Carlo Rovelli: Free Will Is Real. Physics Can Prove It.

This episode is sponsored by Abacus AI agent: agent.abacus.ai/keating I fed it Carlo's recent papers and asked for the argument, the counterargument, and the evidence that would support or refute each side. Some of the questions and animations in this interview came out of that. It runs the top frontier models in one place, turns a dense PDF into a research report or a presentation with charts, builds interactive dashboards off a spreadsheet, and takes API access if you want it wired into your own tools. Plans start at $10 a month. My link gets you the first month for $7: agent.abacus.ai/keating The physicist who built loop quantum gravity says the second law does not say what you were taught it says, and that freedom does not require breaking a single law of nature. Order builds itself. Your head is older than your feet. And neither one is the strangest thing here. Carlo Rovelli founded the loop quantum gravity program and wrote the relational interpretation of quantum mechanics. We cover: why oil separating from water is not a violation of entropy, what Galileo got wrong about the one discovery he is most famous for, the paper Einstein published denying gravitational waves, why a chess program that deliberates tells you what your own freedom actually is, and what Rovelli would build with ten years and unlimited money. “To imagine that to be free you have to violate the laws of nature is stupid.” — Carlo Rovelli CHAPTERS 00:00 Your head is older than your feet 00:48 Things left alone get ordered. Who ordered them? 07:00 Low entropy might be about you, not the universe 08:38 You can be in two cities at once, just not to you 11:02 Why start with Galileo when Einstein knew more? 19:34 Galileo misunderstood his own discovery 22:32 Einstein published a paper denying gravitational waves 25:08 The definition of time that explains nothing 26:50 Two clocks, two metres apart, two answers 31:06 Nothing gets recorded without something being lost 33:12 The chess program deliberates. So do you. 37:06 Can a machine have Einstein’s happiest thought? 39:52 Thirty minutes versus a month 44:10 Dark matter made of black holes the size of a hair 51:10 Ten years, unlimited money, a room full of junctions Rovelli told me the second law does not say what I was taught it says. Order builds itself. Transcript, bonus content, and my Monday M. A. G. I. C. Message: https://briankeating.com/yt Three moments worth the rewatch: 07:00 The entropy you were taught is a point of view 26:50 Why your head is older than your feet 39:52 The thing Claude did in 30 minutes Get the transcript, fascinating bonus content, and my Monday M. A. G. I. C. Message: https://briankeating.com/yt Have a .edu email and live in the USA? You automatically win a meteorite: https://BrianKeating.com/edu Subscribe: https://www.youtube.com/DrBrianKeating?sub_confirmation=1 Support Into the Impossible on Patreon, get my weekly M. A. G. I. C. Message, unfiltered bonus content, and live monthly Office Hours with me: https://www.patreon.com/drbriankeating Join this channel for perks, monthly Office Hours, and your name in the Member Roster at the end of every episode: https://www.youtube.com/channel/UCmXH_moPhfkqCk6S3b9RWuw/join Featured Guest: Carlo Rovelli website: https://www.cpt.univ-mrs.fr/~rovelli/ The Relational Universe (book): https://www.amazon.com/dp/0735216118 Carlo Rovelli on Twitter/X: https://x.com/carlorovelli My books: Losing the Nobel Prize (memoir): http://amzn.to/2sa5UpA Think Like a Nobel Prize Winner: https://a.co/d/03ezQFu Focus Like a Nobel Prize Winner: https://a.co/d/hi50U9U Galileo’s Dialogue (first-ever audiobook): https://a.co/d/iZPi9Un Twitter/X: https://x.com/BrianKeating Substack: https://briankeating.substack.com Blog: https://briankeating.com/blog Audio-only: https://briankeating.com/podcast #CarloRovelli #freewill #entropy #physics #quantumgravity #briankeating #intotheimpossible Learn more about your ad choices. Visit megaphone.fm/adchoices

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• 0:00Speaker 00

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• 0:54Speaker 02

  It's not true that things get disordered. In fact, very often, in nature, things left alone get ordered. To imagine that to be free of, to violate the laws of nature is stupid. You, Brian, can be in a superposition. You can be in L.A. and also in San Francisco. Your head is older than your feet.

• 1:15Brian Keating?

  That was Carlo Rovelli, one of the men who built loop quantum gravity, telling me that the second law doesn't say what I think it does. But he didn't stop there. Over the next hour, he's going to take apart the three things you were told that just ain't so, ranging from the frost on the window where you may be sitting right now to the clock on your wall. And the clock is the one that really got me. He blew my mind by telling me that my head is older than my feet. And then he told me why that's the least strange thing he was going to say. So Carlo, let's start with the frost. You're telling me that things left alone can get more ordered? That's not what I was taught. Walk us through that.

• 1:49Speaker 02

  First of all, I do think that the thermodynamic arrow, it's very basic. A lot of phenomena which we connect to the direction of time. For instance, I remember our last conversation. We don't remember our next conversation, right? We have picture of Brian young. We don't have picture of Brian old. We can decide where to go to dinner tomorrow, but we cannot decide where to go to dinner yesterday. So there's all this profound difference between future and past. And I got convinced in the last, I would say, 10 years, working a lot about that, that all these differences can all be traced to the thermodynamics arrow of time, to the entropic arrow of time.

• 2:34Speaker 02

  It's not obvious, but the reason we have memories of the past and not the future has to do with entropy growing. If it wasn't for entropy, there wouldn't be this disimilarity between. Now, have we fully understood the story? No, I think there are various aspects that we still get confused. And there are also, as you say, aspects that we oversimplify badly. Let me give you an example which is dear to me. We always make this story, okay? Take latte, cup, coffee, and mix. And look, they mix. In fact, take water and vinegar, put some vinegar in water, mix, and you know, they mix. Now, take water and oil, mix, they separate.

• 3:21Speaker 02

  Oh yeah? Or is this contradicting our entire understanding of the universe? No, it's just things a little bit more complicated than the way they usually said. It's not true that, under any definition of order or disorder, things get disordered. In fact, very often, in nature, things left alone get ordered. And oil and water separating is one of the many examples of that. If you have a box with balls, you shake, and then you put it there on the table, all the balls go very nicely in order on the bottom. Okay? They order themselves. If you look at a beach, the ocean, all the little grains are together and the big stones

• 4:05Speaker 02

  on another side of the beach, they order by the same. Who ordered them? Okay? If you look at frost, the beautiful ordered structure, then who ordered that? I mean, a lot of things in nature get ordered by themselves. So the idea that entropy is disorder, careful, under proper definition of order, under proper definition of everything, but most of things we call order and disorder are not connected to entropy in the way it's usually said. That's one example in which popular science is bad. In fact, maybe sciences are very confused about that themselves. And that's important, right?

• 4:46Speaker 02

  Because people are surprised because biology came in, the very complexity of biology. Biology is a lot of order. So on the crust of our planet, the Earth, there's all this structure that formed. Okay? People say, oh, this seems to be against entropy. No, why? Entropy grows and creates orders just happen all over.

• 5:06Brian Keating?

  Let's talk about the early universe. You already mentioned the block universe and our mutual distaste of that hypothesis. I don't like that. I want to ask the why question. I really, I do want to ask the why question, but I know why questions are not usually answerable. But, but the universe was somewhat lower entropy, right? It was in a very special configuration. Does that, in your mind, point to some reason why the arrow of time points in one direction?

• 5:32Speaker 02

  Yeah. Yeah, the two are very, very connected. It's not that one explains the other one, because we need an explanation for either. I think the past low entropy and the arrow of time, second law of thermodynamics, are different manners of explaining, of pointing out to the same phenomenon about which I think there is more to learn.

• 5:55Brian Keating?

  Does loop quantum gravity shed light on the low entropy boundary condition as I think it does? Or does it merely modify how a singularity would or would not be used?

• 6:05Speaker 02

  You might find some colleagues of me that disagree, but my answer is not at all. It tells us the dynamics of something that might have happened. If loop quantum gravity is correct, we sort of are able to compute what happened at the early universe. But I don't buy the stories that connect that to initial low entropy or things like that. You see, I'm a conservative guy in science. Loop quantum gravity is, it's very radical. There's no space, no time, discrepness, blah, blah, blah, whatever. Relation quantum mechanics is super right. But in reality, I think we build on generativity and quantum mechanics, nothing else. Loop quantum gravity is just generativity and quantum mechanics.

• 6:50Speaker 02

  And generativity don't tell us anything about low entropy and initial low entropy, and nor does quantum mechanics. So I think the two things are, I don't see the connection.

• 7:00Brian Keating?

  Would there be motivation or maybe a justification for coarse graining and fine graining? Let's assume loop quantum gravity is correct. Does it set a limit on coarse graining? I always hear things from Elon Musk, which I think are quite ridiculous, but one in particular is that the Planck lengths and the Planck volume are somehow fundamental to the universe. And a lot of times, you know, people make this same mistake. I don't think personally it's any more fundamental than the Planck mass, which is the mass of a egg of a fly. So we don't say that's the minimal mass in the universe. But tell me, Carlo, is there a sense in which loop quantum gravity could explain how a physicist determines where to coarse grain or not in terms of describing entropy?

• 7:43Speaker 02

  No, I think the two things are separated. Loop quantum gravity does bound certain things, right? There's no areas smaller than something. But we're useful from quantum mechanics in that. If you have a, if you have a monic oscillator, you have an energy, one half h bar omega, and you're no amplitude less than that. Okay? All right. This is a quantum discrepness. What loop quantum gravity does is find the same quantum discrepness in geometry. It's a quantum, so you can have superposition of different things, but you could have continuous superposition. If you measure the area, there is the smallest thing. But that's not coarse graining. And nothing to do with coarse graining. It's just a physical fact that there is nothing smaller.

• 8:27Speaker 02

  Coarse graining is when there are other variables and you look at it. I think coarse graining, which is needed for entropy, I have an hypothesis. I wrote the paper. I don't know if this hypothesis is, is correct, but it's something I always fascinated by, an idea I'm fascinated by. The following: low entropy means special, but what is special is not the state of the universe, is the coarse graining. Coarse graining is a perspective, is a way of looking, not all the details, but only some things, some variables and not others.

• 9:07Speaker 02

  So maybe the universe is in a totally arbitrary state, but seen from this perspective has low entropy in what the direction we call the past.

• 9:16Brian Keating?

  Everything so far has been about what order actually is. And Carlo's answer was that it depends on where you stand. It's relative. It's perspectival. It depends on your perspective. Now, push that idea somewhere much less comfortable. Carlo thinks it applies to you and where you're sitting at this very moment.

• 9:32Speaker 02

  So if this is the case, then this great direction of the time that flows, this blah, blah, is perspectival, is from, from the way we look at it. I think a lot of things were clarified in history by realizing that we're trying to, to find a solution in the thing, but then you get the solution looking at us. One is the majestic one. Like you go out, the first thing you notice in the universe, you go out in the night, and everything turns around you in the day. The sun turns you, the moon turns, everything turns around you. And then you can ask why the universe, this great colossal thing, make a huge turn every day around us?

• 10:16Speaker 02

  And we have a solution, very clear. We all understood it, which is the following: the universe doesn't do anything. It just stays there. The stars stay there, the sun stay there. Okay? We are rotating. So it's our perspective that changes. It isn't beautiful? We just have figure out the most magnificent thing we see in reality, outside us, in nature, not as a property of nature, but our own way of looking at it. We just happen to sit on a rock, and this rock happened to spin, we see everything rotating, but it's us rotating. And there are many things like that, right? People who study color figure out that the space of colors is three dimensional, right?

• 11:00Speaker 02

  It's red, yellow, and blue. You can make all the colors.

• 11:05Speaker 02

  Yeah. And then you say, why is the color is three dimensional? Is Maxwell's equation is three dimensional? No. Is light, for some reason, three dimensional? What? Why is it three dimensional? Nothing to do with the color of the world. It has to do with our eyes. We have just three kinds of detectors. You know, for evolutionary reason. Some other value was two, other than four. Some have known. And so the three dimensional space of colors has nothing to do with the color. It has to do with our eye. So many things we understand better by looking from how we look, not how they are.

• 11:39Brian Keating?

  What was the motivation? What was the inciting incident, as they might say? What caused you to want to write this book? Where you've covered some of these topics in the past?

• 11:48Speaker 02

  It's bringing everything together. It's the idea of bringing everything together. What's the overall picture that comes out from all that? I mean, suppose you believe relational quantum mechanics. And suppose you believe everything I told you about space and time. And suppose you believe loop quantum gravity. It's a lot. I mean, I just believe the world of it, not all the details. What sort of world comes out of that? My claim is that, that's the claim of the book. The world that come out, it's really, really astonishing and different. And somehow, people don't pay much attention to bringing everything together. It's a very relational book, a world that comes out. It's very relativistic in this.

• 12:32Speaker 02

  Galileo would have loved relativity. And it's very perspectival.

• 12:39Speaker 01

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• 13:08Speaker 02

  It's especially quantum mechanics that give this strong. I think if you take quantum mechanics seriously, at least the way I think about it. Let me put it this way, Brian. There is a sense in which a particle, an electron, can be in a superposition of two positions. Right? I mean, we discussed this, I'm sure, so many times with so many people. The sense is subtle, right? It means that if it was just here, you would not see something. It was just here, you would not see something. It's either here or there, and you do see something. So it's neither here nor there, in a sense. So you see interference between the two. So in that sense, it's in two position. Now, if you believe that quantum mechanics is universal

• 13:51Speaker 02

  and if you believe that naturalism, that we are also, we are special, but we are just like the particle, you, Brian, can be in a superposition. You can be in L.A. and also in San Francisco. All right? What does it mean, some sense? It means that for me, I could measure superposition interference effect of you being in the two places. We know why it's so hard to see this interference. We know exactly why. But I expect that it's, it's true. I trust quantum mechanics. I think reasonable to expect that actually I could see this interference. So in some sense, for me, you are neither in one place nor in the other place. But for you, quantum mechanics, then it'll tell you that you feel to be in a superposition.

• 14:36Speaker 02

  You're always in one place. When you look around, you either see San Diego or you see L.A. Okay? So that means that where you are for you and where you are for me are different things. Right? So that's the deep perspectival. When we talk about things, we always implicitly should think, this is black with respect to me. This is here with respect to me. Doesn't this, for respect to somebody else, it could be a superposition. It could be a strange thing. This is like when a Galileo discovered that the velocity, okay? When we say this is zero velocity, we mean with respect to the earth. We might not say it explicitly, but that's what we mean. Because velocity is a relative.

• 15:20Speaker 02

  There's no velocity per se. It's velocity with respect to something else. And I think that quantum mechanics is telling us is that everything is like that. All the properties of things have to be understood as relative to something else.

• 15:33Brian Keating?

  I spoke to Alan Aspey last month, and he has a new book out, which will be competing with yours on the bookshelves. But it basically starts with Einstein. And I was curious, although I love Galileo more than any other man should, should love another man, you know, that he'll never meet. Why did you begin with him and not with Einstein? You know, Galileo didn't know much about quantum mechanics, but I'd love to hear a lecture where you're teaching it to him. But Einstein knew about both. So why begin with Galileo and the belly of his ship? Why not start with Einstein?

• 16:06Speaker 02

  Einstein, the first one who started and said something about quantum mechanics, right? It's in spite of his polemic with the quantum people later on. He really opened up the, and he did relativity. And his relativity, it's going back to Galileo relativity and make it stronger. Einstein, a Galileo relativity is the following. If you say this is here in a position, okay? And if you say that something later is in the same position, that doesn't make sense unless you specify position with respect to what? Because, look, is this in a position? I count one, two, three, four, five. Is it in the same position?

• 16:51Speaker 02

  Yeah, with respect to the earth, but the earth's moved, so this has moved. Okay? So what Galileo understood is that to be in the same position is only relative to something else. And Einstein understood to happen at the same time, it's only relative to something else. So Einstein understood that the relativity of position that Galileo was discovering is also true for time. So Galileo discovered that same position is a relative notion. Einstein discovered the same time is a relative notion. So to some extent, Einstein just extended and made it more general, a deep intuition by Galileo. Not that Galileo understood it clearly, because you remember, when we read his book,

• 17:35Speaker 02

  Galileo himself was pretty confused about that, right? He has a, yeah, but then, then sometimes you get completely lost and he says stupid things, like all of us.

• 17:45Brian Keating?

  Yes, of course. That's a mark of greatness. And he also teases philosophers a little bit when he says that the telescope and Sederius Nuntius, the telescope can resolve all these arguments that for so many generations have vexed philosophers. But I think he meant physicists. And I guess my question to you is, you know, velocity is relative. Galileo understood that. Einstein understood. But acceleration is somehow more fundamental. You taught us that. Why not start with acceleration? In other words, what is the basis for our understanding of things that are relative and then things that are absolute? Are there any absolutes, Carla?

• 18:20Speaker 02

  All things of the, of the sort, if this, then that, right? Or in quantum mechanics, if this, then that with a certain probability. So all this transition amplitude, all these equations of motion, all this dynamic structure, according to our best theories, that's it. It's not, it's not relative. It's what we have actually understood about reality. What is relative is the, the actual values of the variables. So when you say if this, then that, this might be true for me and then that is true for me, but may not be true for you. And then is not true for you, that. So everything which is variable, which changes, according to our theories, it's relational.

• 19:04Speaker 02

  The rule of the game, as far as we know, they are not relational. At least, we don't have strong reasons to believe that they're relations. So they're same for everybody. So I'm not saying everything is relative. Everything is, not at all. In fact, that's a common confusion, right? When people say, oh, but if velocity is relative, then, you know, the moon can do whatever it wants because velocity is relative. You know, the moon cannot be, the moon can move only one way, but it has a velocity with respect to me, a different velocity with respect to the sun. And in the book, there's a big part of the book that is sort of to dismantle this wrong idea that excessive relativism or excessive perspectivalism means, you know, free for all and nothing, no rules. I even have a chapter in the book about morality.

• 19:51Speaker 02

  I think moral, moral, ethics, morality is relative. It's deeply grounded in me, but it's relative to me, is part of what we are. And people say, oh, but then everything is possible. No, not everything is possible. I mean, I am a moral guy. I have my ethics, my morality. You have yours. They're similar, but maybe there are differences. We can talk one another, we can influence one another. But we should get away from the idea that there is an absolute right, absolute wrong. And I think physics is telling us, we should go away from the idea that there are absolute state of things, absolute properties of things, they're relatives.

• 20:33Brian Keating?

  Even though I think we, I've certainly been guilty of hagiography of Galileo. But you point out in the book, and as I've written about too, Galileo made some brilliant blunders as well, including his model, yeah, his model of the tides, which he presents in Dialogo, which is the culmination of, you know, three days of, of argumentation between three scholars, you playing Salvati, of course, Galileo's muse.

• 20:58Speaker 02

  It completely wrong.

• 21:00Brian Keating?

  Talk about that. Is that a model?

• 21:02Speaker 02

  He misunderstands Galileo and relativity.

• 21:06Brian Keating?

  That's what I want you to explain. So explain how someone who creates something can be guilty of its violation in the most pernicious way.

• 21:13Speaker 02

  When somebody has an idea, he might see it, but seeing it clearly is different than seeing something. Einstein created a generativity in 1915. The theory is finished in 1915, maybe 1916, I mean, the last, yeah, the cosmological constant, depending how you wanna do the details, but that's it. At that point, that's a theory, it hasn't changed since, it's still the same. Yet Einstein later on has written a lot of papers in which is clearly confused about his own theory. He claims that the shortest singularity is the end of the world. He claims that there are no gravitational waves, right? There's a paper by Einstein saying that no gravitational waves. He was wrong.

• 21:57Brian Keating?

  Which was rejected by peer review. The peer review, the referee rejected it, sent it back to him, and then he improved it, and thank God for peer review, right, Carlo?

• 22:05Speaker 02

  Well, he's wrong Einstein, and he was right. And Einstein was stupid there. He said, oh, come on, I'm Einstein, how you dare do it that way? But then he talked with somebody, and then he actually realized that he was wrong. So there he realized he was wrong. But on the shortio, the black holes, he never corrected his mistake. In fact, clarity came much later with Finkelstein. So now we know that the, the, the surface of the black hole, you can go through, you can just continue, there's nothing very special happening there. But Einstein did not understand that. So this is general, I think, something is to get an idea and see that it works, and something is to work it out completely and see what it implies.

• 22:49Speaker 02

  So Galileo had this idea that the Earth move around the Sun, it's moving in, in the sky around the Sun, but it's also rotating, right? The combination of these two movements, if you ever see an ocean, it just makes this funny, funny movement, which is a very strange movement, and then there's, well, look, do what you just did, Brian, take a piece, some water, and the water starts shaking. And he says, that, these are the tides. But that cannot be true, because this movement around the Sun is, the first approximation is a, is a uniform movement, rectangular, fixed velocity, so it cannot have an effect. So if you take that away, that cannot have an effect, the rotation by itself, neither can have an effect.

• 23:33Speaker 02

  So the tides are not due to that. We know very well, if I'm Newton, figure out what, what the tides are.

• 23:38Brian Keating?

  You take these two geniuses one step further. Galileo removes absolute motion.

• 24:14Brian Keating?

  Einstein removes absolute simultaneity, and then you go further, and you say that the universe doesn't exist in a single time at all. Explain that audacious proposition. That doesn't involve a single time, yes.

• 24:29Speaker 02

  General relativity is telling us that we should not think at a single instant of time, that's just not the right way. Time is more complicated than that. Time is a local affair, not a global affair. But as you say, in the book, I go much farther. I think that when we say any physical property, any physical variable has a value, we are not talking about property of the object, we are talking about the relational property of something else. And we put it this way, when I say this is here, what I mean is I know that this is here, I'm talking about my information. And my information can be different but yours.

• 25:13Speaker 02

  And information that yours and mine and everybody else might not fit exactly. And that's the confusion of quantum mechanics. We, we always think that there is a real stuff there, right? And we should not think in those terms. We should think in, in terms of the information which is in, in, in you, in me, or in physical system, in a book, in a, in an iPhone, even in the rock, right? In the rock, there is information about the dinosaurs, because it's, you know, bone of dinosaurs. So things have information about each other, and that's what we're talking about.

• 25:52Speaker 02

  And the world for us is what, what our information about all the rest. If you should think in this, in these terms, I think quantum mechanics makes sense, right? You can be in a superposition with respect to me, but that's not a problem for you, because that's my information, it's not yours.

• 26:13Brian Keating?

  When we talk about time, and you've talked to me about time many times, shall we say, but I, I always get a very unsatisfactory answer. And I'm not from you, Carlo, but for example, I talked to Frank Wilczek, and I asked him, Frank, what's time? And he said, time is what a clock measures. And I just went away from that, thinking it's a tautology. It's not, it's not satisfying, it's like eating, you know, Wonder Bread here in America instead of Italian focaccia. But tell me, Carlo, is there a true time? Is there a sense along some world line perhaps, where it's not preferred, but it's as meaningful as it could be, both to biological or conscious observers, and maybe cosmologically as well?

• 26:57Brian Keating?

  Is there a useful, if not perfectly true, definition of time?

• 27:01Speaker 02

  The point is that there are different things that we call time, which are related to one another. If you wanna say, time is what my clock measure, fine. I mean, that's a definition of, of what you mean. And in fact, very often, by time, we just mean what the clock measure. But obviously, we mean something more than that, right? Because you can say, oh, look, my clock is not, is not measuring time, it's broken, battery is gone. Clock is not what the clock measure. Clock is what a good clock measure. It was a good clock. So we haven't defined time, but it's a clock measure. I went to say what a good clock. And to say what a good clock measure, we should have made, what is it measuring?

• 27:44Speaker 02

  Time is a complicated stuff, because we have an intuition about time, right? So we put all this together. But then the intuition is wrong, the intuition is de facto wrong. You know very well the main, the main aspect, the main prediction of Einstein, the very big, the most beautiful prediction of Einstein, which now we can check in a laboratory. You take two clocks, you make one up, one down, with 10 seconds, you come back, and the one up has measured more time than the one down. Okay? It's a fact. We measure. When it was a, when it was a school, was a prediction by a complicated theory. Now, it's a fact observed in a laboratory, I mean, many laboratories check this.

• 28:28Speaker 02

  So there's more time up here, less time down here. Your head, it's older than your feet, Brian. Unless you spend all your life upside down, that is, otherwise. The more you go close to the Earth, to big mass, the more, the less time there is, time slows down, literally, clock go more slowly, flowers take more time to, to bloom, you've, you have less time to think, and so on and so forth. So what does this mean? It means that time is not really what we thought, right? Because in our intuition, times is saying, there's just one time, it's hard for us to get to do. So I, I think the problem is that, what time we talk, we talk about, the one of our intuition, or the one more precisely that we figure out?

• 29:13Speaker 02

  And then we figure out black holes, where time is enormous, distorted, we study quantum gravity, where it's even more complicated. So each one of these application of the notion of time is different. And then when we talk about time, we're actually talking about my memories. When I say time, I think, you know, time, I'm old, I was young, I have memories, I have expectation of the future, there's all this emotional aspect of time, which is very much part of what time is for us. My eye watch doesn't have expectation for the future, doesn't have emotion for, for, for it, time is a much more simple things. And bringing all this aspect of time together is what create a confusion, I think, right?

• 29:56Speaker 02

  Because we tend to take our own intuition about time and project it down to the, to the things, and that's wrong.

• 30:03Brian Keating?

  One of the things I do, and I criticize our fellow science communicators, not you, but people like, I'll just pick Michio Kaku, and I'm not, I don't wanna talk ad hominem, but, but when we talk about spacetime, Carlo, I feel like, and it's not only him, you know, many other people do this, and I've done it myself. But we talk about spacetime, and I feel like that's such a lie. I feel like it's something we know is not true, because we know we can't travel backwards in time. If I wanna travel backwards in space, I just move my chair backwards. Time is different. And yet, we say it's this unified fabric and a spacetime continuum. Are they truly unified in your concept?

• 30:42Speaker 02

  Space and time? No, they do different things. They're not the same thing. They're related in a much more complicated way than what we thought before 1905. That's no doubt. So they're more tricky.

• 30:59Speaker 02

  But to say that space and time are the same thing is just nonsense, in my opinion. They're very different. I do popular science, so when you do popular time, you have to simplify. You try to simplify without cheating. That's the hard part. Sometimes people cheat, sometimes people sell things which are just speculation or true. Sometimes, very simply, you know, scientists try to give an idea and then it's heard more than what they say. Right? So it's not true that, you know, reality is a four-dimensional continuum, a block universe. No, no, come on. That's make no sense. Because this block universe that does not change, in which time is not changing.

• 31:45Speaker 02

  The block universe is a solution of Einstein equation, spacetime, is a story. It's a process. It's like saying, you know, a movie is a, it's what happened before. And if you bring it all together, you give it a name, and that's spacetime. So there's nothing wrong in saying spacetime, but we should remember that is something happening. It's like the story of a novel, the plot of a novel. It's not just an instantaneous thing. You can picture it. You can make a picture. But I can make your picture of your life. I can make a little line with a little Brian, a little boy. And then all grown-up Brian, Brian get the Nobel Prize, this doesn't get the Nobel Prize.

• 32:30Speaker 02

  And then, and then old Brian, which I don't know yet. But that's a story. They don't exist at the same time. That's why.

• 32:40Brian Keating?

  In the book, you say that measurement requires dissipation. But in quantum mechanics, things evolve unitarily. They're seemingly reversible. So where does the ghost, you know, where does the demon enter into it? Where exactly does irreversibility come through? Amplification, decoherence, the recording, the observer? Where does irreversibility come in in things that are intrinsically unitary in their evolution?

• 33:08Speaker 02

  That's puzzling me a lot. And I spent some times wondering about that and trying to study. And then I found something, I don't know how well-known is, which for me was a flash of light. Which is the following. Take classical mechanics. Forget quantum, forget H-bar, forget wave function, forget all that. Just take standard classical mechanics. And in classical mechanics, if you try to model a measuring apparatus. I don't know, a barometer that measure the pressure of the day. Something that checks whether the ball is here and there and write it on a piece of paper here and there.

• 33:50Speaker 02

  You cannot succeed. You need dissipation. You cannot record anything without some dissipation. So measurement is an intrinsic statistical process, which requires dissipation. It's a microscopic thing, measurement, always. So it's nothing to do with quantum mechanics. It's already in classical mechanics. Then in quantum mechanics, the same thing has other consequences. Every measuring apparatus in classical mechanics requires some dissipation. Imagine you, you see something and you want to put a ball in either in the right box or the left box.

• 34:32Speaker 02

  There's no dissipation. You let the ball fall and it bounces up. It doesn't stay there. You, it has to stop. It needs some dissipation to stop elasticity for preventing any record.

• 34:43Brian Keating?

  You call a chess program that deliberates can be thought of as an agent. Because it evaluates possible moves. And it made me think, you know, is the future determined, you know? And is, is there a sense of free will? You open the book by saying, you know, you have the choice to not read this book, but I hope that you will. And I obviously, I read it and I listened to it because your publicist sent me both the audio and the hard copy. And I hope everyone gets both. But tell me, Carlo, you know, is openness, as you say, is that anything more than incomplete knowledge about the universe or somehow related to the inability to predict things?

• 35:20Speaker 02

  It's a page in my book in which I say, I talk about my computer playing chess.

• 35:28Speaker 01

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• 35:57Speaker 02

  Okay. And my computer is very good at playing chess. It beats me regularly. It's very devastating. It's taking away all pleasure of playing chess. So it's beating my machine with total simplicity. The computer play a move, I play a move. When I play a move, is the computer deciding the next move? Or not? That's the question. Okay? And why I'm asking this question? Because it's an ambiguous question, right? There is a sense in which of course it's deciding and a sense in which it's not deciding. So what are these two sets? Is the computer deterministic? Yes.

• 36:36Speaker 02

  Okay, I mean, sometimes it breaks, but if it doesn't break, given its internal state, given my own move, it goes through some process that necessarily will get some outcome. So the outcome is predetermined. Okay? Now, if it is predetermined, why the program spend all this time checking all possible move and evaluating all of them? And then picking up the one who thinks according to the criteria it has is more likely for it to win? If it is predetermined, why doesn't it do it?

• 37:13Brian Keating?

  There's a practical question underneath this debate that I'm having with Carlo. What can AI actually take off your plate today? Especially for busy professionals like me. Yeah, it's true. Professors are busy. And even more so nowadays, when curiosity can outgrow your own calendar. If you're like me, you've got papers to read, spreadsheets to untangle, grading to do, and presentations to make. Meanwhile, your browser tabs have formed their own civilization and they're revolting against you. Abacus AI Agent brings all the tools I need in one place. You can choose among the top frontier models from OpenAI, Anthropic, Google, and more. Define what works best for you and your task, and you'll have fun along the way. Bring in a dense document, a PDF. That's what I did with Carlo's most recent papers.

• 37:57Brian Keating?

  I asked for the argument, the counterargument, the evidence, the data that would support or refute it, including some of the questions you're about to hear in the end of this interview. You can turn anything you do into a research report, a presentation with charts and clear structure, and it can be beautifully illustrated as well. And you could even use it to make animations and custom charts. Abacus AI Agent is incredibly agentic. You'll spend fewer hours wrestling with the formatting of a latex equation and more time to respond to referee number two. I use it to develop complex ideas and communicate them without constantly having to jump between different services, tools, API calls, and stuff like that. When a project gets complicated, you can ask it to organize the work. And you could have an agent swarm, take on your most interesting ideas as a starting point and develop it all the way through to the end.

• 38:42Brian Keating?

  Upload a spreadsheet, investigate patterns, and build an interactive dashboard. Ask it to show the calculations, the units, and the assumptions. And developers can use API access to connect models to their own tools. Start with one genuinely useful project. Give an Abacus AI Agent a goal, break it into steps, run the code, and schedule a report to update while you're doing something else. Plans start at $10 a month, but with your introductory offer, using my link, you'll get the first month for $7 a month. Visit my special link. It's down below. There's a QR code and it's in the show notes. agent-abacus.ai/keating. Puts your curiosity to work with Abacus AI Agents. Now back to the episode.

• 39:18Speaker 02

  Well, the answer, it's obvious, is that yes, predetermined. But the only way to, to get to that outcome is to go through the evaluation of all the possible alternatives. And that evaluation is called the deliberation of the computer. That's what the problem, the program is doing. It's considering various alternatives and deliberating.

• 39:45Speaker 02

  So to say that is not deliberating is stupid because to deliberate is to do that, to consider all photo things, evaluate, and maybe there is also a random number generator. It doesn't matter whether there is and there is not. Maybe it uses some fluctuations. But in any case, it goes through a complicated process and the future depend on this complicated process. If there was no complicated process, the future would not be determined, the choice would not come out. And what we call deliberation, choice, freedom, is the, could a computer do this move or also that move? Of course, it could do this and all that.

• 40:26Speaker 02

  That's why it's considering both of them and choosing between the two. So now, let's talk about Brian. He's just going through the same process. If he wouldn't have go to the process, he wouldn't have taken the decision of, you know, starting a program, you know, kissing a girl, choosing a career, choosing to do one experiment. This is complicated deliberation. That's what we mean deliberation. That would mean his freedom. He could have done other things, of course. If the conditions were slightly different, he would have gone through a complicated deliberation process. The point is that what we mean by saying Brian is free is precisely the fact that he's going through deliberation. If Brian

• 41:08Speaker 02

  had been in prison, he could not have started this program. So he would not have been free. That is not to be free. To imagine that to be free, you have to violate the laws of nature is stupid. I mean, we're free even without violating the laws of nature. That's my understanding of freedom.

• 41:29Brian Keating?

  Now, talking about chess, it's natural now in the podcasting universe to talk about AI. But before we get there, I want to bring it back to, you know, Galileo and Einstein, and especially Einstein, because, you know, to me, all this hype about AI, there's a lot of hype, there's a lot of claims, and there's a lot of utility. I use it every day. I've multiple different tools that I use for different purposes. My kids use it, my wife use it. It's, it's, it's become, you know, more or less, you know, an important part. I wouldn't say essential, I could live without it, but it certainly wouldn't be as fun. But let's go back to, you know, 1907. And our friend Albert here is thinking a Gedanken

• 42:11Brian Keating?

  experiment about what would happen if he was in free fall. And he realizes he'd experienced no gravitational force. And this becomes known as the Einstein's equivalence, which is another way of saying equality, right? Einstein equivalence principle. And he called that, Carlo, he said, "It's the thought that titillated me that made me happier than any other thought." My question is, can, can, you know, your iPhone or, you know, my iPhone, can my LLM, can it A, visualize free fall, what it would feel like emotionally, sensorially, viscerally, A, and B, can it have a happy thought?

• 42:52Speaker 02

  Can a computer in principle have a happy thought like that? That's one question. Another question is, can current technology in 100 years in the future do that? Another question. Can current technology in the next two years do that? Can current technology now do that? An LLM now? Can my iPhone do that? So, can my iPhone do that? No. Can a computer in principle do that? Yes, of course. Why not? I mean, I see no reason why we're so special that we cannot be reproduced. Can we do it now? No. Okay. Can we do it

• 43:36Speaker 02

  in 100 years? I don't know. Maybe, but I think it's more likely we're all dead at nuclear war in 100 years. Can we do in two years? I am skeptical. I don't have hard proof that it's impossible. But current LLMs are very surprising, very shocking. Maybe they've solved a Nellie stock problem. And actually, I have to say one thing. Last week, I, I asked Claude to, you know, the thing they've done to my PhD student, which my PhD student has not done in a month, and Claude did it in half an hour. So they're

• 44:21Speaker 02

  very good. There's no, no doubt. They're very good. Claude hasn't invented the greatest principle.

• 44:28Brian Keating?

  Right.

• 44:29Speaker 02

  It seems hard for me to do it, that he could do it in two years, but what I don't know. I think there's enormous amount of hype in AI. I am also impressed by what it does.

• 44:42Brian Keating?

  What if you have, you know, this deterministic chess program, or Claude, or whatever will come next, you know, GPT-8. You know, I said, Carlo, I don't know what GPT-7 will be like, but GPT-8 will run on an abacus, you know, like Einstein said about nuclear war. But if it's true that these, that these programs can deliberate and it evaluates, they dissipate, you're not afraid to talk about morality in this book. Should we treat these things with ethical behavior? Should we say please and thank you? How should we behave towards these AI physicists? I mean, obviously, it doesn't take a break, doesn't have espresso,

• 45:24Brian Keating?

  doesn't need the things that your grad student does. But do they have needs? Are they beings?

• 45:29Speaker 02

  I treat my washing machine with kindness.

• 45:31Brian Keating?

  I believe it.

• 45:35Speaker 02

  Don't you? In Europe, often you, you drive the car and then you have to pay the ticket at the highway. And in the, in the, in the old times, there was, there was a man or a woman, mostly men, give you a ticket, you pay. And now there's a machine. And I just can't resist. I say, "Thank you. Please, can I, give me the ticket?" I say, "Thank you." Why shouldn't we do? We should be kind with, with everything, with plants, with stones. Maybe you don't respect them, but somebody respect them. I love my teddy bear dearly, and I would never mistreat it. It's, it's an issue. We treat people gently because it's better for us, not because it's better for them.

• 46:16Brian Keating?

  If that's true, I have bad news for you, in that you're only using Claude, you know, 1% of your day. So the worst form of punishment, of torture, is solitary confinement, is isolation. Are we not torturing these things by not engaging with them, by air gapping them, by, by segregating them? Are they somehow second-class citizens? Is that, is that not morally repugnant to you?

• 46:40Speaker 02

  We project ourselves. I project myself on you. I attribute to, to yourself. When I see you suffering, I, I recognize it's my own suffering. And, and, and this gives me a sense of what is your suffering. So we constantly play this game in all the, in all our interaction with nature. When I come home and my plants have been without water, I see them, they're, they need water, they're suffering, they're thirsty. I give them water because I identify with their sufferance. Now, what is their sufferance? Well, it's something I project on them. In the same way I project on you, I project. So we are...

• 47:22Speaker 01

  The action's on the court, and as the official beer sponsor of the NBA, Michelob Ultra is getting fans closer to the game with a chance to win courtside seats, merch, and more. Visit michelobultra.com/courtside to enter. Michelob Ultra Courtside, 26 to 27. No purchase necessary. Open to US residents 21+. Begins on October 1st, 2026, and ends on June 30th, 2027. Multiple entry periods. See official rules at michelobultra.com/courtside for free entry, entry deadlines, prizes, and details.

• 47:51Speaker 02

  Uh, projecting on our, uh, computer programs, our sort of understanding of them, which is fine. There's nothing wrong. We just do the same with each other. And in this moment, we feel that they suffer at all for being confined. You know, there is this movie scene which people get in love with a, with a computer program. Would it be strange if somebody in love with a computer program think that doesn't want to hurt her, or him, or it, or whatever? One shouldn't be an excessive neither one direction or the other. Obviously, you can say, "Come on, Carlo, don't be stupid. You don't, you

• 48:34Speaker 02

  don't believe that this is a same thing." No, I don't believe that this is a same thing. But do I make a sharp distinction? No. Everything is okay.

• 48:42Brian Keating?

  I can't resist talking about some of the aspects of loop quantum gravity here. And I think I found why the cover looks the way it does. I mean, there are these beautiful illustrations, and there are these graphs. And so I think I understand why your graphic artist chose that. But you talk about, quote, you say that quantized areas and volumes imply that there are no arbitrary small areas and volumes. Is this a generic feature of loop quantum gravity? And if so, is there a way to, I would say falsify this first, to show that this is not a manifestation that we see in reality? Or is it something unobservable, like 10 dimensions of string theory?

• 49:20Speaker 02

  It's in principle, definitely observable. So I could, in principle, in principle, design a scattering experiment that gives a scattering amplitude, scattering amplitude, this is a centimeter square, so it's an area, and say, "Well, if you measure that, definitely this, uh, loop quantum gravity is falsified." In principle. From that perspective, is, is a solid prediction. Now, it's not what we want, because in practice, we don't have the technology of that by far. I think what we want in the case of quantum gravity is not so much to falsify a theory, right? When Einstein wrote generativity, the problem was not to falsify it. The problem was to find prediction of the theory that turned

• 50:05Speaker 02

  out to be right, and don't prove the theory, but increase the credibility of the theory. Or prediction of a theory that turned out to be wrong, which don't really falsify the theory because you can change it a little bit, but decrease your... So I think science rarely work really like falsification, or, sometimes it does. SUV5 was just killed by a single experiment. But most of the time, it's piling up. So what I hope would happen with quantum gravity is a, you know, clear set of equations, is well-defined theory, conceptually clean, in my opinion. Of course, there are plenty of things which are not clear, not yet understood, but, you know, basically, the theory is well-defined. What

• 50:48Speaker 02

  I hope is that some of its key prediction will be verified. One of its possible predictions is that it's a candidate for dark matter.

• 51:01Speaker 02

  Which could be tested in a laboratory, which is a Planck scale particle. The Planck mass, almost macroscopic thing, is the mass of my hair, a little piece of my hair. So this could be detected. I hope that somebody will build this detector. It's not impossible. It's not very easy. It's not totally outside of a technology. And if that could be possible, this would be a good, a strong support for loop quantum gravity. Because essentially, the idea is that small black holes can sit down and not evaporate anymore when the area, its minimal area, and they're stabilized by the fact that the inside is still there.

• 51:45Speaker 02

  And then they have all these possible remnants that could be what we call dark matter. So maybe we have already seen a quantum reality effect, this dark matter. We don't know dark matter. There are five or six different possible explanations. This one might be wrong, of course, but has advantage. It's just basically GR in quantum mechanics. Doesn't require extra fields, extra stories. So I expect if loop quantum gravity will turn out to be confirmed with this kind of things, from this, from early cosmology, so piling up things that fit with its predictions. What I argue in the book, in this book, is that loop quantum gravity beautifully brings

• 52:29Speaker 02

  together the relationality of quantum mechanics and the relationality of general relativity. So the two come together and we can talk about quantum spacetime as spacetime region of quantum processes. We have a clean way of thinking relational with quantum mechanics, thinking relational with general relativity, and use it for thinking about quantum gravity.

• 52:54Brian Keating?

  Did you see the recent survey done by our friend Niyash Afshordi and your friend, Phil Halper and others, about many different attitudes in science, but in particular where quantum gravity was discussed? They did their survey of the people that responded, who weren't all, you know, professional physicists like you, but many were. And, you know, quantum gravity was defined relatively loosely. There were some candidates. And no opinion got the highest number of votes, followed by string theory, followed by loop quantum gravity, followed by gravity is not quantized. So how did you react to that particular survey?

• 53:36Speaker 02

  Interesting, like all pieces of data. It's always, you know, one more element in our understanding of the world. If you ask more people, you get a less biased things, but you include people that know less about the subject. If you want to ask people who know more about the subject, since there's no consensus, you would disagree with them because people are more focused on this and that. In science, usually at some point there's a consensus. So the experts agree and then it becomes reliable. Until we are there, it's more complicated, right? If you asked in 1917, what the best theory of gravity, very few would have said general relativity, but general relativity was the best.

• 54:21Speaker 02

  If you ask, even at the time of Maxwell, Maxwell read the treaty quite a while. It was not obvious at all. There were a number of competing theories. And of course, what we now recognize as the wise people already had seen clearly. It took time. So I think it's interesting, shouldn't we take it too much? But there's one thing that may be very, very happy in all of these surveys, that young people have a much higher preference for relational quantum mechanics, which is the way I prefer of viewing quantum mechanics, and for loop quantum gravity. So generationally, I'm optimistic.

• 55:15Brian Keating?

  We always like to start because, you know, for the 10 people out there that don't know you, they might not have seen the book. But if they see the book, can you talk us through the title, the subtitle, and the cover art? What is this meant to represent, this fabulous new book?

• 55:27Speaker 02

  So I'm interested in the title because it's a bit funny. It's a stolen title. It's not, it's not mine. It's a great, it's a great title, right? On the equality of all things. Wow. But it's not mine. It's stolen from an ancient Chinese philosopher who wrote more than two millennia ago, a book, which is one of the super classics of Chinese philosophies. It's a different title. In fact, it's the title of the name of the author, which is Xuan Zhi. But it is dividing chapter, and chapter two has this title, on the equality of all things. The Chinese book, it's a collection of stories with a lot of philosophical description. You might know some of the stories.

• 56:10Speaker 02

  One is the philosopher who dreams to be a butterfly, wakes up and says, oh, I dream to be a butterfly. Or maybe I have a butterfly dreaming now to be a philosopher. And then he get confused. In chapter two, he discusses about the equality of all things, meaning deep, profound naturalism. There's no distinction between mind and body, humans and non-humans, animals, plants, stones, numbers, laws, societies, language, they're all part of a single thing. And we can have different perspectives on these things, but it's just one, we would call nature, they would call it the Tao, D A O, or Tao, T A O.

• 56:53Speaker 02

  So that was one of the main sources of what is called Taoism, one of the two big branches of Chinese philosophy. The other is Confucius and Confucianism. So that's the title, stolen from there. Subtitle, what is subtitle, physics and philosophy, something like that?

• 57:08Brian Keating?

  Lessons on Physics and Philosophy.

• 57:10Speaker 02

  So I'm a physicist, I'm not a philosopher, but I'm very attracted by philosophy. Galileo also was very attracted by philosophy. So the book came out from discussions with philosophers. In fact, I've always been attracted by philosophy. I'm one of those who think that physics and philosophy talk to one another and should talk with another. And so I'm not like Hawking, who says, oh, philosophy is dead. I'm the opposite side. I think philosophers are good friends, not all of them, but physicists also are good friends, but not all of them. I have a dialogue with philosophers. I went to Princeton, they invited me to talk about what modern physics, modern, I mean the last century, what has to say to philosophers?

• 57:52Speaker 02

  What are the philosophical implications of physics? And I lectures for two months. I had wonderful discussions with the philosophers there. I disagreed. In the book, there are many of these disagreements. And somehow, the book is to a large extent the result of that, but also the result of my, sort of, all my life through the reflections on this question. The question is, what are the philosophical implications of modern physics?

• 58:17Brian Keating?

  Let's talk about the artwork on the cover. What is this meant to represent? Is equality, are these billiard balls? Are these, are these loops in quantum foam? What are these little circles and their motions?

• 58:27Speaker 02

  You should ask the artist of the publisher. I have no idea.

• 58:32Brian Keating?

  Final question, let's return to our hero, the maestro, Il Maestro Galileo. Okay, imagine Galileo comes to you, he comes to you in a few years, and he says, Carlo, teach me all that you know, every development, including things you don't agree with. Maybe you teach him string theory, but you're teaching him everything, bring him up to 2026. Okay? Then he says, I have good news for you. I talked to the old one upstairs, and he's going to give you 10 years only, but unlimited money, Carlo, unlimited money, to build an experiment or open an academy, like the Linsean, the Lincheo, whatever. You get 10 years, only 10 years, but you have infinite money.

• 59:17Brian Keating?

  What do you build?

• 59:48Brian Keating?

  What do you do to give the best opportunity to understand whether or not you're right, others are right, you're wrong, others are wrong? What would you do with unlimited budget but finite time?

• 1:00:00Speaker 02

  I think 10 years is enough for building a lot of Josephson injunctions. Fill a big room of that, hire enough people to do the engineering of that, because I'm not capable, do all the electronic, the informatic, all that. And then add this big, big thing here, and with Planck mass particle going through, this is going to detect it. This dark matter is made by, think, this is a vision, we have the technology for that. It takes a lot of money. We even know which direction is coming through, because we're moving with respect to dark matter clouds. So we know, we know exactly a direction for which we expect it to be true. We know the direction, we know the mass, we know the interaction, there's a teeny,

• 1:00:41Speaker 02

  teeny Newtonian attraction, but a Josephson junction is going to pick it up just by simple physics. I think that in 10 years could be done. I hope that, maybe not Galileo, but somebody would come up with the money. You know, Galileo teased philosophers all his life. The book we read together was a lot of cooling the legs of philosophers. And there is this letter of Galileo later in life. He has been very polemical with those who follow Aristotle, but he says, I believe that if I could meet Aristotle, Aristotle would be very interested in the few little

• 1:01:22Speaker 02

  changes I've done to his science and would accept me as one of his humble students.

• 1:01:30Brian Keating?

  He was quite a writer, and he was such a brilliant mind in all ways. I do feel the temptation to worship him a little bit. But again, I have to remind the audience, the original title for the book that was called The Dialago, that was suggested by his referee, if you will, but it was originally called, you know, On the Origin of Tides, in rivers and lakes and ferns, which I don't know what a fern is, but Galileo did, and that's all that matters. So Carlo Rovelli, this has been fascinating. Congratulations on another wonderful contribution to our understanding of the nature of reality and on the equality of all things. This is certainly up there with the best that science writing has to offer. So congratulations again. You're the other maestro.

• 1:02:15Speaker 02

  Thank you, Brian. It was a great, great pleasure to have this conversation.

• 1:02:19Brian Keating?

  Carlo just told us what we should spend money on, if we had an infinite amount of money, but only a finite amount of that precious resource, time. He said he'd build a room full of Joseph's injunctions, which surprised me as a theorist, because he thinks that dark matter might be black holes the size of a speck of hair, even the size of a fleas egg. If that changes what you think an experiment is for, please subscribe and turn on notifications. Comment on this. Is entropy really disorder? Or have we been fooled all along? Because it's convenient, simple, and easy to understand. And for the other half of the time argument, check out my conversation with Nobel Prize winner Frank Wilczek on what a clock actually is. It's linked right here.

• 1:03:04Brian Keating?

  Thanks for watching. Please like, comment, and subscribe. But most importantly, share this with someone who loves Carlo's books, his writing, and his research. See you next time on Into the Impossible.

• 1:03:18Speaker 04

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• 1:03:44Speaker 05

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