The Unreasonable Effectiveness of the Klein Bottle | Janna Levin

There is no general relativity. There's no spacetime. There's only the quantum threads, the embroidery, the threads out of which you embroidered this illusion of a continuous spacetime.

Professor Jan Leven, along with co-author Brian Green, published two papers just last month exploring what it would mean for our universe to be compactified on one of the most bizarre objects in the history of math, a Klein bottle. This is a non-orientable surface with surprising physical properties, potentially explaining the origin of matter. Matter that composes you. Is this related to self-referentiality and unprovability?

On this channel, I, Kurt Jungle, interview researchers regarding their theories of reality with rigor and technical depth. Most approaches to CP violation, the matter over antimatter asymmetry that is the reason we exist rather than annihilate, put in that violation by hand as attuned parameters. Jan Leven's papers don't.

"The geometry of the universe breaks the symmetry."

Today we discuss what a girdle has to do with the universe, black holes as elementary particles, and even ER equals EPR. Piggybacking off of the previous Juan Maldacena podcast on this channel as well, the question underneath everything is: What if the deepest laws of physics are not laws at all, but geometry? Professor, is the universe a girdle sentence about itself?

"So, uh, this is something I've definitely struggled with. I think the early universe, the creation of the universe, the idea of setting initial data for the universe, all of that sounds really self-referential. It sounds like the laws of physics are trying to say something about their own genesis. And that ingredient, the self-referential ingredient, is kind of a flag that you might be getting into Gödelian territory. I've never actually formalized this intuition, though I talk about it occasionally and occasionally I'll talk to somebody plausible who could help me struggle through it. It's always good to have a collaborator, but I haven't written it down yet. In some sense, I haven't written down that Gödelian expression, but it does seem to hearken back to those original ideas about there not being a theory of everything."

"Ah, okay. Well, I, I, we got to shut this interview off right now because that's the channel's name. All right. You could add a question mark."

"Perfect. Perfect. Now, let's think about this because a Gödel sentence..."

"...describes its own unprovability. So, it's not merely a self-referential sentence. Is there something, do you mean to say more like that the universe may be a self-referential sentence, or is there something Gödelian about it?"

"Yeah, I think it's both. So, let's just go back to Gödel for people who haven't thought about it for a while. Um, there was famously the liar's paradox, which, which certainly Gödel would have been aware of, uh, in which the liar says, 'This is a lie.' So, if it's a lie, it's true. If it's true, it's a lie, and you have this paradox that exists in language. And I think metaphysicists were sort of lightly, not overly concerned about this. But what Gödel did, which was to bring this to absolutely the next level, was to mathematize the idea. So, he moves from 'this statement is untrue' or 'a lie.' He doesn't do that. He actually formulates 'this statement is unprovable' and he mathematizes that concept. He says, essentially, that there is a true statement about a proof belonging within an axiomatic system that cannot be proven to be true, which is, of course, the claim of the statement. So, the statement is true but unprovable, and that is not inherently paradoxical or inconsistent. So, Gödel says, 'Look, I'm going to preserve my faith in the consistency of this axiomatic system, but I did just show that not all true statements, even in algebra, can be proven to be true.' And that's fantastic. Now, if you look back at the time when he was doing this, and the great mathematician Hilbert had made a call to all mathematicians not to prove all infinite true statements, which is impossible, but to at least render the fairly obvious assumption that all true statements could be provable, to at least ensure that that's the case. And, and in fact, Gödel comes along and does the opposite. So, in some sense, Gödel's work doesn't talk about paradoxes. It's perfectly consistent within mathematics, but it is nonetheless stunning because it suggests that there can be no such thing as a theory of everything for mathematics. You cannot prove some statements simply by marching through the axioms of certain mathematical structures, that there are things even among the numbers that we simply will never know, that we can't know true things that are unknowable. And I think that was a shock to mathematicians, but also it should continue to interest physicists whose, of course, big ambition is to have a theory of everything. So, what can I do about the early universe this way? Oh, could it be that the early universe, somehow the consistency of the initial data and the laws of physics are preserved? Right? There are relations that are true but unprovable. Now, could it be, okay, so two questions here, take whichever one you like. Could it be that the laws of physics or the initial conditions are inconsistent, whatever that would mean?"

"Okay, so that's one horn, one question."

"And then my second question is..."

"...what would the Gödel sentence, supposing this is true and more than just a flowery analogy, what would the Gödel sentence of the universe's formal system be like? The sentence is in a sentence in a certain language."

"So, I'd like to think that it will, the laws of physics and the universe itself, and the way that the universe is crunching, possibly an algorithm crunching this initial data forever, um, that that will, that is consistent. That is, of course, the paradigm of physics. If that's not consistent, then we've got something really, really bad on our hands. And I think Gödel would have said the same thing about algebra. He said, 'I'm going to, I'm going to accept the consistency, but the unprovability,' as opposed to saying this is inconsistent. Um, so, so I think it could be the same thing. Perfectly consistent laws of physics, just ones that we can't, uh, don't allow us to prove certain aspects of the initial conditions. What would the statement be like? Um, again, I've never really tried. So, what Gödel did, which was so amazing, is he invented this code where every symbol, every number, every operation, including a parenthesis, got a, uh, a code, received a numerical code. And so every proof could be mathematized as just a relationship among numbers, very simple algebraic relationship. So, um, so I've never gone to the depths of trying to actually do this. But I mean, now you're kind of inspiring me to, when we get off the phone, not to go to yoga, but instead to..."

"...try to structure the sentence. But I think if we look at, um, 'this statement is unprovable,' which is the kind of English translation of what Gödel did. It would be something like, um, 'these initial conditions cannot be predicted by the laws of physics.'"

"Ah, okay. I would say that that's kind of close to, in, I mean, that that parallels Gödel's structure. It is both self-referential, um, and it can be true, but would intrinsically therefore be unprovable because you can't get to it through the laws of physics."

"So, the laws of physics, it's usually thought of as the laws of physics, and then we have initial conditions or boundary conditions or what have you, and they're separate. So, if the Gödel..."

"...it's been a long struggle. Yeah."

"...statement is a statement in the laws of, like a law itself, then it's not, if it's referring to the boundary conditions, it wouldn't technically be self."

"I would say if you're really talking about the creation of the whole universe, you can't play that game. Like, I can get away with it if I'm teetering a ball on the top of a hill. And I say, 'Look, the laws of physics are Newtonian mechanics, and I'm externally to that adding in the initial data.' But if I want the system to be the entire universe, you, I just don't think you can get away with that. And, um, and I think that that's, we've felt the resistance about why initial data is so strange when we want to apply it to the whole universe. That, that's been a long problem, you know, people have thought about for a long time. Hardy and Hawking, um, uh, principles for the initial state of the wave function of the universe, like trying to say maybe it's not a choice. Maybe there's not a range of initial data. There's only one possibility, and the possibility is set by the laws of physics. Right? That, that seems more holistic to me. I, I think we have an initial data problem whether we like it or not when, when you're, if you're going to talk about the entire universe. Um, so that's why I think therein lies, at least, and again, with Gödel's, uh, once Gödel proved this statement was unprovable, a whole slew of things followed, like uncomputable numbers with Alan Turing. It was just the tip of the iceberg. Now we know that there's an infinite set of uncomputable numbers, numbers about which we will essentially know nothing, but they're numbers. They have facts about them, but they're not numbers we can write an algorithm to predict. They're not numbers about which we can know its intrinsic properties. It's just simply a list of random digits. Um, and the universe could be like this. The initial data is just kind of the tip, could be just the tip of the iceberg."

"Okay. Well, let's talk about Penrose AI and consciousness."

"Okay, fun. I just saw Roger, um, I like to call him Sir Roger, although sometimes the British tease me for that because it's so formal. It's not apparently when someone is knighted, you don't call them Sir Penrose, you call them Sir Roger. Ah, and I think it's quite endearing to call him Sir Roger. Um, but I saw him recently. We had a conversation together at Oxford just in October, and he remains one of the most interesting people I've ever known."

"Great. Okay, I'll place a link to that on screen and in the description as well. So, he also ties uncomputability to consciousness and says AI is not conscious. Computers may never be conscious. Now, you also take the view that AI current AI is not conscious. I imagine for a different reason. So, I want to spell out where do you agree with Roger and where do you diverge with Sir Roger?"

"Yes. Well, uh, I'm not sure of all of his dimensions in that. Last time I spoke to him, we were actually talking about black holes, in fairness. But, um, but I, I think from, from my point of view, AI isn't yet conscious. I am not a person who thinks consciousness is substrate-dependent. I don't see a barrier to consciousness in a different material. That strikes me as really odd. I can imagine it being way too hard for us to simply algorithmically program. I can imagine that. Um, I can imagine that this whole, all that's going on with these biological systems took billions of years to evolve and are just very complex. And so we're kind of stuck with biology because nature did this for us through evolution. Um, but I, I can't find a logical reason to preclude the possibility that it's conceivable that there could be, um, consciousness in a different substrate. So, I'm not against AI consciousness as a possibility. I just think we're, I just believe we're so far off. Even though I am stunned by LLMs, they're incredible, man. And I, you know, I'm not a big, uh, person using AI for, um, emotional nor intellectual support, but man, what a search engine."

"Right?"

"I mean, what a search engine. It is unbelievable. This thing does talk to me. It won't stop using scare quotes. I can't get it to stop doing that."

"What do you mean? So, anytime an LLM wants to say something metaphorical, you'll find a lot of them will put quotes around the word. And I, and I wonder, you know, and I keep saying, 'You don't have to put, I understand what a metaphor is. You don't, you don't have to keep putting a quote around this word.' Like, 'the universe chooses.' Like, if it wants to say the universe chooses a state, it will put quotes around 'chooses.' Like, I find I find that I can't disabuse it from this habit."

"Do you have custom instructions on them?"

"Um, I'm not that deep into it. I think I have, I think I have tried that because this is such a pet peeve of mine."

"I see."

"But anyway, anyway, I, I'm not so deep in my, I, I'm just a newbie in some sense to this whole thing."

"My pet peeve is 'it's not X, it's Y,' that you know, where it's not that the universe cycles, it's that the universe does this and that, and it's just, it's so frustrating. And then M-dashes, right? The M-dashes. Um, I probably have a bit of a bad habit with M-dashes myself."

"Yeah, but that's because LLMs are trained on you. You train the LLMs, right?"

"Right. I mean, there's a lot of things to complain about the LLMs and what it's doing to society, you know, and how people are less and less original every day and more and more average, but, um, but putting, and how can we innovate if we're simply copying ourselves frozen at a particular moment in the history of humanity, you know, all of this stuff. But that's not the big questions. The really interesting questions are these ones about consciousness. And so I, I guess what I, I guess what I feel about it is, if I think about human beings as being a series of chemicals interacting, largely electromagnetism, largely, right? It's usually large molecules forming DNA, RNA, and proteins, and all of this stuff happening just on the basis of electromagnetic interactions, really basic laws of physics. At what stage does that become human consciousness? Of course, one of the most tremendously thorny and evasive, elusive questions that humanity's ever asked. So, I don't see why we're expecting the LLMs or or any AI to, for us to be able to solve that problem before we can solve this problem. Like, we don't understand how this happened. I still cannot, in a laboratory, go from molecules interacting electromagnetically to comprehending why there's an interiority and a sense, an imagination that hallucinates the color red. That absolutely evades us."

"So, as a physicist, where do you stand on the hard problem?"

"So, uh, David Chalmers is a good friend. Um, my, it's funny because David Chalmers basically has become superb at dismantling any attempts to solve the hard problem. That's his job. He is this gatekeeper, and no matter what solution you come at him with, he's going to dismantle your attempt to solve the hard problem. Sometimes, uh, I have other friends in neuroscience who think that it's just a total red herring, that it's just really not the question we should be asking, and it's just silly. I sometimes I liken it to, it's the, it's the 'how' question. So, we can say where, what, who, when, why. We can answer all of these questions about consciousness, somewhat. You know, it's evolution, where it happened, and where it happens, where the, um, biological correlates are, and all of these things are answerable. Nobody thinks that those are the hard problem. The hard problem is how, like, how does a photon hitting my eye and triggering some electromagnetic interaction along some fibers result in me imagining, hallucinating the color red? That, I just, nobody knows that, and nobody's come, in my opinion, anywhere close. And when people try, they're really usually answering a 'why' question. I have, you know, human beings evolved consciousness. Why? Well, because our compute is low. We don't have infinite compute. We struggle to understand all of this data. So, we evolved a mechanism to approximate really quickly. I can, out of the corner of my eye, I know it's a baby. Out of the corner of my eye, I know it's a tree, or, you know, some, or a car is speeding at me. All of that consciousness is a really good tool with low compute. I, I can just, this approximate hallucination I have allows me to survive and very quickly with very approximate, um, uh, understanding. And, and so I understand a lot of the 'why's. You can talk about whether emotions are important, or the unconscious, all of this is 'why' stuff. It's all interesting, but none of it really explains how, how I have an interiority and how I have this hallucination of the world. Um, so, and I think it's a fascinating and wonderful thing. It's basically, we're all obsessed with our hallucinations of the world. It's everything to us, right? But, um, but I would say, uh, that I sometimes wonder a stronger thing, which is, if a machine has tremendous compute, like practically infinite compared to us, will it need to evolve consciousness? Is there any reason why it would have to? Or can it just continue to do perfectly well by simulate, by pretending, by simulating consciousness, the way an LLM does, a large language model? And, and that, I don't know. Maybe, maybe it just won't. Maybe consciousness is a crutch AI won't need, and so it will never develop."

"You know, I have a bone to pick with you."

"Oh, please. I can hang up, you know, and take my toys and go."

"I subscribe to The Economist. Their science and their AI coverage is among the best I've found anywhere. And I say that as someone who reads plenty of it. I'll give you some examples. They just ran an analysis on how attitudes towards science are changing in American politics and what this means for research and funding in scientific institutions moving forward. This sort of high-quality reporting is fantastic. They even covered how dark energy may be weakening over time. Now, if that holds up, it completely changes our understanding of the universe's fate. If you watch this channel, those are exactly the kinds of questions that we explore every week. I subscribe to The Economist because their science and their AI reporting regularly surprises me with how deep it goes. And they're also, of course, known for global affairs, both political and economic reporting. They are top-tier. And interestingly and flatteringly, TOE is one of the only podcasts that The Economist partners with. So, as a listener, you get an exclusive 35% off. That's not a deal that they have just anywhere. Head to economist.com/toe to subscribe. That's economist.com/toe for 35% off."

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"I recently signed this book deal with Penguin."

"Penguin is fabulous. Penguin is wonderful."

"Yes, yes. So, in it, I made this analogy to averted vision. And I haven't heard anyone make that analogy before. And also, I have the characters of Gödel and Turing as well. And then I, and then I see, oh gosh, Jan Leven just beat me to it. I gave a lecture a couple days ago at the Mind at Large conference, which is a conference on panpsychism. And I was saying that, look, some phenomena may be such that when you try to look at it directly, it actually disappears. So, in physics, there's something called a non-Newtonian fluid, which looks fluid, but you touch it, and then it becomes solid. But then the opposite is thixotropic, where it looks solid, but you try to touch it, and it becomes liquidy. It escapes your grasp. And I was saying, potentially, the self is like that. Potentially, consciousness is like that. Potentially, free will is like that. And what happens is, we take this fuzzy, intuitive concept, and we make a formalization of it. We look at that formalization and say it's incoherent. We then conclude it, it does not exist. And I think that's a directly feeling it by not looking at it, but then you try to make it explicit, then it disappears."

"And then I saw that you also made a similar analogy."

"And I was upset with you."

"I'm so sorry."

"Yeah, that's in 'A Madman Dreams of Turing Machines,' where truth is just like that. You can see it, but only out of the corner of your eye. Um, and it disappears when you try to look at it directly. I think it's a beautiful analogy for for what happens. What I was trying to do in 'A Madman Dreams of Turing Machines' is admit that you could not get to the truth of the stories of these lives in an axiomatic way, simply by, as though rolling from theorem to theorem, listing biographical facts. I couldn't write, in other words, non-fiction and get any closer to the truth about them, in the same way that Gödel's true statement can't be arrived at through theorems. And I felt that that underscored sort of this idea of, well, sometimes our human narrative, which destroys things in the process of telling the story, is as close to the truth as you're going to get. You can only get to it out of the corner of your eye, you know."

"Yeah. So, well, now I'm looking forward to your book. Is it fiction, fictionalized?"

"No, no, no. I wanted to bring people to the frontier of physics because people keep thinking the frontier of physics is string theory. It's AdS/CFT. And I'm thinking, that's 20 years, 30 years old. Like, what's the frontier?"

"As I was going through this, I was thinking, okay, because I'm not a physicalist, but I'm not an idealist either. I'm not a monist in the sense of any traditional sense of the word, but I'm philosophically homeless. I don't know what I am. I just am unconvinced of all the, the mainline positions."

"Well, there's always, there's always more to be done. I mean, it's almost this idea that we, we should, we should be reapproaching theories and ideas and saying them different ways, and each person having a unique approach. You know, this idea that, 'Oh, the novel's already been written. There's no new novel.' And of course, that's absurd. It's almost like saying, 'Well, let's not make more human beings because a human being has already experienced the world.' So, nobody else should experience the world. And, um, and of course, that's not what we actually believe. We actually believe that each experience of the world is unique and brings something and experiences something unique."

"Klein bottles."

"Klein bottles. Yeah. Um, well, I'm a little obsessed with them. Oh, can I show you? I have a little Klein, little Oh, I should have brought my glass bottle. Hold on. I have this. Can you see this little Klein bottle?"

"Yeah. Yeah. I actually have a glass 3D Klein bottle. Um, so my friend's an artist, Andrea Lowour, and she makes these little things for me for various, uh, events I do or ideas I'm thinking about. It's really kind of a fun collaboration. But this, of course, looks, is not the really the Klein bottle. This is what the Klein bottle looks like if I force it to live in three Euclidean dimensions. I have to really mess it up. Okay, the Klein bottle, as it lives in 2D, without forcing it to embed in three, is a very symmetric object. It's, it's very symmetric. Now, some symmetries are lost, but not all symmetries are lost. So, the idea of the Klein bottle, if it lives in just 2D, it can be a perfect square, meaning it's as wide as it is high. And I can't do that here. You know, it's all messed up. It looks like it's smaller and bigger, and this is, so this is totally, um, I've had to change the local geometry in order to represent the global topology. Right? But you can have both if you stick in two dimensions. So, then you're really playing a video game. The idea, for instance, let's take the simpler structure, the torus. In the torus, if you exit the right face of, let's say, a square, you re-enter the left face, just like a video game. It's no big deal. You fly off one edge, you re-enter the other edge. It's just a rule of how those edges are glued. You can do the same thing in the video game, going off the top of the screen and re-entering the bottom of the screen, right? And if I want to see what that looks like to me, my three-dimensional self wants to say, 'Well, like, what does that look like?' I want to lift it into three dimensions. I want to glue the sides, make a cylinder. Then I want to take the ends of the cylinder and I want to glue those together and make a donut. And I go, 'Oh, look, the torus is a donut.' But in doing so, I've changed its local geometry. I've made it shorter on the inside and longer on the outside and shorter around the donut part. And all of that's false. All of that's a false, uh, uh, projection of what I did to to to force it to be to show me that the object with which it is topologically equivalent. Right? So, the surface of a donut is topologically equivalent to the real donut, but the real donut lives just in two dimensions. I never lift up the sides. I never, the real donut can be equally wide as it is high. So, the Klein bottle is just like the donut, except for when I glue the sides together, I twist, I twist the sides by 180 degrees. So, in other words, if I'm, let's say this twist happens when you're going out the top, if I go out the top, I come back in, and I have a left-handed glove. It comes back in the bottom, flipped into a right-handed glove."

"I'll be showing some animations on screen over this, so don't worry."

"Okay, cool. Yeah. So, so that, that makes the Klein bottle. It's completely compact. Um, and but it is what's called non-orientable because, uh, when I go one journey around the Klein bottle, it's almost as though, because of this twist, uh, I've come from, it's almost as though I've come to the inside of the Klein bottle. There's no real inside or outside. And if I go back around, I'm in the outside again. And that's a continuous surface. So, it's as though it has no well-defined inside or outside. Okay. Now, the donut does. I can tell what's inside the donut versus what's outside the donut. The Mobius strip, or the Klein bottle, which is the 2D analog, um, it's not orientable in that sense. And because of, it has this funny left-right property. If I take a left-handed glove, one time around, it's now a right-handed glove. It doesn't fit my left hand anymore. I have to send it around the universe another time for it to come back and now fit my left hand. Um, and they're just, they're just fascinating little spaces. Um, the original idea for working on them recently was I wanted to make a ray gun where you like shot left-handed particles into the Klein bottle. So, you had a universe as we know it, three dimensions of space, one dimension of time, large spatial dimensions, plus two additional dimensions that were wrapped up into a Klein bottle. And those dimensions exist everywhere, but they're hard to access because maybe they're small, maybe we live on a brane. There could be various reasons why we don't notice that they're there."

"Wait, sorry, can you repeat that? What's the structure of the, of our large dimensions? And then where does the Klein bottle dimensions live?"

"Yeah. So, they, at every point in our space, just like at every point in our space, there's up, down, left, right, forward, backward. There's also these two other dimensions at every point in space, and they're wrapped into a Klein bottle. And, um, so everywhere I am, I, in principle, if the bottle was large enough, I should be able to stick my hand in there and watch it come back right-handed. You know, my right hand will come back left-handed, vice versa. I see."

"Um, but, but it's possible that it's just too small for me to do that. And the common analogy is, imagine you lived on a very, very, very thin straw, and you were bound to that straw. But you might think the universe was only one-dimensional, and it might take the whole other straw dimension inflating before you realized, 'Oh, wow, there's this other dimension that I live on that I could go round and round.' And if I make it big enough, I might even think I lived on a flat plane. I might lose the sense that I lived on a straw altogether. So, it could be that those dimensions are just really small, and we think we only live in three, but we really have five spatial dimensions."

"Got it. And maybe, maybe that's the reason, or maybe there's another reason why we can't access them, like we're bound, uh, via some interactions to the three-dimensional space, like and that's like a brane, sometimes that's called a membrane, a high-dimensional membrane in this five-dimensional space, and we're glued to this membrane. So, we just, even if that space is big, the Klein bottle is big, and our whole membrane is moving through the Klein bottle. Our whole universe, all the galaxies, everything stuck to this vast universe that we see, is moving through this higher-dimensional Klein bottle, and we just don't even notice it. Um, that is a possibility too. Yeah."

"So, firstly, physicists tend to not like non-orientable surfaces because you can't put spin on them. You can put pin. So, I want you to tell us the difference between spin and pin, and why this is not as much of a concern as we thought."

"Yeah. Um, so we did, we're not the originators of the mathematics of pin structures. But spin structures are, are just a way that people understood they could do things like put fermions or spin-half particles in a universe. And, and this is, uh, what the Dirac equation describes for us. It describes the evolution of a spinning particle in ordinary space. We don't put anything topological on it. We don't assume it's finite, just three, three nice dimensions. The Dirac equation was originally written in 3+1 dimensions, including time, four dimensions. Um, the, the problem with non-orientable manifolds is people thought, 'Oh, yeah, maybe you can't orient the spin structure either.' You know, there is an orientation to the spin structures, and so maybe they just can't live there. But it was shown that you have different structures called pin-plus and pin-minus, depending on the boundary conditions for the fermion. Um, meaning, does the fermion field come back to itself on one trip around the non-orientable space, or does it come back to minus itself? Because you can't, that's not an observable. You can tell the difference. So, both are possible, um, outcomes of taking one full trip around the space. And, um, and simply, it's just been shown that those structures exist. So, there's a reassurance that you can do the Dirac equation even on these non-orientable manifolds. It is not an obstruction. You, you talked earlier about obstructions. It is not an obstruction to building fermions. So, we know we can build fermions. We have trouble building what's called chiral fermions. And chirality is this left-handedness versus right-handedness. Chirality describes your handedness. And we know that particles do come in a handedness. It's a peculiar thing that, um, left-handed particles interact weakly, and that the right-handed counterparts behave differently. Um, so, there's, we want to be able to build left-handed particles because that's the laws of physics that we observe are not, are partial to left-handed particles. We don't know why. Um, but it turns out it's really hard to build chiral fermions. So, that there are reasons why we kind of want to restrict the world that we observe to this brane where we can have chiral fermions, where we don't have, uh, this problem of the left and right being mixed up in these non-orientable manifolds. Cuz if you're a left-handed particle and you travel into this higher dimension, you come back right-handed. That seems really bad because now you've broken something about the gauge symmetry, right? Is you've, you've broken something in a really bad way that's inconsistent. So, we, we, you know, we're, we're trying to understand many things about these higher-dimensional spaces. I thought they might do us some good in that we could take left-handed particles, shoot them into the extra dimension, have them come back right-handed, and by their right-handedness, they would be non-interacting."

"Um, and so I thought, 'Oh, that's kind of cool. You've made something dark.' Right? You've made something that was interacting and you've made it non-interacting. So, you've turned off, you've made it dark, or effectively, as I often say, it's, and many people say, it's better to call things invisible because you've made them invisible, not dark. They don't..."

"Sure."

"...cast a shadow. They're just technically invisible. And I thought this was a really cool idea, but instead, what we got was something really different. Um, and I, I really should say, I have fab, the most fabulous collaborators in this. Is work with Brian Green and Massimo Parizzi, uh, who's just absolutely brilliant particle physicist, string theorist, and Dan Kittel, just an incredible talent in particle physics and string theory. And I'm sort of the spacetime, you know, they're like, I call them my guys, you know? And, uh, it has been one of the greatest pleasures of my research life to work with them and just, um, just run into the cloud of ideas and try to find our way through. But, uh, yeah, so what we ended up finding was equally really exciting, but completely unexpected, at least to us, at least to me. I can't speak for them."

"Tell me about what you bring to the table and what Brian brings to the table. What are the, the relative strengths of everyone? What's your dish at the potluck?"

"It's, you know, it's all, it's all different. We, Brian and I have worked together for many years, as have Dan and I. Massimo, a couple of years. Just a wonderful collaboration. Sometimes one of us just sees something the others aren't seeing. I mean, it's not, I, it's just, uh, we are all bringing different things, but it's not stark. It's not like this person calculated this section of the paper. It's not like that. Um, so everyone has like a global view. If you do, sometimes in more astronomy fields than in theoretical physics, people will, will be, 'I did this data analysis, and that's it. And I did these figures in this larger paper.' I think for us, we all have to have the whole view. And so what we're bringing for each other is sometimes challenging, uh, pressure testing the ideas in each of us will bring different ideas to the table, and we'll work on them as a group. Um, and I think sometimes you really want to be pressure tested by your collaborators in your group and not go out there without having fortified your ideas and, and really crossed your T's and dotted your I's, you know, doing all of this. So, there a lot of what we're doing, a lot of what we're doing is like pushing on it and pressuring it and then streamlining. Um, I think for a long time, we just didn't know what we had. So, you know, you, you're going to your friends and saying, 'Is this a mistake? I'm calculating this. I can't get it to go away. Am I making a mistake? Do you, we all know lots of ways of calculating. Do you see a calculational error, or do you see a different way of doing this calculation?' And sometimes we, we'll have two different ways of doing it and getting the same result, which is really important. Um, so, yeah, I would say that, and, and, and really, it's just a lot of fun to get together for a few hours, and, uh, there's always some point where people will walk past, like my door, and we're all in here, and we're all quiet."

"Nobody's talking."

"We're all thinking. And it's a really funny thing."

"Does it look tense from the outside? They think you're upset with each other, or what?"

"Well, I think physicists are used to this phenomenon, but people who are not physicists remark on it. The strange phenomenon that you'll get together is a flurry of talking, flurry of activity, and then it could be 10 minutes of utter silence, and no discomfort."

"Just until somebody kind of picks up a piece of chalk and meanders over and says, 'Well, what if?' and it starts, you know."

"Um,"

"But, yeah, so I think what, what has been interesting is that what we discovered is that these spaces, uh, violate certain symmetries that you would have had. So, if you're starting with a two-dimensional sheet of paper before you've glued it together, and that sheet of paper is infinite, so you imagine two extra infinite dimensions, you should have this symmetry under translations. You expect the universe to be the same wherever you are. And you, you don't expect to have, um, parity violation, which is this violation of this handedness, this left-right, uh, uh, symmetry gets broken, and something else subtly gets broken. You can also break charge symmetry, which says that the universe or the laws of physics look the same for the particle and, and let's say, the antiparticle. The, the topology can break that for you. So, it gives you something that we actually know we have, which is an asymmetry between matter and antimatter that we don't know how to explain. We don't know why after the Big Bang there wasn't equal proportions of matter and antimatter, why those proportions didn't come together and annihilate and obliterate into light, and thereby leaving us an empty universe devoid of, certainly human beings, you know, planets, stars."

"Right."

"And, um, and we've been trying to understand this, this why there's something instead of nothing. And actually, uh, the Klein bottle is, is just a simple example of a space that the geometry of the universe breaks the symmetry and can prefer differentially favor matter over antimatter, which would explain why there's something instead of nothing. So, it does some funny things."

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"Half of my day is spent in conversations and research. The other half is spent trying to remember what was said and read. That's where Plaud comes in. P-L-A-U-D. I have far too many thoughts. I always tell myself that I'm going to remember them, and then I almost never do. It's incredibly frustrating. But I've been using Plaud for many months now, and it's a huge game-changer. It's actually ridiculous. I've noticed that this channel's output, Theories of Everything, if you've also noticed that it's increased in quality and clarity over the past few months, if it's improved at all, Plaud is responsible for a non-trivial chunk of that. I would say it's something like a 5% gain in thinking. And that workflow compounds fast. If you're a knowledge worker, you know how valuable even incremental small 1%, 2% changes are. This trounces that. What I like is that it removes friction. I'll use the Notepin S when I'm walking, moving around, or just thinking out loud. It's hands-free. I don't have to look at a screen, and I can stay present with the world. I don't have to worry that I'm going to drop my phone. Then I use Note Pro in more structured settings, when I actually want to capture and organize conversations more deliberately. So, instead of ideas slipping away, everything gets captured, processed, and then turned back into something usable. It's basically a system for extending one's working memory into the real world. And if you know anything about intelligence, intelligence is highly correlated with working memory. So, if your work depends on conversations, research, business, medicine, law, this kind of thing matters far more than you'd expect. They're also serious about privacy and security, SOC2, HIPAA, and GDPR compliant. If you want to check it out, go to plaud.ai/curt and use code kurt."

"Now, does it just permit CP violations, or does it predict? Like, what would be the difference between permitting and predicting?"

"Yeah. So, I would say, uh, first, we said it permits. That's the first step. Um, and there's, again, all kinds of different boundary conditions you can impose, and they all lead to slightly different predictions. And so some of the spaces predict this, uh, violation, and, uh, some boundary conditions won't. But you, you really just need one. And, um, and then to predict, I do think is another layer because then you have to say, 'Well, how do I interact with this higher-dimensional space?' And now to have prediction requires more, um, uh, understanding of the cosmology. So, do all of our fundamental quantum fields live in the higher, permeate the higher-dimensional space, or are we stuck to a brane? And so, then these details start to become important in the actual cosmology of how you convert the breaking of the symmetry into the cosmological consequence you want, like there's more matter over antimatter. And that's, I wouldn't say it's a prediction. And I think you're trying to match, then you're trying to match a model to what we observe. So, if I have a brane and the brane moves through this, this bottle, this Klein bottle, it, it interacts with this in a way that breaks the symmetry. And so you're predicting the way the interactions, um, uh, are written. You can predict all kinds of interactions, and the model will select values for the, you, you'll be fitting your model to the observations, kind of thing. So, I'd say it's not exactly predicting, it's allowing, permitting."

"I see."

"It is more permitting, and then the model building uses that permission to do what it wants."

"If I recall correctly, there was a footnote about you weren't able to find a pin-minus structure on the boundary conditions with charge conjugation."

"It was, yeah. Um, with charge parity, we weren't sure. Yeah. Even I can't remember the exact statement. There's a famous line. Do you know this play, Proof?"

"No."

"It's a famous play. Tell me about it. Um, it's about mathematicians where this, the father in the play is a Fields award-winning mathematician, and the daughter is following in her footsteps, but nobody believes she's written her proof. Her own sister, um, doesn't really believe her. And she says, 'Well, here, I'll show you proof. I'll walk you through it.' And she says, 'But you have to give me my notebooks.' And the sister says, 'Well, why would you need my not your notebooks if you wrote the proof?' And she's like, 'It's not a muffin recipe. I mean,'..."

"Oh, right, right, right. Exactly."

"...'I need my notes to talk you through the proof. It's not a muffin recipe.' So, that's a great line. So, sometimes Brian and I joke about that. It's like, 'It's not a muffin recipe.' Who has the notes? You know, we, we've got to look at our own notes. Um, but yeah, we, uh, there was for the charge parity, we couldn't, um, we couldn't be sure that that..."

We had a a minus boundary condition, essentially that we can enforce a minus boundary condition. We kept getting the the plus boundary, the pin plus structure. It it might be that it might be that there's just a phase that one could add. We're not saying we've we've proven it can't be done.

>> And what's the significance of that?

>> I don't think it's particularly significant. I I just think if that that the the topology and the boundary conditions force you to use certain spin structures, that's all we know. Um, maybe somebody who's worked on the spin structure specifically, really deriving them, would find some big significance in it, but I think it might just be with charge parity that you're forced to use the other spin structure. It's not, you know, it's not really that big a deal, I don't think. It's a little surprising we kept going around in a circle on it.

>> So you just mentioned brains and people who are listening know of brains from string theory. Are you just borrowing a tool from string theory, but this particular approach is not string contingent. It just uses a tool?

>> That's exactly right. Yes. So, I like to say, um, string theory requires extra dimensions, but extra dimensions don't require string theory. And, um, so this could be any, uh, fundamental model could have this kind of dimensionality. The CP violation would be broken by the geometry. Nothing stringy about that. Um, even brain worlds don't have to be stringy, though they did come. They were motivated by the idea that beyond strings, you had higher dimensional membranes and maybe we'd be stuck on one of these membranes, and that's why we don't notice the extra dimensions as opposed to requiring that the extra dimensions be small. It's very clever stuff, but all of it, all of it can migrate outside of the stringy context. Um, but the brain world was just a simple way to show proof by concept, right? Proof by example, um, proof of concept by example, just to say, look, I can create, uh, I I can actually show you that I can calculate, um, an asymmetry in particles if I invent a coupling where they live on a brain, and as the brain moves through the Klein bottle, it gets these bursts of particle production, and it notices where it is in the Klein bottle because some of the symmetries have been lost of the space, and it was really just a way of showing how you could get particle production and how you could get the main ingredients that are required for creating matter over antimatter. Um, but it wouldn't, you don't necessarily need a brain scenario to do it. It was just a very, it was just a very clean demonstration of how to exploit the fact that that these topological spaces could be CP violating, charge parity violating.

>> I see. Yeah, it was just, it was just a demonstration. Yeah.

>> Okay. So, let's see if I got this correct. You're not claiming that our four dimensions or 3+1 are is a Klein bottle. You're saying that our potentially 5+1 with the extra two dimensions is somehow a small Klein bottle?

>> I mean, yes.

>> Well, you were actually thinking how can I maybe how can I violate CP symmetry? Okay. And then this is one way.

>> You're not saying that this is necessarily how the universe is. You're using this as a tool, and you're concerning yourself with CP violation because you want to know about baryogenesis, and there are three conditions, and so one of the main conditions that has been unsolved is about CP violation.

>> Mhm.

>> Is that roughly correct, or am I am I off?

>> That's roughly correct. So, I think that there's no, no, you're, I think that's about right. There's a bigger picture. One is saying, uh, I can't, one is saying those extra, those large dimensions that we live in could also be topologically wrapped up. We just don't know it because it's so big. The universe is so big that we're just unaware of that. So, I think that there are multiple things beyond the CP violation that the extra dimensions can do for you. So, the having the extra dimensions, Klein bottle being a simple example, could do things for you like give you dark energy, which is something that we had talked about in previous papers. Um, and the way it can do that is because a small space has a quantum energy associated again with the topology of the space, called the Casimir energy. And this is a well-known result. We we can see Casimir energies in the laboratory with by trying to confine electromagnetic plates. We find that there's a pressure between them because of the difference in the energy between plates where there's a boundary because of the plates versus if there were no plates, and that's called a Casimir energy. You can trap energies by forcing a boundary condition, and topology like forces a boundary condition on the vacuum in such a way that it creates a quantum energy that is different than you would have in infinite space. So it can create a quantum energy. That quantum energy would be felt everywhere. And that is what we think of as a dark energy. Dark energy is this weird vacuum energy that's felt everywhere. We don't know why it has the value it has. Um, but, uh, but it could be that extra dimensions are a way of trapping that energy for you. So it could give you dark energy. There's reasons to think it could contribute to to dark matter models as well. Um, that, uh, that excitations in the extra dimensions could be acting as kind of dark matter particles. Um, it could also be, as we found here, that the same mechanisms are also giving you the CP violation and explaining matter over antimatter. So, it's not a, it's an all-in-one shop, potentially.

>> And this ray gun?

>> Yeah.

>> Is that a pipe dream, or was that an actual, you were hoping to make it an experiment?

>> We, I think we can shoot left-handed particles and have them come back right-handed. I don't think those particles can be the dark matter for subtle reasons having to do with being unable to make chiral fermions in the higher dimensions. Um, so anything that can go into the extra dimension left-handed can come out right-handed. That I'm confident of. And the space can do that for us. And thereby you might say, "Oh, it makes something dark." But then we would say, "Oh, we have a problem making chiral fermions that interact in a chiral gauge theory at all because they're always mixtures of left and right. They're always mixtures of left and right. So I can't make them only left and only interact left-handed." And so that problem, you know, is a problem. So I, I, I, so I think it works. It just didn't, it just didn't, we had more problems than we solved with with that particular, you know, but, um, but again, just that that it doesn't have to be a Klein bottle, it could be a different topological space that breaks CP violation. So I think it's a, the idea is that it's more general than, um, than any specific claims about the specific space, that it's, it's a general result in that sense. In other words, the shape of space might have a lot to do with the universe that we live in, you know, which is pretty interesting.

>> Is the shape of space what's exciting you right now? Is that where your mind is at?

>> I have always loved that topic. I've, um, I think we could also say something like, we'll learn what the geometry of the large dimensions, uh, must be by looking at the shape of the small dimensions. That's also very exciting. The idea that maybe in the early universe, there was a democracy of these finite dimensions. And what we're really trying to understand is why did three spatial dimensions get so big, and the others, however many there may be of them, stayed small or inaccessible? And that if, if there is this, oh, there's there's a causal relation between, uh, why the other dimensions are small and why these are big, it might mean that we could, by probing particle physics, understand the shape of the universe on the largest scales. That stuff's, I thought always been exciting. Um, I, I am thinking about it some more because I think that this is, this topic has given us a lot of really interesting results, um, that are potentially very fruitful for cosmology. Um, so, yeah, I'm still thinking about some offshoots of that, but I also do black holes. I, I think the joke for me is that when I when I work on black holes, for me, that's like concrete reality.

>> Ah.

>> I'm being practical.

>> Yes. Yes.

>> Um, so, sure, I'm still thinking about black holes.

>> So, why don't you walk us through some of the recent results in say, black hole information, like the the page curve or the island formula?

>> Um, well, I know less about the island formula, but just, I, I mean, I'm sure your audience has heard about this a lot, but I think it's always for internal consistency worth sort of stating the problems. Um, the problem, of course, being Hawking's provocation that black holes, just by doing a little sprinkling of quantum mechanics just outside a black hole, not doing anything dramatic like quantum gravity, you know, just, this is got to be true, little bit of quantum mechanics on a mildly curved spacetime, um, and black holes are mildly curved if you make them big enough. I think that surprises people, but it's the same as thing. The Earth, when it's really big, looks flat locally. The bigger it is, kind of the less you notice a curvature. So you're in this mildly curved region around a big black hole, and you have a little quantum mechanics, and the black hole steals one of the particles that come out of a quantum fluctuation vacuum fluctuation, and, um, and it doesn't sound like such a big deal. It's perfectly consistent with quantum mechanics. If we want to take a step back even from there, we can say, look, the Heisenberg uncertainty principle tells us that I can never know for sure where a particle is exactly. But that also means I can never know for sure that it's not there. So Heisenberg uncertainty seems to require the possibility of particles kind of frothing around.

>> Mhm.

>> So I can have empty space, but by Heisenberg uncertainty, I can make a particle and its antiparticle entangled pair in precisely such a way that they cancel each other's details so that they can go back to the vacuum again. Right? What I can't do is make a particle with spin a half and and a pair that has spin one. I can't do that because they can't cancel each other. I have to make a half up with a half down. They can cancel each other. Spin goes away. Positive charge with negative charge can cancel each other. Spin goes away. But they have to be paired so that they neutralize each other perfectly, right? And this is perfectly consistent with what we mean by a vacuum. Doesn't necessarily mean it's exactly empty. Doesn't necessarily mean it has no energy. It really means that on average, it's got no charge, no spin, no colors, you know. So anyway, a particle antiparticle comes up, the black hole can steal either one. It doesn't matter if it's the particle or the antiparticle. And it can steal it in such a way that the other guy is left outside of the event horizon. No longer has its pair. It can't neutralize. It can't get rid of its charge or its spin or any of its other details. It can't go back to the nothingness from whence it came. And so now it lives. It's stuck. It's stuck out here now. And that particle escapes to infinity far away. And some observer from far away sees this particle, maybe it's a photon, maybe it's an electron, maybe it's a positron, and it says, "Oh my gosh, the black hole just radiated a particle because that's kind of what it looks like."

>> Right?

>> Um, but from the black hole's perspective, nothing came from inside. This is crucial. So whatever went into the black hole is not making it out. And that's a disconnected story according to the original story that Hawking was telling. And now you have the following provocation, which is that look, eventually the black hole is shedding its mass as it's absorbing these particles. And we can talk about why it gets less massive and not more massive when it absorbs these things. We could talk about that in a second. But it, it will get less massive. The energy will be conserved, but eventually the curtain is yanked up. The black hole has exploded, all, all it's given off all of its mass to this form of Hawking radiation. And the curtain's gone. The event horizon's gone. And if the event horizon's gone, I'm no longer protected from this terrible confusion about what happened inside the black hole. I'm no longer protected from that. I, I should be able to see what happened to all the stuff that fell into the black hole. And it seems this great crisis that the stuff that went into the black hole seems to be gone, but it's not the same stuff that was radiated away. Those were two separate things. And this is what led to the famed information loss paradox. Quantum mechanics says you cannot destroy information. What happened to the stuff that fell in? It's not in the radiation that came out. That's really bad. And, uh, and general relativity says, well, nothing can get out of the event horizon. So by the time the event horizon's yanked up, it's too late. The stuff, you know, it's over. So nothing can make it out. So this leads to a real conflict, a real paradox. Um, well, so this is all very interesting stuff that everyone's thinking about now.

>> So the standard story is that there's some event horizon. Let's just imagine it as a wall that looks like this, and the black hole, the the blackness is over here, and nothing can come out, but, and then the regular space is over here, and that there is some pair production that occurs here, and from the outside we see something come out of the black hole, but from the black hole's, black hole's perspective, something just falls in. So why would it be that the black hole is evaporating rather than getting larger? Because from the black hole's perspective, more is just coming in.

>> Right? Sometimes you'll have people say, "Oh, it absorbed the negative mass particle." That's not right. There, there is no negative mass particle. It's not absorbing negative mass and thereby getting lighter. But the difference is that time and space in some sense have switched places inside the black hole. So from outside, I might say that's a positive energy particle, my pair that fell in, and it was directed spatially inward in momentum, but because of the relativity of space and time in the interior of a black hole, you say, "Oh no, that was a, that negative momentum is a negative energy. I call that time direction. I call the direction which it's moving the time direction, and it is imparting negative energy. What you're calling negative momentum, I'm calling negative energy." And, uh, and that's totally fine. So that you haven't, you don't have negative mass particles, you haven't violated anything. It's just the relativity of energy and momentum directly reflects the relativity of space and time. And so you actually absorb in your frame of reference, in the interior of the black hole, a negative energy is absorbed, and the black hole gets lighter. So it's completely consistent. Yeah.

>> Do you have a preferred resolution to the black hole information paradox, or do you not even see it as a problem? So, for instance, Sir Roger, when I spoke to him about this, he said, "Why do people put up so much of a fuss? Maybe information is destroyed in black holes. I see no reason why not."

>> Yeah. Yeah. He's, um, he's not the only one. I think the relativists tend to be like, "I can live with that." And the particle physicists are the ones who say, "I cannot live with that." That, and nor should you be able to live with that. You should not, I don't care, you should not be able to live with this. Um, I think there is definitely a resolution. I don't think it's just, "Oh, there's information's destroyed and it's no big deal." I don't think that's the case at all. And I think, in fact, it's this gift we have. It's like the siren song. It's like it's like the, the two laws that we love so much are signaling their demise and telling us where to look, you know, they're, they're guiding the way. So I think it is the most wonderful direction for fundamental physics. I don't think it's a waste of time. But I think that the answer, and I'm not actively working on this, although I mostly just chitchatting with people about it. But, um, I'm observing from afar, but I think the answer to this will will really be a big deal. It will really be a big deal, and we're we are already seeing that in some of the the ideas that are floating around, and I suspect are probably right. Lenny Susskind's holography, Juan Maldacena's AdS/CFT, these are all, I'm sure, are on the right path. But if you take a step back and you say, we still don't nitty-gritty have the answer, what it seems to suggest is that, and this is even harder in the context of what we were just talking about, but we can't even trust the dimensionality of the universe as a firm fact. Um, holography says it might look three-dimensional, but really you only need two. And all of this is an illusion. And you, it, it is granted two that can be interpreted in a different language as though it's three. But you only really need the two. And this is what AdS/CFT is all about. Um, the anti-de Sitter space and the conformal field theory correspondence is that I might have a universe in a box, but it's exactly translatable into a universe just on the lower dimensional boundary. Those are equivalent worlds. So that, you know, so I think the, the things it's saying about the nature of reality are really big things. It's not like, "Oh, now I know how to quantize the metric. Now I know what the indivisible unit of spacetime is, and now I can just do normal." It's not, I don't think we're going to get quantum gravity. I think we're going to get something else. Um, and that's, that's why I love watching that. Yeah.

>> Let's linger on black holes. So you said something, if I'm recalling correctly, and as you know, I haven't had much sleep the past couple weeks. I'm in a a horrible bout of insomnia, which you've also suffered with. So,

>> I'm so sorry about that. Oh, yeah.

>> We'll talk about that later on. If anyone's listening and you're going through something similar, we'll get to that.

>> Some practical tips from Jana.

>> You've solved it. You told me, you promised me. You can cure me.

>> Okay. But if I recall correctly, you said something about you dismissed fuzzballs or soft hair and firewalls. If, if I recall correctly.

>> Oh.

>> And that ER equals EPR cannot follow the chalk, or doesn't follow chalk. Something like that.

>> I would pick those apart. So, um, I would say I think there's something to ER equals EPR. Um, and I'm not going to go into great detail because I don't think it's there yet either. I think even the people who I'm learning this from are struggling to formulate it in a more precise way. So, I'm not going to pretend I'm going to do better than that, you know. But, um, but I think there's something to ER equals EPR. The idea being that, oh, maybe when I entangled a particle with its pair that fell into the black hole, that that thing that fell in is like by a wormhole. Actually also the particle on the outside, and so now those being entangled too isn't violating the monogamy of entanglement. Like I think there's something there, got to be honest. Um, but, uh, but firewalls are a little bit different. Firewalls are what provoked people like Lenny Susskind, uh, uh, to think harder again about something that they thought they had made real progress on. So, so for Lenny, for a while, I think, and again, I don't want to speak for him. Lenny's, Lenny can be really intimidating. So, you know, I don't want him like yelling at me or anything.

>> I spoke to him on the podcast, actually.

>> He's, he's so wonderful. Is one of my favorite people and just such a dream to talk to and just, I mean, what an imagination that man has. Um.

>> Why is he intimidating? What do you mean?

>> Oh, I just, you know, he can't, he, he can get really hot-tempered. So he talks about like, he talks about like how pissed he was at Hawking for having suggested Hawking radiation. I mean, he literally describes being pissed off, like he was in a bad mood, you know. Um, which is kind of funny, but also passionate, you know.

>> Yes. Yes.

>> Um, he said a lot of people didn't think it was a big deal, but right away he was in a really bad mood about it. Um, and I think was also took it very seriously originally. But, um, but I think Lenny's kind of ideas of complementarity, that, oh, maybe it's not such a big deal that you have complementary observables, that, you know, I can't simultaneously know the momentum of a particle and its location, and they're complementary. We've learned to live with this stuff. So maybe simultaneously the information falls in according to an observer that crosses the event horizon, but not to an observer on the outside, and it's not a big deal because there's nobody who can raise the complaint. Nobody can file the complaint. Uh, so this idea of black hole complementarity, I think Lenny felt really confident about it, and then when people like Polchinski came along and started talking about firewalls, he just thought they were wrong, and then again, he was really pissed off when he realized they were right.

>> That they had a point.

>> And, um, I'm trying to think of how to express the firewall point. Basically, they argued because a particle has to be entangled monogamously. You can either entangle it with the pair that came out of the vacuum that needed each other to cancel perfectly and disappear into the vacuum and keep the vacuum a place of no drama, that once you've done that total entanglement, you can't also be entangled with other things like the early radiation coming out of a black hole or the stuff that fell into the black hole, or you can't, you can't do that. It's, you're used up. You're accounted for. You're monogamous. And they used that argument to show that, uh, there are additional stats, which I don't think we should belabor, but essentially that that even in Lenny's formulation, that if the pair couldn't then also be entangled with the one that was created out of the vacuum, so it meant that the vacuum had to be messy. So if you can't be entangled with the thing you came out of the vacuum with, you, you can't neutralize. If you can't neutralize, you're not an empty region of empty, no drama. You are a mess. You're a hot mess. You have charges. You have spins. You have particles because they're not neutralizing. I think is one way of saying it. That's my big shortcut to saying it. And I don't think firewalls are true. I think that they're just too outrageous. It would mean that even relativity at a very non-quantum scale would have to have firewalls, and and I just don't think that can be the case. Um, that, uh, that there's a blazing hot region outside the black hole. Now, I think there are maybe even Lenny does this too. Lenny would say, well, I think of firewalls a little differently. What I think is you would see a firewall if you resisted your fall into the black hole. So let's say you're accelerating like hell so as not to fall into the event horizon. Then you are going to see a firewall because you're, you're not in the vacuum state yourself. You're, you're resisting. You're not in freefall in the natural vacuum there. There are actually, you know, if you brought a detector, you're waving your detector around like crazy under this acceleration trying to fight the black hole. So, yeah, you're, you're detecting a lot of particles, but, you know, so you see a firewall. So, there's a lot of different ways to to talk about the firewall. That argument, I would say, yeah, I would, I would say you would see a firewall. Um, but you don't want the observer who's falling gently across the event horizon, who's not resisting, who's in freefall, who's not experiencing any forces, who's not firing any fuel. You want that person to have an experience of no drama as they cross the event horizon. And I think that indeed, that is what one wants. And, um, so, so that's why people started saying, "Oh my gosh, maybe there's some way of entangling the interior to the exterior." And, yeah,

>> making the the outer particles that they have to be correlated with the same as the ones that they're correlated with. So there's no violation of the monogamy.

>> Um,

>> Yeah, something about that seems to me to be interesting. But, you know, when I talk about black holes too, you know, sometimes I'm just doing astrophysics.

>> Uh-huh.

>> I mean, sometimes I'm just like, there's a black hole in the galaxy that collapsed from a star. And that's what I mean by being really concrete. Those guys are real, and observers can look at them. Yeah.

>> Okay. Let me be non-concrete. Let's imagine you you had a black hole gun. So, not a ray gun, just a tiny microscopic black hole gun. What do you think would happen in your Klein model if you shot a black hole into one of these small dimensions? Does anything interesting happen?

>> Um, I wish I could say it's a simple thing to calculate because even the black hole metric, I have to rethink in the Klein bottle because the black hole metric that we're accustomed to doing has an asymptotically flat space at infinity, and so I, a lot of people have done black holes in higher dimensional spaces, it can be tricky. It's not completely, you know, it's not just a given like a marble I threw a marble in the space. So I'd have to first of all see.

>> It's not a muffin. It's not a, it's not a muffin recipe.

>> Um, not throwing a muffin in there. Um, so can I make a 3D black hole? Is it a 5D black hole? Um, does it have an event horizon in all five directions? Or does it only have an event horizon in three? Like, I'm already like, oh, I got, I have a lot I have to think about. So, um, but it sounds like an interesting thing to try. Even though black holes are extremely complicated, they, they're quite simple in many respects, they're characterized by just a couple numbers like mass and charge and spin. So also particles are characterized by just a few quantum numbers.

>> So do you think black holes should appear on the particle spectrum? And then if not, then where does this analogy break down?

>> It's a great question. I absolutely do think they should. I think black holes being an interesting terrain on which to understand quantum gravity or the information loss paradox is not just a coincidence. It's because there's something fundamental about black holes. They are somehow, I believe, part of the original ingredients of the universe. And, um, and I think exactly what you said is true, that I, an, what does it mean to be an electron? It means exactly its quantum numbers, its charge, its mass, its spin, whatever list you want to add to that to make it an electron. And that's the only thing an electron is. It's not there. It has no other detail than that. You cannot say, "Oh, the electron in my body is somehow different than the electron in an asteroid." Okay? They're interchangeable. And that interchangeability is what we expect of a fundamental particle. And it's very odd that black holes have that property as well. Now, they can have a whole continuum of masses and spins and electric charges. So that might seem a little different, but really the fact that every single black hole with a given set of numbers, charge, mass, spin is indistinguishable by the definition of the event horizon. It has no features. It can have no hair. That's the statement. It can have no hair. No details about the interior of that black hole can be expressed except its charge, mass, and spin. And that makes them feel like fundamental particles. Um, and so I think black holes were already telling us something about themselves even when we looked at pure relativity because that's a result from pure relativity that they are featureless. They're timeless and they're featureless. If I turn off quantum mechanics and Hawking radiation, I just think about general relativity. They do not age. They are utterly timeless in the same way an electron is utterly timeless. Now, they can get heavier. That's true. There are processes, but left to its own devices, there's no clock. There's no watching that thing and seeing what's happening. How long has it been there? Or is it different than this one? This one was formed by a star, and this one was formed by, uh, you know, crushing donkeys together. Like, there's no way you can tell these details about it. Um, and so I think that it was reasonable to suspect that in the early universe, a primordial black hole would form, or or or, you know, a spectrum of primordial black holes will form in the early universe. I think that's completely reasonable to expect that that there stars, a black hole is not a dead star. A dead star is just a way nature figured out how to make a black hole. Um, but there are other ways to make a black hole. Maybe at accelerator experiments, maybe particles crashing together naturally at high energies, maybe the Big Bang. Um, yeah.

>> Is there something more to this analogy? Because I imagine that the, there are two disanalogies that occur.

>> One is that for a particle, you want there to be a field that corresponds, like an electron or Dirac field, or what have you.

>> There's no, as far as I know, a black hole field that creates or annihilates black holes.

>> And then second, that black holes have extreme entropy.

>> So it's like they have some microstructure. They have something else going on.

>> And particles, as far as we know, don't. So do you see those as insurmountable, or what?

>> No, I think that all, I think both of those things is what marches us towards the information loss paradox. Right. It's precisely its entropy that is reflected by its temperature, and, and it's because it's hot that it's emitting particles, right? We can think of it that way. And so it's already was marching us towards something, right? Marching us towards the information loss crisis, but it doesn't seem like the answer is, "Oh, it's just made of of a of a bunch of stuff on the inside, and that stuff eventually comes out," right? So, I think it's saying something really strange about thermodynamics and really strange about gravity being fundamental. I would be less surprised if you told me gravity is not fundamental, and that's why there's no fundamental field, and that's why the, the black hole is not an excitation about a fundamental field. It's because, uh, it's only quantum mechanics.

>> Interesting. Now, there are some people, some of your colleagues, I'm sure, who don't believe gravity is fundamental.

>> Yeah. I think a lot of these people know.

>> Yeah. So what are your conversations with them like?

>> Um, I think, well, I guess I, I think a person to think about and to look to is somebody like Ted Jacobson, who was doing extremely interesting work about thermodynamics of black holes, and who, I, if unless I'm projecting or misinterpreting, very early on, was saying things like, maybe it's not fundamental. I mean, after all, whenever you're in a thermodynamic situation, you better start to suspect that you're looking at lots of things and not a fundamental property, right? Like the temperature in this room is an emergent property of a collective of a bunch of molecules moving around. Um, but if I look deeper and deeper, I'll never find a quantity called temperature.

>> Yes.

>> I'll just never find that quantity. Um, and I think he was thinking about that because of black hole entropy and the laws of black hole thermodynamics very early on. Um, and in a way, I, I think a lot of the attempts to beat black holes into submission and get them to give up their information has kind of brought people long way around to start to say, "Oh yeah, maybe it's really just quantum mechanics all the way down." And again, going back to AdS/CFT, which I am not an expert, to be clear. I've never written a paper in AdS/CFT. But just to say again, that seems to say, look, I can describe the entire universe just in terms of quantum field theory with no gravity whatsoever, none, and that is an equivalent dictionary to the on the boundary to the universe in the box with gravity. So gravity, and that's in at least it seems to say, well, then I could just talk about only quantum fields and there's no gravity, and I have a complete description, if it holds up, right? Um, I think this is exactly where it's all going.

>> But

>> we just haven't figured out how to exactly do it yet, you know. I just haven't figured out how to start with pure quantum mechanics. Like, let's say I take ER equals EPR really seriously, and I think, look, fundamentally, it's only wormholes, and wormholes with entanglement, and, um, making bridges that feel like out of out of causally, you know, causally separated spacetime separations, that, and I just imagine using these as like threads. I can only give my analogy so far. It's like you sew all of these threads, all these quantum entangled wormholes, and from a distance, those threads begin to look like a smooth and continuous spacetime that has an event horizon, right? It's like embroidery. And from a great distance, it resolves into this smooth event horizon that behaves exactly as general relativity dictates. But on closer inspection, there is no general relativity. There's no spacetime. There's only the quantum threads, the, the embroidery, the threads out of which you embroidered this illusion of a continuous spacetime. I think that that is very possible that that's how this whole thing plays out. And that's why they're acting like fundamental particles, but they're acting like they have microstates.

>> Um,

>> Their microstates are maybe these these ER equals EPR things.

>> What do you have against infinity? I love infinity. I love infinity in mathematics. I've just never, I was just taught anytime you have an infinity, you've made a mistake. Even to the point when Roger Penrose shows that it's generically general relativity under, uh, catastrophic gravitational collapse will create a singularity. In the next breath, he says, "Yeah, but I don't really believe it. Quantum mechanics will probably get rid of this." Um, so this idea that suddenly we accept infinity in this one way just always struck me as odd. Now, maybe it's not as lethal in infinity. The idea that the universe is infinite is not as lethal in infinity. I can think of a consistent ways in which my illusion of time unfolding actually appears to me to be an infinite spatial dimension. I can imagine being fooled. You know what I mean? I'm not saying I'm dead dead against it, but I mean, if I'm betting, if I'm betting, and I'm already interested in extra dimensions and the possibility extra dimensions are playing a large role in our cosmology, then why am I accepting their finitude, but not, but but the rest of the universe is infinitude? And I just would much rather begin with a universe on a democratic footing and struggle with the explanation of why did three get large and the others stay small. Um, so, but infinity in mathematics, I absolutely love. You know, the whole counter idea, if I look at the numbers between zero and one, and I extract all the infinite rationals, all of them, I take an infinite number of rationals out of there, I will still have a completely thick, dense, populated, uh, interval between zero and one. I mean, infinity is fascinating. The irrationals are a larger infinity than the rationals. It's amazing. What is it about a physical infinity that you don't like? And what type of physical infinity?

>> Well, the singularity is some, you know, again, I mean, I can imagine yielding to a spatial infinity in certain circumstances, but if I'm having to gamble, and, and when we ask questions like, you know, I'm going to spend my time, uh, working on extra dimensions, that's a gamble. That's a risk I'm taking to invest my time that way. I'm, I'm making that decision to take that risk because, uh, because I do have a sense that a universe that begins instantaneously infinite is, um, an unsatisfying narrative. I mean, sometimes we are motivated by, this is aesthetic, this is unsatisfying, this explanation is ungratifying. Um, just the way it is is not an explanation we like to accept. But, you know, often times maybe it's just the way it is, right? But we, as physicists, we don't take that. It's like we want to dig deeper. We want to dig deeper. So, um, so yes, the idea that the universe is instantaneously infinite strikes me as silly. At least we should be motivated to consider the possibility that the universe is geometrically finite, and it has very rewarding, it sculpts, it sculpts the universe in which we live in all of these ways that we've described. Might be responsible for dark matter, might be responsible for dark energy, might be responsible for whether something is set of nothing. That all of this could be traceable to our geometry. And if I imagine the universe trying this experiment over and over and over again, making universes with different topologies and different shapes, they'll all be slightly different universes. Our matter asymmetry isn't guaranteed, you know, it's not guaranteed. It's just in this one. Um, I find that interesting.

>> So, a volume infinity you don't want. What about the points? Aren't there an infinite still an infinite amount of points in any given region? Or no, you don't like that either.

>> Well, it's not that I don't like that. I just don't know what to do with it. That to me is just a coordinate. That's a math thing. I don't, if you gave me energy density at every one of those literally infinite points, so that I had an infinite energy density, then I'd be concerned, like, what are observables? What are observables? Are there any observables that are infinite? Um, and, um, and you don't want your energy density to be infinite because the same idea, if I was putting energy density at every point, I don't even really know how to do that because I have an infinite number of points, you know, then I presumably I would make a black hole. Um, so even the idea of an infinite number of points, if you do think quantum gravity is going to survive the current crisis, and that at the end of the day, we will discover that there is a smallest unit of spacetime, that would also be a natural way to resolve the problem. So it's almost like the inverse of calculus, you know, Zeno's paradox. How do you make progress at all? And you use calculus in infinitesimally small region, but also in an infinitesimally small time, and you actually can have a velocity and cross spacetime. Well, it's almost the opposite. Well, now I have a, eventually I get to the rock bottom size of a little piece of spacetime. Um, but, uh, but infinities that I don't like. Yeah. Infinite energy densities, infinity and physical observables, I don't so much like.

>> Ah, okay. But not a potential infinity?

>> Well, what kind of, what other infinities are there? I mean, we we dislike infinities enough in string theory that we invoke extra dimensions to get rid of them, right? So string theory has infinities. You can't keep, you can't progress past an infinity. It's a failure. Um, so you invoke extra dimensions, and you can regulate infinities that would have occurred in string theory. You could say string theory is predicting the extra dimensions, um, because other dimensions aren't viable. They don't make sense. They're not viable universes. Um, so, yeah, we don't have, I mean, if you try, you can't name a single observable infinity. The reason I was asking about potential infinity is that,

>> if we're going to take a Gödel theorem or Gödel sentence seriously,

>> Gödel's theorem only applies if you have at least have a potential infinity because you have to model arithmetic. So if we're going to say that, if we're finiteists, like ultra-finitists, then there's a bit of a trickiness with the Gödel theorem. You're saying you only have a Gödel theorem in a continuum. I'm not sure that's the case.

>> Oh, no, no, no. I just mean that if we're going to take that whole Gödel reference, Gödel theorem about the universe seriously, well, a Gödel theorem requires a potential infinity at least somewhere because you have to model arithmetic. So, whatever formal language this sentence is in has to be something that has some form of potential infinity. Well, we can have potential infinities if you mean things like time going forever. I mean, I don't have a problem with that, right? I don't have a problem with saying there's an infinite number of points between zero and one. If I take a ruler, that my coordinate mathematical system has an infinite number of points. Neither of those infinities are troublesome. They don't involve anything measurably infinite. Um, I also do wonder, okay, so you could say like, here's an infinity which I could tolerate, I think, um, the initial data of the universe, however it's seeded, I can suppose entertain the idea that it is an uncomputable number, meaning, um, that the algorithm that is the laws of physics will compute that number for infinity. Um, those are infinities I can handle. I can live with.

>> So, I have a funny question about your writing.

>> Yeah.

>> You mentioned how sometimes narrative can get to a truth that you can't get to otherwise. Did writing teach you anything about physics that doing straight physics, whatever that means, couldn't?

>> Mhm. That's an interesting question. Yes and no. I don't think I ever calculated differently because of having written something. Um, but I think I've understood calculations better having written about them. So even a calculation that I've done, uh, I will understand better being forced to write about it, or I would say understand it from a different angle. Um, I've had ideas from writing, you know, ideas about for physical projects, just by by by writing. Um, I think that translating into this more familiar language has been, it's really important for me personally in terms of, yeah, having a kind of more holistic sense of what I'm working on, why, what the ideas are about. Um,

>> Is writing painful?

>> Oh, excruciating.

>> Okay. Somebody said, somebody said, um, oh, well, you're a writer, so you love writing. And I was like, "No, no, no. I'm a writer, so I hate writing." Like all good writers.

>> Yes.

>> It's excruciating. I don't know how anyone gets it done. I cannot tell you how, I don't know how anyone has written a book.

>> So, tell me your writing process then. What do you do? Are you just, are you getting out a first draft and you don't care about how your first draft is, or are you just writing notes, notes to yourself on your phone, and then you take those little sticky notes, in a sense, and then compile them? What's your writing process?

>> All, all of all of those things. I think sometimes I'm just trying to dislodge. I know I want to write something. I kind of have an idea, but I don't have the whole thing mapped out. So, sometimes you're just laying out ideas, just trying to get them out imperfectly. Um, and, uh, it's so much easier to be your own editor than it is to write the original draft. Uh, so I love getting to the stage where I'm editing a piece. I can do that anytime, all night. Look, that could be, you could say to me, "By Tuesday morning, I need the edited version." That's just a, I have to get it done. But if you told me, "By Tuesday morning, I need an original draft." I'm like, "I just can't promise you that. I just don't know, you know."

>> It's interesting.

>> Do you have a good editor?

>> I haven't had an editor in some sense in a long time. My my book editor was wonderful, Dan Frank. Um, he passed away, sadly. He very unexpectedly. And he was a wonderful editor, but, but just, he was so many people's editor. I mean, he was Cormac McCarthy's editor, and he's just, uh, just a wonderful person, but it's not like he's sitting there, you know, dissecting your every sentence. He's not that kind of an editor, and he's also sort of hoping by the time you're with Dan, you're not really requiring that. So he's working with you at a different level. Um, but

I haven't really had an editor since, in a way, like that, like that kind of relationship like that Steinbeck had with his editor, you know. Um, those special relationships. But Zadie Smith, I was just going to say, one time, a famous novelist said, you know, "Some days I sit down to write and it just nobody shows up, you know. Just a good writer doesn't show up that day and some bad stuff comes out." And I just thought it was such a relief to hear that.

Yeah. So, do you set yourself a quota each day or a habit of a certain schedule or what?

I try to set certain days of the week, like, uh, on these days I'm going to make sure I'm not booked for anything and I'm going to sit down. I'm going to try to write on these days. I'm not the kind of person who can sit down and write between 10:00 and 11:00. If I had a meeting at 9:00 and I have a teaching at, you know, I can't do that. I just can't do that. There's just no point unless I have a lot of time to get up and pace, to try some of the things you said. Try to make some notes, read some stuff, you know, try to turn on some music. I mean, it's just no point if I don't have a, a whole lot of time because I might not get my first word down until the end of the day.

Yeah.

But once it gets flowing, I can get a few things down, right, paragraphs down, even maybe on a good day. Like just. And then, and then coming back to it is a lot easier because you've got, you know, you're you're talking to something then.

Yes.

You're relating to something and you have a whole tone.

And what is it that's holding you back? Is it perfectionism or just lack of ideas or what?

Too many ideas.

Yeah. Sometimes just I don't know sometimes like, uh, you know, I've been writing for Substack. I've been self-motivated writing.

I'll place a link to that on screen as well. Yeah, I thank you. I call it "Higher Dimensions." I keep changing the name though, so I might change the name again. Um, but I, I like the title "Higher Dimensions." It made it sound ecclesiastic, you know, like I was running a cult or something. But, um, but it's really hard sometimes. I, I have a feeling about what I want to write, but I don't, I don't have the actual idea or I don't know what the hook is or I don't know how to get into it or how to lead me in.

Um, what's the hook mean?

Well, so for instance, I have a piece, um, "Whales Don't Want to Go to Mars."

Uhhuh.

And to me, that was really the hook. I knew I wanted to write about why we might not be a successful species, uh, why our example of industrialization might make us doubt that we'll ever encounter extraterrestrial life that is also industrialized as we are, and that they will also have been an unsuccessful species, that will also have had a climate crisis, that will also have made weapons of mass destruction. Um, and, um, and that that might be our kind of tragic flaw. Like we're this apex predator on this planet. We're ingenious. We're creative. There's a lot to, um, you know, be proud of in the human, uh, sort of expression of art and science. Just so much that's so extraordinary about us. And it's our tragic flaw because it also makes us willful and violent and greedy and unable to control ourselves and suicidal. I mean, we're a suicidal species. We're the only species on the surface of the Earth that I'm aware of that developed the capacity to wipe itself out. And, um, and so talking about, I, it, it wasn't a big part of the essay. "Whales Don't Want to Go to Mars," but it was my way in. Here is a successful species. They've been here for 50 million years. They can sing. They can tell stories. They can teach their young. They have some kind of culture that propagates over centuries. But they don't want to go to Mars. You know, they're not trying to build rockets. They're perfectly content and in balance with their ecosystem. And, um, and so I kind of wanted to project about the possibility of an isotopia, a future in which human beings get over the stage that they're at where we live in greater harmony and balance with nature and not in such, um, discord and imbalance that we find ourselves in. And if we get there, then maybe there's some hope for industrialized civilizations to actually spread through the galaxies and for there to be others. I don't know if you know these quotes. Um, "Any sufficiently advanced technology is indistinguishable from magic." That's a famous quote. I think it's Arthur C. Clarke. And then there's somebody else, Schroeder. I can't remember his name. I think he's also a sci-fi writer who said, "Any sufficiently advanced civilization is indistinguishable from nature because it's gotten past, uh, it's, it's disharmony with nature."

But the whales are going extinct. No, from us.

From us.

So would you want, would you rather be a whale or a human right now?

Well, I don't know about "would I rather" because I wouldn't be "I," right? So the philosophers would say, you know, it's a flawed construction. Um, it's not that I would rather be a whale or that I would rather human beings don't exist, like that we were never invented tools. I'm not saying that. I'm just saying we might just not be successful and we shouldn't be surprised that we haven't met, encountered others who are flying around with fuel trying to colonize, you know, planet celestial bodies, that that maybe we just won't last very long. I mean, human beings have only been here hundreds of thousands of years, tops, right? That's not a long run. It's a short run. And the whales, I mean, I'm, I, you know, one of the things I was commenting on in the, this essay, the whales might be here a lot longer, you know, when we're gone, they're going to be fine, right? So whales might be singing songs about us, these crazy bipeds that tried to leave the Earth, you know, and go to Mars. Um, yeah, it's hard to know, but certainly when we talk about destroying the Earth, we're not going to destroy the Earth. We're going to destroy our habitable environment on the Earth.

Right.

Um, presumably other animals will come out of the destruction and take over and and prosper.

Mhm. You mentioned that insomnia induces madness.

Oh, yeah. It induces a form of madness. I've been an insomniac since I was a child. I can remember so distinctly, we had these old clocks. They were flip clocks and the card would flip to the next number, you know, like 4:02 AM. You'd see the three flip over like a card. And I just remember watching that at some point, like, I'm awake, you know, just being aware of being awake in the middle of the night. I don't think I've slept through the night in decades.

Okay. So, you intimately relate.

I intimately relate. Insomnia is not. Every single night I'm up. My, my kids think I'm a ghost. They think I haunt the house. Any hour that they might wake up, there I am.

Yeah. Yeah.

Like, like I literally haunt the house. Um, but I've really struggled with it. But I also, I have bad sleep hygiene. I do everything wrong. I watch, I love watching TV at night.

Mhm. What do you watch?

Oh my god, anything. I am very indiscriminate.

I really, I've really enjoyed "Plurbus," "Severance," you know, all that stuff.

Oh, "Plurbus." "Severance" is great. "Plurbus" in particular. I'm a huge Vince Gilligan fan.

Oh, so clever. The moment that they realize that they're not looking at binary code, but that, um, you know, they're, they're looking at like a biological code. It was just totally, totally ingenious. Um, so I love that kind of stuff. But I also, what was I watching recently? I can't even remember what I was watching. Literally can't remember. I think I was watching "Hacks." I was watching "The Pit." Um, so I do everything wrong. I probably drink too much caffeine. I, you know, you there's a.

Do you take any sleeping medication? Has anything worked for you?

I have taken sleeping medication. I guess it worries me.

Supplements.

I take tons of supplements. I take magnesium, epigenine. Yeah.

Okay.

I definitely take, uh, supplements at night. Magnesium, epigenine, all this kind of stuff. Um, but I do think, I do think I'm, my sleep is better if I do try to discipline myself and listen to something instead of watching something in the final hours, you know, like, um, taking the, the supplements and, um, just generally also not lying there. If I can't sleep, I'm just going to get up and do something. All of that really, it does actually really help. So, I'm getting better. I think I know what I could do to cure my sleep problems. I just, yeah. I just.

What is it? Less stress or what?

Oh, no. Just basically, you know, the hygiene there's, yeah, the sleeping hygiene. Reading the books at night. Don't have, not having the stimulants. Um, don't go out with your friends and have three martinis.

Um, you know, all of it, I think, really would work. You know, do a couple of yoga poses that are the right poses that get your nervous system down. Um, I think if I was really forced to do all of those things properly, it would, it would be better. But I still, I still don't think it would be cured. I think that that's just my sleep cycle. I think my sleep cycle is like a four hours on, then I'm up, and then maybe I can catch another hour somewhere else. And I, that's not unheard of.

Interesting. Do you, are you getting any sleep or are you getting.

Yes, I'm getting, I'm getting some sleep. Last night I had a couple hours and, but it was spread across.

So it wasn't much and it's so horrible because then I start to calculate how much time do I have left and, and then I even emailed you to push it 20 minutes because even at that point, 20 minutes seems like it's plenty of extra time. It relieves my anxiety. Then I open my door because it's hot. So I have to open the door and I'm on a, I'm on a high-rise building. I'm on the top floor. There's no AC yet because it's too early. So it gets super hot. No one else in the building cares because everyone's, if you're at the top floor, the majority are at the lower floor. So it's not a problem for the majority of the people.

Right. Right.

I can't even get a draft through here because if I get a draft, my wife's too cold. And then when I get up.

And then it wakes her and then, and then, and I can't turn on the TV. So, I just lie there and I think and sometimes I take notes. I, I voice notes to myself and, and it's just such a, there's so much pressure, so much stress and then.

I can't accomplish as much the next day.

So then more builds the next time and then I, it, it's like a bout. As soon as I have two nights of no sleep, then I have 14 nights of no sleep.

Right. And do you feel it's a form of madness?

I, I think they're induces. I think it definitely induces. And then I also think that madness also can induce the, the lack of sleep.

Yeah. The mind is a terrible thing. Isn't that the, um, that, uh, yes, the mind is quite relentless.

Yeah.

The mind can be quite relentless. But, you know, when I'm calculating a lot, like when with these recent papers we were talking about with the Klein bottle, when I was really in it. Yeah. And just every day I was calculating. Like right now, I'm kind of more in an ideating phase, like what do I want to work on or what's next? But when I was like that, I enjoyed waking up in the middle of the night. I was fine with it. I was like, ah, it's 3:00. I got from 3:00 to 5:00. I bet I could get something done. You know, got nothing else to do. I'm not going to. And it was a tremendously productive window. So, I think also kind of accepting that that is just the way it was, that I was just going to wake up and I might as well use the time.

Mhm.

Um, in some way that wasn't horrible. You don't want to use the time on something horrible and tedious, but if you're using the time on. Yeah. Yeah.

If I'm lying down, so yes, if I get up, then I can do some, some learning, some calculations, some thinking, some writing. But if I'm trying to get to sleep.

I have such fractionated, such odd ideas. Like my knee up the night in chess moves in this direction. It makes no sense, but it, it makes perfect sense for a moment and then I, and then I snap it. I'm like, what the heck was I just thinking?

Anyhow, speaking of lying down. Yeah.

Speaking of lying, let's say.

You said that a true scientist or something like that, or best scientists don't lie to themselves, that they understand something.

So my question to you is, what are you currently lying to yourself about right now?

H. You know, I, I feel physics is one of those topics where I feel it, it is. We talked metaphorically about the infinite points between zero and one. I feel that way about physics. I'm teaching electricity and magnetism right now to first-year students, um, who are just learning calculus. And there's there are not just multitudes in there. There is so much in there. And of course, I've learned it. I thought I knew it. I thought I knew it so well. But each time I approach the subject, I, I try to ask myself, do I really understand this? Do I really understand this? And I don't try to lie to myself about it. Um, so I, so sometimes I'll ask my students questions that I want them to think about. So I'll ask them, everyone's learned that the nucleus, let's say, is the American Museum of Natural History. And then in this analogy, the electron would be Yankee Stadium, and the rest is empty space, right, in New York City. And so you know this, you've all nod, yes, yes, atoms are mostly empty space. I ask them, why aren't you falling through your chair? They're flummoxed. They've just never asked the question. It's like, it's okay to say you don't really understand something because then you're going to ask about it more and more and more. Why don't you fall through your chair? You don't fall through your chair because of electromagnetism. And that's what we're going to talk about in this class. But then I'll, I'll say like, okay, what's mass? Everyone thinks they know what mass is. And then I'll say, I just don't, I don't know what to tell you. I don't know what it is. What is charge? I can tell you some things about it. I can tell you electric charge is the quantum number in the inter electromagnetic interaction. I can say some things about it. But if I keep leaning on it, do I really know what it is? Like I kind of don't. Outside of that. Outside of it just being a quantum number in an interaction, I don't really know what it is. And, and so I think physics can always be like that. I think that's what's exciting about physics is you start to understand it. You make all this progress. It might be what we were talking about at the beginning. But somehow the harder you look, the more it kind of fades away.

Right. Right.

The more it kind of fades away. And that's why I think some of the smartest people I know get kind of mystical. I mean, not spiritual, they're atheists, I think, but they get kind of mystical about the whole thing. What does it mean that a particle exists? What does it mean that there's a field permeating all of space? That, well, maybe these are just structures that we lay over in order to comprehend this correlation with an objective reality I do believe exists, but maybe this is just the best that we can ever do and that, and that the more we look, you know, the more kind of mystical and diffuse it becomes.

Well, I think that's a great place to end, actually. I want to know, uh, where can the audience find out more about you? I'm going to be placing your Substack and your books on screen and in the description for people to visit.

Yeah.

And there's so much more I could talk to you about.

I, I hope we will again. I think we should.

I did do plenty of research and I even remember some quotes from your Substack.

So, one of them that I wanted to get to, maybe we can get to it and then you could talk about about where people could find you and then you can get to it was about finite. You said that there are an infinite amount of ways for the universe to be finite, but only a finite amount of ways for the universe to be infinite.

Yeah.

And that was a post in February,

if I recall, of this year.

Uhhuh. Yeah. Yeah. Exactly. It is true. It is true. The universe has fewer options for being infinite than it does for being finite. It's an infinite number of ways it can wrap up in a kind of origami. Um, but only a few number of ways it could be completely unfolded. Um, but so it's interesting because for a long time I've just kind of enjoyed being intensely focused on physics for a while. Maybe once books are rare and they're hard. Uh, I do this work out at a place called Pioneer Works where I'm director of sciences and I helped start this cultural center, um, founded by artist Dustin Yellen and, uh, the founding artistic director Gabriel Florence and I make a kind of triad where we've built this place. And so I do this, I do that, I write, you know, and I just sort of felt like I was a little all over the place. And then with this idea, I wanted to on Substack make my own publication, really make it like a publication where I could corral everything together. I think of it as a venue where science equals culture. Um, which might be the alternative name that I end up calling it.

Um, so for me, there's some, yeah, there's some, it's, it's less than a year old, so I've really only been doing this for a few months.

You have quite a following.

Yeah, it's really nice. It's really nice. Um, it's, uh, it's just an interesting place because people are coming because they can see everything there. They can see a little snippet of a novel. They can see something I've written about one of the artists. Sometimes we'll play the actual conversations that were live conversations out in Brooklyn and they'll be live-streamed there. So for me, it's a way of of pulling everything together under one venue and under the one ambition, which to me makes the most sense, that science equals culture, and this is how I like to understand the world. I like to understand the world through scientific thinking. Um, it's what it's, it's what gives me a sense of meaning and connectedness. Um, so sometimes it's really technical, trying to understand higher dimensions or infinities, and sometimes it's about why whales don't want to go to Mars, but to me, those belong together.

Maybe this is a foolish question, but why does connectedness matter?

Well, I, I think that that's a good question. I think it's just the animals that we are. I mean, we are primates. I'm, I have no illusions about us being transcendent. We have these little orbs that are tuned to the sun. We came from a long lineage of evolution. These are just, this is just the one experiment that has gotten this far on Earth. And it's in our evolutionary history that we're social creatures and we needed connecting, you know, this connectedness presumably for survival. And we were searching for meaning. I mean, maybe, maybe the search for meaning that human beings have always pursued since records of cave paintings began. Um, maybe that's just in our DNA, so to speak. And, um, that's just, that's just how we are. And that we shouldn't, we shouldn't require it if we were to bump into another species out there.

I guess presumably we have much else that's inside our DNA that we think we shouldn't pursue. Maybe rage, maybe racism or tribalism or what have you.

So there's some that we say, okay, that's just in us and, and, and we should pursue it, and there's some we say we should not. So connectedness is, I imagine, on the former. Yeah. It's all, these are all interesting questions, like the idea that we have ethics is probably biological and not absolute. You know, that we choose, we declare this is bad, we want to weed this out, and this we think is good. But protecting babies, why do we think it's good? It's in our DNA to respond to babies. So, so then we have a moral code to protect babies, and it's so in our DNA, we feel so strongly about it. It's incomprehensible, like harming a baby. Do you know what I mean? It's so in our, the, the way that we're woven that some people are like, "Well, maybe that's an external morality." And other people are like, "Well, I think that's just our apes. That's the kind of apes we are." Because other mammals don't have that. They simply don't have that. Um, so, but anyway, one thing that does, which you mentioned, which gives me hope, is that yes, we have some bad instincts and that we know are primal and we can trace where they were in our lineage, rage and tribalism and racism and, um, mine and, you know, all this stuff, warring, um, but we have overcome it in some ways. There are examples where we've decided to organize together and to not be like that. And it's actually not that as hard as we once imagined it might be. Like humans have invented government structures and cultural structures, treaties and agreements to transcend those things, and they have had moments of success. So that's one of the things that gives me hope, you know, maybe we really will, as a species, overcome all of those things, you know, in time. Now imagine you're speaking directly to students who are watching.

And there are also artists who watch, and truck drivers who watch, and just a variety of other people. It's, excuse technical, but still.

What advice do you have for those who are, let's just call them learning?

I mean, researchers learning, I don't know what to call them.

Yeah. I think there's all kinds of different people that end up in the field, and that's one thing, just believe that. Don't think because you only see a type or a particular prevalence of a certain type that there's no room for you or the way you think or, um, to that, that there is a place for all different kinds of minds and all different kinds of skills and all different kinds of approaches. Um, and I think to always try to have a big picture. Sometimes I meet grad students and they say, "I work on," and then they'll say something incredibly microscopic, a particular galaxy at a particular wavelength with a particular instrument, and I'll say, "You don't work on that. You've got to, you got to constantly keep your eye on a bigger picture." That's something you're doing right now. But, you know, um, and so to keep the bigger picture, and that's one of the reasons why I like novels and popularizations and different levels of writing because it allows you to see the bigger picture when, um, none of us can be experts in, in all the dimensions that exist out there in physics, uh, and astronomy. We just can't. You can't. Not none of us are simultaneously experts in heavy ion physics and in quantum computing and in, uh, H-alpha. You know, we have to be learning from each other, and we have to be, have this graciousness about what we're learning and this appetite for it, you know? Yeah. I wish I was a student again. Anyway.

Do you?

Yeah. I sort of think I'm a big student most of the time. Like when I'm happiest in my research, it's when I'm kind of bumbling into a new area where I feel very new and I'm really learning a lot. Um, and I'm acquiring a lot.

For the past six years or five years since this podcast has started,

every day I wake up and I'm so, so excited to work, just because I, my working is just learning. I just get to learn and speak to people like you. And like, what a dream.

Yeah. So fabulous. I know. Thank you.

Thank you. So nice to see you, Kurt.

Hi there, Kurt here. If you'd like more content from Theories of Everything and the very best listening experience, then be sure to check out my Substack at curtjongle.org. Some of the top perks are that every week you get brand new episodes ahead of time. You also get bonus written content exclusively for our members. That's C U R T J A I M U N G A L.org. You can also just search my name and the word Substack on Google. Since I started that Substack, it somehow already became number two in the science category. Now, Substack, for those who are unfamiliar, is like a newsletter, one that's beautifully formatted. There's zero spam. This is the best place to follow the content of this channel that isn't anywhere else. It's not on YouTube. It's not on Patreon. It's exclusive to the Substack. It's free. There are ways for you to support me on Substack if you want, and you'll get special bonuses if you do. Several people ask me like, "Hey, Kurt, you've spoken to so many people in the field of theoretical physics, of philosophy, of consciousness. What are your thoughts, man?" Well, while I remain impartial in interviews, this Substack is a way to peer into my present deliberations on these topics, and it's the perfect way to support me directly. kurtjongle.org or search kurtjong substack on Google. Oh, and I've received several messages, emails, and comments from professors and researchers saying that they recommend Theories of Everything to their students. That's fantastic. If you're a professor or a lecturer or what have you, and there's a particular standout episode that students can benefit from or your friends, please do share. And of course, a huge thank you to our advertising sponsor, The Economist. Visit economist.com/toe to get a massive discount on their annual subscription. I subscribe to The Economist, and you'll love it as well. TOE is actually the only podcast that they currently partner with. So, it's a huge honor for me, and for you, you're getting an exclusive discount. That's economist.com/toe. And finally, you should know this podcast is on iTunes. It's on Spotify. It's on all the audio platforms. All you have to do is type in Theories of Everything, and you'll find it. I know my last name is complicated, so maybe you don't want to type in Jaungle, but you can type in Theories of Everything, and you'll find it. Personally, I gain from re-watching lectures and podcasts. I also read in the comment that TOE listeners also gain from replaying. So, how about instead you relisten on one of those platforms like iTunes, Spotify, Google Podcasts, whatever podcast catcher you use, I'm there with you. Thank you for listening.