tall and thin, okay?

00:42:28.160 | Imagine that you went back and forth

00:42:30.760 | between those two mirrors once a second.

00:42:33.480 | That would be a gravitational wave

00:42:35.120 | with a period of once a second.

00:42:37.680 | If you did it 60 times a second, go back and forth.

00:42:40.360 | And then that's all that happens.

00:42:42.720 | It makes you taller and shorter and fatter back and forth

00:42:45.880 | as it goes through you

00:42:47.640 | at the frequency of the gravitational wave.

00:42:50.280 | So the frequencies that we detect

00:42:52.840 | are higher than one a second, but that's the idea.

00:42:56.200 | So, and the amount is small.

00:42:59.480 | - Amount is small, but if you're closer

00:43:02.440 | to the source of the wave, is it the same amount?

00:43:08.320 | - Yeah, it doesn't dissipate.

00:43:11.000 | - It doesn't dissipate.

00:43:12.160 | Okay, so it's not that fun of an amusement ride.

00:43:16.040 | - Well, it does dissipate, but it doesn't,

00:43:19.000 | it doesn't, it's just, it's proportional to the distance.

00:43:22.520 | - Right, it's not--

00:43:23.360 | - It's not a big power or something.

00:43:25.360 | - Gotcha, so, but it would be a fun ride

00:43:29.080 | if you get a little bit closer, or a lot closer.

00:43:31.960 | I mean, like, I wonder what the,

00:43:34.040 | okay, this is a ridiculous question, but I have you here.

00:43:36.800 | (laughs)

00:43:38.240 | Like, the getting fatter and taller,

00:43:40.840 | I mean, that experience, for some reason,

00:43:44.840 | that's mind-blowing to me,

00:43:45.960 | 'cause it brings the distortion of space-time to you.

00:43:50.960 | I mean, space-time is being morphed, right?

00:43:55.400 | Like, this is a wave. - That's right.

00:43:57.280 | - That, how, that's so weird.

00:43:59.880 | - And we're in space, so we're affected by it.

00:44:01.280 | - Yeah, we're in space, and now it's moving.

00:44:03.880 | I don't know what to do with it.

00:44:06.040 | - I mean, does it, okay.

00:44:07.280 | How much do you think about

00:44:10.360 | the philosophical implications of general relativity?

00:44:14.760 | Like, that we're in space-time,

00:44:17.280 | and it can be bent by gravity?

00:44:19.560 | Like, is that just what it is?

00:44:24.080 | Are we supposed to be okay with this?

00:44:26.440 | 'Cause, like, Newton, even Newton is a little weird, right?

00:44:29.600 | But that at least, like, makes sense.

00:44:31.320 | That's our physical world.

00:44:33.160 | You know, when an apple falls, it makes sense.

00:44:36.600 | But, like, the fact that entirety

00:44:38.680 | of the space-time we're in can bend.

00:44:42.360 | - Well-- - That's, that's,

00:44:46.200 | that's really mind-blowing.

00:44:47.040 | - Well, let me make another analogy.

00:44:49.560 | - This is a therapy session for me at this point.

00:44:51.080 | - Yeah, right, another analogy.

00:44:53.040 | - Thank you.

00:44:53.880 | - So, imagine you have a trampoline.

00:44:56.120 | - Yes.

00:44:56.960 | - Okay.

00:44:58.600 | What happens if you put a marble on a trampoline?

00:45:00.720 | Doesn't do anything, right?

00:45:02.920 | - No.

00:45:03.760 | - Just sit. - Maybe a little bit,

00:45:04.800 | but not much.

00:45:05.760 | - Yeah, I mean, just if I drop it,

00:45:07.480 | it's not gonna go anywhere.

00:45:09.320 | Now, imagine I put a bowling ball

00:45:10.840 | at the center of the trampoline.

00:45:12.440 | Now, I come up to the trampoline,

00:45:15.640 | and I put a marble on, what happens?

00:45:17.880 | - It'll roll towards the bowling ball.

00:45:21.560 | - All right, so what's happened is the presence

00:45:24.640 | of this massive object distorted the space

00:45:29.080 | that the trampoline did.

00:45:30.820 | This is the same thing that happens

00:45:33.000 | to the presence of the earth, the earth and the apple.

00:45:37.400 | The presence of the earth affects the space around it,

00:45:40.240 | just like the bowling ball on the trampoline.

00:45:43.960 | - Yeah, this doesn't make me feel better.

00:45:45.640 | I'm referring from the perspective of an ant

00:45:48.240 | walking around on that trampoline.

00:45:50.140 | Then some guy just dropped a ball,

00:45:54.720 | and not only dropped a ball, right?

00:45:56.520 | It's not just dropping a bowling ball.

00:45:59.000 | It's making the ball go up and down,

00:46:02.300 | or doing some kind of oscillation thing,

00:46:04.600 | where it's like waves.

00:46:06.540 | And that's so fundamentally different

00:46:08.460 | from the experience on being on flatland

00:46:10.660 | and walking around and just finding

00:46:12.460 | delicious sweet things as ant does.

00:46:14.660 | And it just feels like, to me,

00:46:16.380 | from a human experience perspective,

00:46:18.340 | completely, it's humbling.

00:46:20.900 | It's truly humbling.

00:46:22.740 | - It's humbling, but we see that kind of phenomenon

00:46:25.100 | all the time.

00:46:26.740 | Let me give you another example.

00:46:29.040 | Imagine that you walk up to a still pond.

00:46:33.040 | - Yes.

00:46:33.880 | - Okay?

00:46:34.700 | Now I throw, you throw a rock in it, what happens?

00:46:39.240 | The rock goes in, sinks to the bottom, fine,

00:46:42.120 | and these little ripples go out, and they travel out.

00:46:46.800 | That's exactly what happens.

00:46:48.360 | I mean, there's a disturbance, which is these safe,

00:46:52.000 | the bowling ball, or black holes,

00:46:54.600 | and then the ripples, they go out in the water.

00:46:58.060 | They're not, they don't have any,

00:46:59.960 | they don't have the rock, any pieces of the rock.

00:47:02.600 | - You see, the thing is, I guess,

00:47:04.400 | what's not disturbing about that is it's a,

00:47:08.220 | I mean, it's a, I guess, a flat, two-dimensional surface

00:47:11.160 | that's being disturbed.

00:47:12.780 | Like, for a three-dimensional surface,

00:47:15.400 | three-dimensional space to be disturbed feels weird.

00:47:19.920 | - It's even worse.

00:47:20.900 | It's four-dimensional, because it's space and time.

00:47:23.520 | - Yeah.

00:47:24.920 | - So that's why you need Einstein,

00:47:26.600 | is to make it four-dimensional.

00:47:28.120 | - To make it okay?

00:47:29.400 | - No, to make it.

00:47:30.800 | - To make it four-dimensional?

00:47:32.240 | - Yeah, to take the same phenomenon

00:47:34.480 | and look at it in all of space and time.

00:47:38.440 | Anyway, luckily for you and I and all of us,

00:47:43.440 | the amount of distortion is incredibly small.

00:47:46.220 | So it turns out that if you think of space itself,

00:47:52.400 | now this is gonna blow your mind too,

00:47:54.360 | if you think of space as being like a material,

00:47:56.680 | like this table, it's very stiff.

00:47:59.960 | You know, we have materials that are very pliable,

00:48:02.080 | materials that are very stiff.

00:48:03.720 | So space itself is very stiff.

00:48:06.560 | So when gravitational waves come through it,

00:48:08.600 | luckily for us, it doesn't distort it so much

00:48:11.200 | that it affects our ordinary life very much.

00:48:14.880 | - No, I mean, that's great.

00:48:18.000 | That's great, I thought there was something bad coming.

00:48:20.080 | No, this is great. - No, not bad.

00:48:20.920 | - That's great news.

00:48:21.760 | So I mean, perhaps we evolved as life on Earth

00:48:25.400 | to be such that for us, this particular set

00:48:30.480 | of effects of gravitational waves is not that significant.

00:48:35.480 | Maybe that's why-- - It is.

00:48:37.280 | You probably used this effect today or yesterday.

00:48:42.280 | So it's pervasive.

00:48:45.640 | Well-- - You mean gravity

00:48:47.040 | or the way, or external?

00:48:49.640 | 'Cause I only-- - Curvature of space

00:48:51.440 | and time. - Curvature of space, how?

00:48:53.400 | I only care personally as a human, right?

00:48:55.800 | The gravity of Earth.

00:48:56.920 | - But you use it every day almost.

00:48:59.080 | - Oh, it's curving. - Because, no, no, no.

00:49:02.800 | It's in this thing.

00:49:04.360 | Every time it tells you where you are.

00:49:07.040 | How does it tell you where you are?

00:49:09.960 | It tells you where you are because we have 24 satellites

00:49:12.840 | or some number that are going around in space

00:49:15.640 | and it asks how long it takes the being

00:49:20.400 | to go to the satellite and come back the signal

00:49:23.320 | to different ones and then it triangulates

00:49:26.200 | and tells you where you are.

00:49:27.440 | And then if you go down the road,

00:49:28.720 | it tells you where you are.

00:49:30.120 | Do you know that if you did that with the satellites

00:49:32.760 | and you didn't use Einstein's equations--

00:49:35.040 | - Oh, no, you wouldn't-- - You won't get

00:49:37.280 | the right answer, that's right.

00:49:39.240 | And in fact, if you take a road that's say 10 meters wide,

00:49:43.640 | I've done these numbers, and you ask how long

00:49:45.720 | you'd stay on the road if you didn't make the correction.

00:49:49.020 | For general relativity, this thing you're poo-pooing,

00:49:52.400 | 'cause you're using every day, you'd go off the road

00:49:55.560 | a minute. - You'd go off the road.

00:49:56.600 | Well, actually, that might be my problem.

00:49:57.440 | - So you use it, so don't poo-poo it.

00:50:00.640 | - Well, I think I'm using an Androids,

00:50:02.320 | and maybe, and the GPS doesn't work that well,

00:50:04.120 | so maybe I'm using Newton's physics,

00:50:06.240 | so I need to upgrade to general relativity.

00:50:08.400 | So, gravitational waves and Einstein had,

00:50:14.280 | wait, Feynman really does have a part in this story?

00:50:17.440 | Was that one of the first kind of experimental

00:50:20.500 | proposed detect gravitational waves?

00:50:22.180 | - Well, he did what we call a Godunkin experiment,

00:50:24.500 | that's a thought experiment, okay, not a real experiment.

00:50:27.700 | But then, after that, then people believe

00:50:31.020 | gravitational waves must exist.

00:50:32.860 | You can kind of calculate how big they are, there's tiny.

00:50:35.940 | And so, people started searching.

00:50:38.200 | The first idea that was used was Feynman's idea,

00:50:41.000 | oh, a variant of it.

00:50:44.200 | And it was to take a great big, huge bar of aluminum,

00:50:48.060 | and then put around, and it's made like a cylinder,

00:50:52.920 | and then put around it some very, very sensitive detectors

00:50:56.120 | so that if a gravitational wave happened to go through it,

00:50:59.440 | it would go (mimics electric shock)

00:51:01.600 | and you'd detect the extra strain that was there.

00:51:04.860 | And that was this method that was used until we came along.

00:51:09.320 | It wasn't a very good method to use.

00:51:12.320 | - And what was the, so we're talking about

00:51:15.560 | a pretty weak signal here.

00:51:17.040 | - Yeah, that's why that method didn't work.

00:51:19.400 | - So what, can you tell the story of figuring out

00:51:22.820 | what kind of method would be able to detect

00:51:25.560 | this very weak signal of gravitational waves?

00:51:28.980 | - So, remembering what happens when you go

00:51:35.180 | to the amusement park, that it's gonna do something like

00:51:39.620 | stretch this way and squash that way,

00:51:41.720 | squash this way and stretch this way.

00:51:44.080 | We do have an instrument that can detect that kind of thing.

00:51:48.360 | It's called an interferometer.

00:51:49.960 | And what it does is it just basically takes usually light,

00:51:56.040 | and the two directions that we're talking about,

00:51:59.760 | you send light down one direction

00:52:02.060 | and the perpendicular direction.

00:52:04.320 | And if nothing changes, it takes the same,

00:52:08.280 | and the arms are the same length.

00:52:09.960 | It just goes down, bounces back.

00:52:13.040 | And if you invert one compared to the other, they cancel.

00:52:16.000 | So there's nothing happens.

00:52:17.800 | But if it's like the amusement park

00:52:20.280 | and one of the arms got, you know, it got shorter and fatter

00:52:23.520 | so it took longer to go horizontally

00:52:25.960 | than it did to go vertically.

00:52:27.700 | Then when they come back, when the light comes back,

00:52:31.000 | that comes back somewhat out of time.

00:52:34.400 | And that basically is the scheme.

00:52:37.040 | The only problem is that that's not done very accurately

00:52:42.040 | in general, and we had to do it extremely accurately.

00:52:45.920 | - So what's the difficulty of doing so accurately?

00:52:50.920 | - Okay, so the measurement that we have to do

00:52:56.800 | is a distortion in time.

00:52:58.760 | How big is it?

00:53:00.440 | One, it's a distortion that's one part in 10 to the 21.

00:53:04.160 | That's 21 zeros and a one.

00:53:06.960 | Okay? - Wow.

00:53:08.400 | And so this is like a delay in the thing coming back?

00:53:11.840 | - It's one of them coming back after the other one,

00:53:15.760 | but the difference is just one part in 10 to the 21.

00:53:19.020 | So for that reason, we make it big.

00:53:23.320 | Let the arms be long.

00:53:25.720 | Okay, so one part in 10 to the 21.

00:53:27.980 | In our case, it's kilometers long.

00:53:31.280 | So we have an instrument that's like kilometers

00:53:33.120 | in one direction, kilometers in the other.

00:53:35.000 | - How many kilometers are we talking about?

00:53:36.440 | Four kilometers?

00:53:37.440 | - Four kilometers in each direction.

00:53:39.400 | If you take then one part in 10 to the 21,

00:53:44.600 | we're talking about measuring something

00:53:46.840 | to 10 to the minus 18 meters.

00:53:51.460 | (Lex laughing)

00:53:54.880 | - Okay.

00:53:55.720 | - Now to tell you how small that is,

00:53:58.200 | the proton thing we're made of,

00:54:01.000 | which you can't go and grab so easily,

00:54:03.040 | is 10 to the minus 15 meters.

00:54:05.560 | So this is one 1,000th the size of a proton.

00:54:08.720 | That's the size of the effect.

00:54:10.560 | Einstein himself didn't think this could be measured.

00:54:15.160 | Have you ever seen?

00:54:16.520 | Actually, he said that,

00:54:18.640 | but that's because he didn't anticipate modern lasers

00:54:22.720 | and techniques that we developed.

00:54:25.900 | - Okay, so maybe can you tell me a little bit

00:54:31.720 | what you're referring to as LIGO,

00:54:33.160 | the Laser Interferometer Gravitational-Wave Observatory.

00:54:37.400 | What is LIGO?

00:54:39.520 | Can you just elaborate kind of the big picture view here

00:54:42.040 | before I ask you specific questions about it?

00:54:44.320 | - Yeah, so in the same idea that I just said,

00:54:47.720 | we have two long vacuum pipes,

00:54:52.560 | 10 to four kilometers long, okay?

00:54:55.820 | We start with a laser beam and we divide the beam

00:55:00.580 | going down the two arms,

00:55:02.920 | and we have a mirror at the other end,

00:55:04.840 | reflects it back.

00:55:06.560 | It's more subtle, but we bring it back.

00:55:09.600 | If there's no distortion in space-time

00:55:12.560 | and the lengths are exactly the same,

00:55:14.120 | which we calibrate them to be,

00:55:16.120 | then when it comes back,

00:55:17.520 | if we just invert one signal compared to the other,

00:55:20.880 | they'll just cancel.

00:55:22.040 | So we see nothing, okay?

00:55:24.900 | But if one arm got a little bit longer than the other,

00:55:28.240 | then they don't come back at exactly the same time.

00:55:30.480 | They don't exactly cancel.

00:55:31.920 | That's what we measure.

00:55:33.080 | So to give a number to it,

00:55:37.440 | we have to do that to,

00:55:40.040 | we have the change of length

00:55:42.240 | to be able to do this 10 to the minus 18 meters

00:55:45.920 | to one part in 10 to the 12th.

00:55:48.080 | And that was the big experimental challenge

00:55:50.280 | that required a lot of innovation to be able to do.

00:55:55.280 | - You gave a lot of credit to, I think,

00:55:59.640 | Caltech and MIT for some of the technical developments

00:56:02.680 | within this project.

00:56:04.400 | Is there some interesting things you can speak to

00:56:07.120 | at the low level of some cool stuff that had to be solved?

00:56:12.600 | Like what are we talking?

00:56:14.040 | I'm a software engineer, so all of this,

00:56:16.920 | I have so much more respect for everything done here

00:56:19.200 | than anything I've ever done.

00:56:20.520 | So it's just code.

00:56:21.560 | - So I'll give you an example of doing

00:56:28.840 | mechanical engineering at a better,

00:56:32.360 | at a basically mechanical engineering and geology

00:56:35.960 | and maybe at a level.

00:56:37.860 | So what's the problem?

00:56:40.560 | The problem is the following,

00:56:42.000 | that I've given you this picture of an instrument

00:56:44.280 | that by some magic, I can make good enough

00:56:47.400 | to measure this very short distance.

00:56:49.880 | But then I put it down here, it won't work.

00:56:53.400 | And the reason it doesn't work

00:56:55.240 | is that the earth itself is moving all over the place

00:56:58.300 | all the time.

00:56:59.400 | You don't realize it, it seems pretty good to you.

00:57:01.720 | - I get it.

00:57:02.560 | - But it's moving all the time.

00:57:03.840 | So somehow it's moving so much that we can't deal with it.

00:57:08.360 | We happen to be trying to do the experiment here on earth,

00:57:11.700 | but we can't deal with it.

00:57:12.980 | So we have to make the instrument isolated from the earth.

00:57:17.720 | - Oh no.

00:57:18.900 | - At the frequencies we're at, we've got to float it.

00:57:21.520 | That's a mechanical, that's an engineering problem,

00:57:23.680 | not a physics problem.

00:57:24.840 | - So when you actually, like we're doing,

00:57:27.560 | we're having a conversation on a podcast right now,

00:57:29.640 | there's, and people who record music work with this,

00:57:33.160 | how to create an isolated room.

00:57:34.880 | And they usually build a room within a room,

00:57:39.240 | but that's still not isolated.

00:57:40.940 | In fact, they say it's impossible to truly isolate

00:57:43.080 | from sound, from noise and stuff like that.

00:57:45.940 | But that's like one step of millions that you took

00:57:50.940 | is building a room inside a room.

00:57:55.040 | You basically have to isolate all.

00:57:56.920 | - Now this is actually an easier problem.

00:57:58.960 | It's just have to do it really well.

00:58:00.680 | So making a clean room is really a tough problem

00:58:03.920 | because you have to put a room inside a room.

00:58:06.120 | You have to, this is really simple engineering, our physics.

00:58:11.120 | Okay, so what do you have to do?

00:58:13.360 | How do you isolate yourself from the earth?

00:58:16.520 | First, we work at, we're not looking at all frequencies

00:58:21.520 | for gravitational waves.

00:58:22.560 | We're looking at particular frequencies

00:58:25.280 | that you can deal with here on earth.

00:58:27.680 | So what frequencies would those be?

00:58:29.480 | You were just talking about frequencies.

00:58:32.320 | - I mean, I don't-- - We know by evolution.

00:58:35.400 | Our bodies know, it's the audio band, okay?

00:58:39.600 | The reason our ears work where they work

00:58:41.840 | is that's where the earth isn't going,

00:58:43.580 | making too much noise.

00:58:45.120 | - Okay, so the reason our ears work the way they work

00:58:47.560 | is 'cause this is where it's quiet.

00:58:49.640 | - That's right.

00:58:50.920 | So if you go to one hertz instead of 10 hertz,

00:58:55.920 | it's the earth is really moving around.

00:58:59.600 | So somehow we live in a, what we call the audio band.

00:59:04.000 | It's tens of hertz to thousands of hertz.

00:59:06.480 | That's where we live, okay?

00:59:09.520 | If we're gonna do an experiment on the earth--

00:59:13.000 | - Might as well do it in the-- - It's the same frequency.

00:59:14.880 | That's where the earth is the quietest.

00:59:16.400 | So we have to work in that frequency.

00:59:18.120 | So we're not looking at all frequencies, okay?

00:59:21.240 | So the solution for the shaking of the earth

00:59:25.620 | to get rid of it is pretty mundane.

00:59:28.680 | If we do the same thing that you do

00:59:32.520 | to make your car drive smoothly down the road.

00:59:35.640 | So what happens when your car goes over a bump?

00:59:38.900 | Early cars did that, they bounced.

00:59:41.360 | Okay, but you don't feel that in your car.

00:59:43.900 | So what happened to that energy?

00:59:46.440 | You can't just disappear energy.

00:59:48.240 | So we have these things called shock absorbers in the car.

00:59:51.520 | What they do is they absorb,

00:59:53.760 | they take the thing that went like that

00:59:56.480 | and they basically can't get rid of the energy

00:59:58.760 | but they move it to very, very low frequency.

01:00:01.960 | So what you feel isn't, you feel it go smoothly, okay?

01:00:06.960 | All right, so we also work at this frequency.

01:00:14.440 | So we basically, why don't we have to do anything

01:00:17.960 | other than shock absorbers?

01:00:19.240 | So we made the world's fanciest shock absorbers, okay?

01:00:23.900 | Not just like in your car where there's one layer of them.

01:00:28.340 | They're just the right squishiness and so forth.

01:00:30.440 | They're better than what's in the cars.

01:00:32.480 | And we have four layers of it.

01:00:34.080 | So whatever shakes and gets through the first layer,

01:00:36.680 | we treat it in a second, third, fourth layer.

01:00:39.320 | - So it's a mechanical engineering problem.

01:00:41.360 | - Yeah, that's what I said.

01:00:42.200 | So it's a real--

01:00:43.680 | - There's no weird tricks to it

01:00:45.240 | like a chemistry type thing or--

01:00:47.520 | - No, no, just well, the right squishiness,

01:00:49.680 | you need the right material inside.

01:00:52.040 | And ours look like little springs, but they're--

01:00:55.400 | - Springs, they're springs?

01:00:57.120 | So like legitimately like shock absorbers?

01:01:00.000 | - Yeah.

01:01:01.520 | - What?

01:01:02.440 | Okay.

01:01:03.280 | - Okay, and this is now experimental physics at its limit.

01:01:07.480 | Okay, so you do this and we make

01:01:09.200 | the world's fanciest shock absorbers,

01:01:11.240 | just mechanical engineering.

01:01:13.440 | - Just mechanical engineering, this is hilarious.

01:01:15.920 | - But we weren't good enough

01:01:18.200 | to discover gravitational waves.

01:01:20.120 | So we did another, we added another feature.

01:01:26.120 | And it's something else that you're aware of,

01:01:30.640 | probably have one, and that is to get rid of noise.

01:01:34.800 | You've probably noise, which is you don't like.

01:01:38.440 | And that's the same principle

01:01:39.920 | that's in these little Bose earphones.

01:01:43.080 | - Noise canceling?

01:01:44.440 | - Noise canceling.

01:01:45.520 | So how do they work?

01:01:48.200 | They basically, you go on an airplane

01:01:50.080 | and they sense the ambient noise from the engines

01:01:54.360 | and cancel it 'cause it's just the same

01:01:56.640 | over and over again, they cancel it.

01:01:59.040 | And when the stewardess comes and asks you

01:02:00.920 | whether you want coffee or tea or a drink or something,

01:02:03.680 | you hear her fine 'cause she's not ambient,

01:02:06.360 | she's a signal, so.

01:02:08.000 | - Are we talking about active canceling?

01:02:09.560 | Like where the actual-- - Active canceling.

01:02:11.920 | - So-- - This is, okay.

01:02:13.880 | - So another-- - Don't tell me

01:02:14.960 | you have active canceling on this.

01:02:18.000 | - Yeah, yeah. - Besides the shock absorbers.

01:02:20.080 | - So inside this array of shock absorbers,

01:02:23.440 | you asked for some interesting--

01:02:26.240 | - This is awesome. (laughs)

01:02:27.960 | - So inside this, it's harder than the earphone problem,

01:02:31.920 | but it's just engineering.

01:02:33.560 | We have to see, measure not just

01:02:35.760 | that the engines still made noise,

01:02:40.200 | but the earth is shaking, it's moving in some direction.

01:02:43.320 | So we have to actually tell not only

01:02:46.000 | that there's noise and cancel it,

01:02:47.520 | but what direction it's from.

01:02:49.100 | So we put this array of seismometers

01:02:52.040 | inside this array of shock absorbers

01:02:55.760 | and measure the residual motion and its direction.

01:03:00.760 | And we put little actuators that push back against it

01:03:05.680 | and cancel it.

01:03:08.400 | - This is awesome.

01:03:10.240 | So you have the actuators and you have the thing

01:03:12.200 | that is sensing the vibrations,

01:03:14.120 | and then you have the actuators that adjust to that

01:03:16.520 | and do so in perfect synchrony.

01:03:18.440 | - Yeah. - What--

01:03:19.920 | - If it all works right.

01:03:21.080 | And so how much do we reduce the shaking of the earth?

01:03:24.080 | - I mean-- - One part in 10 to the 12th.

01:03:29.400 | - One part in 10-- - So what gets through us

01:03:32.260 | is one part in 10 to the 12th.

01:03:36.880 | That's pretty big reduction.

01:03:38.920 | You don't need that in your car, but that's what we do.

01:03:41.160 | And so that's how isolated we are from the earth.

01:03:43.400 | And that was the biggest, I'd say, technical problem

01:03:47.400 | outside of the physics instrument, the interferometer.

01:03:50.280 | - Can I ask you a weird question here?

01:03:53.040 | You make it very poetically and humorously.

01:03:55.760 | You're saying it's just a mechanical engineering problem,

01:03:58.880 | but is this one of the biggest precision

01:04:04.800 | mechanical engineering efforts ever?

01:04:07.600 | I mean, this seems exceptionally difficult.

01:04:09.880 | - It is, and so it took a long time.

01:04:12.400 | And I think nobody seems to challenge the statement

01:04:16.960 | that this is the most precise instrument

01:04:19.800 | that's ever been built, LIGO.

01:04:21.640 | - I wonder what listening to Led Zeppelin sounds

01:04:25.160 | on this thing, 'cause it's so isolated.

01:04:27.280 | I mean, this is like, I don't know.

01:04:30.200 | - No background noise. - No back, it's, wow.

01:04:34.000 | - Wow, wow.

01:04:36.480 | So when you were first conceiving this,

01:04:40.040 | I would probably, if I was knowledgeable enough,

01:04:44.320 | kind of laugh off the possibility that this is even possible.

01:04:48.240 | I'm sure, like how many people believe that this is possible?

01:04:53.200 | Did you believe this was possible?

01:04:54.960 | - I did.

01:04:55.800 | I didn't know that we needed,

01:04:58.400 | for sure that we needed active when we started.

01:05:00.400 | We did just passive, but we were doing the,

01:05:04.120 | tests to develop the active,

01:05:07.000 | to add as a second stage, which we ended up needing.

01:05:09.680 | But there was a lot of, you know,

01:05:13.320 | now there was a lot of skepticism.

01:05:15.680 | A lot of us, especially astronomers,

01:05:18.440 | felt that money was being wasted,

01:05:20.560 | as we were also expensive.

01:05:22.560 | Doing what I told you is not cheap.

01:05:24.440 | So it was kind of controversial.

01:05:26.960 | It was funded by the National Science Foundation.

01:05:30.800 | - Can you just linger on this just for a little longer?

01:05:33.600 | The actuator thing, the active canceling.

01:05:36.000 | Do you remember like little experiments

01:05:42.040 | that were done along the way to prove to the team,

01:05:45.200 | to themselves that this is even possible?

01:05:47.800 | So from our, because I work with quite a bit of robots,

01:05:51.560 | and to me, the idea that you could do it this precisely

01:05:54.320 | is humbling and embarrassing, frankly.

01:05:59.080 | Because like, this is another level of precision

01:06:02.360 | that I can't even, 'cause robots are a mess.

01:06:07.360 | And this is basically one of the most precise robots ever.

01:06:12.400 | Right, so like, is there,

01:06:16.560 | do you remember any like small-scale experiments

01:06:18.600 | that were done that just made this as possible?

01:06:21.000 | - Yeah, and larger scale.

01:06:22.800 | We made a test, that also has to be in vacuum, too,

01:06:28.360 | but we made test chambers that had this system in it,

01:06:31.760 | our first mock of this system, so we could test it.

01:06:34.840 | And optimize it and make it work.

01:06:40.160 | But it's just a mechanical engineering problem.

01:06:42.080 | - Okay. (laughs)

01:06:45.160 | Humans are just ape descendants, I gotcha.

01:06:47.600 | I gotcha.

01:06:49.760 | Is there any video of this?

01:06:51.560 | Like some kind of educational purpose visualizations

01:06:56.280 | of this active canceling?

01:06:58.240 | - I don't think so.

01:07:00.400 | - I mean, does this live on?

01:07:05.040 | - Well, we worked for parts of it, for the active canceling,

01:07:08.560 | we worked for the instruments,

01:07:10.920 | for the sensor and instruments,

01:07:12.880 | we worked with a small company near where you are,

01:07:17.600 | 'cause it was our MIT people that got them,

01:07:20.160 | that were interested in the problem

01:07:22.760 | because they thought they might be able to commercialize it

01:07:25.320 | for making staple tables to make microelectronics,

01:07:29.360 | for example, which are limited by how stable the table is.

01:07:33.240 | I mean, at this point, it's a little expensive.

01:07:36.160 | - So you never know, you never know where this leads.

01:07:40.000 | So maybe on the,

01:07:42.440 | let me ask you, just sticking at it a little longer,

01:07:47.440 | this silly old mechanical engineering problem,

01:07:50.000 | what was, to you, kind of the darkest moment

01:07:55.640 | of what was the hardest stumbling block

01:07:59.240 | to get over on the engineering side?

01:08:00.880 | Like, was there any time where there was a doubt,

01:08:03.040 | where it's like, I'm not sure we would be able to do this,

01:08:05.800 | a kind of a engineering challenge that was hit?

01:08:09.080 | Do you remember anything like that?

01:08:09.920 | - I think the one that,

01:08:11.760 | my colleague at MIT, Ray Weiss, worked on so hard

01:08:18.200 | and was much more of a worry than this.

01:08:21.920 | This is only a question, if you're not doing well enough,

01:08:25.280 | you have to keep making it better somehow.

01:08:28.120 | But this whole huge instrument has to be in vacuum.

01:08:33.120 | And the vacuum tanks are this big around.

01:08:37.840 | And so it's the world's biggest high vacuum system.

01:08:41.440 | And so how do you make it, first of all?

01:08:45.100 | How do you make this four meter long sealed vacuum system?

01:08:50.160 | It has to be made out of--

01:08:51.080 | - Four kilometers long.

01:08:52.000 | - Four kilometers long, would I say something else?

01:08:54.120 | - Meters.

01:08:54.960 | - Four kilometers long.

01:08:56.200 | - Big difference.

01:08:57.040 | - Yeah, and so, but to make it, yeah,

01:09:00.080 | we started with a roll of stainless steel,

01:09:05.000 | and then we roll it out like a spiral

01:09:08.680 | so that there's a spiral weld on it.

01:09:11.360 | Okay, so the engineering was fine, we did that.

01:09:14.640 | We worked through very good companies

01:09:17.080 | and so forth to build it.

01:09:18.860 | But the big worry was, what if you develop a leak?

01:09:23.860 | This is a high vacuum, not just vacuum system.

01:09:29.880 | Typically in a laboratory, if there's a leak,

01:09:32.400 | you put helium around the thing you have,

01:09:37.400 | and then you detect where the helium is coming in.

01:09:41.080 | But if you have something as big as this,

01:09:42.960 | you can't surround it with helium.

01:09:44.560 | - So you might not actually even know that there's a leak

01:09:46.880 | and it will be affecting--

01:09:47.960 | - Well, we can measure how good the vacuum is,

01:09:52.960 | so we can know that, but a leak can develop,

01:09:56.400 | and then we don't, how do we fix it,

01:09:59.120 | or how do we find it?

01:10:00.800 | And so that was, you asked about a worry,

01:10:03.640 | that was always a really big worry.

01:10:06.480 | - What's the difference between a high vacuum and a vacuum?

01:10:09.840 | What is high vacuum?

01:10:11.320 | That's like some delta close to vacuum?

01:10:15.400 | Is it some threshold?

01:10:16.760 | - Well, there's a unit, high vacuum is when the vacuum

01:10:21.760 | and the units that are used, which are TORs,

01:10:24.040 | there's 10 to the minus nine.

01:10:25.440 | - Gotcha.

01:10:26.280 | - High vacuum is usually used in small places.

01:10:31.340 | The biggest vacuum system, period,

01:10:35.200 | is at CERN in this big particle accelerator,

01:10:38.320 | but the high vacuum, where they need really good vacuum

01:10:40.840 | so particles don't scatter in it, is smaller than ours.

01:10:43.920 | So ours is a really large high vacuum system.

01:10:48.920 | - I don't know, this is so cool.

01:10:50.440 | I mean, this is basically by far

01:10:53.440 | the greatest listening device ever built by humans.

01:10:57.280 | The fact that like descendants of apes could do this,

01:11:01.000 | that evolution started with single cell organisms.

01:11:04.300 | I mean, is there any more, I'm a huge,

01:11:07.640 | theory is like, yeah, yeah, but like bridges,

01:11:10.240 | when I look at bridges from a civil engineering perspective,

01:11:13.360 | it's one of the most beautiful creations by human beings.

01:11:15.600 | It's physics, you're using physics to construct objects

01:11:19.120 | that can support huge amount of mass.

01:11:21.920 | And it's like structural, but it's also beautiful

01:11:24.080 | in that humans can collaborate to create that

01:11:26.460 | throughout history.

01:11:27.360 | And then you take this on another level.

01:11:29.920 | This is like, this is like exciting to me beyond measure

01:11:36.040 | that humans can create something so precise.

01:11:39.880 | - But another concept lost in this, you just said,

01:11:43.040 | you started talking about single cell.

01:11:44.760 | - Yeah. - Okay.

01:11:46.320 | You have to realize this discovery that we made

01:11:48.480 | that everybody's bought off on,

01:11:50.080 | happened 1.3 billion years ago, somewhere.

01:11:55.080 | And then the signal came to us.

01:11:56.800 | 1.3 billion years ago, we were just converting on the earth

01:12:00.840 | from single cell to multi-cell life.

01:12:03.520 | So when this actually happened,

01:12:05.640 | this collision of two black holes, we weren't here.

01:12:09.080 | We weren't even close to being here.

01:12:09.920 | - And we're both developing slowly.

01:12:11.160 | - There were single, yeah, we were going from single cell

01:12:15.280 | to multi-cell life at that point.

01:12:16.880 | - All to meet up at this point.

01:12:18.880 | - Yeah.

01:12:19.720 | - Wow, that's like, that's almost romantic.

01:12:23.540 | - It is.

01:12:26.040 | - Okay, so on the human side of things,

01:12:30.720 | it's kind of fascinating 'cause you're talking about

01:12:35.080 | over a thousand people team for LIGO.

01:12:38.080 | - Yeah.

01:12:38.920 | - You started out with around a hundred

01:12:42.520 | and you've for parts of the time at least led this team.

01:12:47.180 | What does it take to lead a team like this

01:12:51.160 | of incredibly brilliant theoreticians and engineers

01:12:56.160 | and just a lot of different parties involved,

01:12:59.400 | a lot of egos, a lot of ideas.

01:13:02.680 | You had this funny example, I forget where,

01:13:06.980 | where in publishing a paper, you have to all agree

01:13:09.780 | on like the phrasing of a certain sentence

01:13:13.500 | or the title of the paper and so on.

01:13:15.480 | That's a very interesting, simple example.

01:13:17.300 | I'd love you to speak to that, but just in general,

01:13:19.300 | how, what does it take to lead this kind of team?

01:13:23.140 | - Okay, I think the general idea is one we all know.

01:13:28.140 | You wanna get where the sum of something

01:13:36.240 | is more than the individual parts is what we say, right?

01:13:39.440 | - Yeah.

01:13:40.600 | - So that's what you're trying to achieve.

01:13:42.120 | - Yes.

01:13:42.960 | - Okay, how do you do that actually?

01:13:44.760 | Mostly if we take multiple objects or people,

01:13:49.000 | I mean, you put them together, the sum is less.

01:13:51.560 | - Yes.

01:13:52.400 | - Why?

01:13:53.240 | Because they overlap.

01:13:54.480 | So you don't have individual things that,

01:13:58.160 | this person does that, this person does that,

01:14:00.880 | then you get exactly the sum.

01:14:03.440 | But what you want is to develop where you get more

01:14:07.040 | than what the individual contributions are.

01:14:09.400 | We know that's very common.

01:14:10.520 | People use that expression everywhere.

01:14:13.260 | And it's the expression that has to be kind of built

01:14:17.420 | into how people feel it's working.

01:14:19.560 | Because if you're part of a team and you realize

01:14:23.960 | that somehow the team is able to do more

01:14:26.680 | than the individuals could do themselves,

01:14:28.820 | then they buy on kind of in terms of the process.

01:14:32.700 | So that's the goal that you have to have is to achieve that.

01:14:37.700 | And that means that you have to realize parts

01:14:44.440 | of what you're trying to do that require,

01:14:50.160 | not that one person couldn't do it.

01:14:51.840 | It requires the combined talents to be able to do something

01:14:56.060 | that neither of them could do themselves.

01:14:58.180 | And we have a lot of that kind of thing.

01:15:00.080 | And I think, I mean, build into some

01:15:03.580 | of the examples that I gave you.

01:15:05.460 | And so how do you then, so the key almost

01:15:10.460 | in anything you do is the people themselves, right?

01:15:13.980 | So in our case, the first and most important was to attract,

01:15:18.980 | to spend years of their life on this,

01:15:24.100 | and the best possible people in the world to do it.

01:15:26.940 | So the only way to convince them is that somehow

01:15:30.840 | it's better and more interesting for them

01:15:34.840 | than what they could do themselves.

01:15:37.040 | And so that's part of this idea.

01:15:40.560 | - I got you, yeah, that's powerful.

01:15:42.240 | But nevertheless, there's best people in the world,

01:15:45.160 | there's egos.

01:15:46.160 | Is there something to be said about managing egos?

01:15:48.880 | - Oh, that's, the human problem's always the hardest.

01:15:51.920 | And so that's an art, not a science, I think.

01:15:55.840 | I think the fact here that combined,

01:16:00.380 | there's a romantic goal that we had to do something

01:16:05.380 | that people hadn't done before,

01:16:06.980 | which was important scientifically and a huge challenge,

01:16:11.980 | enabled us to say, take and get,

01:16:19.940 | I mean, what we did, just to take an example,

01:16:21.680 | we used the light to go in this thing, comes from lasers.

01:16:26.100 | We need a certain kind of laser.

01:16:27.640 | So the kind of laser that we used,

01:16:30.720 | there were three different institutions in the world

01:16:35.720 | that had the experts that do this,

01:16:37.800 | maybe in competition with each other.

01:16:40.080 | So we got all three to join together and work with us

01:16:44.280 | to work on this, as an example.

01:16:46.200 | So that you had, and they had the thing

01:16:50.500 | that they were working together on a kind of object

01:16:53.320 | that they wouldn't have otherwise,

01:16:55.160 | and were part of a bigger team

01:16:57.460 | where they could discover something

01:16:59.280 | that isn't even engineers.

01:17:01.080 | These are engineers that do lasers,

01:17:03.160 | and they're part of our laser physicists.

01:17:07.080 | - So could you describe the moment or the period of time

01:17:12.080 | when finally this incredible creation of human beings

01:17:18.400 | led to a detection of gravitational waves?

01:17:21.620 | - It's a long story.

01:17:22.580 | Unfortunately, this is a part that we started--

01:17:26.020 | - Failures along the way kind of thing, or what?

01:17:28.380 | - All failures, that's all, it's built into it.

01:17:31.040 | - Okay.

01:17:31.880 | - If you're not--

01:17:32.700 | - Just mechanical engineering.

01:17:34.500 | (both laughing)

01:17:35.900 | - You build on your failures, that's expected.

01:17:38.380 | So we're trying things that no one's done before.

01:17:40.680 | So it's technically not just gravitational waves,

01:17:43.580 | and so it's built on failures.

01:17:46.340 | But anyway, we did, before MEVE,

01:17:49.480 | and the people did R&D on the concepts.

01:17:54.480 | But starting in 1994, we got money

01:17:58.240 | from the National Science Foundation to build this thing.

01:18:01.100 | It took about five years to build it.

01:18:04.820 | So by 1999, we had built the basic unit.

01:18:09.820 | It did not have active seismic isolation at that stage.

01:18:15.160 | It didn't have some other things that we have now.

01:18:18.360 | What we did at the beginning was

01:18:21.760 | stick to technologies that we had at least enough knowledge

01:18:29.640 | that we could make work or had tested in our own laboratories.

01:18:35.000 | And so then we put together the instrument,

01:18:37.840 | we made it work.

01:18:39.840 | It didn't work very well, but it worked.

01:18:41.700 | And we didn't see any gravitational waves.

01:18:44.680 | Then we figured out what limited us,

01:18:46.360 | and we went through this every year for almost 10 years,

01:18:51.360 | never seeing gravitational waves.

01:18:54.080 | We would run it, looking for gravitational waves for months,

01:18:59.080 | learn what limited us, fix it for months,

01:19:03.760 | and then run it again.

01:19:05.320 | Eventually, we knew we had to take another big step,

01:19:09.680 | and that's when we made several changes,

01:19:12.160 | including adding these active seismic isolation,

01:19:16.400 | which turned out to be a key.

01:19:17.900 | And we fortunately got the National Science Foundation

01:19:23.960 | to give us another couple hundred million dollars,

01:19:27.640 | a hundred million more, and we rebuilt it,

01:19:31.480 | or fixed, or improved it.

01:19:34.560 | And then in 2015, we turned it on,

01:19:39.560 | and we almost instantly saw this first collision

01:19:44.560 | of two black holes.

01:19:51.960 | And then we went through a process of,

01:19:58.600 | do we believe what we've seen?

01:20:00.240 | - Yeah, I think you're one of the people

01:20:02.040 | that went through that process.

01:20:03.080 | Sounds like some people immediately believed it.

01:20:05.200 | - Yeah.

01:20:06.040 | - And then you were like, "It's disgusting."

01:20:07.320 | - So as human beings, we all have different reactions

01:20:09.920 | to almost anything, and so quite a few of my colleagues

01:20:13.320 | had a eureka moment immediately.

01:20:15.560 | I mean, it's--

01:20:16.400 | - It's amazing.

01:20:18.360 | - The figure that we put in our paper,

01:20:22.600 | first is just data.

01:20:25.600 | We didn't have to go through fancy computer programs

01:20:28.920 | to do anything.

01:20:30.080 | And we showed next to it the calculations

01:20:35.080 | of Einstein's equations, and it looks just like

01:20:37.760 | what we detected.

01:20:38.800 | - Wow.

01:20:39.640 | - And we did it in two different detectors

01:20:41.360 | halfway across the US, so it was pretty convincing.

01:20:44.760 | But you don't wanna fool yourself.

01:20:49.800 | So we had, being a scientist, we had, for me,

01:20:54.800 | we had to go through and try to understand

01:20:57.240 | that the instrument itself, which was new,

01:20:59.040 | I said we had rebuilt it, couldn't somehow generate

01:21:02.720 | things that looked like this.

01:21:04.720 | That took some tests, and then the second,

01:21:08.160 | you'll appreciate more, we had to somehow convince ourselves

01:21:12.360 | we weren't hacked in some clever way.

01:21:14.440 | - Cybersecurity question.

01:21:15.880 | - Yeah, even though we're not on the internet.

01:21:18.480 | - Yeah, no, it can be physical access too.

01:21:22.320 | Yeah, that's fascinating.

01:21:24.400 | It's fascinating that you would think about that.

01:21:26.080 | I mean, not enough.

01:21:31.680 | I mean, 'cause it matches prediction,

01:21:35.520 | so the chances of it actually being manipulated

01:21:37.400 | is very, very low, but nevertheless.

01:21:40.400 | - We still could have disgruntled all the graduate students

01:21:42.960 | who had worked with us earlier that--

01:21:45.200 | - Who want you to, I don't know how that's supposed

01:21:47.600 | to embarrass you.

01:21:48.520 | I suppose, yeah, I suppose I see,

01:21:50.760 | but about what I think you said, within a month,

01:21:55.520 | you kind of convinced yourselves officially.

01:21:57.240 | - Within a month, we convinced ourselves.

01:21:59.360 | We kept 1,000 collaborators quiet during that time.

01:22:03.200 | Then we spent another--

01:22:04.400 | - That's funny.

01:22:05.240 | - Month or so trying to understand what we'd seen

01:22:09.160 | so that we could do the science with it

01:22:12.640 | instead of just putting it out to the world

01:22:14.520 | and let somebody else understand

01:22:15.880 | that it was two black holes and what it was.

01:22:18.960 | - The fact that 1,000 collaborators were quiet

01:22:22.160 | is a really strong indication

01:22:23.800 | that this is a really close-knit team.

01:22:25.640 | - Yeah, and they're around the world.

01:22:29.040 | - Well, either strong-knit or tight-knit

01:22:33.160 | or a strong dictatorship or something.

01:22:36.480 | - Yeah, either fear or love.

01:22:37.880 | You can rule by fear or love.

01:22:38.960 | - Yeah, right.

01:22:39.800 | - You can go back to Machu Belly.

01:22:41.800 | All right, well, this, I mean,

01:22:43.300 | this is really exciting that that was,

01:22:48.700 | that's a success story 'cause it didn't have

01:22:52.080 | to be a success story, right?

01:22:54.640 | I mean, eventually, perhaps you could say it'll be an event,

01:22:57.320 | but it could have taken it over a century to get there.

01:23:00.080 | - Oh, yeah, yeah.

01:23:01.240 | It's, and it's only downhill now, kind of.

01:23:06.240 | (both laughing)

01:23:10.040 | - What do you mean it's only,

01:23:11.320 | you mean with gravitational waves?

01:23:12.600 | - Well, yeah, we've now,

01:23:15.240 | we now, well, now we're off because of the pandemic,

01:23:18.960 | but when we turned off,

01:23:20.400 | we were seeing some sort of gravitational wave event

01:23:24.600 | each week.

01:23:26.960 | Now we're fixing, we're fixing,

01:23:28.760 | we're adding features where it'll probably be,

01:23:31.200 | when we turn back on next year,

01:23:32.720 | it'll probably be every one every couple of days,

01:23:35.880 | and they're not all the same.

01:23:37.160 | So it's learning about what's out there in gravity

01:23:40.720 | instead of just optics.

01:23:42.640 | And so it's all great.

01:23:46.020 | We're only limited by,

01:23:47.520 | the fantastic thing,

01:23:50.640 | other than that this is a great field

01:23:53.760 | and it's all new and so forth,

01:23:55.600 | is that experimentally,

01:23:57.520 | the great thing is that we're limited by technology

01:24:02.520 | and technical limitations, not by science.

01:24:06.920 | So the, another,

01:24:12.640 | a really important discovery that was made before ours

01:24:17.640 | was what's called the Higgs boson,

01:24:19.240 | made on the big accelerator at CERN.

01:24:21.800 | You know, this huge accelerator,

01:24:23.280 | they discovered a really important thing.

01:24:25.680 | It's, you know, we have Einstein's equation,

01:24:28.160 | E equals MC squared.

01:24:30.000 | So energy makes mass or mass can make energy,

01:24:33.360 | and that's the bomb.

01:24:34.360 | But the mechanism by which that happens,

01:24:38.280 | not vision, but how do you create mass from energy,

01:24:42.780 | was never understood until there was a theory of it

01:24:51.080 | about 70 years ago now.

01:24:54.040 | And so they discovered it's named after a man named Higgs.

01:24:58.560 | It's called the Higgs boson.

01:25:00.520 | And so it was discovered,

01:25:02.700 | but since that time,

01:25:04.360 | and I worked on those experiments,

01:25:06.880 | since that time,

01:25:07.720 | they haven't been able to progress very much further,

01:25:10.040 | a little bit, but not a lot further.

01:25:12.120 | And the difference is that we're really lucky

01:25:14.440 | in what we're doing,

01:25:17.360 | in that there you see this Higgs boson,

01:25:21.640 | but there's tremendous amount of other physics that goes on,

01:25:24.400 | and you have to pick out the needle

01:25:25.720 | in the haystack kind of physics.

01:25:28.280 | You can't make the physics go away, it's there.

01:25:30.920 | In our case, we have a very weak signal,

01:25:34.080 | but once we get good enough to see it,

01:25:36.360 | it's weak compared to where we've reduced the background,

01:25:40.080 | but the background is not physics, it's just technology.

01:25:44.280 | It's getting ourselves better isolated from the earth

01:25:48.120 | or getting a more powerful laser.

01:25:50.640 | And so since 2015, when we saw the first one,

01:25:55.640 | we continually can make improvements

01:25:59.020 | that are enabling us to turn this into a real science

01:26:03.200 | to do astronomy, a new kind of astronomy.

01:26:05.920 | It's a little like astronomy.

01:26:07.720 | I mean, Galileo started the field.

01:26:12.400 | I mean, he basically took lenses that were made for classes

01:26:16.640 | and he didn't invent the first telescope,

01:26:20.280 | but made a telescope, looked at Neptune

01:26:25.280 | and saw that it had four moons.

01:26:27.720 | That was the birth of not just using your eyes

01:26:31.120 | to understand what's out there.

01:26:33.800 | And since that time,

01:26:34.720 | we've made better and better telescopes, obviously,

01:26:37.200 | and astronomy thrives.

01:26:39.740 | And in a similar way, we're starting to be able to crawl,

01:26:44.040 | but we're starting to be able to do that

01:26:47.560 | with gravitational waves.

01:26:49.920 | And it's gonna be more and more that we can do

01:26:53.560 | as we can make better and better instruments,

01:26:55.600 | because as I say, it's not limited by-

01:26:58.340 | - Physics. - Picking it out of others.

01:27:00.960 | Yeah, it's not limited by the physics.

01:27:02.600 | - So you have an optimism about engineering,

01:27:04.880 | that as human progress marches on,

01:27:09.880 | engineering will always find a way

01:27:14.500 | to build a large enough device,

01:27:17.380 | accurate enough device to detect the-

01:27:19.700 | - As long as it's not limited by physics,

01:27:21.500 | yeah, they'll do it.

01:27:22.740 | - So you, two other folks, and the entire team

01:27:31.260 | won the Nobel Prize for this big effort.

01:27:35.440 | There's a million questions I can ask for,

01:27:39.420 | but looking back,

01:27:41.900 | where does the Nobel Prize fit into all of this?

01:27:51.260 | If you think hundreds of years from now,

01:27:54.720 | I venture to say that people will not remember

01:27:59.160 | the winners of a prize.

01:28:01.480 | But they'll remember creations like these.

01:28:03.480 | Maybe I'm romanticizing engineering.

01:28:05.560 | But I guess I wanna ask,

01:28:09.440 | how important is the Nobel Prize in all of this?

01:28:11.840 | - Well, that's a complicated question.

01:28:16.200 | As a physicist, it's something,

01:28:20.880 | if you're trying to win a Nobel Prize, forget it,

01:28:23.880 | because they give one a year.

01:28:27.240 | So there's been 200 physicists

01:28:31.140 | who have won the Nobel Prize since 1900.

01:28:33.340 | And so that's, you know,

01:28:36.320 | so things just have to fall right.

01:28:39.300 | So your goal cannot be to win a Nobel Prize.

01:28:42.260 | It wasn't my dream.

01:28:43.480 | It's tremendous for science.

01:28:49.420 | I mean, why the Nobel Prize for a guy

01:28:51.940 | that made dynamite and stuff is what it is,

01:28:55.300 | it's a long story.

01:28:56.140 | But it's the one day a year where actually the science

01:29:00.160 | that people have done is all over the world and so forth.

01:29:04.320 | Forget about the people again.

01:29:06.360 | It is really good for science.

01:29:08.840 | - Celebrating science.

01:29:10.040 | - It celebrates science for several days,

01:29:13.760 | different fields, chemistry, medicine, and so forth.

01:29:18.200 | And everybody doesn't understand everything about these.

01:29:21.680 | They're generally fairly abstract,

01:29:24.280 | but then it's on the front page

01:29:27.000 | of newspapers around the world.

01:29:28.240 | So it's really good for science.

01:29:29.920 | It's not easy to get science on the front page

01:29:32.080 | of the New York Times.

01:29:33.120 | It's not there.

01:29:34.180 | Should be, but it's not.

01:29:36.780 | And so the Nobel Prize is important in that way.

01:29:42.460 | It's otherwise, you know,

01:29:46.640 | I have a certain celebrity that I didn't have before.

01:29:52.400 | - And now you get to be a celebrity

01:29:54.240 | that advertises science.

01:29:55.440 | It's a mechanism to remind us how incredible,

01:29:59.520 | how much credit science deserves in everything we do.

01:30:02.800 | - Well, it has a little bit more.

01:30:04.880 | One thing I didn't expect, which is good,

01:30:07.720 | is that we have a government,

01:30:12.040 | I'm not picking on ours necessarily,

01:30:16.160 | but it's true of all governments,

01:30:17.480 | are not run by scientists.

01:30:18.800 | In our case, it's run by lawyers and businessmen.

01:30:23.640 | Okay?

01:30:25.200 | And at best, they may have an aide or something

01:30:27.920 | that knows a little science.

01:30:29.560 | So our country is, and all countries,

01:30:34.240 | are hardly to take into account science

01:30:39.240 | in making decisions.

01:30:42.760 | - Yes. - Okay.

01:30:44.080 | And having a Nobel Prize,

01:30:48.240 | the people in those positions actually listen.

01:30:53.240 | So you have more influence.

01:30:55.800 | I don't care whether it's about global warming

01:30:57.640 | or what the issue is.

01:30:59.080 | There's some influence which is lacking otherwise.

01:31:02.720 | And people pay attention to what I say.

01:31:06.400 | If I talk about global warming,

01:31:07.840 | they wouldn't have before I had the Nobel Prize.

01:31:11.240 | - Yeah, this is very true.

01:31:13.880 | You're like the celebrities who talk.

01:31:17.080 | Celebrity has power.

01:31:19.080 | - Celebrity has power.

01:31:20.400 | - And that's-- - And that's a good thing.

01:31:22.120 | - That's a good thing, yeah.

01:31:23.240 | - Singling out people, I mean, on the other side of it,

01:31:26.160 | singling out people has all kinds of,

01:31:29.520 | whether it's for Academy Awards or for this,

01:31:32.760 | have unfairness and arbitrariness and so forth and so on.

01:31:36.680 | So that's the other side of the coin.

01:31:41.120 | - Just like you said,

01:31:41.960 | especially with the huge experimental projects like this,

01:31:45.320 | it's a large team and it does,

01:31:47.880 | the nature of the Nobel Prize is singles out

01:31:50.240 | a few individuals to represent the team.

01:31:52.240 | Nevertheless, it's a beautiful thing.

01:31:55.560 | What are ways to improve LIGO in the future,

01:31:59.600 | increase the sensitivity?

01:32:01.520 | I've seen a few ideas that are kind of fascinating.

01:32:04.640 | Is, are you interested in them?

01:32:06.640 | Sort of looking, I'm not speaking about five years.

01:32:09.480 | Perhaps you could speak to the next five years,

01:32:11.660 | but also the next hundred years.

01:32:13.800 | - Yeah, so let me talk to both the instrument

01:32:17.080 | and the science, okay?

01:32:19.040 | Since that's, they go hand in hand.

01:32:21.000 | I mean, the thing that I said is if we make it better,

01:32:23.920 | we see more kinds of weaker objects and we do astronomy,

01:32:28.040 | okay?

01:32:28.880 | We're very motivated to make a new instrument,

01:32:32.920 | which will be a big step, the next step,

01:32:36.400 | like making a new kind of telescope or something.

01:32:39.320 | And the ideas of what that instrument should be

01:32:43.600 | haven't converged yet.

01:32:45.600 | There's different ideas in Europe.

01:32:47.280 | They've done more work to kind of develop the ideas,

01:32:52.280 | but they're different from ours and we have ideas.

01:32:56.640 | So, but I think over the next few years,

01:32:59.000 | we'll develop those.

01:33:01.120 | The idea is to make an instrument

01:33:02.560 | that's at least 10 times better than what we have,

01:33:06.000 | what we can do with this instrument,

01:33:07.720 | 10 times better than that.

01:33:09.480 | 10 times better means you can look 10 times further out.

01:33:13.120 | 10 times further out is a thousand times more volume.

01:33:18.160 | So, you're seeing much, much more of the universe.

01:33:22.400 | The big change is that if you can see far out,

01:33:26.680 | you see further back in history.

01:33:28.760 | - Yeah, you're traveling back in time.

01:33:30.600 | - Yeah, and so we can start to do what we call cosmology

01:33:35.480 | instead of astronomy or astrophysics.

01:33:39.360 | Cosmology is really the study of the evolution of the-

01:33:43.440 | - Oh, interesting, yeah.

01:33:45.360 | - And so then you can start to hope

01:33:48.440 | to get to the important problems

01:33:51.640 | having to do with how the universe began,

01:33:56.440 | how it evolved and so forth,

01:33:58.120 | which we really only study now with optical instruments

01:34:04.440 | or electromagnetic waves.

01:34:08.320 | And early in the universe, those were blocked

01:34:12.040 | because basically it wasn't transparent,

01:34:15.040 | so the photons couldn't get out

01:34:17.800 | when everything was too dense.

01:34:19.920 | - What do you think, sorry, on this tangent,

01:34:21.720 | what do you think an understanding of gravitational waves

01:34:24.600 | from earlier in the universe can help us understand

01:34:27.160 | about the Big Bang and all that kind of stuff?

01:34:28.880 | - Yeah, yeah, that's, so-

01:34:30.760 | - But it's a non, it's another perspective on the thing.

01:34:35.760 | Is there some insights you think could be revealed

01:34:38.800 | just to help a layman understand?

01:34:41.120 | - Sure, first, we don't understand,

01:34:43.040 | we use the word Big Bang,

01:34:44.160 | we don't understand the physics

01:34:45.840 | of what the Big Bang itself was.

01:34:48.340 | So I think my, and in the early stage,

01:34:55.240 | there were particles and there was a huge amount of gravity

01:34:58.260 | and mass being made.

01:35:00.200 | And so the big, so I'll say two things.

01:35:05.200 | One is, how did it all start?

01:35:09.360 | How did it happen?

01:35:10.200 | And I'll give you at least one example

01:35:12.080 | that we don't understand, but we should understand.

01:35:15.800 | We don't know why we're here.

01:35:17.720 | - Yes, no, we do not.

01:35:19.620 | - I don't mean it philosophically.

01:35:23.080 | I mean it in terms of physics, okay?

01:35:26.080 | Now, what do I mean by that?

01:35:27.220 | If I go into my laboratory at CERN or somewhere

01:35:30.600 | and I collide particles together or put energy together,

01:35:33.880 | I make as much antimatter as matter.

01:35:36.200 | Antimatter then annihilates matter and makes energy.

01:35:41.840 | So in the early universe, you made somehow,

01:35:46.840 | somehow a lot of matter and antimatter,

01:35:51.100 | but there was an asymmetry.

01:35:52.760 | Somehow there was more matter and antimatter.

01:35:55.680 | The matter and antimatter annihilated each other,

01:35:58.200 | at least that's what we think.

01:35:59.660 | And there was only matter left over,

01:36:01.800 | and we live in a universe that we see this all matter.

01:36:05.960 | We don't have any idea.

01:36:07.360 | We have an ideas, but we don't have any,

01:36:09.900 | we don't have any way to understand that

01:36:12.280 | at the present time with the physics that we know.

01:36:15.360 | - Can I ask a dumb question?

01:36:16.680 | Does antimatter have anything like a gravitational field

01:36:21.680 | to send signals?

01:36:24.960 | So how does this asymmetry of matter, antimatter,

01:36:29.960 | could be investigated or further understood

01:36:33.680 | by observing gravitational fields

01:36:35.480 | or weirdnesses in gravitational fields?

01:36:37.640 | - I think that in principle, if there were, you know,

01:36:42.380 | anti-neutron stars instead of just neutron stars,

01:36:47.020 | we would see different kind of signals,

01:36:49.620 | but it didn't get to that.

01:36:52.120 | We live in a universe that we've done enough

01:36:54.640 | looking 'cause we don't see matter,

01:36:57.080 | anti-protons anywhere, no matter what we look at,

01:37:00.120 | that it's all made out of matter.

01:37:02.160 | There is no antimatter except when we go in our laboratories.

01:37:05.160 | So, but when we go in our laboratories,

01:37:09.200 | we make as much antimatter as matter.

01:37:11.360 | So there's something about the early universe

01:37:13.220 | that made this asymmetry.

01:37:15.400 | So we can't even explain why we're here,

01:37:17.740 | that's what I meant.

01:37:18.720 | - Yeah.

01:37:19.560 | - Physics-wise, not, you know,

01:37:22.880 | not in terms of how we evolved and all that kind of stuff.

01:37:26.960 | So-

01:37:27.800 | - So there might be inklings of,

01:37:30.240 | of some of the physics that gravitational-

01:37:36.160 | - So gravitational waves don't get obstructed like light.

01:37:40.160 | So I said light only goes to 300,000 years.

01:37:42.840 | So it goes back to the beginning.

01:37:44.560 | So if you could study the early universe

01:37:46.520 | with gravitational waves, we can't do that yet.

01:37:49.440 | Then it took 400 years to be able to do that

01:37:52.780 | with optical, but then you can really understand

01:37:56.640 | the very, maybe understand the very early universe.

01:38:00.500 | So in terms of questions like why we're here

01:38:05.500 | or what the Big Bang was, we should be,

01:38:09.800 | we can in principle study that with gravitational waves.

01:38:12.680 | So to keep moving in this direction,

01:38:15.440 | it's a unique kind of way to understand our universe.

01:38:20.600 | - Do you think there's more Nobel Prize level ideas

01:38:23.220 | to be discovered in relation to-

01:38:25.380 | - I'd be shocked if there-

01:38:26.660 | - Gravitational waves.

01:38:27.500 | - If there isn't, not even going to that,

01:38:30.100 | which is a very long range problem.

01:38:31.820 | But I think that we only see with electromagnetic waves

01:38:36.820 | 4% of what's out there.

01:38:39.700 | There must be, we looked for things

01:38:45.020 | that we knew should be there.

01:38:47.180 | There should be, I would be shocked

01:38:52.180 | if there wasn't physics, objects, science,

01:38:57.520 | and with gravity that doesn't show up

01:38:59.600 | in everything we do with telescopes.

01:39:02.000 | So I think we're just limited

01:39:05.300 | by not having powerful enough instruments yet to do this.

01:39:09.700 | - Do you have a preference?

01:39:11.760 | I keep seeing this E. Lisa idea.

01:39:17.260 | - Yeah.

01:39:18.100 | - Do you have a preference for earthbound

01:39:23.100 | or spacefaring mechanisms for-

01:39:27.140 | - They're complementary.

01:39:28.180 | It's a little bit like-

01:39:29.020 | - A signal.

01:39:29.860 | - It's completely analogous

01:39:32.300 | to what's been done in astronomy.

01:39:34.300 | So astronomy from the time of Galileo

01:39:37.340 | was done with visible light.

01:39:40.420 | - Yeah.

01:39:41.260 | - The big advances in astronomy in the last 50 years

01:39:45.180 | are because we have instruments

01:39:46.340 | that look at the infrared, microwave,

01:39:49.940 | ultraviolet, and so forth.

01:39:51.700 | So looking at different wavelengths has been important.

01:39:55.620 | Basically going into space means

01:39:58.460 | that we'll look at instead of the audio band,

01:40:00.760 | which we look at, as we said, on the earth's surface,

01:40:03.580 | we'll look at lower frequencies.

01:40:05.780 | So it's completely complementary

01:40:07.860 | and it starts to be looking at different frequencies

01:40:10.880 | just like we do with astronomy.

01:40:14.460 | - It seems almost incredible to me engineering-wise,

01:40:17.100 | just like on earth, to send something

01:40:19.140 | that's kilometers across into space.

01:40:23.860 | Is that harder to engineer?

01:40:26.540 | - It actually is a little different.

01:40:28.460 | It's three satellites separated

01:40:31.820 | by hundreds of thousands of kilometers.

01:40:34.020 | And they send a laser beam from one to the other.

01:40:38.360 | And if the triangle changes shape a little bit,

01:40:44.020 | they detect that from a passage.

01:40:46.060 | - Did you say hundreds of thousands of kilometers?

01:40:48.700 | - Yeah.

01:40:49.540 | - Sending lasers to each other.

01:40:51.240 | (laughing)

01:40:54.340 | Okay.

01:40:56.460 | - It's just engineering.

01:40:57.460 | - Is it possible though?

01:41:01.620 | - Yes. - Is it doable?

01:41:02.460 | - Yes.

01:41:03.660 | - Okay.

01:41:04.500 | That's just incredible 'cause they have to maintain,

01:41:10.100 | I mean, the precision here is probably,

01:41:12.180 | there might be some more, what is it?

01:41:14.380 | Maybe noise is a smaller problem.

01:41:16.900 | I guess there's no vibration to worry about,

01:41:20.180 | like seismic stuff.

01:41:21.940 | So getting away from earth, maybe you get away from--

01:41:23.820 | - Yeah, those parts are easier.

01:41:25.180 | They don't have to measure it as accurately

01:41:27.320 | at low frequencies.

01:41:28.600 | But they have a lot of tough engineering problems.

01:41:33.580 | In order to detect that the gravitational waves

01:41:40.900 | affect things, the sensors have to be

01:41:44.180 | what we call free masses, just like ours,

01:41:46.620 | are isolated from the earth.

01:41:48.140 | They have to isolate it from the satellite.

01:41:51.100 | And that's a hard problem.

01:41:53.220 | They have to do that pretty, not as well as we have to do it

01:41:55.540 | but very well.

01:41:57.100 | And they've done a test mission

01:41:59.620 | and the engineering seems to be,

01:42:01.800 | at least in principle, in hand.

01:42:04.400 | This'll be in the 2030s when it--

01:42:07.260 | - 2030s? - Yeah.

01:42:08.500 | - This is incredible.

01:42:10.700 | This is incredible.

01:42:13.600 | Let me ask about black holes.

01:42:17.260 | So what we're talking about is observing

01:42:20.020 | orbiting black holes.

01:42:24.740 | I saw the terminology of binary black hole systems.

01:42:28.940 | - Binary black holes.

01:42:30.260 | - That's when they're dancing?

01:42:32.940 | Okay.

01:42:33.780 | - They're both going around each other

01:42:34.620 | just like the earth around the sun.

01:42:36.180 | - Okay, is that weird that there's black holes

01:42:38.600 | going around each other?

01:42:40.100 | - So the finding binary systems of stars

01:42:43.100 | is similar to finding binary systems of--

01:42:45.980 | - Of black holes.

01:42:46.820 | - Well, they were once stars.

01:42:48.220 | So we haven't said what a black hole is physically yet.

01:42:55.900 | - Yeah, what's a black hole?

01:42:56.900 | - So black hole is, first it's a mathematical concept

01:43:01.260 | or a physical concept, and that is a region of space.

01:43:05.660 | So it's simply a region of space

01:43:07.380 | where the curvature of space-time

01:43:10.820 | in the gravitational field is so strong

01:43:13.220 | that nothing can get out, including light.

01:43:18.240 | And there's light gets bent in the gravitation,

01:43:23.980 | if the space-time is warped enough.

01:43:26.420 | And so even light gets bent around and stays in it.

01:43:29.660 | So that's the concept of a black hole.

01:43:31.500 | So it's not a, and maybe you can make,

01:43:35.140 | maybe it's a concept that didn't say how they come about.

01:43:39.620 | And there could be different ways they come about.

01:43:43.500 | The ones that we are seeing,

01:43:45.900 | there's a, we're not sure.

01:43:50.180 | That's what we're trying to learn now is what they,

01:43:52.540 | but the general expectation is that they come,

01:43:57.160 | these black holes happen when a star dies.

01:44:01.300 | So what does that mean that a star dies?

01:44:03.780 | What happens?

01:44:05.320 | A star like our sun

01:44:06.720 | basically makes heat and light by fusion.

01:44:11.940 | It's made of, and as it burns,

01:44:15.960 | it burns up the hydrogen and then the helium,

01:44:18.920 | and then, and slowly works its way up

01:44:22.020 | to the heavier and heavier elements that are in the star.

01:44:25.820 | And when it gets up to iron,

01:44:27.960 | the fusion process doesn't work anymore.

01:44:30.680 | And so the stars die, and that happens to stars.

01:44:34.100 | And then they do what's called a supernova.

01:44:37.360 | What happens then is that a star is a delicate balance

01:44:41.000 | between an outward pressure from fusion

01:44:43.840 | and light and burning,

01:44:46.360 | and an inward pressure of gravity

01:44:49.020 | trying to pull the masses together.

01:44:52.560 | Once it burns itself out, it goes,

01:44:55.100 | and it collapses, and that's a supernova.

01:44:57.840 | When it collapses, all the mass that was there

01:45:00.720 | is in a very much smaller space.

01:45:04.000 | And if a star, if you do the calculations,

01:45:07.480 | if a star is big enough,

01:45:09.580 | that can create a strong enough gravitational field

01:45:12.920 | to make a black hole.

01:45:14.040 | Our sun won't.

01:45:16.400 | It's too small. - Too small.

01:45:19.280 | - And we don't know exactly what,

01:45:22.940 | but it's usually thought that a star has to be

01:45:25.540 | at least three times as big as our sun

01:45:29.820 | to make a black hole, but that's the physical way there.

01:45:32.320 | You can make black holes.

01:45:33.960 | That's the first explanation

01:45:35.960 | that one would give for what we see,

01:45:42.040 | but it's not necessarily true.

01:45:44.320 | We're not sure yet.

01:45:45.540 | - What we see in terms of, for the origins of black holes?

01:45:48.680 | - No, the black holes that we see in gravitational waves.

01:45:52.880 | - But you're also looking for the ones

01:45:54.960 | who are binary solar systems.

01:45:56.800 | - So they're binary systems,

01:45:58.680 | but they could have been made from binary stars,

01:46:01.000 | so there's binary stars around, so that's--

01:46:03.800 | - Gotcha, so the first explanation

01:46:06.280 | is that that's what they are.

01:46:07.680 | - Gotcha.

01:46:08.520 | - Other explanation, but what we see has some puzzles.

01:46:14.920 | This is kind of the way science works, I guess.

01:46:17.560 | We see heavier ones than up to,

01:46:24.280 | we've seen one system that was 140 times

01:46:28.900 | the mass of our own sun.

01:46:32.000 | That's not believed to be possible

01:46:35.040 | with the parent being a big star

01:46:39.240 | because big stars can only be so big,

01:46:41.840 | or they are unstable.

01:46:45.600 | It's just the fact that they live in an environment

01:46:49.280 | that makes them unstable.

01:46:51.320 | So the fact that we see bigger ones,

01:46:53.880 | they maybe come from something else.

01:46:56.080 | It's possible that they were made in a different way

01:47:01.960 | by little ones eating each other up,

01:47:04.480 | or maybe they were made,

01:47:06.400 | or maybe they came with the Big Bang,

01:47:09.120 | what we call primordial,

01:47:11.480 | which means they're really different,

01:47:12.960 | they came from that.

01:47:14.080 | We don't know at this point.

01:47:15.640 | If they came with the Big Bang,

01:47:17.160 | then maybe they account for what we call dark matter

01:47:20.440 | or some of it.

01:47:21.280 | - Hmm, like there was a lot of them,

01:47:23.040 | if they came with, 'cause there's a lot of dark matter.

01:47:26.240 | - Yeah.

01:47:27.480 | - But will gravitational waves give you

01:47:29.960 | any kind of intuition about the origin of these oscillating?

01:47:34.480 | - We think that if we see the distributions,

01:47:37.840 | enough of them,

01:47:38.680 | the distributions of their masses,

01:47:41.000 | the distributions of how they're spinning.

01:47:43.640 | So we can actually measure

01:47:45.360 | when they're going around each other,

01:47:47.360 | whether they're spinning like this or--

01:47:49.960 | - The direction of the spin?

01:47:51.040 | Or no, the orientation.

01:47:52.360 | - Whether the whole system has any wobbles.

01:47:55.760 | - What?

01:47:57.280 | So this is now, okay.

01:48:00.080 | We're doing that.

01:48:01.440 | - And then you're constantly kind of crawling back

01:48:03.760 | and back in time.

01:48:04.600 | - And we're crawling back in time

01:48:06.280 | and seeing how many there are as we go back.

01:48:08.720 | And so do they point back to--

01:48:10.600 | - So you're like, what is that discipline called?

01:48:13.040 | Cartography or something?

01:48:14.080 | You're like mapping the early universe

01:48:18.800 | via the lens of gravitational waves.

01:48:21.960 | - Not yet the early universe,

01:48:23.280 | but at least back in time.

01:48:24.160 | - Earlier, right.

01:48:25.680 | So black holes are this mathematical phenomenon,

01:48:30.680 | but they come about in different ways.

01:48:33.320 | We have a huge black hole

01:48:35.400 | at the center of our galaxy and other galaxies.

01:48:39.080 | Those probably were made some other way.

01:48:40.840 | We don't know when the galaxies themselves

01:48:43.520 | had to do with the formation of the galaxies.

01:48:45.600 | We don't really know.

01:48:47.120 | So the fact that we use the word black hole,

01:48:50.400 | the origin of black holes might be quite different

01:48:52.960 | depending on how they happen.

01:48:56.080 | They just have to in the end have a gravitational field

01:48:58.600 | that will bend everything in.

01:49:00.440 | - How do you feel about black holes as a human being?

01:49:04.040 | There's this thing that's nearly infinitely dense,

01:49:08.080 | doesn't let light escape.

01:49:12.000 | Isn't that kind of terrifying?

01:49:13.400 | Feels like the stuff of nightmares.

01:49:15.760 | - I think it's an opportunity.

01:49:17.960 | - To do what exactly?

01:49:20.400 | (laughing)

01:49:21.360 | - So like the early universe is an opportunity.

01:49:24.960 | If we can study the early universe,

01:49:26.680 | we can learn things like I told you.

01:49:28.480 | And here again, we have an embarrassing situation in physics.

01:49:33.120 | We have two wonderful theories of physics,

01:49:37.120 | one based on quantum mechanics, quantum field theory.

01:49:41.480 | And we can go to a big accelerator like at CERN

01:49:45.320 | and smash particles together

01:49:47.080 | and almost explain anything that happens beautifully

01:49:51.400 | using quantum field theory and quantum mechanics.

01:49:54.800 | Then we have another theory of physics

01:49:56.840 | called general relativity,

01:49:58.120 | which is what we've been talking about most of the time,

01:50:00.680 | which is fantastic at describing things at high velocities,

01:50:05.640 | long distances, and so forth.

01:50:10.280 | So that's not the way it's supposed to be.

01:50:15.280 | We're trying to create a theory of physics,

01:50:17.920 | not two theories of physics.

01:50:20.200 | So we have an embarrassment

01:50:21.640 | that we have two different theories of physics.

01:50:24.520 | People have tried to make a unified theory,

01:50:27.840 | what they call a unified theory.

01:50:29.040 | You've heard those words for decades.

01:50:32.400 | They still haven't.

01:50:33.480 | That's been primarily done theoretically

01:50:37.360 | or people actively do that.

01:50:40.920 | My personal belief is that like much of physics,

01:50:45.880 | we need some clues.

01:50:47.760 | So we need some experimental evidence.

01:50:49.600 | So where is there a place?

01:50:52.280 | If we go to CERN and do those experiments,

01:50:54.520 | gravitational waves or general relativity don't matter.

01:50:57.620 | If we go to study our black holes,

01:51:01.160 | elementary particle physics doesn't matter.

01:51:03.560 | We're studying these huge objects.

01:51:05.440 | So where might we have a place

01:51:07.840 | where both phenomenon have to be satisfied?

01:51:10.960 | An example is black holes.

01:51:12.920 | - Inside black holes.

01:51:13.920 | - Yeah.

01:51:15.060 | So we can't do that today.

01:51:17.000 | But when I think of black hole,

01:51:18.840 | it's a potential treasure chest

01:51:22.440 | of understanding the fundamental problems of physics

01:51:27.440 | and maybe can give us clues

01:51:31.320 | to how we bring the embarrassment

01:51:34.440 | of having two theories of physics together.

01:51:37.680 | That's my own romantic idea.

01:51:39.880 | - What's the worst that could happen?

01:51:41.400 | It's so enticing.

01:51:42.400 | Just go in and look.

01:51:43.920 | Do you think, how far are we away from figuring out

01:51:47.680 | the unified theory of physics,

01:51:50.200 | a theory of everything?

01:51:51.600 | What's your sense?

01:51:52.720 | Who will solve it?

01:51:54.360 | Like what discipline will solve it?

01:51:56.200 | - Yeah.

01:51:57.040 | I think so little progress has been made

01:52:05.240 | without more experimental clues, as I said,

01:52:10.240 | that we're just not able to say that we're close

01:52:16.000 | without some clues.

01:52:20.680 | The most popular theory these days

01:52:25.560 | that might lead to that is called string theory.

01:52:28.640 | - Yeah.

01:52:29.480 | - And the problem with string theory is it works,

01:52:32.880 | it solves a lot of beautiful mathematical problems

01:52:35.840 | we have in physics.

01:52:37.560 | And it's very satisfying theoretically,

01:52:42.560 | but it has almost no predictive,

01:52:49.220 | maybe no predictive ability

01:52:50.960 | because it is a theory that works in 11 dimensions.

01:52:55.960 | We live in a physical world of three space

01:53:00.000 | and one time dimension.

01:53:02.040 | In order to make predictions in our world

01:53:05.920 | with string theory,

01:53:07.520 | you have to somehow get rid of these other seven dimensions.

01:53:11.260 | That's done mathematically

01:53:13.960 | by saying they curl up on each other

01:53:15.760 | on scales that are too small to affect anything here.

01:53:19.840 | But how you do that, and that's okay,

01:53:22.040 | that's an okay argument,

01:53:23.400 | but how you do that is not unique.

01:53:26.140 | So that means if I start with that theory

01:53:29.680 | and I go to our world here,

01:53:31.400 | I can't uniquely go to it.

01:53:33.800 | - Which means it's not predictive.

01:53:35.280 | - It's not predictive.

01:53:36.600 | - And that's actually--

01:53:37.880 | - And that's a killer, that's a killer.

01:53:39.800 | - And string theory is,

01:53:41.240 | it seems like from my outsider's perspective

01:53:43.200 | has lost favor over the years,

01:53:45.080 | perhaps because of this very idea.

01:53:46.760 | - Yeah, it's a lack of predictive power.

01:53:48.280 | I mean, science has to connect to something

01:53:52.080 | where you make predictions as beautiful as it might be.

01:53:56.280 | So I don't think we're close.

01:53:57.800 | I think we need some experimental clues.

01:54:01.840 | It may be that information

01:54:04.680 | on something we don't understand presently at all,

01:54:07.920 | like dark energy, or probably not dark matter,

01:54:11.200 | but dark energy or something might give us some ideas.

01:54:14.520 | But I don't think we're,

01:54:17.120 | I can't envision right now in the short term,

01:54:22.120 | meaning the horizon that we can see

01:54:27.520 | how we're gonna bring these two theories together.

01:54:30.600 | - A kind of two-part question,

01:54:35.000 | maybe just asking the same thing in two different ways.

01:54:38.080 | One question is,

01:54:40.200 | do you have hope that humans will colonize the galaxy,

01:54:45.200 | so expand out, become a multi-planetary species?

01:54:49.720 | Another way of asking that,

01:54:51.200 | from a gravitational and a propulsion perspective,

01:54:54.160 | do you think we'll come up with ways

01:54:55.560 | to travel closer to the speed of light,

01:54:57.160 | or maybe faster than the speed of light,

01:54:59.760 | which would make it a whole heck of a lot easier

01:55:02.400 | to expand out into the universe?

01:55:06.120 | - Yeah.

01:55:06.960 | Well, I think,

01:55:10.680 | that's very futuristic.

01:55:15.640 | I think we're not that far from being able

01:55:17.880 | to make a one-way trip to Mars.

01:55:21.840 | That's then a question of,

01:55:26.760 | whether people are willing to send somebody

01:55:30.560 | on a one-way trip.

01:55:31.640 | - Oh, I think they are.

01:55:33.240 | There's a lot of, the Explorer's burned bright

01:55:36.040 | and with their hearts.

01:55:36.880 | - Yeah, yeah, exactly.

01:55:37.720 | - There's a lot of people willing to die

01:55:38.560 | for the opportunity to explore new territory.

01:55:42.080 | - Yeah, so, you know,

01:55:45.440 | this recent landing on Mars is pretty impressive.

01:55:49.960 | They have a little helicopter that can fly around.

01:55:51.960 | You can imagine,

01:55:54.000 | you can imagine in the not too distant future

01:55:56.600 | that you could have,

01:55:57.800 | I don't think civilizations colonizing,

01:56:01.080 | I can envision,

01:56:02.240 | but I can envision something more like the South Pole.

01:56:06.360 | We haven't colonized Antarctica,

01:56:09.080 | 'cause it's all ice and cold and so forth,

01:56:12.960 | but we have stations.

01:56:16.360 | So we have a station that's self-sustaining

01:56:18.600 | at the South Pole.

01:56:19.800 | I've been there.

01:56:21.160 | It has--

01:56:22.000 | - Wow, really?

01:56:22.840 | - Yeah.

01:56:23.840 | - What's that like?

01:56:24.920 | 'Cause there's parallels there to go to Mars.

01:56:29.960 | - It's fantastic.

01:56:31.920 | - What's the journey like?

01:56:33.440 | - The journey involves going,

01:56:36.080 | the South Pole station is run in the US

01:56:39.800 | by the National Science Foundation.

01:56:43.040 | I went because I was on the National Science Board

01:56:46.520 | that runs the National Science Foundation.

01:56:49.520 | And so you get a VIP trip if you're healthy enough

01:56:52.440 | to the South Pole to see it,

01:56:55.040 | which I took.

01:56:57.200 | You fly from the US to Australia,

01:57:00.640 | to Christ Church in Australia, Southern Australia.

01:57:05.640 | And from there you fly to McMurdo Station,

01:57:11.240 | which is on the coast.

01:57:12.480 | And it's the station with about a thousand people

01:57:15.720 | right on the coast of Antarctica.

01:57:17.440 | It's about a seven or eight hour flight,

01:57:21.560 | and they can't predict the weather.

01:57:23.040 | So when I flew from Christ Church to McMurdo Station,

01:57:28.040 | they tell you in advance,

01:57:29.720 | you do it in a military aircraft,

01:57:32.400 | they tell you in advance

01:57:33.720 | that they can't predict whether they can land

01:57:36.240 | 'cause they have to land on--

01:57:37.720 | - That's reassuring.

01:57:39.440 | - Yeah, and so about halfway the pilot got on and said,

01:57:44.440 | "Sorry, this is a," they call it a boomerang flight.

01:57:48.360 | You know, a boomerang goes out and comes back.

01:57:50.920 | So we had to stay a little while in Christ Church,

01:57:53.760 | but then we eventually went to McMurdo Station

01:57:56.980 | and then flew to the South Pole.

01:58:00.360 | The South Pole itself is,

01:58:04.140 | when I was there, it was minus 51 degrees.

01:58:07.760 | That was summer.

01:58:08.700 | It has zero humidity.

01:58:14.600 | And it's about,

01:58:21.800 | 11,000 feet altitude

01:58:23.640 | because it's never warm enough for anything to melt.

01:58:28.120 | So it doesn't snow very much,

01:58:29.600 | but it's about 11,000 feet of snowpack.

01:58:33.200 | So you land in a place that's high altitude,

01:58:36.040 | cold as could be,

01:58:39.080 | and incredibly dry,

01:58:41.920 | which means you have a physical adjustment.

01:58:46.480 | The place itself is fantastic.

01:58:51.480 | They have this great station there.

01:58:54.680 | They do astronomy at the South Pole.

01:58:56.680 | - Nature-wise, is it beautiful?

01:58:58.320 | What's the experience like?

01:59:01.400 | Or is it like visiting any town?

01:59:03.000 | - No, it's very small.

01:59:05.000 | There's only less than 100 people there

01:59:08.160 | even when I was there.

01:59:09.440 | There were about 50 or 60 there,

01:59:13.600 | and in the winter there's less, half of that.

01:59:16.260 | Their winter.

01:59:17.100 | - It gets real cold.

01:59:19.280 | - It gets really cold, yeah.

01:59:20.940 | But it's a station.

01:59:25.440 | I mean, we haven't gone beyond that.

01:59:30.800 | On the coast of Antarctica,

01:59:32.480 | they have greenhouses and they're self-sustaining

01:59:35.480 | in McMurdo Station,

01:59:36.640 | but we haven't really settled more

01:59:39.400 | than that kind of thing in Antarctica,

01:59:42.320 | which is a big country,

01:59:47.320 | or a big plot, a big piece of land.

01:59:52.460 | So I can't envision kind of colonizing

01:59:58.220 | at people living so much,

02:00:00.140 | as much as I can see the equivalent

02:00:04.740 | of the South Pole Station.

02:00:06.180 | - Well, in the computing world,

02:00:07.780 | there's an idea of backing up your data,

02:00:11.020 | and then you wanna do off-site backup

02:00:13.040 | to make sure that if your whole house burns down,

02:00:18.420 | that you can have a backup off-site of the data.

02:00:21.220 | I think the difference between Antarctica and Mars

02:00:25.380 | is Mars is an off-site backup.

02:00:27.560 | That if we have nuclear war,

02:00:29.120 | whatever the heck might happen here on Earth,

02:00:31.560 | it'd be nice to have a backup elsewhere.

02:00:33.640 | And it'd be nice to have a large enough colony

02:00:35.720 | where we sent a variety of people,

02:00:38.120 | except a few silly astronauts in suits,

02:00:43.120 | have an actual vibrant,

02:00:45.140 | get a few musicians and artists up there,

02:00:49.120 | get a few, maybe one or two computer scientists.

02:00:52.420 | Those are essential.

02:00:53.720 | Maybe even a physicist, but I'm not sure.

02:00:56.160 | - Yeah, maybe not.

02:00:57.440 | So that comes back to something you talked about earlier,

02:01:00.520 | which is the Fermi's paradox,

02:01:03.640 | because you talked about having to escape.

02:01:07.640 | And so the missing, one number you don't know how to use

02:01:11.720 | in Fermi's calculation, or Drake, who's done it better,

02:01:15.160 | is how long do civilizations last?

02:01:17.360 | - Yeah.

02:01:18.200 | - We've barely gotten to where we can communicate

02:01:22.860 | with electricity and magnetism,

02:01:25.200 | and maybe we'll wipe ourselves out pretty soon.

02:01:28.320 | - Are you hopeful in general?

02:01:29.720 | Like you think we've got another couple hundred years

02:01:31.560 | at least?

02:01:32.400 | Are you worried?

02:01:35.440 | - Well, no, I'm hopeful,

02:01:39.280 | but I don't know if I'm hopeful in the long term.

02:01:42.440 | If you say,

02:01:43.280 | are we able to go for another couple thousand years?

02:01:51.720 | I'm not sure.

02:01:52.680 | I think we have where we started,

02:01:56.480 | the fact that we can do things

02:01:58.080 | that don't allow us to kind of keep going,

02:02:00.780 | or there can be, whether it ends up being a virus

02:02:04.040 | that we create, or it ends up being the equivalent

02:02:07.040 | of nuclear war, or something else.

02:02:09.680 | It's not clear that we can control things well enough.

02:02:12.980 | - So speaking of really cold conditions,

02:02:15.520 | and not being hopeful, and eventual suffering,

02:02:20.080 | and destruction of the human species,

02:02:22.360 | let me ask you about Russian literature.

02:02:24.560 | You mentioned, how's that for a transition?

02:02:27.120 | I'm doing my best here.

02:02:28.320 | You mentioned that you used to love literature

02:02:31.520 | when you were younger, and you were even,

02:02:34.040 | or hoping to be a writer yourself,

02:02:36.600 | that was the motivation.

02:02:38.240 | And some of the books I've seen that you listed

02:02:41.280 | that were inspiring to you was from Russian literature,

02:02:46.280 | like I think Tolstoy, Dostoevsky, Solzhenitsyn.

02:02:50.880 | - Yeah, right.

02:02:52.280 | - Maybe in general you can speak to your fascination

02:02:55.000 | with Russian literature, or in general,

02:02:57.240 | what you picked up from those.

02:02:59.960 | - Not surprised you picked up on the Russian literature.

02:03:02.360 | - I'm sorry. - With your background,

02:03:03.720 | but that's okay.

02:03:04.880 | (both laughing)

02:03:06.920 | When I--

02:03:08.240 | - You should be surprised I didn't make

02:03:09.720 | the entire conversation about this.

02:03:11.400 | That's the real surprise.

02:03:13.000 | - I didn't really become a physicist,

02:03:20.880 | or want to go in science, until I started college.

02:03:24.160 | So when I was younger, I was good at math,

02:03:27.360 | and that kind of stuff, but I didn't really,

02:03:29.720 | I came from a family, nobody went to college,

02:03:32.120 | and I didn't have any mentors.

02:03:34.580 | But I liked to read when I was really young.

02:03:38.240 | And so when I was very young, I read,

02:03:41.200 | I always carried around a pocketbook and read it.

02:03:44.840 | And my mother read these mystery stories,

02:03:48.200 | and I got bored by those eventually.

02:03:49.800 | And then I discovered real literature,

02:03:51.640 | I don't know at what age, but about 12 or 13.

02:03:55.320 | And so then I started reading good literature,

02:03:58.920 | there's nothing better than Russian literature, of course.

02:04:02.160 | - Thank you.

02:04:03.000 | I heard you. - Reading good literature.

02:04:05.360 | So I read quite a bit of Russian literature at that time.

02:04:10.360 | And so you asked me about, well, I don't know,

02:04:19.880 | I'll say a few words, Dostoevsky.

02:04:22.080 | So what about Dostoevsky?

02:04:23.920 | For me, Dostoevsky was important in,

02:04:28.920 | I mean, I've read a lot of literature

02:04:33.320 | 'cause it's kind of the other thing I do with my life.

02:04:35.840 | And he made two incredible,

02:04:39.080 | and in addition to his own literature,

02:04:41.560 | he influenced literature tremendously by having,

02:04:45.300 | I don't know how to pronounce, polyphony.

02:04:49.180 | So he's the first real serious author

02:04:52.160 | that had multiple narrators.

02:04:54.700 | And he absolutely is the first.

02:05:00.360 | And he also was the first,

02:05:02.240 | he began existential literature.

02:05:07.360 | So the most important book that I've read in the last year

02:05:11.960 | when I've been forced to be isolated

02:05:14.520 | was existential literature.

02:05:17.160 | I decided to reread "Camus, The Plague."

02:05:21.560 | - Oh yeah, that's a great book.

02:05:23.800 | - It's a great book, and it's right now to read it.

02:05:26.040 | It's fantastic. - I think that book

02:05:27.180 | is about love, actually.

02:05:29.320 | Love for humanity, for all men.

02:05:32.360 | - It has all the, if you haven't read it in recent years,

02:05:36.120 | I had read it before, of course,

02:05:37.580 | but to read it during this, 'cause it's about a plague,

02:05:41.280 | so it's really fantastic to read now.

02:05:43.600 | But that reminds me of, he was a great existentialist,

02:05:47.440 | but the beginning of existential literature was Dostoevsky.

02:05:50.960 | - Dostoevsky, yeah.

02:05:51.840 | - So in addition to his own great novels,

02:05:54.520 | he had a tremendous impact on literature.

02:05:59.520 | - And there's also, for Dostoevsky,

02:06:02.040 | unlike most other existentialists,

02:06:04.660 | he was, at least in part, religious.

02:06:07.320 | I mean, religiosity permeated his idea.

02:06:11.280 | I mean, one of my favorite books of his is "The Idiot,"

02:06:13.560 | which is a Christ-like figure in there.

02:06:16.840 | - Well, there's Prince Mishkin, is that his name?

02:06:19.000 | - Prince Mishkin, yeah.

02:06:19.840 | - Yeah, Mishkin.

02:06:20.680 | - Yeah, Mishkin.

02:06:21.500 | - Yeah.

02:06:22.340 | - That's one thing about,

02:06:24.040 | so you read it in English, I presume?

02:06:25.920 | - Yeah, yeah.

02:06:26.760 | - Yeah, so that's the names,

02:06:28.100 | that's what gets a lot of people,

02:06:29.240 | is there's so many names, so hard to pronounce,

02:06:31.160 | you have to remember all of them.

02:06:33.040 | It's like, you have the same problem.

02:06:35.440 | - But he was a great character, so that, yeah.

02:06:38.320 | - I kind of, I have a connection with him,

02:06:42.840 | 'cause I often, the title of the book, "The Idiot,"

02:06:47.280 | is, I kind of, I often call myself an idiot,

02:06:50.760 | 'cause that's how I feel, I feel so naive about this world,

02:06:53.760 | and I'm not sure why that is,

02:06:57.780 | maybe it's genetic or so on,

02:06:59.720 | but I have a connection,

02:07:03.440 | a spiritual connection to that character.

02:07:05.120 | - To Mishkin.

02:07:05.960 | - To Mishkin, yeah, that you're just--

02:07:08.320 | - But he was far from an idiot.

02:07:10.120 | - No, in some sense, in some sense.

02:07:14.520 | But in another sense, maybe not of this world.

02:07:17.360 | - In another sense, he was, yeah.

02:07:19.160 | I mean, he was a bumbler, a bunker.

02:07:21.240 | - But you also mentioned Solzhenitsyn,

02:07:25.520 | very interesting, did--

02:07:27.840 | - And he always confused me, of course,

02:07:29.880 | he was really, really important

02:07:34.000 | in writing about Stalin,

02:07:38.000 | and first getting in trouble,

02:07:42.400 | and then later he wrote about Stalin in a way,

02:07:47.400 | I forget what the book was,

02:07:51.360 | in a way that was very critical of Lenin.

02:07:54.400 | - Yeah, he's evolved through the years,

02:07:58.320 | and he actually showed support for Putin eventually.

02:08:00.600 | It was a very interesting transition he took,

02:08:05.200 | no, journey he took through thinking about Russia

02:08:09.080 | and the Soviet Union,

02:08:11.160 | but I think what I get from him is basic,

02:08:16.160 | it's like Viktor Frankl has this "Man's Search for Meaning,"

02:08:19.400 | I have a similar kind of sense

02:08:20.880 | of the cruelty of human nature,

02:08:27.320 | cruelty of indifference,

02:08:29.360 | but also the ability to find happiness

02:08:31.400 | in the small joys of life,

02:08:33.720 | that's something, there's nothing like a prison camp

02:08:37.320 | that makes you realize you could still be happy

02:08:40.280 | with a very, very little.

02:08:41.720 | - Well, yeah, his description of how to make,

02:08:45.880 | how to go through a day and actually enjoy it

02:08:49.240 | in a prison camp is pretty amazing.

02:08:51.920 | - Yeah.

02:08:52.760 | - Oh, and some prison camp,

02:08:53.760 | I mean, it's the worst of the worst.

02:08:55.440 | - The worst of the worst.

02:08:56.520 | And also just, you do think about

02:08:59.760 | the role of authoritarian states,

02:09:02.840 | in hopeful, idealistic systems

02:09:09.120 | somehow leading to the suffering of millions.

02:09:12.000 | And I, you know, this might be arguable,

02:09:15.920 | but I think a lot of people believe that Stalin,

02:09:20.460 | I think genuinely believed that he's doing good

02:09:22.580 | for the world, and he wasn't.

02:09:25.920 | This is a very valuable lesson that

02:09:27.920 | even evil people think they're doing good.

02:09:32.620 | Otherwise it's too difficult to do the evil.

02:09:36.440 | The best way to do evil is to believe,

02:09:38.520 | frame it in a way like you're doing good.

02:09:40.800 | And then this is a very clear picture of that,

02:09:44.600 | which is the Gulags.

02:09:46.340 | And Solzhenitsyn is one of the best people to reveal that.

02:09:51.000 | - Yeah.

02:09:51.840 | The most recent thing I read, it isn't actually fiction,

02:09:56.680 | was the woman, I can't remember her name,

02:09:59.400 | who got the Nobel Prize about within the last five years.

02:10:03.840 | I don't know whether she's Ukrainian or Russian,

02:10:06.260 | but their interviews, have you read that?

02:10:09.920 | - Interview of Ukrainian survivors of--

02:10:12.920 | - Well, I think she may be originally Ukrainian.

02:10:16.040 | The book's written in Russian and translated into English,

02:10:19.300 | and many of the interviews are in Moscow and places.

02:10:23.000 | But she won the Nobel Prize

02:10:24.400 | within the last five years or so.

02:10:26.720 | But what's interesting is that

02:10:28.760 | these are people of all different ages,

02:10:32.740 | all different occupations and so forth,

02:10:36.480 | and they're reflecting on their reaction

02:10:39.800 | to basically the present Soviet system,

02:10:43.940 | the system they live with before.

02:10:45.480 | There's a lot of looking back by a lot of them with,

02:10:50.180 | well, it being much better before.

02:10:56.120 | - Yeah.

02:11:00.020 | I don't know what,

02:11:02.720 | in America, we think we know the right answer,

02:11:05.260 | what it means to build a better world.

02:11:08.580 | I'm not so sure.

02:11:10.200 | I think we're all just trying to figure it out.

02:11:12.520 | - Yeah, there's-- - We're doing our best.

02:11:14.560 | - I think you're right.

02:11:15.720 | - Is there advice you can give to young people today,

02:11:20.740 | besides reading Russian literature at a young age,

02:11:24.760 | about how to find their way in life,

02:11:27.760 | how to find success in career or just life in general?

02:11:31.840 | - Uh, I just,

02:11:36.840 | my own belief, it may not be very deep,

02:11:41.240 | but I believe it.

02:11:42.080 | I think you should follow your dreams,

02:11:43.920 | and you should have dreams,

02:11:45.880 | and follow your dreams if you can,

02:11:47.960 | to the extent that you can.

02:11:49.920 | And we spend a lot of our time

02:11:52.840 | doing something with ourselves,

02:11:54.760 | in my case, physics, in your case, I don't know,

02:11:57.280 | whatever it is, machine learning and this.

02:11:59.960 | (chuckles)

02:12:02.220 | We should, yeah, I should have fun.

02:12:06.400 | - What was, wait, wait, wait, wait,

02:12:07.960 | follow your dreams, what dream did you have?

02:12:10.960 | 'Cause there's-- - Well, originally I was--

02:12:14.600 | - 'Cause you didn't follow your dream.

02:12:16.120 | I thought you were supposed to be a writer.

02:12:16.960 | - Well, I changed along the way.

02:12:17.960 | I was gonna be, but I changed.

02:12:20.320 | - What happened? - That was what happened?

02:12:22.920 | Oh, I read, I decided to take

02:12:26.920 | the most serious literature course in my high school,

02:12:30.360 | which was a mistake.

02:12:31.320 | I'd probably be a second-rate writer now.

02:12:33.880 | - Could be a Nobel Prize-winning writer.

02:12:37.080 | - And the book that we read,

02:12:42.080 | even though I had read Russian novels,

02:12:47.460 | I was 15, I think, cured me from being a novelist.

02:12:52.460 | - Destroyed your dream? - Yes.

02:12:54.640 | - Cured you, okay, what was the book?

02:12:56.720 | - "Moby Dick." - Okay.

02:12:59.240 | - So why "Moby Dick?" - Yeah, why?

02:13:01.440 | - And so I've read it since, and it's a great novel.

02:13:06.160 | Maybe it's as good as the Russian novels.

02:13:07.760 | - I've never made it through.

02:13:08.680 | I, well, it was too boring, it was too long.

02:13:11.040 | - Okay, your words are gonna mesh with what I say.

02:13:14.160 | - Excellent. - And you may have

02:13:15.400 | the same problem at a older age.

02:13:17.800 | - Maybe that's why I'm not a writer. (laughs)

02:13:19.440 | - It may be, so the problem is, "Moby Dick" is,

02:13:24.080 | what I remember was there was a chapter

02:13:27.000 | that was maybe 100 pages long,

02:13:29.560 | all describing this, why there was Ahab and the white whale,

02:13:33.920 | and it was the battle between Ahab

02:13:35.880 | with his wooden peg leg and the white whale.

02:13:39.400 | And there was a chapter that was 100 pages long,

02:13:41.840 | in my memory, I don't know how long it really was,

02:13:44.340 | that described in detail the great white whale

02:13:48.920 | and what he was doing and what his fins were like

02:13:51.160 | and this and that, and it was so incredibly boring,

02:13:54.880 | the word you used, that I thought,

02:13:57.360 | if this is great literature, screw it.

02:14:00.320 | - Oh, fascinating. - Okay?

02:14:02.400 | Now, why did I have a problem?

02:14:04.200 | I know now in reflection, because I still read a lot,

02:14:07.280 | and I read that novel, you know,

02:14:11.960 | after I was 30 or 40 years old,

02:14:16.960 | and the problem was simple, I diagnosed what the problem was.

02:14:20.520 | I, that novel, in contrast to the Russian novels,

02:14:25.400 | which are very realistic and, you know, point of view,

02:14:29.040 | is one huge metaphor.

02:14:31.560 | - Oh, yeah.

02:14:32.900 | - At 15 years old, I probably didn't know the word,

02:14:35.880 | and I certainly didn't know the meaning of a metaphor.

02:14:38.160 | - Yeah, like, why do I care about a fish?

02:14:40.040 | Why are you telling me all about this fish?

02:14:41.760 | - Exactly, it's one big metaphor,

02:14:44.040 | so reading it later as a metaphor, I could really enjoy it.

02:14:48.240 | But the teacher gave me the wrong book,

02:14:50.020 | or maybe it was the right book,

02:14:51.120 | 'cause I went into physics, and so,

02:14:53.000 | but it was truly, I think, I may oversimplify,

02:14:58.320 | but it was really that I was too young to read that book,

02:15:00.600 | because, not too young to read the Russian novels,

02:15:03.560 | interestingly, but too young to read that,

02:15:06.120 | because I probably didn't even know the word,

02:15:08.160 | and I certainly didn't understand it as a metaphor.

02:15:11.400 | - Well, in terms of fish,

02:15:12.240 | I recommend people read "Old Man and the Sea,"

02:15:14.400 | much shorter, much better, still a metaphor, though, so,

02:15:17.480 | but you can read it just as a story

02:15:19.800 | about a guy catching a fish, and it's still fun to read.

02:15:24.180 | I had the same experience as you, not with Moby Dick,

02:15:30.300 | but later in college, I took a course on James Joyce.

02:15:32.980 | Don't ask me why.

02:15:34.580 | I was majoring in computer science,

02:15:36.060 | I took a course on James Joyce,

02:15:37.940 | and I was kept being told that he is widely considered,

02:15:42.500 | by many considered, to be the greatest literary writer

02:15:46.800 | of the 20th century.

02:15:48.860 | And I kept reading, I think, so his short story is,

02:15:51.840 | "The Dead," I think it's called, it was very good.

02:15:54.060 | Well, not very good, but pretty good.

02:15:56.580 | And then, "Ulysses." - It's actually very good.

02:15:58.300 | - It is very good.

02:15:59.140 | I mean, "The Dead," the final story,

02:16:00.900 | still rings with me today.

02:16:02.380 | But then, "Ulysses" was, I got through "Ulysses"

02:16:06.260 | with the help of some Cliff Notes and so on, but,

02:16:08.660 | and so I did "Ulysses" and then "Finnegan's Wake."

02:16:11.340 | The moment I started "Finnegan's Wake,"

02:16:13.740 | I said, "This is stupid.

02:16:17.420 | That's when I went full into, I don't know,

02:16:21.660 | that's when I went full Kafka, Bukowski,

02:16:24.780 | like people who just talk about the darkness

02:16:27.340 | of the human condition in the fewest words possible,

02:16:30.680 | and without any of the music of language.

02:16:35.680 | So it was a turning point as well.

02:16:38.580 | I wonder when is the right time

02:16:40.820 | to appreciate the beauty of language.

02:16:45.060 | Like even Shakespeare, I was very much off-put

02:16:47.220 | by Shakespeare in high school,

02:16:48.700 | and only later started to appreciate its value

02:16:52.020 | in the same way.

02:16:52.860 | Let me ask you a ridiculous question.

02:16:55.800 | - Okay.

02:16:58.140 | - I mean, because you've read Rush Literature,

02:17:02.820 | let me ask this one last question.

02:17:05.800 | I might be lying, there might be a couple more,

02:17:09.540 | but what do you think is the meaning of this whole thing?

02:17:12.340 | You got a Nobel Prize for looking out

02:17:16.660 | into the, trying to reach back

02:17:18.580 | into the beginning of the universe,

02:17:20.660 | listening to the gravitational waves,

02:17:22.780 | but that still doesn't answer the why.

02:17:26.380 | Why are we here?

02:17:29.280 | Beyond just the matter and antimatter.

02:17:32.440 | The philosophical question.

02:17:35.340 | - The philosophical question about the meaning of life

02:17:39.340 | I'm probably not really good at.

02:17:41.560 | I think that

02:17:44.340 | the

02:17:45.180 | the individual meaning,

02:17:50.200 | I would say rather simplistically,

02:17:55.140 | is whether you've made a difference,

02:17:59.300 | a positive difference, I'd say,

02:18:00.900 | for anything besides yourself.

02:18:02.880 | Meaning you could have been important to other people,

02:18:09.180 | or you could have discovered gravitational waves

02:18:11.860 | that matters to other people or something,

02:18:13.580 | but something beyond just existing on the Earth

02:18:17.340 | as an individual.

02:18:18.420 | So your life has meaning if you have affected

02:18:23.100 | either knowledge or people or something beyond yourself.

02:18:29.900 | - Do you-- - That's a simplistic

02:18:33.220 | statement, but it's about as good as I can have.

02:18:36.220 | - That may, in all of its simplicity, it may be very true.

02:18:42.380 | Do you think about,

02:18:43.600 | does it make you sad that this ride ends?

02:18:47.900 | Do you think about your mortality?

02:18:49.660 | - Yeah.

02:18:51.640 | - Are you afraid of it?

02:18:54.100 | - I'm not exactly afraid of it, but saddened by it.

02:18:59.100 | And

02:18:59.920 | you know, I'm old enough to know that

02:19:04.780 | I've lived most of my life,

02:19:08.180 | and

02:19:10.780 | I enjoy being alive.

02:19:12.820 | I can imagine being sick and not wanting to be alive,

02:19:15.500 | but I'm not.

02:19:16.420 | And so

02:19:18.140 | I'm--

02:19:20.940 | - It's been a good ride.

02:19:22.940 | - Yeah, and I'm not happy to see it come to an end.

02:19:26.180 | I'd like to see it prolong.

02:19:27.980 | But

02:19:28.820 | I don't,

02:19:31.060 | I don't fear the dying itself,

02:19:36.980 | or that kind of thing.

02:19:38.260 | It's more I'd like to prolong

02:19:40.740 | what is, I think, a good life

02:19:45.260 | that I'm living and still living.

02:19:48.060 | - That's kind of,

02:19:49.160 | it's sad to think that the fineness of it

02:19:53.740 | is the thing that makes it special.

02:19:57.820 | And also sad to,

02:20:02.480 | to me at least, it's kind of,

02:20:06.420 | I don't think I'm using too strong of a word,

02:20:08.260 | but it's kind of terrifying, the uncertainty of it.

02:20:10.820 | The mystery of it, you know.

02:20:14.660 | - The mystery of death.

02:20:15.820 | - The mystery of it, yeah, of death.

02:20:18.220 | When we're talking about the mystery of black holes,

02:20:20.000 | that's somehow distant, that's somehow out there.

02:20:22.460 | And the mystery of our own--

02:20:24.620 | - But even life, the mystery of consciousness,

02:20:27.580 | I find so hard to deal with too.

02:20:31.020 | I mean, it's not as painful.

02:20:32.860 | I mean, we're conscious, but the whole magic of life,

02:20:36.700 | we can understand, but consciousness,

02:20:38.700 | where we can actually think and so forth, it's pretty--

02:20:43.460 | - It seems like such a beautiful gift

02:20:45.100 | that it really sucks that we get to let go of it,

02:20:48.440 | we have to let go of it.

02:20:49.980 | What do you hope your legacy is?

02:20:51.980 | As I'm sure they will.

02:20:53.620 | Aliens, when they visit,

02:20:54.740 | and humans have destroyed all of human civilization.

02:20:58.220 | Aliens read about you in an encyclopedia

02:21:00.580 | that we'll leave behind.

02:21:02.140 | What do you hope it says?

02:21:03.740 | - Well, I would hope they,

02:21:06.100 | to the extent that they evaluated me,

02:21:10.780 | felt that I helped move science forward

02:21:13.940 | as a tangible contribution,

02:21:17.140 | and that I served as a good role model

02:21:21.060 | for how humans should live their lives.

02:21:24.260 | - And were part of creating

02:21:27.340 | one of the most incredible things humans have ever created.

02:21:32.340 | - So yes, there's the science,

02:21:33.940 | that's the Fermi thing, right?

02:21:35.680 | - And the instrument, I guess.

02:21:38.220 | - And the instrument.

02:21:39.060 | The instrument is a magical creation,

02:21:41.940 | not just by a human, by a collection of humans.

02:21:44.980 | The collaboration is,

02:21:47.740 | that's humanity at its best.

02:21:53.140 | I do hope we last quite a bit longer,

02:21:59.340 | but if we don't, this is a good thing to remember humans by.

02:22:04.340 | At least they built that thing.

02:22:06.420 | That's pretty impressive.

02:22:08.580 | Barry, this was an amazing conversation.

02:22:10.100 | Thank you so much for wasting your time

02:22:12.100 | in explaining so many things so well.

02:22:14.420 | I appreciate your time today.

02:22:15.740 | - Thank you.

02:22:16.580 | - Thanks for listening to this conversation

02:22:19.860 | with Barry Barish.

02:22:21.260 | To support this podcast,

02:22:22.660 | please check out our sponsors in the description.

02:22:26.060 | And now, let me leave you with some words

02:22:28.180 | from Werner Heisenberg, a theoretical physicist

02:22:31.540 | and one of the key pioneers of quantum mechanics.

02:22:34.440 | "Not only is the universe stranger than we think,

02:22:39.500 | "it is stranger than we can think."

02:22:42.420 | Thank you for listening and hope to see you next time.

02:22:46.500 | (upbeat music)

02:22:49.080 | (upbeat music)

02:22:51.660 | [BLANK_AUDIO]

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

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