#305 – Martin Rees: Black Holes, Alien Life, Dark Matter, and the Big Bang

Lord Martin Rees is a cosmologist and astrophysicist at Cambridge University and co-founder of the Centre for the Study of Existential Risk. Please support this podcast by checking out our sponsors: – Lambda: https://lambdalabs.com/lex – InsideTracker: https://insidetracker.com/lex to get 20% off – Indeed: https://indeed.com/lex to get $75 credit – ExpressVPN: https://expressvpn.com/lexpod and use code LexPod to get 3 months free – Onnit: https://lexfridman.com/onnit to get up to 10% off EPISODE LINKS: Martin’s Twitter: https://twitter.com/lordmartinrees Martin’s Website: https://www.martinrees.uk Martin’s Books: If Science is to Save Us: https://amzn.to/3yXRqsc The End of Astronauts: https://amzn.to/3B604ro On the Future: https://amzn.to/3OlzLjB PODCAST INFO: Podcast website: https://lexfridman.com/podcast Apple Podcasts: https://apple.co/2lwqZIr Spotify: https://spoti.fi/2nEwCF8 RSS: https://lexfridman.com/feed/podcast/ YouTube Full Episodes: https://youtube.com/lexfridman YouTube Clips: https://youtube.com/lexclips SUPPORT & CONNECT: – Check out the sponsors above, it’s the best way to support this podcast – Support on Patreon: https://www.patreon.com/lexfridman – Twitter: https://twitter.com/lexfridman – Instagram: https://www.instagram.com/lexfridman – LinkedIn: https://www.linkedin.com/in/lexfridman – Facebook: https://www.facebook.com/lexfridman – Medium: https://medium.com/@lexfridman OUTLINE: Here’s the timestamps for the episode. On some podcast players you should be able to click the timestamp to jump to that time. (00:00) – Introduction (06:39) – Understanding the universe (15:09) – Human limitations and AI (24:05) – Dark matter (31:25) – Vast universe (39:07) – Alien life (52:59) – Space exploration (1:17:22) – Future technology (1:28:44) – Newton and Einstein (1:32:46) – Black holes (1:46:27) – Cosmological threats (2:13:31) – Advice for young people (2:16:02) – Mortality

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Lex Fridman?

  The following is a conversation with Lord Martin Rees, emeritus professor of cosmology and astrophysics at Cambridge University and co-founder of the Center for the Study of Existential Risk. And now, a quick few second mention of each sponsor. Check them out in the description. It's the best way to support this podcast. We've got Lambda for deep learning, InsideTracker for longevity, Indeed for hiring, ExpressVPN for privacy, and Omnit for supplements. Choose wisely, my friends. And now, I want to the full ad reads. As always, no ads in the middle. I try to make this interesting, but if you skip them, please still check out our sponsors. I enjoy their stuff. Maybe you will too. This show is brought to you by Lambda. Computers, workstations, laptops, servers, cloud compute, all for deep learning.

• 0:45Lex Fridman?

  I love Lambda. I won't stop sharing how much I love these systems. They just make it super simple for you to do deep learning. They configure everything for you. I think they have Windows systems, but if you know what's good for you, you're gonna go Linux. Everything works. PyTorch, TensorFlow, everything is set up, the full stack. It just works and it's super powerful machines. So the laptop, obviously, is really impressive because it can be on the go. I'm going to be using it for more mobile robotics, both training. It's really important to say it's powerful enough to do training. But in general, it's just an incredible company that does both cloud and what's the opposite of cloud, offline computing systems, plug and play access to very powerful computation, specialized for machine learning. So you've got all the GPUs you can possibly use. There you go. That's poetry.

• 1:30Lex Fridman?

  So it's good both for individual researchers and huge companies. What else can I say? You can check them out at lambdalabs.com/lex. I just think it's great to support what they're doing for the machine learning community, making it easy, what they're doing for companies that are interested in doing machine learning, just making it easy, making it classy and sexy. Love what they're doing. Glad there's people like that out there. This show is also brought to you by InsideTracker, a service I use to track biological data. They have a bunch of plans, most of which include a blood test. It gives you a lot of information they can use to make decisions about your health. They have algorithms, machine learning algorithms, that analyze that data. That includes your blood data, DNA data, and fitness tracker data that comes from your body.

• 2:13Lex Fridman?

  Right? This is very specific to your body and gives you a clear picture of what you need to do. This is obviously what should be done in the 21st century. Combined with my conversation with Demis Hassabis from Deep Mind about the future of sort of science, of biological applications of machine learning, medical applications of machine learning. It's so, so, so exciting. And being able to make these large-scale machine learning systems that give you advice based on your specific individual data, that's really, really exciting. Just even outside of it being beneficial to your life, I think you should also consider supporting them for this big mission. It's gonna help a lot of people. So go to insat

• 2:56Lex Fridman?

  tracker dot com slash Lex and for a limited time, you get special savings for being a listener. This show is also brought to you by Indeed, a hiring website. I've used them as part of many hiring efforts I've done for the teams I've led, especially engineering teams, but all kinds of teams. They have tools like Indeed Instant Match, giving you quality candidates with resumes that indeed fit your job description immediately. I'm actually currently looking for translators and overdubbers to help me with some of the projects I'm doing here in Ukrainian and Russian. I speak the languages, but I want to have like a strong team that brings out the best from these people. And it's all a fascinating new challenge and I want to hire the best people in the world to help me. I want to

• 3:39Lex Fridman?

  connect the world and language is a barrier that separates us. And so I'm looking to hire people to help me and I'll probably tweet about it, all that kind of stuff. Anyway, Indeed is a tool I'll definitely use to help me find great folks. For only a limited time, Indeed has a special offer for the listeners of this podcast. Check it out at indeed.com slash Lex. This show is also brought to you by ExpressVPN. You should know, friends, that the ISPs, the internet service providers can still track you even if you use basic protection like incognito mode on Chrome. They can still get your data. As I travel...

• 4:22Lex Fridman?

  Whether it's watching shows on Netflix, or just protecting your privacy on the internet from all the ISPs and everybody who wants to collect your data, or just in general, as you travel to different parts of the world and you want to read different kinds of news. I mean, VPN is essential. And my favorite VPN has always been, for many, many years, ExpressVPN, with a big sexy button that just works super fast, works on any device, any operating system, at least any that I know of, including Linux, my favorite operating system. You can go check them out at expressvpn.com/lexpod for an extra three months free. I've been using it for many years. Why don't you join me, friend, in this journey that's protected,

• 5:07Lex Fridman?

  at least in part, with a good VPN? This episode is also brought to you by Onnit, a nutrition supplement and fitness company. They make AlphaBrain. Perhaps you've heard of it. I don't take it every day, but I do take it often when I have an especially serious, kind of difficult, deep work session, when I'm preparing for certain difficult conversations. I mean, this is particularly for engineering. If I'm unsure how I'm going to solve the different design parts, especially early on in the design stage of the project. But I also think of conversations as a kind of design. And so in trying to sort of visualize the big picture of a conversation and then zooming into very specific parts of a conversation, I have to really think hard.

• 5:52Lex Fridman?

  And for that, AlphaBrain can be a big boost. So I'll take it in those cases. It helps clear the mind, helps maintain focus, sleep, and I gotta say, power naps, of course, are really essential. But on top of that, something like AlphaBrain really helps. You can check them out at lexfridman.com/onnit to get a special discount. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Martin Rees.

• 6:39Lex Fridman?

  In your 2020 Scientific American article, you write that, quote, "Today, we know that the universe is far bigger and stranger than anyone suspected." So what do you think are the strangest, maybe the most beautiful, or maybe even the most terrifying, things lurking out there in the cosmos?

• 6:57Speaker 01

  Well, of course, we're still groping for any detailed understanding of the remote parts of the universe. But of course, what we've learnt in the last few decades is really two things. First, we've understood that the universe had an origin about 13.8 billion years ago in a so-called big bang, a hot, dense state, whose very beginnings are still shrouded in mystery. And also, we've learnt more about the extreme things in it: black holes, neutron stars, explosions of various kinds. And one of the most potentially exciting discoveries in the last 20 years, mainly the last 10, has been the realisation that most of the stars in the sky are orbited

• 7:42Speaker 01

  by retinues of planets, just as the sun is orbited by the Earth and the other familiar planets. And this, of course, makes the night sky far more interesting. What you see up there aren't just points of light, but there are planetary systems. And that raises the question, could there be life out there? And so that is an exciting problem for the 21st century.

• 8:02Lex Fridman?

  So when you see all those lights out there, you immediately imagine all the planetary worlds that are around them. And they potentially have all kinds of different lives, living organisms, life forms, or different histories.

• 8:18Speaker 01

  Well, that we don't know at all. We know that these planets are there. We know that they have masses and orbits rather like the planets of our solar system. But we don't know at all if there's any life on any of them. I mean, it's entirely logically possible that life is unique to this Earth, doesn't exist anywhere. On the other hand, it could be that the origin of life is something which happens routinely, given conditions like the young Earth, in which case there could be literally billions of places in our galaxy where some sort of biosphere has evolved. And settling where the truth lies between those two extremes is a challenge for the coming decades.

• 8:59Lex Fridman?

  So certainly, we're either lucky to be here, or very, very, very lucky to be here.

• 9:06Speaker 01

  I guess that's so, yes.

• 9:07Lex Fridman?

  That's the difference. Where do you fall, your own estimate, your own guess on this question? Are we alone in the universe, do you think?

• 9:17Speaker 01

  I think we're foolish to give any firm estimate, because we just don't know. And that's just an example of how we are depending on greater observations. And also, incidentally, in the case of life, we've got to take account of the fact that, as I always say to my scientific colleagues, biology is a much harder subject than physics. And most of the universes we know about could be understood by physics. But we've got to remember that even the smallest living organism, an insect, is far more complicated with layer on layer complexity than the most complicated star or galaxy.

• 9:57Lex Fridman?

  You know, that's the funny thing about physics and biology. The dream of physicists in the 20th century, and maybe this century, is to discover the theory of everything. And there's a sense by... That once you discover that theory, you will understand everything. If we unlock the mysteries of how the universe works, would you be able to understand how life emerges from that fabric of the universe that we understand?

• 10:26Speaker 01

  I think the phrase "theory of everything" is very misleading. And because it's used to describe a theory which unifies the three laws of microphysics, electricity, magnetism, and the weak interaction with gravity. So it's an important step forward for particle physicists. But the lack of such a theory doesn't hold up any other scientists. Anyone doing biology or most of physics is not held up at all through not understanding sub-nuclear physics. They're held up because they're dealing with things that are very complicated. And that's especially true of anything biological. So what's holding up biologists is not a lack of the so-called "theory of everything",

• 11:09Speaker 01

  it's the inability to understand things which are very complicated.

• 11:13Lex Fridman?

  What do you think will understand first? How the universe works, or how the human body works? Deeply, like from a fundamental, deep level?

• 11:23Speaker 01

  Well, I think, perhaps we can come back to it later, that... Are only limited prospects of ever being able to understand with unaided human brains the most fundamental theories linking together all the forces of nature. I think that may be a limitation of the human brains. But I also think that we can, perhaps aided by computer simulations, understand a bit more of the complexity of nature. But even understanding a simple organism from the atom up is very, very difficult. And I think extreme reductionists have a very misleading perception.

• 12:05Speaker 01

  They tend to think that, in a sense, we are all solutions of Schrödinger's equation, et cetera. But that isn't the way we'll ever understand anything. It may be true that we are reductionists in the sense if we believe that that's the case. We don't believe in any special life force in living things. But nonetheless, no one thinks that we can understand a living thing by solving Schrödinger's equation. To take an example which isn't as complicated. Lots of people study the flow of fluids like water. Why waves break, why flows go turbulent, things like that. This is a serious branch of applied mathematics and engineering. And in doing this, you have concepts of viscosity, turbulence, and things like that.

• 12:51Speaker 01

  Now, you can understand quite a lot about how water behaves and how waves break in terms of those concepts. But the fact that any breaking wave is a solution of Schrödinger's equation for 10 to 30 particles, even if you could solve that, which you clearly can't, would not give you any insight. So the important thing is that every science has its own irreducible concepts.

• 13:19Speaker 01

  In which you get the best explanation. So it may be in chemistry, it's things like valence. In biology, the concept in cell biology. And in ecology, there are concepts like imprinting, et cetera. And in psychology, there are other concepts. So in a sense, the sciences are like a tall building. Where you have basic physics, the most fundamental, then the rest of physics, then chemistry, then cell biology, et cetera. All the way up to the, I guess economist and the penthouse and all that. And we have that. And that's true in a sense, but it's not true.

• 14:02Speaker 01

  That it's like a building in that it's made unstable by an unstable base. Because if you're a chemist, biologist or an economist, you're facing challenging problems. But they're not made any worse by uncertainty about sub nuclear physics.

• 14:21Lex Fridman?

  And at every level, just because you understand the rules of the game or have some understanding of the rules of the game, doesn't mean you know what kind of beautiful things that game creates.

• 14:33Speaker 01

  Right, so if you're interested in birds and how they fly, then things like imprinting the baby on the mother and all that, and things like that are what you need to understand. You couldn't even in principle solve this方程式 equation, how an albatross wanders for thousands of miles of the southern ocean and comes back and then coughs up food for its young. That's something we can understand in a sense and predict the behaviour. But it's not because we can solve it on the atomic scale.

• 15:09Lex Fridman?

  You mentioned that there might be some fundamental limitation to the human brain.

• 15:13Speaker 01

  Yes.

• 15:13Lex Fridman?

  That limits our ability to understand some aspect of how the universe works. That's really interesting. That's sad, actually. If, if, if to the degree it's true, it's sad. So what do you mean by that?

• 15:27Speaker 01

  I would simply say that just as a monkey can't understand quantum theory or even Newtonian physics, there's no particular reason why the human brain should have evolved to be well matched to understanding the deepest aspects of reality. And I suspect that there may be aspects that we are not even aware of and couldn't really fully comprehend. But as an intermediate step towards that, one thing which I think is a very interesting possibility is the extent to which AI can help us. I mean, I think if you take the example of so-called theories of everything, one of which is string theory. String theory involves very complicated geometry and structures in 10 dimensions.

• 16:12Speaker 01

  And it's certainly, in my view, on the cards that the physics of 10 dimensions, very complicated geometry, may be too hard for a human being to work through, but could be worked through by an AI with the advantage of the huge processing power, which enables them to learn world championship chess within a few hours just by watching games. So there's every reason to expect that these machines could help us to solve these problems. And of course, if that's the way we came to understand whether the string theory was

• 16:54Speaker 01

  right, it should be in a sense frustrating because you wouldn't get the sort of aha insight, which is the greatest satisfaction in doing science. But on the other hand, if a machine churns away a 10-dimensional geometry, figuring out all the possible origami's wound up in extra dimensions, if it comes out at the end, spews out the correct mass of the electron, the fact that there are three kinds of neutrinos, something like that, you would know that there was some truth in the theory. And so we may have a theory which we come to trust because it does predict things that we can observe and check. But we may never really understand the full workings of it.

• 17:36Speaker 01

  To the extent that we do more or less understand how most phenomena can be explained in a fundamental way. Of course, in the case of quantum theory, many people would say, understand, there's still some mysteries. You don't quite understand why it works. But there could be deeper mysteries when we get to these unified theories. Whereas a big gap between what a computer can print out for us at the end and what we can actually grasp and think through in our heads.

• 18:05Lex Fridman?

  Yeah, it's interesting that the idea that there could be things a computer could tell us that is true. And maybe it can even help us understand why it's true a little bit.

• 18:15Speaker 01

  Yep.

• 18:16Lex Fridman?

  But ultimately, it's still a long journey to really deeply understand the whys of it.

• 18:22Speaker 01

  Yes, and that's a limitation of our brain.

• 18:24Lex Fridman?

  We can try to sneak up to it in different ways, given the limitations of our brain. Have you, I've gotten a chance to spend the day at DeepMind, talk to Demis Hassabis. His big dream is to apply AI to the questions of science, certainly to the questions of physics. Have you gotten a chance to interact with him?

• 18:43Speaker 01

  Well, I know him quite well. He's one of my heroes, certainly. And I remember.

• 18:48Lex Fridman?

  I'm sure he would say the same.

• 18:49Speaker 01

  And I remember the first time I met him. He said that he was like me, he wanted to understand the universe. But he thought the best thing to do was to try and develop AI. And then with the help of AI, he'd stand more chance of understanding the universe.

• 19:02Lex Fridman?

  Yeah.

• 19:03Speaker 01

  And I think he's right about that. And of course, although we're familiar with the way his computers play Go and chess, he's already made contributions to science through understanding protein folding better than the best human chemists. And so already he's on the path to showing ways in which computers have the power to learn and do things by having a bit to analyze enormous samples in a short time to do better than humans. And so I think he would resonate with what I've just said, that it may be that in these other fundamental questions, the computers will play a crucial role.

• 19:45Lex Fridman?

  Yeah, and they're also doing quantum mechanical simulation of electrons. They're doing a control of of high-temperature plasma fusion reactors.

• 19:55Speaker 01

  Yes, that's a new thing, which is very interesting. They can suppress the instabilities in these tokamaks better than any other way.

• 20:01Lex Fridman?

  Yeah. And it's just the march of progress by AIs in science is is is making big strides. Do you think an AI system will win a Nobel Prize in the century? What do you think?

• 20:18Lex Fridman?

  And does that make you sad?

• 20:20Speaker 01

  If I can digress and put you in a plug for my next book.

• 20:23Lex Fridman?

  Yes.

• 20:24Speaker 01

  It has a chapter saying why Nobel prizes do more harm than good.

• 20:27Lex Fridman?

  Yes.

• 20:28Speaker 01

  So on a quite separate subject, I think Nobel prizes do greatly damage to the percept of the way science is done. Of course, if you ask who or what deserves the credit for any scientific discovery, it may be often someone who has an idea, a team of people who work on a big experiment, et cetera. And of course, it's the quality of the equipment, which is crucial. And certainly in the subjects I do in astronomy, the huge advances we've had come not from us being more intelligent than Aristotle was, but through us having far, far better data from powerful telescopes on the grounds and in space.

• 21:10Speaker 01

  And also, incidentally, we've benefited hugely in astronomy from our computer simulations. Because if you are a subatomic physicist, then of course you crash together the particles in a big accelerator like the one at CERN and see what happens. But I can't crash together two galaxies or two stars and see what happens. But in the virtual world of a computer. One can do simulations like that. And the power of computers is such that these simulations can yield phenomena and insights which we wouldn't have guessed beforehand.

• 21:52Speaker 01

  And the way we can feel we're making progress in trying to understand some of these phenomena, why galaxies have the size and shape they do and all that, is because we can do simulations tweaking different initial conditions and seeing which gives the best fit to what we actually observe. And so that's a way in which we've made progress in using computers. And incidentally, we also now need them to analyze data because one thinks astronomy has been traditionally a rather data-poor subject. But the European satellite called Gaia has just put online the speeds and colors and properties of nearly two billion stars in the Milky Way, which we can do fantastic analyses of.

• 22:37Speaker 01

  And that, of course, could not be done at all without just the number of fancy capacitors of computers.

• 22:42Lex Fridman?

  And the new methods of machine learning actually love raw data, the kind that astronomy provides, organized, structured, raw data.

• 22:51Speaker 01

  Yeah, well, indeed, because the reason they really have a benefit over us is that they can learn and think so much faster. That's how they can learn to play chess and go. That's how they can learn to diagnose lung cancer better than a radiologist, because they can look at a hundred thousand scans in a few days, whereas no human radiologist sees that many a lifetime.

• 23:15Lex Fridman?

  Well, there's still magic to the human intelligence, to the intuition, to the common sense reasoning.

• 23:22Speaker 01

  Well, we hope so.

• 23:24Lex Fridman?

  For now. What is the new book that you mentioned?

• 23:27Speaker 01

  The book I mentioned is called If Science Is to Save Us. It's coming out in September. And it's on the, well, the big challenges of science, climate, dealing with biosafety and dealing with cyber safety. And also it's got chapters on the way science is organized, universities and academies, et cetera.

• 23:52Lex Fridman?

  Institutions.

• 23:53Speaker 01

  And the ethics of science and...

• 23:57Lex Fridman?

  And perhaps the limits.

• 23:58Speaker 01

  And the limits, yes, yeah.

• 24:00Lex Fridman?

  Well, let me actually just stroll around the beautiful and the strange of the universe. Over 20 years ago, you hypothesized that we would solve the mystery of dark matter by now. So unfortunately, we didn't quite yet.

• 24:17Lex Fridman?

  First, what is dark matter and why has it been so tough to figure out?

• 24:22Speaker 01

  Well, I mean, we learned that galaxies and other large-scale structures, which are moving around, but prevented flying apart by gravity, would be flying apart if they only contain the stuff we see, if everything in them was shining. And to understand how galaxies formed and why they do remain confined to the same size, one has to infer that there's about five times as much stuff producing gravitational forces than the total amount of stuff in the gas and stars that we see. And that stuff is called dark matter.

• 25:05Speaker 01

  That's the leading name. It's not dark. It's just transparent, et cetera. And the most likely interpretation is that it's a swarm of microscopic particles, which have no electric charge, and the very small cross-sections are hitting each other and hitting anything else. So they swarm around and we can detect their collective effects. And when we do computer simulations of how galaxies form and evolve and how they emerge from the big bang, then we get a nice, consistent picture if we put in five times as much mass in the form of these mysterious dark particles.

• 25:47Speaker 01

  And for instance, it works better if we think they're non-interacting particles than if we think they're a gas which would have shock waves and things. So we know something about the properties of these, but we don't know what they are. And the disappointment compared to my... Guess twenty years ago, is that particles answering this description have not yet been found. It was thought that the big accelerator, the Large Hadron Collider at CERN, which is the world's biggest, might have found a new class of particles, which would have been the obvious candidates. And it hasn't. And some people say, well, dark matter can't be there, etc. But what I would argue is that there's a huge amount of parameter space

• 26:28Speaker 01

  that hasn't been explored. There are other kinds of particles called axions, which behave slightly differently, which are good candidates. And there's a factor of ten powers of ten between the heaviest particles that could be created by the Large Hadron Collider, and the heaviest particles which on theoretical grounds could exist without turning into black holes. So there's a huge amount of possible particles which could be out there as remnants of the Big Bang, but which we wouldn't be able to detect so easily. So the fact that we've got new constraints on what the dark matter could be, doesn't diminish my belief that it's there in the form of particles, because we've only explored a

• 27:13Speaker 01

  small fraction of parameter space.

• 27:15Lex Fridman?

  So there's this search, you're literally, upon an unintended, are searching in the dark, here in this giant parameter space of possible particles. You're searching for, I mean, there could be all kinds of particles.

• 27:30Speaker 01

  There could be, and there's some which may be very, very hard to detect. But I think we can hope for some new theoretical ideas, because one point which perhaps you'd like to discuss more is about the very early stage of the Big Bang. And the situation now is that we have an outlined picture for how the universe has evolved, from the time when it was expanding in just a nanosecond, right up to the present. And we could do that, because after nanosecond, the physics of the material is in the same range that we can test in the lab. After a nanosecond, the particles move around like those in the Large Hadron Collider.

• 28:15Speaker 01

  If you wait for one second, they're rather like in the centres of the hottest stars. And nuclear reactions produce hydrogen, helium, et cetera, which fit today. So we can with confidence extrapolate back to when the universe was a nanosecond old. Indeed, I think we can do it with as much confidence as anything a geologist tells you about the early history of the Earth. And that's huge progress in the last fifty years. But any progress puts in sharper focus new mysteries. And of course, the new mysteries in this context are, why is the universe expanding the way it is? Why does it contain this mixture of atoms and dark matter and radiation? And why does it have the properties which allow galaxies to form?

• 29:00Speaker 01

  Being fairly smooth but not completely smooth. And the answer to those questions are generally believed to lie in a much, much earlier stage of the universe, when conditions were much more extreme and therefore far beyond the stage where we had the foothold in experiments. Very theoretical. And so we don't have a convincing theory, we just have ideas. Until we have something like string theory or some other clues to the ultra early universe, that's going to remain speculative. So there's a big gap. And to say how big the gap is, if we take the observable universe out of a bit more than ten billion light years,

• 29:40Speaker 01

  then when the universe was a nanosecond old, that would have been squeezed down to the size of our solar system or compressed into that volume. But the times we're talking about, when the key properties of the universe were first imprinted, were times when that entire universe was squeezed down to the size of a tennis ball or baseball, if you prefer, and to emerge from something microscopic. So it's a huge extrapolation. And it's not surprising that, since it's so far from our experimental range of detectability, we are still groping for ideas.

• 30:18Lex Fridman?

  But you think first theory will reach into that place and then experiment will perhaps one day catch up.

• 30:26Speaker 01

  Well, I think in a sense it's a combination. I think what we hope for is that there'll be a theory which applies to the early universe, but which also has consequences which we can test in our present day universe, like discovering my nutrients exist or things like that. And that's the thing which, as I mentioned, we may perhaps need a bit of AI to help us to calculate. But I think the hope would be that we will have a theory which applies under the very, very extreme early stages of the universe, but which gains credibility and gains confidence

• 31:08Speaker 01

  because it also manages to account for otherwise unexplained features of the low energy world and what people call the standard model of particle physics, where there are lots of undetermined numbers. So it may help with that.

• 31:21Lex Fridman?

  So we're dancing between physics and philosophy a little bit, but what do you think, what do you think happened before the Big Bang? So this seems, this feels like something that's out of the reach of science.

• 31:35Speaker 01

  It's out of the reach of present science because science develops and as the front is advanced, then new problems come into focus that couldn't even have been postulated before. I mean, if I think of my own career, when I was a student, the evidence for the Big Bang was pretty weak, whereas now it's extremely strong. But we are now thinking about the reason why the universe is the way it is and all that. So I would put all these things we've just mentioned in the category of speculative science. And I don't see a bifurcation between that and philosophy. But of course, to answer your question, if we do want to understand the very early

• 32:18Speaker 01

  universe, then we've got to realize that it may involve even more counterintuitive concepts than quantum theory does, because it's a condition even further away from everyday world than quantum theory is. And remember, our lives. Our brains evolved and haven't changed much since our ancestors roamed the African savanna and looked at the everyday world. And it's rather amazing that we've been able to make some sense of the quantum micro world and of the cosmos, but there may be some things which are beyond us and certainly, as we implied, there are things that we don't yet understand at all. And of course, one concept we might have to jettison is the idea of three dimensions

• 33:02Speaker 01

  of space and time just ticking away.

• 33:07Speaker 01

  There are lots of ideas. I mean, I think Stephen Hawking had an idea that talking about what's, what happened before the big bang, it's like asking what happens if you go north from the North Pole. You know, it somehow closes off. That's just one idea. I don't like that idea, but that's a possible one. And so we just don't know what happened at the very beginning of the big bang, whether many big bangs rather than one, et cetera. And those are issues which we may be able to get some foothold on from some new theory. But even then, we won't be able to directly test the theories.

• 33:52Speaker 01

  But I think it's a heresy to think you have to be able to test every prediction of a theory. Let me give you another example. We take seriously what Einstein's theory says about the inside of black holes, even though we can't observe them, because that theory has been vindicated in many other places, in cosmology and black holes, gravitational waves and all those things. Likewise, if we had a theory which explained some things about the early history of our big bang and the present universe, then we would take seriously.

• 34:29Speaker 01

  The inference, if it predicted many big bangs, not one, even though we can't predict the other ones. So the example is that we can take seriously a prediction if it's the consequence of a theory that we believe on other grounds. We don't need to be able to detect another big bang in order to take it seriously.

• 34:48Lex Fridman?

  It may not be a proof, but it's a good indication that this is the direction where the truth lies.

• 34:56Speaker 01

  Yeah, if the theory is getting confidence in other ways.

• 34:59Lex Fridman?

  Yes. Where do you sense, do you think there's other universes besides our own?

• 35:05Speaker 01

  Those sort of well-defined theories which make assumptions about the physics at the relevant time, and this time, incidentally, is 10 to the power minus 36 seconds, or earlier than that. So this tiny sliver of time. And there are some theories, famous by Andrew Linde, the Russian cosmologist now at Stanford, called eternal inflation, which did predict an eternal production of new big bangs, as it were. And that's based on specific assumptions about the physics. But those assumptions, of course, are just hypotheses which aren't vindicated. But there are other theories which only predict one big bang.

• 35:49Speaker 01

  So I think we should be open-minded and not dogmatic about these options until we do understand the relevant physics. But there are these different scenarios, very different ideas about this. But I think all of them have the feature that physical reality is a lot more extensive than what we can see through our telescope. I think even most conservative astronomers would say that, because we can see out with our telescopes to a sort of horizon, which is about...

• 36:22Speaker 01

  Depending on how you measure it, it's maybe fifteen billion light years away or something like that. But that's horizon of our observations is no more physical reality than the horizon around you if you're in the ocean and looking out at your horizon. There's no reason to think that the ocean ends just beyond your horizon. And likewise, there's no reason to think that the aftermath of our big bang ends just at the boundary of what we can see. Indeed, there are quite strong arguments that it probably goes on about a hundred times further. It may even go on so much further that all combinatorials are replicated and there's

• 37:04Speaker 01

  another set of people like us sitting in a room like this.

• 37:08Lex Fridman?

  Every possible combination of...

• 37:09Speaker 01

  Yeah, that could happen. That's not logically impossible, but I think many people would accept that it does go on and contain probably a million times as much stuff as what we can see within our horizon. The reason for that, incidentally, is that if we look as far as we can in one direction and in the opposite direction, then the conditions don't differ by more than one part in a hundred thousand. So that means that if we're part of some finite structure, the gradient across the part we can see is very small. And so that suggests that it probably does go on a lot further. And the best estimates say it must go on at least twenty times further.

• 37:49Lex Fridman?

  Is that exciting or terrifying to you, just the spans of it all, the wide, everything that lies beyond the horizon? That example doesn't even hold for Earth, so it goes way, way farther. And on top of that, just to take your metaphor further with the, on the ocean. While we're on top of this ocean, not only can we now see beyond the horizon, we also don't know much about the depth of the ocean. Nor the actual mechanism of observation that's in our head.

• 38:24Speaker 01

  Yes. No, I think there was an analysis of all those points you make, yes, yes. But I think even the solar system is pretty vast by human standards. And so I don't think the perception of this utterly vast cosmos need have any deeper impact on us than just realizing that we are very small on the scale of the external world.

• 38:52Lex Fridman?

  Yeah, it's humbling, though. It's it's humbling in, depending where your ego is, it's humbling.

• 39:00Speaker 01

  Well, if you start off very un-humble indeed, it may make a difference. But for most of us, I don't think it makes much difference. And, uh, well, there's a more general question, of course, about, uh, um, whether, um, the human race as such is something which is, uh, very special. Or if, on the other hand, um, it's just one of many such species elsewhere in the universe, or indeed existing at different times in our universe.

• 39:31Lex Fridman?

  It, to me, it feels, uh, almost obvious that the universe should be full of alien life, perhaps dead alien civilizations, but just the, the vastness of space. And it just feels wrong to think of Earth as somehow special. It sure as heck doesn't look that special. When you, the more we learn, the less special it seems.

• 39:57Speaker 01

  Well, I mean, I don't agree with that as far as, as life is concerned, because, remember that we don't understand how life began here on Earth.

• 40:06Lex Fridman?

  Yes.

• 40:06Speaker 01

  And we don't understand, although we know there is an evolution of simple life to complex life, we don't understand, uh, what caused the transition between complex chemistry and the first, um, replicating metabolizing entity we call a life.

• 40:22Lex Fridman?

  Yes.

• 40:22Speaker 01

  That's the mystery. Um, and, uh, uh, si- serious physicists and chemists are now thinking about it, but we, we don't know. So we therefore can't say, was it a rare fluke?

• 40:34Lex Fridman?

  Yeah.

• 40:35Speaker 01

  Which would not have happened anywhere else? Or was it something which, uh, involves a process that would have happened in any other planet where conditions were like they were on the young Earth? Um, so we, we can't say that now. Um, I, I think many of us would indeed bet that probably some kind of life exists elsewhere. But even if, um, you accept that, then, um, there are many contingencies going from simple life to, um, uh, present day life. And, and some biologists like Stephen J. Gould, uh, thought that if you reran evolution, you'd end up with something quite different, and maybe not with an intelligent species. So the contingencies in evolution, um, may...

• 41:19Speaker 01

  Militate against the emergence of intelligence, even if life gets started in lots of places. So I think these are still completely open questions. And that's why it's such an exciting time now that we are starting to be able to address these. I mean, I mentioned the the fact that the origin of life is a question that we may be able to understand, and serious people are working on it. It's usually put in the sort of two difficult box. Everyone knew it was important, but they didn't know how to tackle it or what it's meant to do. But it's not like that now. And that's partly because of clever experiments. But I think most importantly, because we are aware that we can look for life in other places,

• 41:59Speaker 01

  other places in our solar system, and of course, on the exoplanets around other stars. And within ten or twenty years, I think two things could happen, which would be really, really important. We might, with the next big telescope, be able to image some of the Earth-like planets around other stars.

• 42:21Lex Fridman?

  Image, like, get a picture?

• 42:23Speaker 01

  Well, actually, let me caveat that it'd take fifty years to get a resolved image, but but but to actually detect the light. Because now, of course, these exoplanets are detected by their effect on the parent star. They either cause their parent star to dim slightly when they transit across in front of it. And so we see the dips, or their gravitational pull makes the star wobble a bit. So so most of the the five thousand plus planets that have been found around other stars, they've been found indirectly by their effect.

• 42:54Lex Fridman?

  Yes.

• 42:55Speaker 01

  In one of those two ways on the parent star.

• 42:56Lex Fridman?

  You could still do a pretty good job of estimating size.

• 42:59Speaker 01

  Yeah.

• 42:59Lex Fridman?

  All those kinds of things.

• 43:01Speaker 01

  The size and the mass you can estimate. But but detecting the the actual light from one of these exoplanets hasn't really been done yet, except for one or two very, very bright big planets.

• 43:14Lex Fridman?

  So maybe like James Webb Telescope would be.

• 43:16Speaker 01

  Well, James Webb may do this, but even better will be the European Ground Based Telescope. Called unimaginably the Extremely Large Telescope, which has a thirty-nine metre diameter mirror, thirty-nine metres mosaic weight and sheets of glass, and that will collect enough light from one of these exoplanets around a nearby star, um to be able to um separate out its light from that of the star, which is a millionth of times brighter, and get the spectrum of the planet and see if it's got oxygen or chlorophyll and things in it. Uh so that that will come. Um Ja- James Webb may may make some some steps there. Um but

• 43:59Speaker 01

  I think we can look forward to learning quite a bit um in the next twenty years because I like to say um supposing that aliens looking at the solar system, then they'd see the sun as an ordinary star, they'd see the earth as in Carl Sagan's phrase, a pale blue dot, lying very close in the sky to its star, our sun, and much, much, much fainter. But if they could observe that dot, they could learn quite a bit. They could perhaps get the spectrum of the light and find the atmosphere. They'd find the shade of blue was slightly different, depending on whether the Pacific Ocean or landmass of Asia was facing them, so they could infer the length of the day and the oceans and continents, and maybe

• 44:44Speaker 01

  something about the seasons and the climate. And that's the kind of calculation calculation and inference we might be able to draw within the next ten or twenty years about other exoplanets. And um and evidence of some sort of biosphere on one of them would of course be crucial, and it would rule out the still logical possibility that life is unique. But there's another way in which this may happen in the next twenty years. People think there could be something swimming under the ice of Europa and Enceladus, and probes are being sent to maybe not quite go under the ice, but detect the spray coming coming out to

• 45:24Speaker 01

  see if there's evidence for organics in that. And if we found any evidence for an origin of life that had happened. In either of those places, that would immediately be important because if life has originated twice independently in one planetary system, the solar system, that would tell us straight away it wasn't a rare accident and must have happened billions of times in the galaxy. At the moment, we can't rule out it being unique. And incidentally, if we found life on Mars, then that would still be ambiguous because people have realized that this early life could have got from Mars to Earth or vice versa on meteorites.

• 46:06Speaker 01

  So if you found life on Mars, then some skeptics could still say if it's a single origin. But I think

• 46:13Lex Fridman?

  But Europa is far enough

• 46:14Speaker 01

  That's far enough away, yeah.

• 46:15Lex Fridman?

  Statistically because

• 46:16Speaker 01

  Yes, so that's why that would be especially

• 46:19Lex Fridman?

  It's always the skeptics that ruin a good party, but

• 46:24Speaker 01

  But we need them, of course.

• 46:25Lex Fridman?

  We need them at the party. We need some skeptics at the party. But boy, would that be so exciting to find life on one of the moons. Because it means

• 46:36Speaker 01

  But of course, that won't be the, that'll just be any kind of vegetation or life. The question of the aliens or science fiction is a different matter.

• 46:45Lex Fridman?

  Intelligent aliens. Yeah, but if you have a good indication that there's life elsewhere in the solar system, that means life is everywhere.

• 46:57Speaker 01

  Yep.

• 46:57Lex Fridman?

  And that, that's, I don't know if that's terrifying or what that is, because if life is everywhere, why is intelligent life not everywhere? Why, I mean, you've talked about that most likely alien civilizations, if they are out there, they would likely be far ahead of us, the ones that would actually communicate with us.

• 47:20Speaker 01

  Yes.

• 47:21Lex Fridman?

  And that, again, one of those things that is both exciting and terrifying. You've mentioned that they're likely not to be of biological nature.

• 47:31Speaker 01

  Well, I think that's important. Of course, again, it's speculation, but in speculating about intelligent life and I I take the search seriously. In fact, I chair the committee that the Russian-American investor Yuri Milner supports, looking for intelligent life. He's putting ten million dollars a year into better equipment and getting time on telescopes to do this. And so I think it's worthwhile, even though I don't hold my breath for success, it's very exciting. But that does lead me to wonder what might be detected. And I think, well, we don't know, we've got to be open-minded about anything, we've no idea what it could be.

• 48:14Speaker 01

  And so any anomalous objects, or even some strange shiny objects in the solar system, or anything, we've got to keep our eyes open for. But I think if we ask, what about a planet like the Earth where evolution had taken more of the same track? Then, as you say, it wouldn't be synchronized. If it had lagged behind, then of course it would not have got to advanced life, but it may have had a head start. It may have formed on a planet around an older star. Okay? But then let's ask what we'd see. It's taken nearly four billion years from the first life to us, and we've now got this

• 48:56Speaker 01

  technological civilization, which could make itself detectable to any alien life, aliens out there. But I think most people would say that this civilization of flesh and blood creatures in a collective civilization may not last more than a few hundred years more. I think that the, some people would say it will kill itself off, but I'm more optimistic. And I would say that what we're going to have in future is no longer the slow Darwinian selection, but we're going to have what I call secular intelligent design, which will

• 49:40Speaker 01

  be humans designing their progeny to be better adapted to where they are. And if they go to Mars or somewhere, they're badly adapted, they want to adapt a lot. And so they will adapt, but there may be some limits to what could be done with flesh and blood. And so they may become... Largely electronic, download their brains and have and be electronic entities. And if they're electronic, then what's important is that they're near immortal. And also, they won't necessarily want to be on a planet with an atmosphere or gravity.

• 50:22Speaker 01

  They may go off into the blue yonder and they and if they're near immortal, they won't be daunted by interstellar travel, taking a long time. And so if if we looked at what would happen on the earth in the next millions of years, then there may be these electronic entities which have been sent out and are now far away from the earth, but still sort of burping away in some in some fashion to be detected. And so this this therefore leads me to think that if there was another planet which had evolved like the earth and was ahead of us, it wouldn't be synchronized, so we wouldn't see a flesh and blood civilization,

• 51:07Speaker 01

  but we would see these electronic progeny, as it were. And then this raises another question, because there's the famous argument against there being lots of aliens out there, which is that they would come and invade us and eat us or something like that, you know, that's a common idea, which Femi is attributed to have been the first to say. And I think there's a escape clause to that, because these entities would be, say, that they evolved by second intelligence design, designed by their predecessors and then designed by us. And whereas Darwinian selection requires two things, it requires aggression and intelligence.

• 51:57Speaker 01

  This future intelligence may favor intelligence because that's what they were designed for, but it may not favor aggression. And so these future entities, they may be sitting deep thoughts, thinking deep thoughts, and not being at all expansionist. So they could be out there.

• 52:18Lex Fridman?

  Yeah.

• 52:19Speaker 01

  And we can't refute their existence in the way the Fermi paradox is supposed to refute their existence because these would not be aggressive or expansionist.

• 52:29Lex Fridman?

  Well, maybe evolution requires competition, not aggression. And I wonder if competition can take forms that are non-expansionary. So you can still have fun competing

• 52:39Speaker 01

  Yeah, yeah.

• 52:39Lex Fridman?

  in the space of ideas, which may be primarily

• 52:43Speaker 01

  It'll all be philosophers, perhaps, yeah.

• 52:46Lex Fridman?

  In a way, right. It's an intellectual exercise versus a sort of violent exercise. So what does this civilization on Mars look like? So do you think we would more and more, you know, maybe start with some genetic modification and then move to basically cyborgs, increasing integration of electronic systems, computational systems into our bodies and brains?

• 53:14Speaker 01

  This is the theme of my other new book out this year, which is called The End of Astronauts.

• 53:19Lex Fridman?

  The End of Astronauts.

• 53:21Speaker 01

  Co-written with my old friend and colleague from Berkeley, Don Goldsmith. And it's really about the role of human spaceflight versus sort of robotic spaceflight. And just to summarize what it says, it argues that the practical case for sending humans into space is getting weaker all the time as robots get better, more capable. Robots fifty years ago couldn't do anything very much, but now they could assemble big structures on space or in space or on the moon, and they could probably do exploration.

• 54:00Speaker 01

  The present ones on Mars can't actually do the geology, but future AI will be able to do the geology, and already they can dig on Mars. And so if you want to do exploration of Mars, and of course even more of Enceladus or Europa, where you could never send humans, we depend on robots. And they're far, far cheaper because to send a human to Mars requires feeding them for 200 days on the journey there and bringing them back, and neither of those are necessary for robots. So the practical case for humans is getting very, very weak. And if humans go, it's only as an adventure, really.

• 54:42Speaker 01

  And so the line in our book is that human spaceflight should not be pursued by NASA or public funding agencies because it has no practical purpose, but also because it's especially expensive if they do it, because they would have to be risk averse in launching civilians into space. I can illustrate that by noting that the shuttle was launched 135 times, and it had two spectacular failures, which each killed the seven people in the crew.

• 55:23Speaker 01

  And it had been mistakenly presented as safe for civilians, and there was a woman schoolteacher killed in one of them, and it was a big national trauma, and they tried to make it safer still. But if you launch into space, just the kind of people prepared to accept that sort of risk, and of course, test pilots and people who go hang gliding and go to the South Pole, etc., are prepared to accept a 2% risk at least for a big challenge, then of course you do it more cheaply. And that's why I think human spaceflight should be left to the billionaires and their sponsors,

• 56:05Speaker 01

  because then the taxpayers aren't paying, and they can launch simply those people who are prepared to accept high risks. Space adventure, not space tourism. And we should cheer them on. And as regards where they would go...

• 56:24Speaker 01

  Then low Earth orbit, I suspect, can be done quite cheaply in future. But going to Mars, which is very, very expensive and dangerous for humans. The only people who would go would be these adventurers, maybe on a one-way trip, like some of the early polar explorers and Magellan and people like that. You know, and we would cheer them on. And I expect, and I very much hope, that by the end of a century, there will be a small community of such people on Mars, living very uncomfortably, far less comfortably than at the South Pole or the bottom of the ocean or the top of Everest.

• 57:06Speaker 01

  But they will be there, and they won't have a return ticket, but they'll be there. Incidentally, I think it's a dangerous illusion to think, as Elon Musk has said, that we can have mass emigration from the Earth to Mars to escape the Earth's problems. It's a dangerous illusion because it's far easier to deal with climate change on Earth than to terraform Mars to make it properly habitable to humans. And so there's no planet B for ordinary risk-averse people. But for these crazy adventurers, then you can imagine that they would be trying to live on Mars as great pioneers.

• 57:50Speaker 01

  And by the end of a century, then there will be huge advances compared to the present in two things: first, in understanding genetics, so as to genetically redesign one's offspring; and secondly, to use cyborg techniques to implant something in our brain or indeed think about downloading, etc. And those techniques will...

• 58:15Speaker 01

  One hopes to be heavily regulated on Earth, on prudential and ethical grounds. And of course, we are pretty well adapted to the Earth, so we don't have the incentive to do these things in the way they were there. So our argument is that it'll be those crazy pioneers on Mars, using all these scientific advances, which will be controlled here, away from the regulators, they will transition into a new post-human species. And so if they do that, and if they transition into something which is electronic eventually, because there may be some limits to the capacity of flesh and blood brains anyways, then those

• 58:59Speaker 01

  electronic entities may not want to stay on the planet like Mars, they may want to go away. And so they'll be the precursors of the future evolution of life and intelligence coming from the Earth. And of course, there's one point which perhaps astronomers are more aware of than most people. Most people are aware that we are the outcome of four billion years of evolution. Most of them nonetheless probably think that we humans are somehow the culmination, the top of the tree.

• 59:31Lex Fridman?

  Yes.

• 59:32Speaker 01

  But no astronomers could believe that, because astronomers know that the Earth is four and a half billion years old. The Sun has been shining for that length of time, but the Sun has got six billion years more to go before it flares up and engulfs the inner planet. So the Sun has less than halfway through its life, and the expanding universe goes on far longer still, maybe forever. And I'd like to quote Woody Allen, who said, "It turns out it's very long, especially towards the end." So we shouldn't think of ourselves as maybe even the halfway stage in the emergence of cosmic complexity.

• 1:00:11Speaker 01

  And so these entities who are post-cursors, they will go beyond the solar system. And of course, even if there's nothing else out there already, then they could populate the rest of the galaxy.

• 1:00:25Lex Fridman?

  And maybe eventually meet the others who are out there expanding as well.

• 1:00:29Speaker 01

  Yeah.

• 1:00:30Lex Fridman?

  Expanding and populating.

• 1:00:31Speaker 01

  Yes.

• 1:00:32Lex Fridman?

  With expanded... Capacity for life and intelligence, all those kinds of things.

• 1:00:37Speaker 01

  Well, they might, but again, all better off because I can't conceive what they'd be like. They won't be green men and women with eyes on stalks, you know, maybe something quite different. We just don't know. But there is an interesting question, actually, which comes up when I've sometimes spoken to audiences about this topic, that the question of consciousness and self-awareness. Because, you know, going back to philosophical questions, I mean, is whether an electronic robot would be a zombie, or would it be conscious and self-aware? And I think there's no way of answering this empirically.

• 1:01:19Speaker 01

  And some people think that consciousness and self-awareness is an emergent property in any sufficiently complicated networks that they would be. Others say, well, maybe it's something special to the flesh and blood that we're made of, we don't know. And in a sense, this may not matter to the way things behave, because they could be zombies and still behave as though they were intelligent. But I remember after one of my talks, someone came up and said, "Wouldn't it be sad if these future entities, which were the main entities in the universe, had no self-awareness, so there was nothing which could appreciate the wonder and mystery of the universe

• 1:02:03Speaker 01

  and the beauty of the universe in the way that we do?" And so it does perhaps affect one's perspective of whether you welcome or deplore this possible future scenario, depending on whether you think the future post-human entities are conscious and have an aesthetic sense, or whether they're just zombies.

• 1:02:25Lex Fridman?

  And of course, you have to be humble to realize that self-awareness may not be the highest form of being.

• 1:02:35Lex Fridman?

  That humans have a very strong ego and a very strong sense of identity, like personal identity connected to this particular brain.

• 1:02:44Speaker 01

  Yeah, yeah.

• 1:02:45Lex Fridman?

  Uh, it's not so obvious to me that that is somehow the the highest achievement of a life form, that maybe this kind of-

• 1:02:56Speaker 01

  I think something collective would be-

• 1:02:57Lex Fridman?

  It's possible that, uh, well, I think from an alien perspective, when you look at Earth, it's not so obvious to me that individual humans are the atoms of intelligence. It could be the entire organism together, the collective intelligence. And so we humans think of ourselves as individuals, we dress up, we wear ties and suits, and we give each other prizes, but in reality, the intelligence, the things we create that are beautiful emerges from our interaction with each other. And that may be where the intelligence is, ideas jumping from one person to another over generations.

• 1:03:34Speaker 01

  Yes, but we have experiences where we can appreciate-

• 1:03:39Lex Fridman?

  Yes.

• 1:03:39Speaker 01

  uh, beauty and wonder and all that. And a zombie may not have those experiences.

• 1:03:46Lex Fridman?

  Yeah, or it may have a very different, we have a very black and white harsh description of zon- like a philosophical zombie zombie, that could be just a very different way to experience.

• 1:04:01Lex Fridman?

  And, you know, in terms of the explorers that colonized Mars,

• 1:04:08Lex Fridman?

  I, um, I mean, there, there's several things I want to mention. One, it's just at a high level, to me, that's one of the most inspiring things humans can do, is reach out into the unknown. That's in the space of ideas, in the space of science, but also the explorers.

• 1:04:25Speaker 01

  Yes, no, I agree with that.

• 1:04:25Lex Fridman?

  And, and that inspires people here on Earth more. Uh, I mean, it did in their, you know, when going to the moon or going out to space in the 20th century, that inspired a generation of scientists. I think that also-

• 1:04:41Lex Fridman?

  Could be used to inspire a generation of new scientists in the 21st century by reaching out towards Mars. So in that sense, I think what Elon Musk and others are doing is actually quite inspiring. It's not No, I agree. It's not a recreational thing. It's actually has a deep humanitarian purpose of really inspiring the world. And then on the other one, to push back on your thought, you know, I don't think Elon says we want to escape Earth's problems. It's more that we should allocate some small percentage of resources to have a backup plan. And because Yes.

• 1:05:22Lex Fridman?

  You yourself have spoken about and written about all the ways we clever humans could destroy ourselves. Yes. And I'm not sure, it does seem, when you look at the long arc of human history, it seems almost obvious that we need to become a multi-planetary species over a period if we are to survive many centuries. It seems that as we get clever and clever with the ways we can destroy ourselves, Earth is going to become less and less safe.

• 1:05:58Lex Fridman?

  So in that sense, this is one of the things, you know, people talk about climate change, and that we need to respond to climate change, and that's a long-term investment we need to make. But it's not really long-term. It's a span of decades. I think what Elon is doing is a really long-term investment. We should be working on multi-planetary colonization now if we were to have it ready five centuries from now. And so taking those early steps. And then also, there's something happens when you're caught, when you Go into the unknown and do this really difficult thing. You discover something very new. You discover something about robotics or materials engineering or nutrition

• 1:06:43Lex Fridman?

  or neuroscience or human relations or political systems that actually work well with humans. You discover all those things. And so it's a it's worthy effort to go out there and try to become cyborgs.

• 1:06:57Speaker 01

  Yeah, no, I agree with that. I think the only different point I'd make is that this is going to be very expensive if it's done in a risk averse way. And that's why I think we should be grateful to the billionaires if they're going to sort of foster these opportunities for thrill seeking risk takers who we can all admire.

• 1:07:22Lex Fridman?

  Yeah. By the way, I should push back on the billionaires because there's sometimes a negative connotation to the word billionaire. It's not a billionaire. It's a company versus government because governments are billionaires and trillionaires.

• 1:07:33Speaker 01

  Yeah, yeah.

• 1:07:34Lex Fridman?

  It's not it's not the wealth. It's the capitalist imperative. So which I think deserves a lot more praise than people are giving it. I'm I'm troubled by this sort of criticism like it's billionaires playing with toys for their own pleasure. I think what some of these companies like SpaceX and Blue Origin are doing is some of the most inspiring engineering and even scientific work ever done in human history.

• 1:08:09Speaker 01

  No, I agree. I think the people who've made the greatest wealth are people who've really been mega benefactors. I mean, I think, you know.

• 1:08:18Lex Fridman?

  Some of them, some of them.

• 1:08:19Speaker 01

  Yeah, yes, some of them, but but but those who founded Google and all that and and even Amazon, they're they're they're beneficiaries. Then they're quite different category in my view from those who just shuffle around money or or or or crypto coins and things like that.

• 1:08:39Lex Fridman?

  Now you're really talking trash.

• 1:08:42Speaker 01

  Yes. But but but but I think if they use their money in these ways, that's fine. But but I think it's true that far more money is owned by us collectively as taxpayers. But I think the fact is, it's in a democracy. There'd be big resistance to exposing human beings to very high risks if, in a sense, we share responsibility for it.

• 1:09:05Lex Fridman?

  Yeah, I don't know.

• 1:09:06Speaker 01

  And that's the reason, I think, it would be done much more cheaply by these private funders.

• 1:09:12Lex Fridman?

  That's an interesting hypothesis, but I have to push back. I don't know if it's obvious why NASA spends so much money and takes such a long time to develop the things it was doing. So before Elon Musk came along, because I would love to live in a world where government actually uses taxpayer money to get some of the best engineers and scientists in the world and actually work across governments, Russia, China, United States, European Union, together to do some of these big projects. It's strange that Elon is able to do this much cheaper, much faster. It could have to do with risk aversion, you're right.

• 1:09:53Speaker 01

  Well, I think it's that, it's that he had all the, the whole assembly within this one building, as it were, rather than depending on a supply chain. But I think it's also that he had a Silicon Valley culture and had younger people, whereas the big aerospace companies, Boeing and Lockheed Martin, they had people who were left over from the Apollo program in some cases, and so they weren't quite so lively. And indeed, quite apart from the controversial issues of the future of human spaceflight, in terms of the next generation of big rockets, then the one that Musk is going to launch

• 1:10:35Speaker 01

  for the first time this year, the huge one, is going to be far, far cheaper than the one that NASA's been working on at the same time. And that's because it will have a reusable first stage. And it's going to be great. It can launch over 100 tons into Earth orbit, and incidentally, that's going to be, make it feasible to do things that I used to think were crazy, like having solar energy from space. That's no longer so crazy if you can do that. And also for science, because its nose cone could...

• 1:11:13Speaker 01

  Contain within it something as big as the entire unfurled James Webb Telescope mirror and therefore you can have a big telescope much more cheaply if you can launch it all in one piece and so it's going to be hugely beneficial to science and to any practical use of space to have these cheaper rockets that are far more completely reusable than any NASA had so I think mosques are a tremendous service to the space exploration and the whole space technology through these rockets certainly.

• 1:11:46Lex Fridman?

  Plus, it's some big sexy rocket, it's just great engineering.

• 1:11:51Speaker 01

  Of course, yeah, yeah.

• 1:11:52Lex Fridman?

  It's like looking at a beautiful big bridge that humans are capable, us descendants of apes are capable to do something so majestic.

• 1:12:00Speaker 01

  Yes, and also the way they land coming down on this bar, that's amazing.

• 1:12:04Lex Fridman?

  It's both controls engineering, it's increasing sort of intelligence in these rockets, but also great propulsion engineer, materials, entrepreneurship, and it just inspires, it just inspires so many people.

• 1:12:19Speaker 01

  No, I'm entirely with you on that, yeah.

• 1:12:22Lex Fridman?

  So, would it be exciting to you to see a human being step foot on Mars in your lifetime?

• 1:12:28Speaker 01

  Yes, I think it's unlikely in my lifetime since I'm so ancient, but I think this century it's going to happen and I think that that will indeed be exciting and I hope there will be a small community by the end of a century, but as I say, I think they they may go with one-way tickets or accepting the risk of no return and so they've got to be people like that and I still think it's going to be hard to persuade the public to send people when you say straight out that they may never come back. But of course, the Apollo astronauts, they took a high risk and in fact, in my previous

• 1:13:10Speaker 01

  book, I quote the speech that's been written for Nixon to be read out if Neil Armstrong got stuck on the moon. And it was written by one of his advisors and a very eloquent speech, you know, about how they have come to a noble end, et cetera, but of course, there was a genuine risk at that time, but...

• 1:13:37Speaker 01

  That may have been accepted, but clearly the crashes of the shuttle were not acceptable to the American public, even when they were told that this was only a 2% risk, given how often they launched it. And so that's what leads me to think that it's got to be left to the kind of people who are prepared to take these risks. And I think of American Adventure as a guy called Steve Fossett, who was an aviator, did all kinds of crazy things, you know, and then a guy who fell supersonically with parachutes from very altitude.

• 1:14:18Speaker 01

  All these people, we all cheer them on. They extend the bounds of humanity. But I don't think the public will be so happy to fund them.

• 1:14:28Lex Fridman?

  I mean, I disagree with that. I think if we change the narrative, we should change the story.

• 1:14:32Speaker 01

  You think so?

• 1:14:33Lex Fridman?

  I think, I think there's a lot of people, because the, the, the public is happy to fund folks in other domains that take bold, giant risks. First of all, military, for example, military.

• 1:14:45Speaker 01

  Oh, military, obviously, yes, yes.

• 1:14:48Lex Fridman?

  I think this is, in the name of science, especially if it's sold correctly, I sure as I would go up there with a risk, with a, I would, I would take a 40% chance risk of death for something that's.

• 1:15:01Speaker 01

  I would. I might want to be even older than I am now. But then I would go.

• 1:15:05Lex Fridman?

  I guess what I'm trying to communicate is, there's all, there's a lot of people on Earth, that's the nice feature, and I'm sure there's going to be a significant percentage, or some percentage of people that are, they take on the risk for the adventure. So, and I, I particularly love that that risk of adventure when taking on inspires people, and just the ripple effect it has across the generation, especially among the young minds, is perhaps immeasurable. But you're thinking.

• 1:15:37Lex Fridman?

  That sending humans should be something we do less and less, sending humans to space. That it should be primarily an effort, the work of space exploration should be done primarily by robots.

• 1:15:51Speaker 01

  Well, I think it can be done much more cheaply, obviously, on Mars. And no one's thinking of sending humans to Enceladus or Europa, the outer planets. And the point is, we will have much better robots. Because, let's take an example. You've seen the pictures of the moons of Saturn and the picture of Pluto and the comet taken by probes. And Cassini spent thirteen years going around Saturn and its moons after seven year voyage. And those are all based on nineteen nineties technology. And if you think of how smartphones have advanced in twenty years since then, just think

• 1:16:33Speaker 01

  how much better one could do instrumenting some very small sophisticated probe. I could send dozens of them to explore the outer planets. And that's the way to do that, because no one thinks you could send humans that far.

• 1:16:48Speaker 01

  But I would apply the same argument to Mars. And if you want to assemble big structures, like, for instance, radio astronomers would like to have a big radio telescope on the far side of the moon, so it's away from the Earth's background artificial radio waves. And that could be done by assembling, using robots without people. So on the moon and on Mars, I think everything that's useful can be done by machines, much more cheap than by humans.

• 1:17:23Lex Fridman?

  Do you know the movie Two Thousand One: A Space Odyssey?

• 1:17:26Speaker 01

  Of course, yes. But you must be too young to have seen that when it came out, obviously.

• 1:17:31Lex Fridman?

  Ah, yeah.

• 1:17:31Speaker 01

  I remember seeing it when it came out.

• 1:17:33Lex Fridman?

  You saw it when it came out?

• 1:17:35Speaker 01

  Yeah, yeah, fifty years ago.

• 1:17:37Lex Fridman?

  Sixty, when was it, sixty?

• 1:17:40Speaker 01

  It was.

• 1:17:41Lex Fridman?

  In the sixties?

• 1:17:42Speaker 01

  Yeah, that's right. Still a classic.

• 1:17:45Lex Fridman?

  It's still probably, for me, the greatest AI movie ever made.

• 1:17:50Speaker 01

  Yes, yes, I agree.

• 1:17:51Lex Fridman?

  One of the great space movies ever made.

• 1:17:54Speaker 01

  Yes.

• 1:17:54Lex Fridman?

  So.

• 1:17:56Lex Fridman?

  Well, let me ask you a philosophical question, since we're talking about robots exploring space. Do you think HAL 9000 is good or bad? So for people who haven't watched.

• 1:18:07Speaker 01

  Yeah.

• 1:18:08Lex Fridman?

  This computer system makes a decision to basically prioritize the mission that the ship is on over the humans that are part of the mission. Do you think HAL is good or evil?

• 1:18:24Speaker 01

  If you ask me, probably in that context, it was probably good, but I think you're raising what is, of course, very much an active issue in everyday life about the extent to which we should entrust any important decision to a machine. And there again, I'm very worried because I think if you are recommended for an operation or not given parole from prison, or even denied credit by your bank, you feel you should be entitled to an explanation. It's not enough to be told that the machine has a more reliable record on the whole than humans have of making these decisions.

• 1:19:08Speaker 01

  You think you should be given reasons you could understand. And that's why I think the present societal trend to take away the humans and leave us in the hands of decisions that we can't contest is a very dangerous one. I think we've got to be very careful of the extent to which AI, which can handle lots of information, actually makes the decisions without oversight. And I think we can use them as a supplement, but to take the case of radiology and cancer. I mean, it's true that the

• 1:19:47Speaker 01

  Radiologist hasn't seen as many X-rays of cancerous lungs as the machine. So the machine could certainly help, but you want the human to make the final decision. And I think that's true in most of these instances. But if we turn a bit to the short-term concerns with robotics. I think the big worry, of course, is the effect it has on people's self-respect and their labour market. And I think my solution would be that we should arrange to tax more heavily the big international conglomerates which use the robots

• 1:20:29Speaker 01

  and use that tax to fund decently-paid, dignified posts of the kind where being a human being is important. Above all, carers for old people, teachers' assistants for young, gardeners in public parks, and things like that. And if the people who are now working in mind-numbing jobs in Amazon warehouses or in telephone call centres are automated, but those same people are given jobs where being a human is an asset, then that's a plus-plus situation.

• 1:21:08Speaker 01

  And so that's the way I think that we should benefit from these technologies, take over the mind-numbing jobs and use machines to make them more efficient, but enable the people so displaced to do jobs where we do want a human being. I mean, most people, when they're old, the rich people, if they have the choice, they want human carers and all that, don't they? They may want robots to help with some things, empty the bedpans and things like that, but they want real people. And certainly in this country, and I think even worse in America,

• 1:21:50Speaker 01

  the care of old people is completely inadequate and it needs just more human beings to help them cope with everyday life and look after them when they're sick. And so that seems to be the...

• 1:22:04Speaker 01

  Way in which the money raised in tax from these big companies should be deployed.

• 1:22:08Lex Fridman?

  So that's in the short term, but if you actually just look, the fact is where we are today to long term future in a hundred years, it does seem that there is some significant chance that the human species is coming to an end in its pure biological form. There's going to be greater and greater integration to genetic modification than cyborg type of creatures. And so you have to think, all right, well, we're going to have to get from here to there. And that process is going to be painful. And that, you know, how there's so many different trajectories that take us from one place to another. It does seem that we need to deeply respect

• 1:22:53Lex Fridman?

  humanness and humanity. Basic human rights, human welfare, like happiness and all that kind of.

• 1:23:02Speaker 01

  No, absolutely. And that's why I think we ought to try and slow down the application of these human enhancement techniques and cyborg techniques for humans for just that reason. I mean, and that's why I want to lead into the people on Mars. Let them do it. But but so things are for just that reason.

• 1:23:19Lex Fridman?

  But they're people too. Okay, people on Mars are people too. I tend to, you know.

• 1:23:24Speaker 01

  But they are very poorly adapted to where they are. Right. That's why they need modification, whereas we're adapted to the Earth quite well, so we don't need these modifications. We're, we're happy to be humans living in in the environment where our ancestors lived, so we don't have the same same motives. So I think there's a difference, but I agree, we don't want drastic changes probably in a lifestyle. And that indeed is a worry because some things are changing so fast. But I think I'd like to inject a note of caution. If you think of the way progress in one technology goes, it goes in a sort of spurt, it goes up very fast and then it levels off. Let me give you.

• 1:24:09Speaker 01

  Two examples, well, one we've had already, a human spaceflight. At the time of the Apollo program, which was only twelve years after Sputnik one. I was alive then, and I thought it would only be ten or twenty years further before there were footprints on Mars. But as we know, for reasons we could all understand, that was and still remains the high point of human space exploration. And that's because it was funded for reasons of superpower rivalry at huge public expense. But let me give you another case, civil aviation. If you think of the change between nineteen nineteen, when that was Alcock and Brown's first transatlantic fight,

• 1:24:54Speaker 01

  to nineteen seventy nine, the first flight of the jumbo jet, it's a big change. But it's more than fifty years since nineteen sixty nine, and we still have jumbo jets more or less the same. So that's an example of something which developed fast and says ever. And to take another analogy, we've had huge developments in mobile phones. But I suspect the iPhone twenty four may not be too different from the iPhone thirteen. Because they develop, but then they saturate. And then maybe some new innovation takes over in stimulating economic growth.

• 1:25:31Lex Fridman?

  Yeah, so it's that we have to be cautious about being too optimistic. And we have to be cautious about being too cynical. I think that is.

• 1:25:41Speaker 01

  Well, optimistic is begging the question, I mean, do we want this very rapid change?

• 1:25:46Lex Fridman?

  Right, so first of all, there's some degree to which technological advancement is something, is a force that can't be stopped. And so the question is about directing it versus stopping it.

• 1:25:57Speaker 01

  Well, it can be sort of sloped or slow. We'll take human spaceflight, there could have been footprints on Mars if America had gone on spending four percent of the federal budget on the project after.

• 1:26:10Lex Fridman?

  Yes.

• 1:26:10Speaker 01

  Apollo.

• 1:26:11Lex Fridman?

  But the reason.

• 1:26:12Speaker 01

  There were very good reasons, but and we could have had supersonic flight. But Concorde came and went during the fifty years.

• 1:26:22Lex Fridman?

  But the reason it didn't progress is not because we realize it's not good for human society. The reason it didn't progress is because it couldn't make, uh, sort of from a capitalist perspective, it couldn't make, uh, there was no short term or long term way for it to make money. So for me.

• 1:26:42Speaker 01

  But isn't, but that's the same as saying it's not good for society.

• 1:26:46Lex Fridman?

  I don't think everything that makes money is good for society and everything that doesn't make money is bad for society. Right. That's a, that's a difficult, that's a difficult thing we're always contending with when we look at social networks. It's not obvious, even though they make a tremendous amount of money, that they're good for society, especially how they're currently implemented with advertisement and engagement maximization. So that's the constant struggle of.

• 1:27:14Speaker 01

  Oh, you know, I agree with you. As many innovations are damaging. Yes. Yeah. Yes.

• 1:27:19Lex Fridman?

  Uh, well.

• 1:27:20Speaker 01

  But I would have thought that supersonic flight was, uh, something that would benefit only a tiny elite.

• 1:27:26Lex Fridman?

  Sure.

• 1:27:27Speaker 01

  A huge expense and environmental damage. That was obviously something which they're very glad not to have, in my opinion.

• 1:27:33Lex Fridman?

  Yeah, but perhaps there was a way to do it where it could benefit the general populace. If you were to think about airplanes, wouldn't you think that in the early days airplanes would have been seen as something that can surely only benefit one percent at most of the population as opposed to a much larger percentage. There, there's, there's another aspect of capitalist system that's able to drive down costs. Once you get the thing kind of going, so that, you know, we get together maybe with taxpayer money and get the thing going at first. And once it gets going, companies step up and drive down the cost and actually make it so that, uh, blue collar folks can actually start using the stuff.

• 1:28:13Speaker 01

  Yeah, sometimes that does happen. That's good.

• 1:28:16Lex Fridman?

  Yeah. So it's, that's again, the, the double edged sword of, uh, human civilization that some technology hurts us, some benefits us, and we don't know ahead of time. We can just do our best and.

• 1:28:29Speaker 01

  There's a gap between what could be done and what.

• 1:28:33Speaker 01

  We collectively decide to do.

• 1:28:36Lex Fridman?

  Yes.

• 1:28:36Speaker 01

  In the in the term, you could push forward some developments faster than we do.

• 1:28:42Lex Fridman?

  Let me ask you, in your book on the future prospects for humanity, you imagine a time machine that allows you to send a tweet-length message to scientists in the past, like to Newton.

• 1:28:54Speaker 01

  Yes.

• 1:28:55Lex Fridman?

  What tweet would you send? It's an interesting thought experiment. What message would you send to Newton about what we know today?

• 1:29:03Speaker 01

  Well, I think he'd love to know that there were planets around other stars.

• 1:29:08Speaker 01

  He'd he'd like to know that.

• 1:29:09Lex Fridman?

  That would really blow his mind.

• 1:29:11Speaker 01

  He'd like to know that everything was made of atoms. He'd like to know that if he looked a bit more carefully through his prisms

• 1:29:19Speaker 01

  and looked at light, not just from the sun, but from

• 1:29:24Speaker 01

  from some flames, he might get the idea that different substances emitted light of different different colors and he might have been triggered to discover some things that had to wait two or three hundred years. Could have given him those clues, I think.

• 1:29:41Lex Fridman?

  It's kind of, it's fascinating to think, to look back at how little he understood. People at that time understood about our world.

• 1:29:52Speaker 01

  Yes.

• 1:29:52Lex Fridman?

  And how much we've.

• 1:29:53Speaker 01

  And certainly about the cosmos, because of course.

• 1:29:55Lex Fridman?

  About the cosmos, yes.

• 1:29:56Speaker 01

  Well, if we think about astronomy, then until about 1850,

• 1:30:03Speaker 01

  astronomy was a matter of

• 1:30:06Speaker 01

  the positions of how the stars and the planets moved around, etc. Of course, that goes back a long way, but Newton understood why the planets moved around in ellipses. But he didn't understand why the solar system was all in a plane, what we call the ecliptic. And he didn't understand, and no one did till the mid 19th century, what the stars are made of. I mean, they were thought to be made of some fifth essence, not earth, air, fire and water like everything else, you know. And it was only after 1850, when people did use prisms, well, precisely to get to get spectra, that they realized that the the sun was made of the same stuff as the earth, and indeed, the stars were.

• 1:30:50Speaker 01

  And it wasn't till 1930, the people.

• 1:30:55Speaker 01

  Knew about nuclear energy and knew what kept the sun shining for so long. So it was quite late that some of these key ideas came in, you know, which would have completely transformed Newton's views and of course the entire scale of the galaxy and the rest of the universe.

• 1:31:13Lex Fridman?

  Just imagine what he would have thought about the Big Bang or even just general relativity.

• 1:31:18Speaker 01

  Absolutely.

• 1:31:18Lex Fridman?

  Just gravity, just him and Einstein talking for a couple of weeks.

• 1:31:23Speaker 01

  Yeah.

• 1:31:24Lex Fridman?

  Would he be able to make sense of spacetime and the curvature of spacetime?

• 1:31:30Speaker 01

  Well, I think, given a quick course, I mean, he was sort of, if one looks back, he was really a unique intellect in a way, you know, and he said that he thought better than everything, everyone else by thinking on things continually and thinking very deep thoughts. And so he was a utterly remarkable intellect, obviously. But of course, scientists aren't all like that. I think it's one thing that interests me, having spent a life amongst scientists, what a variety of mindsets and mental styles they have.

• 1:32:03Lex Fridman?

  Yes.

• 1:32:04Speaker 01

  And, well, just to contrast Newton and Darwin, Darwin said, and he's probably correct, that he thought he just had as much sort of common sense and reasoning power as the average lawyer. And that's probably true because his ability was to sort of connect data and think through things deeply. That's a quite different kind of thinking from what was involved in Newton or someone doing abstract mathematics.

• 1:32:38Lex Fridman?

  I think in the 20th century, the coolest, well, there's the theory, but from an astronomy perspective, black holes is one of the most.

• 1:32:53Lex Fridman?

  Fascinating entities to have been through theory and through experiment to have emerged.

• 1:32:59Speaker 01

  Obviously, I agree. It's an amazing story that, well, of course, what's interesting is Einstein's reaction because, of course, although, as you know, we now accept this is one of the most remarkable predictions of Einstein's theory, he never took it seriously and believed it.

• 1:33:16Lex Fridman?

  Yeah.

• 1:33:17Speaker 01

  Although it was a consequence of a solution of his equations which someone discovered just a year after his theory, Schwarzschild, but he never took it seriously and others did. But then, of course, well, this is something that I've been involved in actually finding evidence for black holes and that's come in the last 50 years and so now there's pretty compelling evidence that they exist as the remnants of stars or big ones in the centers of galaxies. And we understand what's going on. We have ideas vaguely on how they form. And of course, gravitational waves have been detected and that's an amazing piece of technology.

• 1:34:01Lex Fridman?

  LIGO is one of the most incredible engineering efforts of all time.

• 1:34:05Speaker 01

  That's an example where the engineers deserve the most of the credit because the precision is, as they said, it's like measuring the thickest of a hair at the distance of Alpha Centauri.

• 1:34:16Lex Fridman?

  Yeah, it's incredible.

• 1:34:17Speaker 01

  Ten to the minus 21.

• 1:34:18Lex Fridman?

  So maybe actually if we step back, what are black holes? What do we humans understand about black holes and what's still unknown?

• 1:34:27Speaker 01

  Einstein's theory, extended by people like Roger Penrose, tells us that black holes are, in a sense, rather simple things, basically, because they are a solution of Einstein's equations. And the thing that was shown in the 1960s by Roger Penrose in particular and by a few other people was that a black hole, when it forms and settles down, is defined just by two quantities, its mass and its spin. So they're actually very standardized objects. It's amazing that objects as standardized as that can be so big and can lurk in the rest of the solar system. And so that's

• 1:35:09Speaker 01

  the situation for a ready-formed black hole. But the way they form, obviously, is very messy and complicated. And one of the things that I've worked on a lot is what the phenomena are, which are best attributed to black holes and what may lead to them and all that.

• 1:35:29Lex Fridman?

  Richard, can you explain to that? So what are the different phenomena that lead to a black hole? Let's talk about it. This is so cool.

• 1:35:37Speaker 01

  Yes, okay, okay. Well, I mean, I think one thing that only became understood really in the 1950s, I suppose, and beyond was how stars evolve differently depending on how heavy they are. The sun burns hydrogen to helium, and then when it's run out of that, it can actually be a white dwarf. And we know how long that will take. It'll take about 10 billion years altogether, its lifetime. But big stars burn up their fuel more quickly. And more interestingly, because when they've turned hydrogen to helium, they then get even hotter, so they can fuse helium into carbon and go up the periodic table. And then

• 1:36:19Speaker 01

  they eventually explode when they have an endocrine crisis, and they blow out that process material, which, as a digression, is crucially important because all the atoms inside our bodies were synthesized inside a star, a star that lived and died more than 5 billion years ago before our solar system formed. And so we each have inside us atoms made in thousands of different stars all over the Milky Way. And that's an amazing idea. My predecessor, Fred Hoyle, in 1946 was the first person to suggest that idea. And that's been borne out. That's a wonderful idea. So that's how massive stars explode. And they leave behind something which is very exotic and of two kinds. One possibility

• 1:37:04Speaker 01

  is a neutron star, and these were first discovered in 1967, 68. These are stars a bit heavier than the sun, which are compressed to an amazing density. So the whole mass of more than the sun's mass is in something about 10 miles across. So they're extraordinarily dense, the exotic physics. And they've been studied in immense detail. And they've been real laboratories, because the good thing about astronomy, apart from exploring what's out there, is to use the fact that the cosmos has provided us with a lab with far more extreme conditions than we could ever simulate.

• 1:37:47Speaker 01

  And so we learn lots of basic physics from looking at these objects. And that's been true of neutron stars. But for black holes, that's even more true, because the biggest stars, when they collapse, they leave something behind in the center, which is too big to be a stable white two or four neutron star and becomes a black hole. And we know that there are lots of black holes weighing about ten or up to fifty times as much as the sun, which are the remnants of stars. They were detected first fifty years ago, when a black hole was orbiting around another star and grabbing material from the other star, which swirled into it and gave us X-rays.

• 1:38:29Speaker 01

  So the X-rays astronomers found these objects orbiting around an ordinary star and emitting X-ray radiation very intensely, varying all of a short timescale. So something very small and dense was giving that radiation. That was the first evidence for black holes. But then the other thing that happened was realizing that there was a different class of monster black holes in the centers of galaxies. And these are responsible for what's called quasars, which is when something in the center of a galaxy is grabbing some fuel and outshines all the hundred billion stars or so in the rest of the galaxy.

• 1:39:10Lex Fridman?

  Giant beam of light.

• 1:39:13Speaker 01

  And in many cases, it's a beam.

• 1:39:15Lex Fridman?

  Is that, that's gotta be the most epic thing the universe produces is quasars?

• 1:39:21Speaker 01

  Well, it's a debate of what's the most epic, but quasars maybe, or maybe gamma ray bursts or something. But they are remarkable and they were a mystery for a long time. And they're one of the things I worked on in my younger days.

• 1:39:36Lex Fridman?

  So even though they're so bright, they're still a mystery? And but you can only see them.

• 1:39:41Speaker 01

  They're less a mystery now. I think we do understand basically what's going on.

• 1:39:45Lex Fridman?

  How were quasars discovered?

• 1:39:47Speaker 01

  Well, they were discovered when astronomers found things that looked like stars and that they were small enough to be a point like, not absorbed by a telescope, but outshone an entire galaxy.

• 1:40:00Lex Fridman?

  Yeah.

• 1:40:01Speaker 01

  And.

• 1:40:01Lex Fridman?

  That's suspicious.

• 1:40:02Speaker 01

  Yes, but then they realized that what they were, they were objects which you now know are black holes, and they were, black holes were capturing gas, and that gas was getting very hot, but it was producing far more energy than all the stars added together. And it was the energy of the black hole that was lighting up all the gas in the galaxy. So you've got a spectrum of it there. So this was something which was realized from the 1970s onwards. And as you say, the other thing we've learned is that they often do

• 1:40:44Speaker 01

  produce these jets squirting out, which could be detected in all wavebands. So there's now a standard picture.

• 1:40:52Lex Fridman?

  Black hole generating jets of light.

• 1:40:55Speaker 01

  Yeah.

• 1:40:55Lex Fridman?

  At the center of most galaxies.

• 1:40:57Speaker 01

  Yes, that's right.

• 1:40:58Lex Fridman?

  Do we know, do we have a sense if every galaxy has one of these big, big boys, big black holes?

• 1:41:05Speaker 01

  Well, most galaxies have big black holes. They're varying size. The one in our galactic center.

• 1:41:11Lex Fridman?

  Do we know much about ours?

• 1:41:12Speaker 01

  We do, yes. We know it weighs about as much as four million suns, which is less than some, which are several billion in other galaxies. But we know this, the one in our galactic center isn't very bright or conspicuous, and that's because not much is falling into it at the moment. If a black hole is isolated, then of course it doesn't radiate. It only, all that radiates is gas swirling into it. Which is very hot or has magnetic fields.

• 1:41:44Lex Fridman?

  It's only radiating the thing it's murdering or consuming, however you put it.

• 1:41:49Speaker 01

  Yeah, that's right. And so, so it's thought that our galaxy may have been brighter, brighter sometime in the past. But now, and that's when the black hole formed or grew. But, but now it's not catching very much gas. And so it's, it's rather, it's rather faint and detected indirectly and by fairly weak radio emission. And, and so I think the answer to your question is that we suspect that most galaxies have a black hole in them. So that means at some stage in their lives, or maybe one or more stages, they went through a phase of being like a quasar where that black hole captured gas and became very, very bright.

• 1:42:32Speaker 01

  But for the rest of their lives, the black holes are fairly crescent because there's not much gas falling into them.

• 1:42:40Lex Fridman?

  And so this universe of ours sprinkled a bunch of galaxies and giant black holes with like very large number of stars orbiting these black holes and then planets orbiting. Likely, it seems like planets orbiting almost every one of those stars. And just this beautiful universe of ours. Well, what happens when galaxies collide? When these two big black holes collide, is that?

• 1:43:13Speaker 01

  Yes. Well, what would happen is that, well, and I should say that this is going to happen near us one day, but not for four billion years, because the Andromeda Galaxy, which is the biggest galaxy near to us, which is about three million light years away, which is a big disk galaxy, with the black holes as hub, rather like our Milky Way. And that's in.

• 1:43:39Speaker 01

  Falling towards us because they're both in a common gravitational potential well. And that will collide with our galaxy in about four billion years.

• 1:43:48Lex Fridman?

  But it'll be, it'll be, maybe it'll be less a collision and more of a dance because there'll be like a swirling situation.

• 1:43:54Speaker 01

  Well, it's swirling, but eventually there'll be, there'll be a merge here. They'll go through each other and then merge. In fact, there are nice movies to be made of this, you know, computer simulations.

• 1:44:05Lex Fridman?

  Yes.

• 1:44:05Speaker 01

  And it'll go through. And then there's a black hole in the center of Andromeda and our galaxy. And the galaxy, the black holes will settle towards the center.

• 1:44:20Lex Fridman?

  Yes.

• 1:44:20Speaker 01

  Then they will orbit around each other very fast and then they will eventually merge. And that'll produce a big burst of gravitational waves.

• 1:44:29Lex Fridman?

  Yes.

• 1:44:29Speaker 01

  A very big burst.

• 1:44:30Lex Fridman?

  That an alien civilization with a LIGO-like detector will be able to detect.

• 1:44:35Speaker 01

  Yes, well, in fact, we'll, but we can detect these with, they're lower frequencies than the ways that to be detected by LIGO. So there's a space interferometer which can detect these. They're about, it's about one cycle per hour. Rather than about a hundred cycles per second.

• 1:44:53Lex Fridman?

  Yes.

• 1:44:53Speaker 01

  It's the ones that detect it. But that, that will happen. But thinking back to what will happen in four billion years to any of our descendants, they'll be okay. Because the, the two disk galaxies will merge. It'll end up as a sort of amorphous elliptical galaxy. But the stars won't be much closer together than they are now. It'll, it'll still be just twice as many stars in a structure almost as big. And so the chance of another star colliding with our sun would still be very small.

• 1:45:27Lex Fridman?

  Yeah, because there's actually a lot of space between.

• 1:45:30Speaker 01

  Indeed.

• 1:45:31Lex Fridman?

  Stars and planets.

• 1:45:32Speaker 01

  Yes, the chance of a star getting close enough to affect our solar system's orbit is small and it won't change that very much. So you can be reassured.

• 1:45:40Lex Fridman?

  A heck of a starry sky, though. What would that look like?

• 1:45:45Speaker 01

  Well, it won't make much difference even to that, actually. It'll just be.

• 1:45:48Lex Fridman?

  Wouldn't that look kind of beautiful when you're swirling, or is, oh, because it's swirling so slowly?

• 1:45:52Speaker 01

  Yeah, but they're far away, so it'd be twice as many stars in the sky.

• 1:45:57Lex Fridman?

  Yeah, but the pattern changes in interesting ways.

• 1:46:00Speaker 01

  Pattern will change a bit, and there won't be the Milky Way, because the Milky Way across the sky is because we are looking in the disk of our galaxy. And you lose that, because the disk will be so disrupted. And it'll be a more sort of spherical distribution. And of course, many galaxies are like that. And that's probably because they have been through mergers of this kind.

• 1:46:23Lex Fridman?

  If we survive four billion years, we would likely be able to survive beyond that.

• 1:46:27Speaker 01

  Oh, yeah.

• 1:46:29Lex Fridman?

  What's the other thing on the horizon for humans? In terms of the sun burning out, all those kinds of interesting cosmological threats to our civilization?

• 1:46:41Speaker 01

  Well, I think on the cosmological timescale, because it won't be humans, because

• 1:46:47Lex Fridman?

  Something else, yeah.

• 1:46:47Speaker 01

  Even if evolution's going no faster than Darwinian. And I would argue it will be faster than Darwinian in the future. Then we're thinking about six billion years before the sun dies. So any entities watching the death of the sun, if they're still around, they'd be as different as much as we are from slime mold or something, you know. And far more different still if they become electronic. So on that timescale, we just can't predict anything. But I think going back to to the human timescale. Then we've talked about whether there'll be people on Mars by the end of a century. And even in these long perspectives, then indeed, this century is very special.

• 1:47:32Speaker 01

  Because it may see the transition between purely flesh and blood entities to those which are sort of cyborgs. And that'll be an important transition in biology and complexity in this century. But of course, the other importance, and this has been the theme of a couple of my older books, is that this is the first century when one species, namely our species, has the future of the planet in his hands. And that's because of two types of concerns. One is that there are more of us, we're more demanding of energy and resources. And therefore, we are for the first time

• 1:48:14Speaker 01

  Changing the whole planet through climate change, loss of biodiversity and all those issues. This has never happened in the past because having enough humans have been much in part. So this is an effect that's obviously is high on everyone's agenda now and rightly so because we've got to ensure that we leave a heritage that isn't eroded or damaged to future generations. And so that's one class of threats. But there's another thing that worries me, perhaps more than many people seem to worry, and that's the threat of misuse of technology.

• 1:48:54Speaker 01

  And so this is particularly because technologies empower even small groups of malevolent people or indeed even careless people to create some effect which could cascade globally. And to take an example, a dangerous pathogen or pandemic. I mean, my worst nightmare is that there could be some small group that can engineer a virus to make it more virulent or more transmissible than a natural virus. This is so called gain-of-function experiments, which were done on the flu virus 10 years ago and can be done for others.

• 1:49:39Speaker 01

  And of course, we now know from COVID-19 that our world is so interconnected that a disaster in one part of the world can't be confined to that part and will spread globally. So it's possible for a few dissidents with expertise in biotech could create a global catastrophe of that kind. And also, I think we need to worry about very large-scale disruption by cyberattacks. In fact, I quote in one of my books, a 2012 report from the American Pentagon about the possibility of a state-level cyberattack on the electricity grid in eastern United

• 1:50:24Speaker 01

  States, which is, it could happen. And it says at the end of this chapter that this would merit a nuclear response. This is a pretty scary possibility. That was 10 years ago. And I think now, what would have needed a state actor then?

• 1:50:41Speaker 01

  Could be done perhaps by a small group empowered by AI. And so there's obviously been a an arms race between the the cyber criminals and the cyber security people. Not clear which side is winning, but the the main point is that as we become more dependent on more integrated systems, then we get more vulnerable. And and and so we have the knowledge, then the misuse of that knowledge becomes more and more of a threat. And and as I say, bio and cyber are are the the two biggest concerns. And if we depend too much on AI and complex systems, then just breakdowns, it may be that they they break down.

• 1:51:26Speaker 01

  And even if it's innocent breakdown, then it may be pretty hard to mend it. And just think how much worse the pandemic would have been if we'd lost the internet in the middle of it. You know, which we depended more than ever for communication, everything else on on on the internet and Zooms and all that. And if that had broken down, that would have made things far worse. And those are the kinds of threats that we, I think, need to be more energized and politicians need to be more energized to minimize. And one of the things I've been doing the last year through being a member of our part of our parliament is sort of I helped to instigate a committee to think more on better preparedness for

• 1:52:10Speaker 01

  extreme technological risks and things like that. So they're a big concern in my my mind that we've got to make sure that we can benefit from these advances, but safely, because the stakes are getting higher and the benefits are getting great, as we know. Huge benefits from from computers, but but also huge downsides as well.

• 1:52:34Lex Fridman?

  And one of the things this war in Ukraine has shown, one of the most terrifying things outside of the humanitarian crisis is that, at least for me, I realized.

• 1:52:51Lex Fridman?

  That the human capacity to initiate nuclear war is greater than I thought. I thought the lessons of the past have been learned. It seems that we hang on the brink of nuclear war with this conflict like every single day. With just one mistake or bad actor or the actual leaders of the particular nations launching a nuclear strike and all hell breaks loose. So then add into that picture cyber attacks and so on that can lead to confusion and chaos.

• 1:53:30Lex Fridman?

  And then out of that confusion, calculations are made such that a nuclear launch is, a nuclear weapon is launched and it's, and then you're talking about, I mean, I don't, directs probably sixty, seventy percent of humans on earth are dead instantly. And then the rest, I mean, it's basically ninety nine percent of the human population is wiped out in the period of five years.

• 1:54:02Speaker 01

  Well, it may not be that bad, but it will be a devastation for civilization, of course. And of course, we were quite right that this could happen very quickly because of information coming in and there's hardly enough time for human collected and careful thought. And there have been recorded cases of false alarms, several where there have been suspected attacks from the other side and fortunately they've been realized to be false alarms soon enough, but this could happen. And there's a new class of threats, actually, which in our center in Cambridge, people are thinking about, which is that the commander control system of

• 1:54:49Speaker 01

  The nuclear weapons and the submarine fleet and all that is now more automated and could be subject to cyber attacks. And that's a new threat which didn't exist thirty years ago. And so I think indeed it's we're in a sort of scary world, I think. And it's because things happen faster and human beings aren't in such direct and immediate control because so much is delegated to machines. And also because the world is so much more interconnected, then some local event can cascade globally in a way it never could in the past and much faster.

• 1:55:32Lex Fridman?

  Yeah, it's a double edged sword because the interconnectedness brings a higher quality of life across a lot of metrics.

• 1:55:44Speaker 01

  Yeah, it can do, but of course, there again, I mean, if you think of supply chains where we get stuff from around the world, then one lesson we've learnt is that there's a trade off between resilience and efficiency and it's resilient to have an inventory and stock and to depend on local supplies, whereas it's more efficient to have a long supply chain. But the risk there is that a break in one link in one chain can screw up car production. This has already happened in the pandemic. So there's a trade off and there are other examples. I mean, for instance, the other thing we learnt was that it may be efficient to have

• 1:56:27Speaker 01

  ninety five percent of your hospital intensive care beds occupied all the time, which has been the UK situation, whereas to do what the Germans do and always keep twenty percent of them free for an emergency is really a sensible precaution. And so I think we've probably learnt lots of lessons from COVID nineteen and they would include rebalancing the trade off between resilience and efficiency.

• 1:56:53Lex Fridman?

  Boy, the the fact that COVID nineteen, a pandemic that could have been a lot, a lot worse, brought the world to its knees anyway.

• 1:57:02Speaker 01

  It could be far worse in terms of its fatality rate or something like that.

• 1:57:06Lex Fridman?

  Fatality rate, yeah. So the fact that that, I mean, it revealed so many flaws in our human institutions.

• 1:57:13Speaker 01

  Yeah, yeah. Yes, and I think I'm rather pessimistic because I do worry about the bad act or the small group who can produce catastrophe. And if you imagine someone with access to the kind of equipment that's available in university labs or industrial labs, and they could create some dangerous pathogen, then even one such person is too many. And how can we stop that? Because it's true that you can have regulations, I mean, academies are having meetings, et cetera, about how to regulate these new biological experiments, et cetera, make them safe.

• 1:57:57Speaker 01

  But even if you have all these regulations, then enforcing regulations is pretty hopeless. We can't enforce the tax laws globally, we can't enforce the drug laws globally. And so similarly, we can't readily enforce the laws against people doing these dangerous experiments, even if all the governments say they should be prohibited. And so my my line on this is that all nations are going to face a big trade off between three things we value: freedom, security, and privacy. And I think different nations will make that choice differently.

• 1:58:41Speaker 01

  The Chinese would give up privacy.

• 1:58:45Speaker 01

  And have more certainly more security, if not more liberty. But I think in in our countries, I think we're going to have to give up more privacy. In the same way.

• 1:58:58Lex Fridman?

  That's a really interesting trade off. But there's also something about human nature here where I personally believe that all humans are capable of good and evil. And there's some aspect to which we can fight this by encouraging people, incentivizing people towards the better angels of their nature. So in order for a small group of people to create, to engineer deadly pathogens, you have to have people that for whatever trajectory took them in life, wanting to do that kind of thing.

• 1:59:37Lex Fridman?

  And if we can aggressively work on a world that sort of sees the beauty in everybody and encourages the flourishing of everybody in terms of mental health, in terms of meaning, in terms of all those kinds of things. That's one way to fight the development of

• 1:59:59Lex Fridman?

  of weapons that can lead to atrocities.

• 2:00:01Speaker 01

  Yes, and I completely agree with that and to reduce the reason why people feel embittered.

• 2:00:06Lex Fridman?

  Yes.

• 2:00:07Speaker 01

  But of course, we've got a long way to go to do that because if you look at the present world, nearly everyone in Africa has reason to feel embittered because their economic development is lagging behind most of the rest of the world and the prospects of getting out of the poverty trap is is rather bleak, especially if the population grows. Because for instance, they can't develop like the eastern tigers by cheap manufacturing because robots are taking that over. So that they will naturally feel embittered by the inequality. And of course, what we need to have is some sort of mega version of the Marshall Plan that helped Europe in the post World War Two era

• 2:00:53Speaker 01

  to enable Africa to develop. That will be not just an altruistic thing for Europe to do, but in our interest because otherwise.

• 2:01:03Speaker 01

  Those in Africa will feel massively disaffected. And indeed, it's a manifestation of the excessive inequalities. The fact that the 2,000 richest people in the world have enough money to double the income of the bottom billion. And that's an indictment of the ethics of the world. And this is where I've had, my friend Steven Pinker and I have had some contact. We wrote joint articles on bio threats and all that. But he writes these books being very optimistic about quoting figures about how life expectancy has gone up, infant mortality has gone down, literacy has gone up and all those things. And he's quite right about that.

• 2:01:46Speaker 01

  And so he says the world's getting, getting better.

• 2:01:50Lex Fridman?

  Do you disagree with your friends, Steven Pinker?

• 2:01:53Speaker 01

  Well, I mean, I, I, I agree with those facts, okay? But, but I think he misses out, he misses out part of the picture. And because there's a new class of threats which hang over us now, which didn't hang over us in the past. And I would also question whether we have collectively improved our ethics at all. Because let's think back to the Middle Ages. It's true that, as Pinker says, the average person was in a more miserable state than they are today on average. For all the reasons he quantifies, that's, that's fine. But in the Middle Ages, there wasn't very much that could have been done to improve people's lot in life because of lack of knowledge and lack of science, et cetera.

• 2:02:39Speaker 01

  So the gap between the way the world was, which was pretty miserable, and the way the world could have been, which wasn't all that much better, was fairly narrow. Whereas now, the gap between the way the world is and the way the world could be is far, far wider.

• 2:02:56Speaker 01

  And therefore, I think we are ethically more at fault in allowing this gap to get wider than it was in medieval times. And so I would very much question and dispute the idea that we are ethically in advance of our predecessors collectively.

• 2:03:15Lex Fridman?

  That's a lot of interesting hypotheses in there. And I don't, there, it's a fascinating question of how much is the size of that gap between the way the world is and the way the world could be is a reflection of our ethics, or maybe sometimes it's just a reflection of a very large number of people. Like, maybe it's a technical challenge, too. It's not just-

• 2:03:37Speaker 01

  Well, of our political systems.

• 2:03:39Lex Fridman?

  Political systems, like how many, and we're trying to figure this thing out. Like, there's 20th century tried this thing that sounded really good on paper of collective, the communism type of things. And it's like, turned out at least the way that was done there, that leads to atrocities and the suffering and the murder of tens of millions of people. Okay, so that didn't work. Let's try democracy. And that seems to have a lot of flaws, but it seems to be the best thing we got so far. So we're trying to figure this out as our technologies become more and more powerful, have the capacity to do a lot of good to the world, but also unfortunately have the capacity to destroy the entirety of the human civilization.

• 2:04:20Speaker 01

  And I think it's social media generally, which makes it harder to get a sort of moderate consensus, because in the old days, when people got their news filtered through responsible journalists in this country, the BBC and the main newspapers, et cetera, they would muffle the crazy extremes. Whereas now, of course, they're on the internet, and if you click on them, you get to the more extreme. And so I think we are seeing a sort of dangerous polarization, which I think is going to make all countries harder to govern. And that's something which I'm pessimistic about.

• 2:04:57Lex Fridman?

  So to push back, it is true that brilliant people like you highlighting the limitations of social media is making you realize the stakes and the failings of social media companies. But at the same time, they're revealing the division. It's not like they're creating it. They're revealing it in part. And so that puts a lot of-

• 2:05:19Lex Fridman?

  That puts the responsibility into the hands of social media and the opportunity in the hands of social media to alleviate some of that division. So it could, in the long arc of human history, result, so bringing some of those divisions and the anger and the hatred to the surface so that we can talk about it. And as opposed to disproportionately promoting it, actually just surfacing it so we can get over it.

• 2:05:45Speaker 01

  Well, you're assuming that the fat cats are more public spirited than the politicians. And I'm not sure about that.

• 2:05:50Lex Fridman?

  I think there's a lot of money to be made in being publicly spirited. I think there's a lot of money to be made in increasing the amount of love in the world, despite the sort of public perception that all the social media companies has are interested in doing is making money. I think that may be true, but I just personally believe people being happy is a hell of a good business model. And so making as many people happy, helping them flourish in a long-term way, that's a lot of ways to make, that's a good way to make.

• 2:06:29Speaker 01

  Well, I think, on the other hand, I think guilt and shame are good motives to make you behave better in future.

• 2:06:34Lex Fridman?

  Okay.

• 2:06:35Speaker 01

  That's my experience.

• 2:06:37Lex Fridman?

  From maybe in the political perspective, certainly, but it does make sense now that we can destroy ourselves with nuclear weapons, with engineered pandemics and so on, that the aliens would show up. That if I was the, you know, had a leadership position, maybe as a scientist or otherwise in an alien civilization, and I would come upon Earth, I would try to watch from a distance, do not interfere.

• 2:07:13Speaker 01

  Yeah.

• 2:07:14Lex Fridman?

  And I would start interfering when these life forms start becoming quite, have the capacity to be destructive. And so, I mean, it is an interesting question when people talk about UFO sightings and all those kinds of things. That at least

• 2:07:31Speaker 01

  These are benign aliens you're thinking of.

• 2:07:33Lex Fridman?

  Benign, yes. I mean, they benign, almost curious, almost.

• 2:07:41Lex Fridman?

  Partially, as with all curiosity, partially selfish to try to observe, is there something interesting about this particular evolutionary system? Because I'm sure even to aliens, Earth is a curiosity.

• 2:07:54Speaker 01

  Yeah, well, it's in a very special stage.

• 2:07:57Lex Fridman?

  Special, special.

• 2:07:59Speaker 01

  Perhaps the century is very special.

• 2:08:01Lex Fridman?

  Yes.

• 2:08:01Speaker 01

  Among the forty-five million centuries the Earth experienced already. So it is a very special time where they should be specially interested. But I think going back to the the politics. The other problem is getting people who have short-term concerns to care about the long term. By the long term, I now mean just looking thirty thirty years or so ahead. You know, I know people who've been scientific advisors to governments and things. And they may make these points, but of course they don't have much traction. Because, as we know very well, any politician has an urgent agenda of very worrying things to deal with. And so they aren't going to prioritize these issues which are longer

• 2:08:46Speaker 01

  longer term and less immediate and don't just concern their constituents, they concern distant parts of the world. And so I think I think what what we have to do is to

• 2:08:59Speaker 01

  enlist charismatic individuals to convert the public. Because if the if the politicians know the public care about something,

• 2:09:09Speaker 01

  climate change as an example, then they will make decisions which take cognizance of that. And I think for that to happen, then we do need some public individuals who are respected by everyone and who have a high profile. And in the climate context. Well, I would say that I've mentioned four very disparate people who've had such a big effect in the last few years. One is Pope Francis, the other is David Attenborough, the other is Bill Gates, and the other is Greta Thunberg. And those four people have certainly had a big shift in public opinion.

• 2:09:50Speaker 01

  And even changed the rhetoric of business, although how deep that is, I don't know.

• 2:09:56Lex Fridman?

  I, yeah.

• 2:09:57Speaker 01

  But politicians can't let these issues drop down off the agenda. If there's a public clamor, and it needs people like that to keep the public clamor going.

• 2:10:10Lex Fridman?

  To push back a little bit, so those four are very interesting, and I have deep respect for them. They have, except David Attenborough, David Attenborough is really, I mean, everybody loves him. I mean, I can't say, but the, you know, with Bill Gates and Greta, there's, that also create a lot of division.

• 2:10:28Speaker 01

  Oh, sure, yeah, yeah.

• 2:10:29Lex Fridman?

  And this is a big problem, so it's not just charismatic. I put that responsibility actually on the scientific community and.

• 2:10:36Speaker 01

  Pope does too, yeah.

• 2:10:37Lex Fridman?

  Yep, and the politicians, so we need the charismatic leaders, and they're rare.

• 2:10:46Speaker 01

  Yeah, yeah.

• 2:10:46Lex Fridman?

  When you look at human history, those are the ones that make a difference. Those are the ones that, not deride, they inspire the populace to think long term. The JFK, we do, we'll go to the moon in this decade, not because it's easy, but because it is hard. There's no discussion about like, short term political gains or any of that kind of stuff in the vision of going to the moon.

• 2:11:19Speaker 01

  Yeah, yeah.

• 2:11:19Lex Fridman?

  Or going to Mars, or taking on gigantic projects, or taking on world hunger, or taking on climate change, or the education system, all those things that require long term significant investment, that requires.

• 2:11:34Speaker 01

  But it's hard to find those people, and incidentally, I think another problem, which is a downside of social media, is that of younger people I know, the number who would contemplate a political career.

• 2:11:50Speaker 01

  Has gone down because of the pressures on them and their family from social media. It's a hell of a job now. And so I think we are all losers because the quality of people who choose that path is really dropping. And as we see by the quality of those who are in these competitions.

• 2:12:12Lex Fridman?

  That said, I think the silver lining there is the quality of the competition actually is inspiring because it's it's it shows to you that there's a dire need of leaders, which I think would be inspiring to young people to step into the fold. I mean, great leaders are not afraid of a little bit of a little bit of fire on social media. So if you have you have a 20 year old kid now, 25 year old kid is seeing how the world responded to the pandemic, seeing the geopolitical division over the war in Ukraine, seeing the brewing war between the West and China. We need great leaders and there's a hunger for them and the time will come when when they step up.

• 2:12:56Lex Fridman?

  I I I believe that. But also to add to your list of four, he doesn't get enough credit. I've been defending him in this conversation. Elon Musk, in terms of the fight in climate change, but he also has led to a lot of division. But we need more David Ennerbrass.

• 2:13:14Speaker 01

  Yeah, no, no, I mean, I'm a fan.

• 2:13:17Lex Fridman?

  Definitely.

• 2:13:18Speaker 01

  I mean, I've heard him described as a 21st century Brunel for his innovation and that's true, but whether he's an ethical inspiration, I don't know.

• 2:13:28Lex Fridman?

  Yeah, he has a lot of fun on Twitter. Well, let me ask you to put on your wise sage hat. What advice would you give to young people today? Maybe they're teenagers in high school, maybe early college.

• 2:13:46Lex Fridman?

  What advice would you give to a career or have a life they can be proud of?

• 2:13:52Speaker 01

  Yes, well, I'd be very diffident really about offering any wisdom, but I think I think they should they should realize that the choices they make at that time are important. And from the experience of I've had and with many friends, many people don't realize that opportunities are open until it's too late. They somehow think that some opportunities are only open to a few privileged people, and they don't even try, and that they could succeed.

• 2:14:29Speaker 01

  But if I focus on people working in some profession I know about like science, I would say, pick an area to work in where new things are happening, where you can do something that the old guys never had a chance to think about. Don't go into a field that's fairly stagnant, because then there won't be much to do, or you'll be trying to tackle the problems that the old guys got stuck on. And so I think in science, I can give people good advice that they should pick a subject where there are exciting new developments, and also, of course, something which suits

• 2:15:11Speaker 01

  their style, because even within science, which is just one profession, there's a big range of style between the sort of solitary thinker, the person who does field work, the person who works in a big team, et cetera, and whether you like computing or mathematical thought, et cetera. So pick some subject that suits your style and where things are happening fast, and be prepared to be flexible. That's what I'd say, really.

• 2:15:35Lex Fridman?

  Keep your eyes open for the opportunity throughout, like you said. Go to a new field, go to a field where new cool stuff is happening.

• 2:15:43Speaker 01

  Yeah, yeah.

• 2:15:43Lex Fridman?

  And just keep your eyes open.

• 2:15:44Speaker 01

  Yes, that's patistute-ness, but I think most of us, I include myself in this, didn't realize these sort of things until too late.

• 2:15:53Lex Fridman?

  Yeah, I think this applies way beyond science.

• 2:15:58Lex Fridman?

  What do you make of this finiteness of our life? Do you think about death? Do you think about mortality? Do you think about your mortality? And are you afraid of death?

• 2:16:08Speaker 01

  Well, I mean, I'm not afraid because I, I think I'm lucky. I feel lucky to have laughed as long as I have. And, and to have been fairly lucky in, in my life in many respects compared to, to most people. So I feel very fortunate. This reminds me of this current emphasis on living much longer than the so-called Altos laboratories, which have been set up by billionaires. There's one in San Francisco, one in La Jolla, I think, and one in Cambridge. And they're, they're funded by these guys who, when young, wanted to be rich. And now they're rich, they want to be young again.

• 2:16:54Speaker 01

  They won't find that quite so easy. And do we want this? I don't know if, if there was some elite that was able to live much longer than others. That would be a really fundamental kind of inequality. And I think if it happened to everyone, then that might be an improvement. It's not so obvious. But I, I think for my, my part, I think to have lived as, as long as most people and had a fortunate life is all I can expect and a lot to be grateful for.

• 2:17:30Speaker 01

  Those are all the passages.

• 2:17:31Lex Fridman?

  Well, I am incredibly honored that you sit down with me today. I thank you so much for life of exploring some of the deepest mysteries of our universe and of our humanity and thinking about our future with existential risks that are before us. It's, it's a huge honor, Martin, that you sit with me and I really enjoyed it.

• 2:17:53Speaker 01

  Well, thank you, Lex. I thought we couldn't go on for as long as this, but we could have gone on much longer.

• 2:17:58Lex Fridman?

  Exactly. Thank you so much. Thank you for listening to this conversation with Martin Rees. To support this podcast, please check out our sponsors in the description. And now let me leave you with some words from Martin Rees himself. I'd like to widen people's awareness of the tremendous time span lying ahead for our planet and for life itself. Most educated people are aware that were the outcome of nearly 4 billion years of Darwinian selection. But many tend to think that humans are somehow the culmination. Our sun, however, is less than halfway through its lifespan. It will not be humans who watch their sun's demise 6 billion years from now.

• 2:18:42Lex Fridman?

  Any creatures that then exist will be as different from us as we are from bacteria or amoeba. Thank you for listening. I hope to see you next time.