Into the Impossible With Brian Keating - Is the Universe a Simulation? Andrew Pontzen [Ep. 466]

Episode Date: November 17, 2024

Please join my mailing list here 👉 https://briankeating.com/list to win a meteorite 💥 Simulations today are powerful tools for exploring the mysteries of our universe, but how close can they come to replicating reality? Can we recreate everything through simulations, or are there limits we can’t overcome? And how do today’s powerful simulations shape our understanding of everything from galaxies to climate change? Here today, to answer all of these questions and more, is none other than Andrew Pontzen. Andrew is a cosmologist and professor known for his expertise in using computer simulations to understand the universe. He’s the author of The Universe in a Box, where he unpacks the complexities of cosmic simulations and their surprising limitations. Pontzen’s work is at the cutting edge of how we model and predict phenomena ranging from galaxy formation to climate change, bridging theoretical physics with practical, big-picture questions about reality. As we head toward an era where simulations and AI are central to scientific discovery, these questions are more important than ever.  Tune in to learn about the power and limitations of simulation!  Key Takeaways:  00:00 Intro 00:44 Is it possible to simulate reality?  04:49 Early simulation experiments  10:30 Fluid dynamics and weather simulations  13:51 Judging a book by its cover  16:01 End of the universe 19:13 Cosmic microwave background and spinning universes 24:11 Verification and validation 27:34 Big Bang controversy and the JWST 31:35 Galaxy simulations  42:23 Multiverse and quantum computing  48:58 Ethics and energy impact of high-performance computing 55:34 Outro Additional resources:  ➡️ Learn more about Andrew:  📚 Get The Universe in a Box: https://a.co/d/2V7vuFR  ✖️ Follow Andrew on Twitter: https://x.com/apontzen ➡️ Follow me on your fav platforms: ✖️ Twitter: https://twitter.com/DrBrianKeating  🔔 YouTube: https://www.youtube.com/DrBrianKeating?sub_confirmation=1  📝 Join my mailing list: https://briankeating.com/list  ✍️ Check out my blog: https://briankeating.com/cosmic-musings/  🎙️ Follow my podcast: https://briankeating.com/podcast  Into the Impossible with Brian Keating is a podcast dedicated to all those who want to explore the universe within and beyond the known. Make sure to follow/subscribe so you never miss an episode! Learn more about your ad choices. Visit megaphone.fm/adchoices

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Even if we could solve the equations that we write down perfectly, we are not literally reproducing the universe. I think we always have to start from that point, that there is no perfect solution to this problem. Any sufficiently advanced technology is indistinguishable from magic. Open the pod bay doors, out. Andrew Ponson, welcome to the Into the Impossible Podcast. Great to have you. Oh, thanks for having me. In your book, you conclude with a simultaneous discussion of two extremely hot-button issues, aliens in the universe and a hypothetical,

instantiation of the simulation hypothesis, popularized by many time past guest Nick Bostrom. Is it possible knowing, as you do, so much about simulations of cosmic and terrestrial phenomena? Is it even possible computationally, energetically, for any civilization to truly simulate reality such that you and I perceive that we're having this conversation, but it's truly just a giant version of Minecraft? Short answer, no. I don't think it is. But of course, I mean, the long answer can take a very long time indeed because there's a huge amount to kind of unpack in what seems to be a kind of straightforward question. There's actually a huge amount going on there under the surface. And in a sense, that was one of the things I wanted to write about in the book.

The short answer is that the richness of our universe, and we can actually measure that in something that maybe we'll come on to, I don't know, called qubits. that's bits in a quantum computer. The number of qubits accessible within our universe is a fixed number. And we can kind of make estimates of that number. It's some humongous number. The exact number doesn't matter too much, but it's absolutely humongous. And the thing is, if you wanted to simulate that with perfect fidelity, you would need a quantum computer with that many cubits. So in other words, you would need to use the resources of the entire universe to simulate the universe. And so, you know, at the heart of it, that is why I just do not believe that this is really a kind of plausible explanation for kind of future path of simulations. We've had on your countrymen and Nobel laureate, Tim Palmer, discussing his book on chaos and computer simulations, which has a very famous anecdote about abysmal weather forecasting in your fine country.

We'll get into that. we talk a lot about climate change skepticism on the podcast with him from two years ago now, the interview that we did. And, you know, part of the impression that he came made to me was that to simulate the climate, we, according to him, need a CERN-level, you know, climate simulator, et cetera. But ideally, we'd have an earth-sized simulator. Doesn't that response that you just made, you know, about qubits, I mean, we could translate that to classical computing and just ordinary.

bits, don't the sort of proponents of skepticism or the skeptics about anthropogenic climate change, don't they have a point then to say, well, if you can't, you know, if you need a full-sized computer to simulate galaxies in the entire universe, why not, you know, say that there are limitations to the very much smaller than Earth-sized simulations that we use for anthropogenic climate change concerns? What do you say to those critics? Well, the thing to bear in mind is that when it comes to climate simulations, we are not trying, and I say we in a broad sense, I mean, I have nothing to do with climate simulations myself, but we as a community are not trying to reproduce the Earth in every detail. That's the

first thing. That's just not part of the goal. What one is trying to extract from climate simulations is some impression of the patterns that our planet may go through in the future. And the kind of thing about simulations of the universe as a whole, but also of our planet, is it does prove to be possible to draw out certain patterns despite the fact that not every single detail is represented in there. So I think, you know, again, this is one of the kind of driving motivations for me writing about this, that this is actually at the heart of what we do in simulations is we try to find ways to simplify, it has to be simplified, to fit inside a computer, and yet still get insights and and valid insights into the kind of patterns that are going on in our universe or on our planet.

You've pioneered many of these, I guess you can call them experiments. I've had some trouble. You know, I'm an experimental cosmologist. You can see the W-Map globe in the background. And actually, the W-Map was my grand advisor, David Wilkinson. So I've been doing this a long time. And I always found it distasteful. You know, we have colleagues around here that talk about they have a laboratory for brown dwarfs.

you know, my colleague Andrew Bergger, Adam Bergesser. Yeah, he's not doing lab work, you know, per se. And Mike Norman, who is my colleague here at UC San Diego, does many, many great simulations and the flat iron. And all these groups do similar. And some of them call themselves experimentalists or they're doing experiments. And I always kind of laughed at them, you know, silly scientists. You know, when you learn how to use a wirebonder and, you know, a vacuum, a turbo-molecular pump,

then you can call me. I'm so arrogant, right? But in the book, you talk about a very early simulation of the galaxy using light bulbs, photomultiplier tubes and so forth. This was a real experiment. Whoever was doing that can you talk about that incredible experiment with light bulbs and how this was a true, honest to goodness experiment? Much to my chagrin. The interesting thing about simulations is in some sense, it doesn't matter whether they're running on a computer or not. The fact that we have bits and that we have computer code and so on is, it's a thing.

kind of almost beside the point. You know, what we're really trying to do is build systems that allow us to get some insight into other systems. And the other system happens to be this huge thing that we call the universe, or perhaps some kind of portion of it. But in the end, what we use to make the simulation of it doesn't have to be a computer. And you're absolutely right that some of the earliest attempts to simulate the universe did not make use of computers at all. So that's true, for example, for simulating the weather and the climate. There were various early attempts to do that just with pen and paper, but also when it came to galaxies, this incredible experiment that was done, I think, in Lund University, if I remember correctly, where it involved

a kind of whole laboratory full of light bulbs and actually whole groups of stars, because you can't have enough light bulbs to represent all the stars in a galaxy. If you measure the intensity of light coming from a bulb, as you move away from that bulb, the intensity of that light drops off in a very particular way. It's called the inverse square law. And that is essentially how gravity works as well, that the force of gravity as you move away from a massive object also drops off as an inverse square law. So within a laboratory, it was possible to measure the intensity of light coming from different directions and use that as a proxy for what the force of gravity would be if you kind of scaled this up to galaxy sizes.

And then, you know, move the bulb, literally physically move the bulbs around as though they were stars being pulled around inside a galaxy by the force of gravity. And I just think it's a really neat example of, you know, what we're really trying to do is make one physical thing stand in for another. The scientist there, Holmberg that you describe in the book, talk about the ways that the techniques that he invented, including the drift step and the kickstep, that you're still using. You and your ilk are still using these, Andrew. I found it fascinating.

Can you explain what are these things and how do we implement them in today's modern simulations? I've talked about the force of gravity. So the first thing you have to do, if you want to know how a galaxy or a collection of galaxies or anything much out in space is going to move, is figure out what that force of gravity is. and you can use that force to work out how things are accelerating. In other words, the change in their motion is going to be like. But that's just like a snapshot. It's just a moment in time. If I go around in this lab that, as you say, Holmberg had,

go around in the lab and measure the light intensity in different places. I can figure out the forces. This gives me a snapshot of how the motion should be changing. And that change in motion that I can get from doing, that is we call it a kick because we imagine, okay, you can think of these forces as just every now and again they kick anything that's there like a star onto a slightly different trajectory than the one it was on previously. And then we do what's called a drift step. Now in the laboratory, this would consist of moving the light bulbs in a straight line along their current

direction of travel by a certain amount, which is proportional to their speed. In the real universe, this all happens at the same time. You know, the forces are acting and they're kind of reshaping the trajectories continually of the stars out there in the real universe. But in a lab, you can't really do that. That becomes too complex. So what you end up doing is you move it along a straight line

and that's the drift. Then you recalculate all of these forces, or you re-measure them, and you put things onto new trajectories, and that's the kick that you've done, and then you drift again. And in this way, you sort of take baby steps and watch how the thing changes over time

through these kind of kick, drift, kick, drift cycles. So it's a kind of way of splitting up the different things that are going on in the real universe into steps that we can actually concretely take either in a lab or on a computer. Yeah, I found it truly amazing that these tools are still employed in many different ways

throughout the realm, you know, from cosmological simulations to in these early simulations to much later ones where we still can't replicate, you know, the full-scale objects as we just talked about. It requires, you know, the entire universe or the entire climate is the best. And these are, you know, really belying the fact that we're talking about here are complex systems, right, that can't be replaced except faithfully replaced, except with their exact one-to-one correspondence. And yes, we have to make approximations, of course.

You know, the other thing that I was very much interested in is the sort of weather simulations where we, you know, I often show my students, you know, a hurricane and then a spiral galaxy. Or I show the Orion Nebula and M51 I have somewhere in the background over here. You know, these have these superficial resemblances. But do they have actual, in other words, if our climate friends in the next building over, Tim Palmer, if they made some stupendous breakthrough, if they had a CERN for climate change, could we immediately port that over one to one and then apply it in the simulations that you do? Maybe not immediately, but there's definitely a lot in common.

And I mean, the most fundamental thing they have in common is that they both deal with what we call in the physics world, we call them fluids, which would suggest it's stuff like water or oil, but it's more general than that. it's actually anything that can kind of be moved around and it's not a solid, but it can be moved around. So we would include the air around us as a fluid, for instance, because that can be moved around if you've got a fan or whatever, and material that the atmosphere is made out of here on Earth, so the air that it's made out of, but also the moisture in the atmosphere, that can be thought of as a fluid. And all the gas in the universe can be thought of as a fluid.

And that has a technical meaning to it. It means that we can follow certain equations that tell us how we think it should behave. And of course, it's not kind of the most fundamental views. It goes back to our earlier conversation that you are not directly talking about what we know it's actually made out of, which of course is molecules and atoms and the subatomic particles that make those up. But it's an extremely good, effective view of what's going on. and it just considers material to be something that can be reshaped and it can be compressed or it can expand, it can be pushed around, it can push on other bits of the fluid and so on.

So there are these rules that are encoded into something called the Navia Stokes equations, named after some 19th century physicists. And those rules or equations just encapsulate beautifully how material of this sort behaves on mass. So to a large extent, when we look at a weather forecast or a climate change prediction, it is based around these Navier-Stokes equations, and they also apply in the universe at large. So being able to solve them better in one domain does help in another domain, but the particular circumstances we're trying to solve them under also varies quite a bit. We are now due for a slight commercial break to promote your wonderful new book,

the universe in the box. And I'd like you to do what you're never supposed to do, which you're forbidden to do, according to some, which is to judge a book by its cover. So you've got the British version, UK version there and paperback, and that is prompting me to do the internet. I listen to it. You narrate beautifully. If you ever need a fallback career, your molyfluous voices. tones will be useful to all authors that don't want to record their own audiobooks like me.

The Universe in a Box. Explain the title, subtitle, and this artwork on the cover. All right, yeah. So the universe in a box is the idea that you can take the universe and fit it inside a box, which is a computer. Now, I think our conversation already has made clear that it's a bit, you know, it's a bit tongue-in-cheek, right? You can't really do that. And the book, of course, unpicks why you can't do it and how nonetheless you can get insights into the universe from attempting to fit some of its phenomena into the box that we call a computer. That's the idea behind the sort of main title. Interestingly, the subtitle is different in different additions around the world. So here in the UK, it's called the universe in a box a new

cosmic history. The idea being that I think in the UK market, we were particularly highlighting that it talks both about cosmological history, but also about some of the historical figures who've contributed to our ability to even do this or even dream of doing this. And they're perhaps a little less well-known than some of the kind of big figures of theoretical cosmology that we more often talk about. So that's the UK subtitle. The US subtitle simulations and the quest to code the cosmos is, I guess, a little bit more literal and focuses in more on the actual coding side, which it's in there.

But I think a lot of the book really talks about the things that lead up to the code rather than the code itself, if you like. There's no shortage of books. There's another book by upcoming guests, Rameel Dave, Davi. I guess I'll ask him how to pronounce his name when we finally do meet. If you're out there, Rameel, I'm planning to... Your summer starts now with Memorial Day deals at the Home Depot. It's time to fire up summer cookouts with the next grill,

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which is unique because it's unique in many ways, Andrew. It probably covers the most number of former, you know, past guest on the Into the Impossible podcast, including Richard Dawkins makes an appearance in a book about astronomical simulations, which I found fascinating. As I already mentioned, the appearance by Nick Bostrom, who did me an incredible honor once. He sent me a PR pitch to come on the podcast. And in it, it said, Nick Bostrom has appeared on the Joe Rogan Experience, the Lex Friedman podcast and into The Impossible with Brian Keating. That was very flattering to be in that company.

But I want to bring up another book, which is that by Katie Mack, who, as I understand, was your former office mate. Is that true? That's absolutely true. Yeah, we shared an office at Cambridge University for a couple of years, I think. And I had her on many, many years ago. And towards the end of the book, she's interviewing folks, including Hierania Pyrrhus, who is a very close advisor to the Simon's Observatory for many years. And Hyrania says it's very depressing about the end of the universe. I don't know what else to say about it. It does provoke some perspective taking, very depressing. We have a lot of utter darkness. And then she quotes Andrew Ponson. It momentarily makes me feel sad, agrees Andrew Ponson.

Then I very quickly start worrying. What does you mean by that? What are you worried about? At the end of the universe, according to Katie, won't come for many dozens of billions of years. What do you worry about? I remember Katie coming here talking to me about this. I can't remember exactly what I was saying to her. But I mean, I think my overall feeling about this is, yes, the end of the universe is a bit sad, you know, the idea that there is a finite lifespan to our universe and we can't just go on forever. But it's a very, very, very long time indeed, as Katie writes about. And I think, you know, my worry is nearly always over kind of much shorter term things. You know, I worry about where we're headed here on earth in here and now,

or, you know, in decades or centuries, much more than I worry about the long-term future of cosmology. I suppose this is part of the, and you must experience this, this is part of the weirdness of being a cosmologist, that on the one hand, one is grappling with some of these absolutely huge ideas and huge spans of time and things that have enormous implications. And yet, on the other hand, you live your life like anybody else. And there is a certain level of partition in your head that you can comprehend intellectually

what's going on in the universe, which is fantastic. And it's so exciting to be alive at a time when we can comprehend some of these things intellectually. But in a sort of instinctive human sense, I still kind of worry much more about what's going on around us right now than about the long-term fate of the galaxy or the sun or the universe as of. whole. Talk about the work that you did go into with the cosmic microwave background. Beach ball that, you know, is also representative of how the bread gets buttered around the Keating household. Talk about the work that you did in the CMB. You seem to take a break from simulation research to do some actual pencil and paper theory, as I understand it. So explain what was the outcome of that research? And why did

it distract you from your, you know, putting particles in a box? As I talk about in the book, I have had a moment of kind of crisis in my relationship to simulation. I tell my students, if you don't, you're not a good graduate student. Yeah. I mean, I think whenever you start digging into something, right, you see where the bodies are buried and it relates to the stuff we've already talked about, right? I mean, simulations. And I think actually, you know, there's a serious point here that we can be guilty sometimes

in the simulation community of portraying simulations as a literal snapshot of our universe and really telling us about the real universe. And of course, it's not. You know, you start digging into it and you realize there are all of these simplifications, all of these approximations. And I had this kind of moment of crisis when I was doing my PhD where I thought,

yeah, this just, it doesn't really make any sense at all. Of course, I later came out of that. And I reached what I think is a kind of considered view of this, which is that there are some severe shortcomings, but it can also tell you something very important as well. Anyway, so I was having this crisis and I just looked around in the department, what else is there to do? And it was right around the time. Of course, there was huge excitement around WMAP. The WMAP results, the first results from WMAP came out right around the time

I was starting my PhD. And I was in a department where people were thinking about the cosmic microwave background a lot. There were characters like George F. Starview there who'd done a huge amount of early work on figuring out. Also a past guest on the podcast. Right, right. So he's done a huge amount of work and figuring out what the properties of it would be. And so I just kind of went, went around asking people, you know, is there anything I can do on this? And it was Anthony Chalner, who I end up working with closely, who would later play a big role in things like the Plank satellite. And he came up with this suggestion. He'd seen stuff about spinning universes. So one of the weird things about Einstein's general relativity is that it permits things like the entire

universe to spin, which is quite a strange idea when you stop and think about it. Apart from anything, you might think, spin relative to what? And I think Einstein would have worried about about this if you'd been thinking about spinning universes. I don't think he ever spent much time thinking about this. I think his buddy, his buddy, Kurt, Gerdale. Yeah, indeed, indeed. Gerdel had written down what we call the metric for one of the first ever thought of spinning universes, and it had very strange properties. Like, for example, it permits time travel. So, so Kurt Gerdel had cited this as like a kind of problem with general relativity. And I've never seen any evidence it bothered Einstein too much. Nonetheless,

if our universe were to be found to be spinning, it would be profound. because it would open up a lot of weirdnesses in general relativity. And it would also cast doubt on a lot of the kind of prevalent theories of what was going on in the early universe. So these are theories like inflation. Despite being on somewhat dodgy territory, we do lean on quite heavily in cosmology. So it was interesting to work with these universes.

And we realized we could calculate what imprint they would leave on the cosmic microwave background. and more specifically on the polarization. So Stephen Hawking, some years before, and also John Barrow, had done some work on calculating this. But we came along and we basically calculated everything there was to know about if you're in a spinning universe, what impact would that have on the cosmic microwave background? We did some quick check against the W-map data as it was available then,

and we found, yes, there's no evidence at all that our universe is spinning. And later on, a student of mine, many, years later came and did a really careful comparison with the plank data, which was later kind of really high resolution view of the cosmic microwave background. And again, absolutely no evidence at all that the universe spins. So it's one of those things where, yeah, I mean, the answer, of course, is a bit disappointing. You know, if we'd found that the universe is spinning, we'd probably have been on our way to Stockholm to pick up a Nobel Prize or something. But on the other hand, I learned a huge amount of physics doing this. It was a fun calculation. And, you know,

it's good to check these things. In computational cosmology, there's often a distinction between what I call maybe verification, are we solving the equations correctly, and validation, are we solving the correct equations? How do you approach this competing tension and the challenge that these two different competing ideas face in your research? I think one has to be incredibly clear about what we're trying to achieve when we perform a simulation. So the first thing to say is we know we never kind of fully correctly solve the equations that we're trying to solve. Even if we could solve the equations that we write down

perfectly, and that is beyond us, you know, it's just not possible. As I was mentioning earlier, you know, we're not solving the equations of quantum field theory or something. So, you know, we are not literally reproducing the universe. So I think we always have to start from that point, that there is no perfect solution to this problem. So we're always doing some approximations. So then you have to kind of approach quite carefully to say, okay, what am I going to do then? I know I'm doing approximations.

I know that there's some freedom within those approximations about what I choose to approximate and how. And therefore, to some extent, I can get different answers depending on what kind of approximations I make. So you can play the game of trying to match everything there is to match. that's known about the universe, for example. So you end up, this is through something called subgrid, which maybe we'll come onto in detail.

I mean, you end up with the ability to kind of tweak things within your simulations and you get different results and you can play the game of let's try and match everything there is to match in the universe. Let's go and see all the observations that have ever been taken of galaxies and galaxy clusters and try and match them. And some people do play this game. You know, they tweak the parameters that they've got in front of them, and then they get a nice looking universe and go, yeah, we've done it. I think that that's, you know, not the most helpful approach to this.

Normally what the best thing to do is, is to be very open and honest about the fact that there is this freedom, but then to restrict what you're going to fit your simulation to. So you say, okay, I want to make sure that I get certain things about the universe right, and I'm going to use the fact that I can tweak things within my simulation to do that. But then I'm going to draw a line and say, okay, that's what I calibrate on. And now here's my prediction. And in the end, you know, even in cosmology, we can make predictions. It's not like we can go out into the universe to test them,

but we can make predictions for what a new telescope or new facility is going to discover. So I think that, in essence, I think is the best, you know, the best simulation work does that. It kind of draws a line around what you're going to force the simulation to match and then makes a prediction for something new and then goes and tests it. And, you know, sometimes those predictions do come out to be right. Not always, but sometimes they do. And then you feel like you're learning something. You're stepping forwards and your understanding of how the universe sort of ticks on these large scales. You may be aware of this, but about two years ago in the summer of 2022, there was all this great hullabalogue, great controversy about whether or not the Big Bang even happened.

Because these images from the James Webb Space Telescope appeared to show galaxies that were more mature. They had disc shapes. They were rotating. And this was claimed by a cosmologist, amateur cosmologist named Eric Lerner, to be evidence that the Big Bang never happened, which is also the title of his book, when the Hubble Deep Field came out, you know, before you were born. And the question I have for you is, you know, what kind of new advances in simulations have there been to kind of dissuade you from the, even having any credulity in the, in the veracity of the hypothesis there was no Big Bang?

How do simulations help us disprove that conjecture? If you'd focus in on, was there a Big Bang specifically, then, in fact, it's your field the cosmic microwave background, which is the single most compelling piece of evidence. If you just want to point to one thing to say, look, this really happened, then it would be the cosmic microwave background and the fact that we can compute its detailed properties, and that was a prediction, right? And then it turned out to be correct. So, you know, if that's your goal just to show that the Big Bang happened loosely in the way that we think, then that's the way I would do it. In terms of the simulations, though, you know,

these images from James Webb Space Telescope did cause a stir within the professional community. They showed galaxies which were brighter than I think most people were expecting to see at very, very early times. So the point is, you know, James Webb is essentially looking back in time because it peers so deep into the universe. It's seeing light that's taken most of the age of the universe to reach us. And contrary to, I think, what most people were expecting, it saw a few really bright galaxies. back in in at those early times. I was immediately skeptical that this told us anything kind of that earth shattering about the history of the universe. Certainly given the other evidence we have for the big bang, it would not kind of shift me from my belief in the fundamental correctness of

the basic big bang picture. But I think it has provoked a lot of discussion among simulators about you know how did we go wrong here? You know, why why is it? that we weren't expecting to see such bright things. And a few simulators, by the way, point back to papers that they published before James Webb launched and said, actually, you know, we got it right. So it's not that everyone got it wrong.

I think it's just that the sort of overall consensus within the community was expecting fewer really bright things. And honestly, I don't think it's a fully solved problem. A few things have happened since then. First of all, some of the really bright galaxies turned out to be misidentified. So, you know, in the really early days of James Webb, some of those things that were claimed to be really bright things

very early in the history of the universe turned out to be a bit of a mistake. And actually, they'd just been misidentified. They were actually closer to us and therefore not quite so ancient as we thought. But another thing that's probably going on is that the way that stars form in the very early universe isn't yet fully understood.

That we kind of understand how stars form in today's universe, universe because we have telescopes where we can see stellar nurseries where new stars are forming. But in the early universe, this probably happened in quite a different way. You know, the early universe was much denser, for one thing. And for another thing, it didn't have the kind of heavy elements that are in the universe today. And both of those things can make quite a big difference to how stars form and therefore what exactly you would expect to see within an early galaxy. But this is still being quite actively debated and I think James Webb is certainly proving provocative. Absolutely. No, it's fascinating. I talked with Chris Haywood at the Flatiron Institute not

too long ago about the role of feedback. And you mentioned this already in the context of having a discussion about what subgrid, you know, resolution scale effects there are. But let's take a bigger step backwards and go back to somebody I'd heard about, you know, we have posters of her and the astronomy department. UC San Diego, a brand new astronomy department, you know, still unwrapping. It still has that new department smell, you know, just last year formed Alison Coyle, his chair.

Beatrice Tinsley, again, I'd seen her. Not to some things about her, but she turns out to play, you know, sort of an equal role to, you know, say her counterpart, who actually did work here, which is Vera Rubin, who work with Margaret and Jeffrey Burbage. And, in fact, It's peak pollination season, and my business is scaling fast. To keep the nectar flowing, I need a phone plan with top priority data speeds.

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Am I wrong there? And if you'd be kind enough to kind of discuss her contributions to the field that we now study in galaxy simulations. I think you're absolutely right to put them on an equal pedestal. You know, Vera Rubin obtained some of the most compelling evidence for dark matter in the early days as that theory of what. our universe is made out of, started to gather steam. And Beatrice Tinsley, you know, around a similar time, maybe even slightly earlier, was thinking about how galaxies change and evolve over time. And she was particularly interested in this because at the time, cosmology was a very, very different field. One of the big characters in cosmology at the time was Alan Sandage.

And he was trying to use galaxies as what we would now call a standard candle. So in other words, he was assuming that if you see one galaxy and another galaxy in different parts of the universe, on average, they shine with the same brightness. I mean, not down to every single object being identical, but just on average they would shine with the same brightness. And he was using that supposed fact to map out the expansion of the universe by seeing where different galaxies were and how they were moving. and one of the key ingredients in this to figure out how far away is a galaxy is to look at how bright a light are you receiving from it. And if you want to use that as a way to figure out its distance and thereby map out the universe,

you have to assume you know, at least on average, how bright a galaxy is. And so Alan Sandidge was assuming that. And then along came Beatrice Tinsley and did a PhD thesis where she was pretty much operating in isolation. She was very, very isolated. She was working on a topic in Texas that not many other people were interested in, but she got hold of access to an early computer and just went, okay, well, if we're assuming that all of these galaxies shine the same,

then one of the things that we are sort of quietly assuming is that they don't change over time either. Because when we look to different distances, we're seeing light, delayed by different lengths of time. So if galaxies change over time, then Alan Sandage's assumptions are all wrong. So she programmed what we could now recognize as the kind of bare bones of a galaxy simulation into sort of rudimentary computer that was available at the time. And she did the kind of exercise we were talking about a moment ago. She didn't know, you know, exactly how to simulate a galaxy. Nobody did. Still nobody does. But what she was able to do was kind of scan over, well, what are the different things that might be happening inside a galaxy?

And how would that affect how the galaxy shines? And in particular, as stars age, eventually they die. And so if stars are dying, then the brightness of a galaxy is dimming and its color is changing as well. So all of these different things, she kind of programmed into her code. And then she found there is no way that you can make galaxies that just sit, there staying the same brightness for all time. And so in this kind of calm methodical way, using what we can now recognize as one of the first ever galaxy simulations, she just undermined the whole of Alan Sandige's program. And that was, you know, one of the big programs of cosmology at the time and completely changed how people thought about how to map out the universe and

what indeed the fate of the universe would be, which was one of the consequences of Alan Sandige's work and for doing that well she she got a lot of grief I think Alan Sandage was not happy at all and and it took a long time for her ideas to kind of get fully recognized within the community hey there fellow Voyagers into the impossible tis I your fearful host professor Brian Keating here with a tiny little homework assignment before we get back to the episode and that's to make sure that you're subscribed to the podcast either following it or subscribing to it depending on your podcast catcher of choice. I did some research of my own and found out that about half of you are actually following or

subscribing to the podcast. So please do that. And for some extra credit, if you're looking to boost your position on the grading curve, please leave a rating or review. It really helps us out tremendously. Do it. Do it now. Before you forget, let's go back to the episode.

Yes, she certainly did. And if I'm not mistaken, she also kind of had some. impact on this notion of feedback and evolution, which play such a big role in the context of the galactic simulations that actually faithfully represent what galaxies look like. Can you talk about, yeah, subgrid rules for feedback, the importance of feedback, resolution effects, and sort of the cutting edge, the bleeding edge of this field? You're absolutely right. So her work in particular with Larsen kind of was some of the first to really talk about the effect. of feedback. And perhaps the easiest way to think about this at first is to go back to the weather.

And if you're sitting there on a hot day and you look up and you start to see these kind of bubbling up thunder clouds start to form. And in principle, you know, there's no reason why you couldn't represent that with the equations we were talking about earlier on, the Navia Stokes equations. But if it's this hot day that started out nice and clear, you've found. find that these clouds form, they're really quite small. You know, the clouds that form, there are a kilometre or two kilometers across. And this process, if you're trying to map the weather across a whole country, let alone the whole world, a kilometer or two is very, very small compared to the kind of ground you're trying to cover. And so early weather simulations, even

up to a few years ago, could not simultaneously keep track of a whole country or the whole world, and also have the computer power to see tiny little clouds forming across that huge area. So what people did was that they said, okay, well, we're not going to see this happen just by solving the equations. We have to put in something else. We have to put in by hand an extra rule. Even though we know that it happens for a different reason, within the simulation, we're just going to put in a rule. And the rule just says, on a hot day when the atmosphere is in a certain state, then thunder clouds will start to form. And we'll just force the simulation to do that because it ought to do it itself, but it doesn't have the computational power to actually see that happening. You put it in by hand, and if you're doing weather simulations, you end up with a bunch of what we were talking about earlier on, parameters.

You don't know exactly how fast these clouds will form, for example, so you have a nod that you can turn on your simulation. You can make them form faster or slower. You don't know exactly how fast they should form. You dial the knob up and down until you find you're starting to get good weather forecasts. And then you go, okay, I've figured out what that knob should be set to. It's sort of dirty, you know. It's not the vision that we like to have of physics as, okay, we can just derive everything from a beautiful equation and derive it all on a piece of paper

and figure out everything that should happen. But it works. It works extremely well for weather simulations. It also works in the context of climate that you were talking about earlier on. We know that because we can look at what's called paleo-climate data. So in other words, data from ice cores and things like that that tell us how the climate was in the past.

And again, you need these subgrid rules, but you can tweak them, and then you can make predictions for new bits of data that you're getting and so on. So that's what happens in the world of weather and climate, and we have to do it in the universe as well. And for us in the universe, small is not a few kilometers across. It's light years across, in fact, because the universe is so vast that a galaxy is thousands and thousands of light years across.

So if you want to know what's going on across that whole galaxy, then you can't really also have the computer power to be seeing what's going on on sort of one light year scales. And that includes things like stars forming, you know, really important things like the actual stars that we're going to see in the galaxy form. Of course, a star is quite a small thing

on the kind of scales that we're talking about. So you need to put in these subgrid rules for how the stars form and also what the stars then do to their surroundings. So the stars dump lots of energy in the form of radiation, or in the case of massive stars, after a few million years, they can explode as supernovae. And that also dumps a whole bunch of energy into the galaxy, into the very kind of large-scale system that you care about.

So somehow or other, you need to capture all of this, and you're not going to do it just by solving the nice, neat, laws of physics that you would like to solve. So you have to put in a subgrid. Tinsley and Larson was some of the first to kind of really recognize this in that context of galaxy formation. The other thing that kind of surprised me to encounter in the way that I did in this book, the universe in a box, was sort of the notion of a universe in a box. In other words, why be so as past guest, Andrea Linde said so universe-specific?

Why not talk about the multiverse and have that as our baseline? Talk about the way the multiverse can come into play, both in standard cosmological simulations, as well as in quantum computers and the Everettian many worlds interpretation of quantum mechanics. In a straightforward sense, we can make multiverses within our computers, in the sense that we can perform multiple simulations.

So we don't just need to do one brilliant simulation. We, of course, do many simulations, partly because we want to try different things, but also we can do things like change some of the fundamental parameters that describe our universe. For instance, how much matter does it have in it? So you can perform simulations that have a little bit more or a little bit less and find out how do they behave relative to the others. In simulation world, we can, universe is a cheap, right? We can generate as many of them as we like and see how they behave.

When it comes to the real universe and whether we live in a multiverse, in other words, is our actual universe one of many? I have always been struck by this idea of the Everettian multiverse. It's this incredible notion put forward by Hugh Everett, that one way to make sense of some of weirdnesses of quantum mechanics. And in particular, the kind of weirdness of something called wave function collapse, which is where when you do an experiment on quantum scales, it seems like what you're actually experimenting on changes when you observe it. And that is this notion of wave function collapse. That is very uncomfortable. And this idea that Hugh Everett had was that

an alternative to that is to imagine that we actually live in. this much, much richer multiverse, which in effect, it kind of splits out into multiple distinct universes where lots of different possibilities play out in parallel. And mathematically speaking, this kind of holds water. It does work as a way of explaining some of the oddities of quantum mechanics. Whether it's comfortable or not is more a matter of taste. But as we kind of explore quantum systems more and more, and we build more and more complicated quantum systems. I think it's David Deutsch who has pointed out that, you know, if you can build a quantum computer, if you can actually start building quantum computers that take advantage of these weird quantum effects,

you're almost left with no alternative but to imagine that this computer works by taking advantage of this much, the way we call it is a much bigger state space, but, you know, colloquially it's like that there really are kind of parallel universe is doing a lot of the computational heavy lifting if those computers work. And when you look at the universe, you find it has quantum imprints in it. In fact, when we perform our simulations, we have to start from a state which is dominated by randomness, which is thought to occur from quantum effects during period of inflation that we mentioned briefly earlier on. If that's true, then when did the universe undergo wave function collapse to become the one universe we see today? Well, the sort of,

the easiest answer in a sense, as Hugh Everett would say, is it never did. You know, you don't have to imagine some weird moment at which the universe suddenly collapses and becomes a classical single universe, it can just never undergo way function collapse and these parallel universes can just exist side by side. That's the idea, and of course it's fiercely controversial, but I've always found it actually makes sense of a huge amount of stuff that we already know. Along the lines of things that were claimed to be known at least two years ago in December, 2022, physicist led by friend Maria Spiroplu at Caltech claimed that we found a quantum system, that exhibits key properties of a gravitational wormhole,

yet is sufficiently small to implement on today's quantum hardware. What's the current status of that claim of physicists observing a wormhole or Einstein Rosenbridge using a quantum computer? So I'm not familiar with that exact work, but I mean there's a lot of work being done into quantum systems that in some sense mimic aspects of quantum gravity, including quantum black holes and like you say, quantum wormholes. So I can't speak to that particular paper, but I mean the key thing about all of

these things is that they have quite a lot in common with simulations in a sense. In fact, I'm involved in a collaboration which is looking at aspects of the early universe using a quantum system and other parts of that collaboration are looking at quantum black holes. Now, the thing to bear in mind is that they are always analogues, right? So it is a system. that you've carefully designed to... You said this place was steps from the water. We just haven't found the steps yet. How much did we save?

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When you want savings, not surprises. It matters where you use. Stay. Hilton for the stay. Have some of the same properties that we think these real systems in the real universe should have. So if it's a quantum black hole or a quantum wormhole or so on, they are, they're designed quite carefully to kind of mimic some of those things and you can learn a certain amount by studying those in a lab. They're really fascinating experiments. What one has to be really careful to do, just the same way as we do with simulations, you know, you have to draw kind

a sharp line and say, okay, yes, we can learn a lot by doing this, but it is not the same as literally having a quantum black hole that you can play with in your lab, or literally having a quantum wormhole that you can play with in your lab. The analogy that we're drawing between these two quite different bits of physics will have limitations to it. And I think I'm quite confident in saying that in a general sense, even though I'm not at a detailed level familiar with that particular work that you mention. As we wrap up, I want to cover a couple of things that have come to mind recently, and that has to do, first of all, with the state of the art of high performance computing,

and also the so-called ethics of using them and their carbon footprints, et cetera. We just had in the United States announced a potential acquisition by Microsoft of the defunct for 40 years, three-mile island or more, nuclear power plant. So I've learned that the carbon impact, the energy demands of a single AI search is about nine or ten times the conventional search query energy demands. What are the impacts of that on the growth curve? Unless I'm mistaken, some of the simulations, at least the ones that aren't for the military, they seem to saturate because as the computers get more powerful, more people want to use them. So talk about the energy impact, the ethics of doing these types of simulations. and what is the state of the art? What are you excited about?

The energy impact is very much on people's minds who work in this field, as you might expect. We tend to now estimate what carbon footprint we are pathing. And it probably won't surprise you to learn that it is a tiny fraction of what the world's data centers are using. It's a really minute fraction. So to give you an example, something called the Flamingo simulations, some of the largest simulations which have ever been performed. They just came out in the last few months. They have a climate impact that's roughly equivalent to two people taking a transatlantic flight.

So, say, London to New York in economy. So I think it's a return trip, actually. So it's like two people taking a return trip, London to New York and back. That is the biggest or maybe close to the biggest cosmological simulation ever performed. That's not to say we should ignore that, but it's not an absolutely enormous thing, and it certainly doesn't start to get to the point where you worry about it next to, say, the explosive growth in AI, which you mentioned. Just because of its much broader applications, of course,

is of course going to have a much bigger impact. People do worry about this, and I think it makes us think about making sure that we are making most efficient use of the resources that we have at our disposal, which we should be doing anyway, right? I mean, in the end, it's taxpayers who are funding these things. So, you know, it's right that we look at the efficiency, but I don't think that it's sort of having a noticeable impact in and of itself. It is very exciting, you know, that we live at a time where computer power continues to grow very, very fast. But, But what we're finding is that a lot of the really state-of-the-art computational facilities now work with quite specialized chips, quite specialized hardware, and what we used to call graphics processor units, GPUs.

These are the things that have become the bread and butter of AI because they are extremely good at doing very, very repetitive operations in very large numbers. And this is proving a challenge that, you know, the progress in computer power up to a few years, ago, we could just sit on the back of that and it more or less suited our needs if we wanted to simulate the universe. Now, because it's become a somewhat more specialized, a lot of the direction of growth is towards AI. That ability to do loads and loads of things repetitively is not ideally suited to simulating the universe, but mainly because when you try to simulate the universe, although there are some operations in there that are very repetitive, there's also a lot of communication that has to go on. So that one bit of the universe talks to another bit of the

universe through gravity and through sending out pressure waves and so on. So there's a lot of communication between different bits of the universe. And this is where it gets really hard to take advantage of the latest hardware, because AI tends to be all about just having lots of, you know, lots of your AI queries going on in parallel, but they're completely unaware of the other AI queries that are going on. So we've got we've got some big challenges in trying to make good use of the hardware platforms that are becoming available. And last but not least, I couldn't help but think when you talk in the book about all these sort of neologisms like smarticles or smarticles, I think you call them smarticles, right? This is something that you've coined.

I thought back to this famous poem that is obliquely perhaps referenced in your book. You discuss the discovery of Neptune, which is kind of the first instance of people discovering dark matter. The poem I recently learned from reading it with all my kids, when I heard the learned astronomer who's so depressed, Walt Whitman's very depressed about the night sky being brought to the mere fact of numbers. And then, of course, Feynman comes back. He also makes a lot of appearances in this book. But to say, well, why can't a scientist talk about the beauty just as much as a poet? You know, why? Because he knows that Jupiter is not a god, but is made of methane. How do you react to this, you know, kind of maybe cheapening of the beauty of astronomical appearances and so forth?

The cosmology. Cosmos means beauty, after all, in Greek. Does what you do maybe take away from the beauty of understanding the universe? Or does it enhance it? I think it enhances it. I mean, I guess I'm with Feynman on this, as you might predict. I think, you know, understanding something adds layers to your appreciation of it. And it goes back to something we were discussing earlier as well, that, you know, as a cosmologist, you can go and make calculations of these things, and we can build these computer simulations

that are giving us different insights into the way that the universe works. That doesn't change my fundamental relation to my life or to the way that I look at the universe. I still kind of walk along and when I see the night sky, it still makes me feel the same things. And knowing more about it, I think, can only enhance one's appreciation for it. It doesn't take away. And I certainly just feel in awe of how amazing the universe that we've got to live in is. Andrew Ponson, now at Durham. Thank you for this wonderful conversation and this wonderful book, The Universe in a Box,

simulations and the quest to code the cosmos, a lot of K-literative phraseology there. Andrew, thanks so much. Thanks. I appreciate it. Hey, everybody. I just wanted to thank you for listening to the episode. And I had recorded an audio essay. I'd like you to let me know what you think about it.

It was recorded after my trip to Los Angeles, Holly Weird, this past week. And I really had a great time on the diary of a CEO podcast. So these are my thoughts and recollections of the event. I'll have a blog post about it and you should subscribe to my Monday Magic mailing list in order to get some of this goodness distilled for your perusal. So without further ado, stay tuned for an audio outro for a change essay about by phenomenal experience on Diary of a CEO, which will be coming out on YouTube and a podcast in a couple weeks. I'm told. So enjoy.

Recording this after going on Diary of the CEO and had a phenomenal times, Stephen Bart, that they told me it would be three hours, maximum, very tight, very professional organization. Two or three or four people contacted me beforehand, and this is one of these opportunities I got nights to being out there in the public sphere, having, in this case, my friend Andrew Bustamante on the podcast. And he was very selfless. and connected me to the team over at the OIC. I heard from them, you know, oh, we'll look into it.

And, you know, thanks for the recommendation. You know, we'll be in touch. And then I didn't hear anything for several months, weeks, at least. And then eventually about a month ago, I got an email from their producer. And he said, we're going to lock in a date with you. Steve will be in Los Angeles. He'll come up to L.A.

from San Diego. And I did just that. I just finished recording. Instead of three hours, it was four and a half hours. It doesn't really include a bathroom break. So it was far exceeded my expectations in terms of length, but also in terms of the range of topics, the breadth of topics that we discussed,

is really a unique individual, incredibly humble, very self-effacing, extremely honest person. He has no guile. He has no heirs that he puts on. And this is the young man. He was 32. And he's fully invested at least in the band of podcasting, social media, tens of millions of followers.

There's hobnobs around on occasion. You know, it's not his preferred mode of activity, but he hobnops with celebrities and royalty, literally. The teacher king, at least Prince William, who's got him on Speeddoll. Does things for the Crown. It's just an incredible man. He really self-aid, never had a handout.

Born in Botswana, moved to London, did one day of college, dropped out, and now he's, you know, got several businesses, several hundred million dollars and assets under management, social media company. And then his podcast is the biggest, second biggest. It's the biggest in Europe, biggest in England for sure.

And he's truly this human individual. His excellent in whatever he does. And he has the self-evacing character that, you know, he looks up to people like Joe Rogan and others. And yet he's every bit in their league. Maybe in some ways I feel he's even more professional. And that's not the takeaway from Joe Rogan. But my experience there was, you know,

Joe is, when you're with him, he makes you feel like you're the most important person in the room. But aside from that, he's not really thinking about the guest or preparation or, you know, reading a book or something. You know, he's extremely educated. He might watch a podcast or might read, you know, a tweet or two. But Joe is not the type of person that's going to, you know, do the extensive research. And Stephen's team not only does research, but he does, he reads the books. I sent him. He reads actually not as much on social media at all.

but he, I don't know he is of social media, but he didn't use that to investigate, you know, my background story. He was really deeply engaging with my, with my books, one of the two books. And he's at the first hour talking about science, what is cosmology, what is the Big Bang. He's got a very diverse audience, about 50, 50, men and women. It's very different from the into the impossible audience, 85, 15. We talked very little about politics, which was wonderful. We talked about importance of having spaces away. from politically charged venues.

And he really liked that. It's clear he'd never add on somebody like me. He was a scientist that does the type of science that I do. And he just let me speak. He didn't want to use any of the cans tough, which is kind of funny because his team, you know, prep me. Here are the 10 opening questions. He's going to ask and that's that.

And he kind of just, on there, out of the room, he was like, screw that. I'm not going to do that. I just want you to talk. He really is a masterful conversation, the last he gets you to be vulnerable. and feel things. Also, he can share his own things.

He has a genuine curiosity. I felt he was reaching out in an effort to maybe understand more about religion. From my perspective, he had never met. Somebody like me was practicing Jew, text Judaism seriously. And we have, you know, we had a lump to talk about with respect to religion. A lot more than wanted to talk about it, to be honest. But he was just so determined to kind of see my perspective and be open to my Eddie my instruction.

But in the end, I think he's very comfortable where he's at. He's comfortable in his out skin. He's so young, 32. And so cheerful. Just an amazing person who can talk to everybody from Bitcoin grows to experts in human psychology, longevity, and mostly stays away from hot, you know, tomics of the day. That controversy and salaciousness refers to O.D. He had one episode recently with Lou Elizando's Ufalo Maxinalist.

And he has a book he's promoting and some say shilling this book and I tried to engage with Lou and his team sent me his book and his audio book and never followed up after a couple of conversations even though he's been on many, many events where he goes and speaks. And the next guy up is Taco Ben's Hasbush. So I'll be serious about engaging with a real scientist, at least right now. That's okay. I'm kind of, I've been ambivalent recently about where the podcast fits in my life portfolio, whether or not I want to really go pro and dedicate a larger fraction of my time in my life. I've recently donesized with team from six or seven videos a week and audio clips and self-forans down to just one, maybe two sometimes. and it's really kind of relaxed me and made me feel less anxiety. Even though I have a team, I still feel final quality control rests with me. Little things that a lay person might not notice, like how the captions are, titled, how faithful they are to what the guest is saying.

Did they say, you know, I want to know what there is to do, and I want to know what he did, and then the caption comes out from AI to his death or something like that. That's very embarrassing, you know, because I'll be on screen with it, be a video editor won't be. So just not having to outsourcing it to a team, you still have to think about it. It's kind of frustrating. Even if you pay a large amount of money as I did, now has been reduced significantly. So the opportunity that I had to glimpse Stephen Barton's each guy, you know, I must spend millions of dollars.

I mean, he flew to Los Angeles. He spends a week, 10 days in L.A., maybe a week or 10 days of New York, and then the rest is at London. His team, when he goes overseas, I've heard it's basically half a million dollar, maybe a million dollars each time he comes overseas. He's got 10 people, sound, lighting, cameras, kind of set design. He replicates the same set in America as he has in London. You've seen the famous set.

And I don't want to do that. There's no danger I'm going to do that. He's got, as I said, 10 million total followers around the world. So it really is a big part of what he does. Not all of he does. He does the version of Shark Tank, the original version of Shark Tank in the UK called Dragon's Den. And this is, you know, keeps him sort of active and just engaged.

But the podcast is really the hub of his business, of his life. It's the front door, the business card that he shows to the world. And, you know, I've got other things I need to do. I've got a very thriving research group with half a dozen, dozen employees, colleagues, partners, working on paper. giving lectures around the country, around the world in some cases, traveling to funding agencies, and then all the teaching duties that I have for education, classes, advising, letters of recommendation, mentorship, undergraduates, graduate students, only different things from me.

And then unlike Stephen, although I wish it on him, you know, I've got a very busy, active family life, young family, wife, kids, talked about fatherhood, talked about meaning, purpose, connections to how to think about God, not necessarily assuming God exists, kept coming back to it. And he was very dogged of his determination to get, for me, seeking answers. And I told him,

if you're seeking an answer or proof of God, you're out of luck. No one can give you that, least of all me. But he's so curious, and we talked God, maybe another outsh. And then he has a series of questions that he always asks that kind of went off topic. And I tried to be very attentive to the,

answering the questions. A couple times I strayed and he brought me back in an expert fashion. Hell, he's really pro at interviewing very deep eye contact. He's taking notes on this little iPad and sending messages to his producer to get clips made from certain comments that I made. And I brought a ton of demonstrations, telescopes, meteorites, dinosaur fossils, all sorts of really cool stuff. And the thing that I think resonated most with them is they gave him an actual real fragment of the planet ours. And that segued into Elon Musk's desires to go to Mars. And he asked me about my brief podcast than I did with Elon. And I can tell Elon's a real hero of his person that he most liked to get on the diary of the CEO.

I'm going to hope maybe someday to facilitate that because I would love to see that. It would be a different style of interview than Elon is done with Joe Rogan multiple times. I am not defined by my credit, even if it's low. Hey, Experian can help. You can get your FICO score and boost it instantly free. Get the Experian app now. Results will vary. Not'll introduce credit information impacted by Experian Boost.

See App Store for details. Treatment, more times, and etc. Those guys are great, but it's great to us. Steven's very different. Lex really nobody. There was nobody in Lex's house. We're in a quarry with them three years ago. That interview is coming up on almost eight and a half million views.

So far, it's 15th most popular video. favorite did, conversationally. I'm really proud of that. Who knows? This one could see no. It just depends on his audience. Lex's audience, much more technical, interested in all the details, experiments, history, science.

The one thing I did want to do is Steve's audience, given that the name is Diary of the CEO is connect my hero, Galileo, to this concept of what a CEO is, how pragmatic, entrepreneurial, how cunning, how clever Galileo was for good reason, for self-preservation, for survival of his family, for legacy, and how ultimately he sort of failed. He died more or less, you know, penniless, not quite penniless, but he was imprisoned in his villa in our Chetri, Italy that I've been to many times and left paying homage to. And he paid for his brilliance with his freedom. You know, he talked about him and dear Arm of Bruno.

I don't make this podcast intro, audio intro, into a full-length simulacrum of the episode, Stephen, but he did have a phenomenal. nominal time with him. At the end, he gives out, it's a really thoughtful gifts. They're actually taking pictures of us. I noticed they were taking pictures, but I thought it was for thumbnail and this thing. I'm actually taking pictures to make a souvenir scrapbook. I thought it was just a journal that they gave, you know, has on the front diary of a CEO, which contains a copy that he holds contains questions from all the guests that have ever been on the show. He asks a question of each guest, and that question comes from the previous guest to be on the podcast. So, for example, example, I left the question for his guest that he's actually recording with right now.

As I record this on Tuesday night, after doing four and a half hours with me, he came back to the studio at 5.30, right? I grabbed the quick workout, dinner, drink, whatever. And he's back in the studio right now at 5.30 to probably 9 p.m. and he'll do this for four more days. And then we'll go back to the UK. And it's kind of the only thing you, you know, the only a thing that a 32-year-old and a team of 20-somethings and 30-somethings could really do. But I wish, upon him to not have the freedom to do this in the future. I hope that he someday has a family as a serious partner. It's talked about her on his show. She's the right one for him. I hope that they'll find connection to be bonded together and hopefully start a family because, you know,

people liking don't start a family. The world is going to be a worst place. So really had a just truly unique experience with him. Gifts kind of put it over the top. I gave him a telescope because he had never seen the surface of the moon or the moons of Jupiter. He played such a central role in my career in my life as an astronomer. And I wanted to give him that gift so he could feel that same feeling. I felt, you know, 30, 40 years ago. Hopefully he and his team are so eager, energetic, curious, and incredibly professional.

These people are at the apex of this industry. And, you know, he kind of denigrated himself. Like, why am I doing this? I should just move to Bali. And then I think, what would I do? I just start a podcast, put things on Instagram. So he's doing what he's supposed to be doing. And I told him that.

And you should keep doing it and do it for many years. But eventually, Stephen, if you're listening, I want you to give it all up and become a dad. You don't have to give up the podcast for more than a few weeks, hopefully. And all the babies, you're fighting to every shred of consciousness that you have to preserve your sanity and life at your baby's life. Well, that's for a few weeks. But when it's over, you'll be a different person. You'll have deeper conversations than you already have it.

And I truly wish that upon you and on any of you that are looking for partner in life. And you'll see when the episode comes out, how that connects to the final question that was asked of me. And how emotional that was a good way for me. He's really an expert at what he does. So I want to give you that quick little audio intro. Hopefully this sound is okay. I'm trying to optimize the audio, if not I'll record it again. or release it as a blog, who knows, as I said, I'm kind of unwilling to put in the work,

at least in podcasting, so that I may put in the work into my family and into my scientific research while I still can't. They'll come a day when I'm really not that good at research anymore. Hopefully that day is long in the future. When that day comes, I'll revert to education, including maybe full-time podcast, as well as, you know, full-time teaching, whatever that means at the university. I'm so privileged to be and really have a lot of gratitude. We talked about how the simple gratitude expressions are the single best motivation to think of yourself in terms of a higher power,

trying to seek the truth, whether or not there is a higher power, I don't know. But to seek out to be on a quest and never stop. And I think he embodies not. At the very end, he gave me this very touching soliloquy about how wonderful. He thinks what I'm doing is and compared me. said Neil deGrasse Tyson, who will be an upcoming guest? Tell me into the impossible podcasts. So he was really giving me phrase for the ability to communicate complex topics in a simple

but not oversimplified way so that everybody can understand it and partake of science in the way that they deserve. So I give you for this self-indulgent recording. I hope you will enjoy the upcoming episodes. Stay tuned for episodes of Max Tagmark. And with Brian Green, Yildegrauss Tyson, really a star-studded end of the year. I just did a two-hour conversation with Steve Wolfram. I know, I know.

It doesn't sound like I'm really cutting back on podcasts, but trust me, these will be spread out, spread thin, so that I could kind of relax into the end of the year. The beginning of 2025, it's going to be an incredible year. For me personally, professionally, scientifically, I can't wait to show you some of the stuff I've been working on for the last decade with my colleagues, friends. I just want to thank you all for being a part of this journey

and giving me the sense, at least, that there's a voice on the other end of the line. You've kind of thought about the movie interstellar, which I saw recently for the first time, embarrassing to say. But those scenes where Jessica Chastain, young Perth, is sending messages into the void to talk to her father, Matthew McCona, and Cooper. And she's just transmitting. She doesn't know if anybody's off there receiving. Turns out he is receiving. And it means everything to him. Hopefully I get feedback more frequently than every 23 years or whenever he got it in that wonderful movie, which I wish I'd seen earlier.

But at least I got to see it, you know, came out on one of my kids was newborn. And I got to see it with two of my kids. It's very special. Let's see that movie, which is as much about fatherhood, parenthood as it is about science, technology, et cetera. Courtesy of my friend and past guest, Kip Thorne, who did all the scientific visualization work. Anyway, more in store. Stay tuned. And the one thing I learned from, Stephen, is never forget, never assume that you guys are subscribed. If you guys are following the podcast, please press that follow button, subscribe to the podcast, join on YouTube, trying to grow it. quantity has the quality all its own. Never get to Bartlett night like numbers, but it's just fun to know

that I'm having an impact. So leave a comment. Let me know what you think. And that keeps me going. Just like Cooper going through the center of Gartan's Shoeu. Thanks very much. Now let's go into the opponent. Enjoy more ways to save at Ralph's like low prices in every aisle. And when you download the Ralph's app, you can clip and save more with digital coupons every week. Plus, you can earn fuel points to save up to $1 per gallon at the pump. At Ralph's, you can enjoy more ways to save and more rewards every time you shop. So it's always easy to save big every day

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