The Equation That Changed How Physicists Think About Reality | Juan Maldacena

What if Einstein's two strangest ideas, wormholes and quantum entanglement, were the same idea? My guest today spent his career proving that they are. The so called Einstein wrote some paper on the fact that the full Schwarzschild solution contains two black holes that are Connected. the Einstein-Podolsky Rosen paper that talks about entanglement. And we now think that these two things are related.

My guest is Juan Mel Decena, the physicist who in nineteen ninety seven wrote the most cited paper in theoretical physics. The claim he just made that wormholes in entanglement are the most important thing. The same thing is called ER equals EPR. If he's right, the structure of space time is built out of quantum information itself.

the information of the things you threw in uh is contained in this radiation. According to general relativity it will look like the information is lost. According to quantum mechanics we would expect it to be preserved. So there is a conflict between the two things. Quantum matter didn't obey this property then He also told me which problem in physics he'd most like to solve before he dies. The answer was not what I expected.

The most important problem quantum gravity is to understand the beginning of the Big Bang. That's really the problem that I would like most strongly to solve. Well I'll say no welcome to UC San Diego for your second appearance on the podcast. Yeah, thank you, Brian. It's a pleasure to be here.

You're here giving the Dashin lecture all the way from the Institute for Advanced Study, which I think is on Einstein Lane, is that correct? I'm not doxing you, right, to say you're on one Einstein Lane, here's Einstein over here. What do you think he'd be, you know, kind of Most interested to learn or if you could have ten minutes alone with him, what would you tell him about?

Well I think black holes uh would be probably something he would be r really interested in. Mhm. I would particularly want to tell him about want to ask him whether he thought that His two papers from nineteen thirty five would be related, the so called Einstein Rosen paper on the the fact that the full Schwarzschild solution contains two black holes that are connected and uh Einstein Podovsky wrote some paper that talks about entanglement. And we now think that these two things are related.

This E R equals EPR, right? That's your one of the things you're known for. Many many things you're known for. One surprising thing would be that they that they are a consequence of gravitational collapse and uh that are naturally produced in the universe. Now in the last few years, really in the last few years we had lots of experimental evidence for black holes, right?

From um collisions that produce gravity waves to imaging the matter near the black hole near the s o of the black hole that is near the center of the Milky Way to, you know, looking at stars that orbit this uh black hole. Yeah, so we have uh lots of evidence for these black holes now. Then the other surprise I think would be black hole thermodynamics. I think that would be something really

Interesting in the sense that there's a connection between the loss of thermodynamics and black holes, that black holes have an entropy, they have a temperature. I think that would be uh a lot of fun for him.

I mean gravitational wave's another thing he predicted that he thought would never be observed and I think he got a paper rejected and then he said I don't want to deal with a referee and another thing that Well, he first predicted gravity waves, then he thought maybe they don't exist, and then the referee said that no, they do exist, you made a mistake here. Yeah. That's what I say. When people say peer review is bad, it's harmful, it's not.

Well I mean the this case uh was a good good example of uh useful well well, I guess you got a good reviewer. Yeah, that's right. Yeah, that led to multiple Nobel prizes, uh Hulse and Taylor and then LIGO and who knows what else it'll do. But yeah, I always tell my students uh aspire so that your blunders or the things you don't think will ever work will lead to multiple Nobel prizes.

Yeah, now it's a central part of cosmology, so Wanna talk today about the realities of black holes and of things like the holographic principle, which is one of again, many things you're known for in your amazing uh career. I was talking to a non-scientist, but a very smart lay person. And he was asking me, well, you know, if the holographic principle is correct, you know, some people say, well, we might be living inside of a black hole and things like that.

But I always point out, you know, there's no such thing as a isolated hydrogen atom floating around the universe that's truly can be solved by the Schrdinger equation. In other words, there's always perturbation.

To my knowledge, there's n such thing as a Schwarzschild black hole either, right? That's perfect. There's a cur black holes, we know of uh the ergosphere surrounding them. So in what sense is the holographic principle or the fact or or proposition that we could be living inside a Is that just uh pure theoretical because of the realities of real black holes? The holographic principle as applied to our universe, we don't know whether it's correct or not. Explain the holographic principle first.

The holographic principle is the idea that you can describe quantum gravity in some region of the universe by... some theory of uh ordinary quantum mechanics that lives in the boundary of that region. It remains a big idea as formulated this way. Now in some special cases, some special universes, so universes which are infinitely big and so on.

Then we can go to a surface that is very, very far away and uh define there a very concrete theory that whose laws of physics we can define. And in that case, if they are supposed to describe the interior of those universes. Those universes are not the universe we live in. They have slightly different well, they they have different laws of physics, they have a different value for the cosmological constant. But

In in those universes that there is a lot of evidence that this relationship is true. Now, there in those universes you can consider black holes uh that are inside this universe. The black holes can have perturbation, matter around and The idea is that those would be described by uh the theory that lives on the boundary. And there are some comparisons we can make. Uh one let's say catch or one thing that makes it hard.

is that the theory that lives on the boundary involves strongly interacting particles. And so it's not completely obvious how to solve this theory. And so you have to apply some techniques. There are some things you can calculate but not everything you would like to calculate. So that's in order to compare the two things. And we are learning more on how the dictionary gets built between this uh quantum description on the boundary and the gravity description in the interior.

When you say lives on the boundary, what does that mean? Is that like a separate Hilbert space or Lives in the boundary means that these are particles that move on a space which is has the geometry of the boundary. It doesn't have the extra dimension. And the idea is that you can think in two alternative waves. Either you have particles that live on that boundary, or you have the gravity description that lives in the interior. And the idea is that these particles are strongly interacting and

the gravity description is some kind of emergent property. It's not something that was there in the very beginning in the formulation of the theory, but it looks like it's an approximation to the underlying dynamics. Does that gravitational theory does that produce GR or something different?

So the idea is that w when these particles are strongly interacting and in some special cases that we understand then it would produce uh general relativity. In fact in the examples we understand it produces general relativity plus string theory also. At short distance. So there is some approximation where it's just just general relative relativity with some particular matter content. And then also strings and stuff like that. Those are in the cases we

We understand. We don't know whether string theory is necessary for this discussion or whether this is valid more generally, or maybe string theory is the only way to quantize gravity. that produce you know the excitations and things like the fermions, you know, three Yeah, you can have fermions, you can have all that When you said strongly interacting, does that mean like the strong force or does it just mean like short range interaction?

strong interaction I mean that the coupling between the particles is very strong, so that if you have two particles that collide, they very uh th they will they will scatter very very easily. The Strong interactions are called strong because precisely the the interactions are strong at the level of let's say inside the proton and so on. And in addition, the the type of particles that we have also have interactions similar to the strong interactions.

the the so called uh gauge theory it's a it's a tip it's a type of of interactions that involves the property, let's say, called color, which uh is um is a type of charge but of which the the sign is not just plus minus, but there are like three different types of charges. In in nature there are three three different types. In this theories we consider there is a large number of types, uh

Yeah, so there there are theories somewhat similar to the theories we have in nature, but not exactly the theories we have in nature. What we have are some examples of this involving the Let's say sh they are just theories and models. You could say it's a model of uh quantum gravity. And one of the advantages of this description and the reason that it was developed was that it could give a full quantum description of the gravitational spacetime.

We don't just get general relativity, but the quantum version of general relativity. And we hope that by having these models, we will understand the quantum gravity more, and then eventually, of course, the objective is in the end to understand quantum gravity. our own real world. So somehow to extract uh lessons from this to to be able to apply them to our real world.

Just at a basic layperson level, you know, I'm not gonna do this, but you know, take your laptop, you're gonna be speaking later, throw it into a black hole. What happens and does it depend on what type of black hole it is? If you throw anything into a black hole, well your laptop and so on.

it will um it will fall and you will lose sight of it. So the time it takes light for going a distance of order the size of the black hole, all the information about that laptop is e effectively lost to you. So in the sense that you will not see it anymore and uh any perturbation you had of the metric that was due to the fact that there was a laptop will be lost. So the influences decrease ex exponentially fast. Okay, this is fine. This is what happens with classical black holes.

But as we were saying before, black holes have some entropy. En entropy in in physics we interpret it as arising from statistics and is a measure of uh how many states the black hole can have, how many If you wish, bytes can be stored in this, or qubits can be stored in this black hole. On the surface or on the volume? Well, the formula for the entropy is just the surface, so then you might be tempted to say it's in the surface but

in the classical solution the matter falls in and goes into the black hole, so you you could be free to say it's in the interior. What that somehow suggests this picture that the black holes have a finite uh amount of entropy is that uh that information is not completely lost somehow. In fact when you throw in the

...computer into the black hole, the area... ...the mass of the black hole grows a little bit and the area grows a little bit... ...and the entropy becomes larger. It becomes larger by an amount which is bigger than the...

uh than the entropy that was than the amount of information that was in the in your laptop. And you can use the loss of physics to to show that uh this is always the case. Whenever you send something into the black hole, the the entropy always increases the question is is this lost forever or not and in principle you could say it's lost forever and you might think because the you know goes into a black hole and then well never come out according to classical physics

But the new the new aspect is that these thermal effects, in particular Hawking radiation, implies that the black hole will emit something. It emits some radiation that in the first approximation is thermal and carries no information. But it's saying that the black hole will start losing mass, so it will get smaller. And eventually the black hole might perhaps disappear completely and become...

We'll get some radiation. And you could wonder where the information of the things you threw in uh is contained in this radiation.

If it is contained it will be contained in a very subtle way. But the question is whether in principle it's contained. The reason we're asking this question is not because we are desperate to find this information, but We are a little bit desperate, but the reason we are desperate is just because it's a problem that will force us to understand quantum mechanics and gravity together and how things work.

according to general relativity will look like the information is lost and according to quantum mechanics we would expect it to be preserved and so there's a conflict between the two things and we hope that by solving this conflict we we learn better quantum gravity. The most important problem of quantum gravity is not the black hole information problem. No. The the most important problem quantum gravity is to understand the beginning of the Big Bang. So understand

what happened in the very beginning. That's really the problem that I would like uh most strongly to solve, right? But the black hole information problem has the advantage of being more a more concrete problem and that that we have some tools to address it. So that that's why there is effort and progress in in this problem. And getting back to my question about real black holes that aren't static, that have charge, that spin.

Is that true? Is it also true that, you know, you get the exact same Hawking radiation or if not in a curve maximal curve black hole? So we should say what that is, but In a in a black hole with an ergosphere like interstellar, you know, think about gargantua, real black holes, do they have the same phenomenon?

The question is whether real black holes are emitting Hawking radiation. The problem is that the temperature for well real black holes that we've known we know that they exist, they have masses of order solar mass or higher.

Those black holes have a temperature which is very small, many orders of magnitude smaller than the temperature of the cosmic microwave background. So even if the black hole didn't have any matter swirling around, which they do, so and that matter is at even higher temperatures.

Even then, even just the cosmic microwave background would be swamping the Hawking radiation in the sense that the cosmic microwave background would be falling into the black hole and the Hawking radiation would be a tiny effect. So the answer is uh no for the for the big black holes.

Hawking radiation is an irrelevant uh phenomenon and it uh of course hasn't been observed and there is little ho well, it's all probably not going to be observed any time. in the a foreseeable future, uh, for astrophysical black holes. This would make you think why why why people think about Hawking radiation if it is such an irrelevant Thing.

I I would like to to point out to point something out, which is that this phenomenon of Hawking radiation is uh inspired uh the the theoretical development of or discovery of some other phenomenon, which is the generation of fluctuations uh in an expanding cosmology. So in a black hole there is a horizon or there is a region you can't observe and can access, and that's somehow ultimately responsible for this thermal effect.

If you live in a universe that is expanding uh fairly rapidly, like as we think it was during the early epochs of inflation, then you expect a similar thermal effect. that temperature and the associated phenomenon will change the properties of the inflaton and will produce fluctuations in the shape of the inflaton.

And we think that that that's the leading theory for the m generation of the primordial fluctuations. So the fluctuations that make the the universe not perfectly uniform. So the the universe is somewhat uniform at large scales, but not perfectly uniform. Well, as you know very well, you've been

studying this uh uh in homogeneities uh for during your whole career and made uh wonderful discoveries. But it's ultimately a similar f we we think it they also arose from quantum fluctuations and uh it's the same phenomenon as Hawking radiation.

So in this case, learning something for black holes, so Hawkins paper was earlier than the papers that discussed uh this phenomenon in in inflation, helped us understand something about cosmology that now forms part of more or less standard cosmology, I would say. Um And um we similarly hope that understanding these other aspects of black holes will help understand in, you know, earlier epochs of cosmology. Right.

So in some sense the i the idea that phenomena discovered for black holes could be helpful for cosmology has already happened and uh we we we hope to repeat this. Hold on to that because what Juan just said about black holes accidentally gave cosmologists the equation that explains what the universe has structure at all. That's on a small footnote. And that's where I come in.

We've only discovered black holes with much more large masses than the sun, and yet the ones that are most likely to produce observable Hawking radiation are the small ones, and I kind of always meant to me, you know, for people that conjecture that say primordial black holes could be

dark matter or could have truly existed since the dawn of of time, but basically, that sort of is hard to reconcile. So w what do you make of attempts to solve the, you know, m missing matter problem and even recently solve some dark energy phenomena using black holes, basically, which may or may not be primordial. From the particle physics point of view and from the

model building point of view, they are not the most I would say they're not the most natural thing or mo not the simplest uh thing you could think about and b for dark matter. So there are maybe other particle physics ideas that are a little

might seem more likely. But well, we'll see. I mean, but maybe maybe they are. And of course if uh dark matter uh is black holes in the range uh where they are allowed then Hawking radiation would be relevant. So I mean it would be Present and would be, you know, bigger the temperature would be higher than the C and B temperature.

You are known and kind of remarkable to me because you study things, you know, at the forefront of theoretical physics, but you also aren't afraid to take on philosophical, you know, kind of uh

uh discussions and and one of the you know papers I s I think uh read from twenty twenty four is called Real Observers Solving Imaginary Problems paper. What is that? What is the purpose of that paper? And I want to talk later about your uh Beauty in the Beast paper. You have such great title That paper had to do with um

computations in the sitter space more precisely. It is sometimes useful to consider the Euclidean version of some spacetimes. Euclidean version is basically you take the usual universe. And you make the the time you change the sign in the metric in the time direction. and that makes a space which is purely spatial. In the case of expanding the Sitter universe, that is a sphere. So you can consider Einstein's gravity on a sphere. We would expect that type of universe to be computing.

uh the thermodynamics of uh the cater space. The the the reason is the following. That evolution in imaginary time, or this procedure I've just mentioned, is useful because if you solve that evolution, you're basically calculating the

uh thermal partition function, or or th you're calculating sort of thermodynamic properties of the system. This is something that is true for any physical system. And if you do that for the Cater space, you would expect that it should be telling you about the thermodynamics of the CTR. Now this is not a new idea, this idea goes back to Gibbons and Hawkeye. Yeah.

And uh if you did that then you get that the this the Ceter space has some entropy, which is the area of the horizon. So formula very similar to the black hole entropy formula. In fact they That paper was the same time as they discussed, also the same thing for black holes. Now, so all of this is perfectly nice and so on, but if you calculate the first quantum correction, so calculate not just the...

Einstein action for the sphere, but also the quantum fluctuations, uh including the quantum fluctuations. The quantum fluctuations uh they would give a negative value for the partition function. So let the the number of states would be negative. And depending on the dimensions, in some cases it's imaginary. It's some I to the power of the number of dimensions of space time. So

So this was something confusing that was found. But I think Hawking already noticed that there were some issues with some sign. Polchinski calculated more precisely what the sign is. More recently, with trying to understand better the physics of the sitter space.

it was understood that in order to construct the Hilbert space it was useful to include an observer so that you include an observer and the degrees of freedom of the observer were important, some of the degrees of freedom to define the Hilbert space.

And so what that paper did was notice that if you don't consider just a sphere, but the sphere with a the trajectory of a particle, um then there are some other minus signs from the the trajectory of these particles or some other eyes that cancel the And then you get something nice and positive. Well, actually th this this in the paper I originally got something positive, then uh Victor I was student of mine pointed out a mistake, then I got something negative. Ha ha ha.

And then uh and then eventually uh a group from Stanford with Douglas Stanford and collaborators, they found another mistake and so now now it's possible. So it's uh Yeah, a triple negative and well you that's uh how many things work in science.

remember reading a brief history of time. I am I started reading it in high school. I couldn't finish it until I I in fact I didn't finish it until about five years ago. But it but it was a good thing I didn't because I I don't think I could have understood the kind of what he was doing in that book until much, much later.

But one of the things when he brings up this this you know kind of what's called a wick rotation, right? Yeah. He he brings it up and he says, Well, imagine we're just gonna build this as a trick, you know, we're just gonna do a trick. We're gonna introduce imaginary time, you know, no the number square root of negative one.

in front of the time component. And when we do that, it's called a wick rotation. And then we can solve all these things as if it's taking place in Euclidean space. So it's it's it but don't worry, dear reader. It's just a simple m and then the rest of the book is just basically assuming that's true. And then he goes on to say You know, and then we'll have the mind of God. What do you make of this? I mean, what is the reality of it? I guess I'm asking Wigner's question, you know, why is math so

useful. Like one thing that always blows my mind, and I try to impress it on my students, is, you know, in classical mechanics, we have Lagrangians, we have Poisson brackets, you can do all sorts of things.

If you take a Poisson bracket and commutation bracket, you get, you know, the product of these things and they cancel out. The Poisson bracket for classical observers is zero. But if you if you say it's quantum mechanical, you do the commutation relation, you get the square root of negative one. and all of a sudden all of quantum mechanics can emerge from it. It's sorta bizarre, right? What level are these things tricks? I mean, when you see the imaginary number and you talk about in this paper

Is it real? Maxwell's fields have imaginary solutions too, but they're not real, but we can observe only real things. So where where does a person go with this? I I I like a story that uh apparently Lorenz, so that's the same person of the Lorenz transformations, he was tasked with uh calculating how water go gets into the various canals and how to design some dams and so on.

So he, with some people, they wrote a report on how this should be calculated. And in the beginning of this report, he says, well, we're going to use complex numbers, but... At the very end all the heights of the water and so on are going to be real, don't worry about that. And I guess at the time i it it was thought it would be necessary to explain this point. N now any any engineering student uh uses complex numbers to solve this this type of problems, uh with oscillations and so on.

And yeah, well it's a trick but it's a trick that simplifies in that case it's a trick that simplifies the the the the calculation. And in this case maybe similar. So everything we measure, we o we we always measure real numbers. And so the imaginary numbers, that's how they were invented for discussing the roots of polynomials and so on. But they

They are useful tricks and I I yeah. But i it's true that it's a trick that is used so often and so much that it seems that there is something deep about it. When we think about all the other mathematical structures, so you start off with the square root of negative one, you get quantum mechanics, you get all sorts of interesting phenomena. Then you have spin one half particles can be described by these uh SOSU2 matrices, yeah, two by two matrices that are complex.

And then later you can have uh SU3, you can have quaternions. And then I think there are octonians, but then nothing ha like you people obviously could keep going, right? All the powers are two. But D does anything correspond to whatever hexadec hexa sexadecimal D.

Bueno, el problema es que los números complejos tienen muchas de las propiedades de los números de los números de los números. Y después de empezar a ir a los otros, no tienen todas las propiedades de los números de los números de los números de los números.

So they they become uh I I would say they become a l uh less useful. I mean quaternions were invented and they could be useful for describing rotations in space, but they are not used that much. I mean it's not something I I I'm not sure whether engineers use it, for example. Ha ha. For this purpose. I guess for Yeah, well maybe they're useful some things. I I I I wouldn't uh

I wanna talk about one of the things you're most known for. When I was getting my PhD, you know, in late uh nineties at Brown. I remember some conference and everyone's so excited and at the end they they did the Macarena, but they called it the Maldissena. Take us back to those times. You know the this ADS CFT. What is it?

How did you come upon it? Uh give us the origin story. Well ADSFT is this connection between y you know, universes which are large and with negative cosmological constant. So that's an ADS, anti-de-sitter space time. So the sitter is the one with positive cosmological constant, this is with negative cosmological constant.

And CFT is that is a type of uh field theory. So field theories are the theories uh that we use to describe relativistic particles. And conform means it has some scaling symmetry. And the idea is that these two are uh connected. uh is this uh instantiation of the holographic uh this holographic idea. So it's a concrete example. So that conference took place after this paper and after people had worked on it and there are many other interesting properties.

And so uh Jeff Harvey wrote this uh song. I mean that the Macarena was the song that was popular at the time, right? What do you say to people that often, you know? have said the mathematics, like with string theory, is beautiful, but we live in a we certainly don't live seem to live in ADS space. So is it just pure again like a wick rotation? Is it something that we should use as a useful tool, or could it describe reality and we just haven't found evidence for Well, we made a sign error.

Of course. Uh typo, we gotta retract it. Paper is uh zero citation. Yes, yes. So the Cater space is much closer to our universe and I would very much like to have something I mean, we we we everyone would very much like to have something like this in the Cater space and Hopefully understanding the anti-desitter case will be useful for understanding the desitter case. I hope that the understanding of the desitter case would have happened already and I hope it will happen soon. Yeah.

And but maybe we'll need maybe a new conceptual idea. So people who say that this is not the physical universe are r are correct. But you know, we hope it's close enough that we can extract some lessons. The other thing we we talked about briefly our last conversation four years ago, I can't believe it, was wormholes and and even humanly traversable wormholes. What is a human traversable wormhole? What good is it other than for solving a lot of issues in Hollywood where you're off to tomorrow?

Yeah, before you discuss what the wormhole is. So in in Einstein theory the the structure of space time is dynamical and curved so the spacetime can be deformed, right? Okay, so it can be deformed a little bit and you know, when Einstein developed his theory he thought, Okay, these deformations will be small. Then there were some even larger deformations like black holes and okay, that that's a more d drastic thing. But then you can have some other types of deformations where

you drill a hole in space time and you connect to another region of space. So you can have, for example, a space time like this. Imagine a membrane, you you dig a hole in these two portions of the membrane and you somehow connect them. But you connect them through A tube that is not embedded in this space now, it's just a very short tube. Okay or my Klein bottle over there.

Yeah. So something exotic like this. So and the question is are these configurations allowed? Are they possible in general relativity? Science fiction authors love it because you could go in one end and come out in the other and you could travel faster than the speed of light, for example. This is something that they could allow if they were possible.

But it would be a little funny because the structure of special relativity and is and s general relativity is based on the idea of a maximum speed for propagation of signals. In general relativity, you're not allowed to put any space time. So you're not allowed to say, Oh, I have this spacetime. you you have to obey certain equations, right?

And the equations roughly say that the the curvature of your space-time uh should be equal to the density of matter. Then you can say, okay, fine, I if I want to build some space-time, I just put appropriate matter and then I will be able to have uh any space-time I want. But then there is a catch, because matter has to obey certain properties. You cannot have matter, let's say, with a negative energy or things like this. At least in classical physics, you can't have that.

And once you put in that constraint on the types of matter you are allowed to have, then you forbid the wormholes that I would allow you to propagate faster than the speed of light. That is also forbidden in the full quantum theory. In the quantum theory, we think that...

In quantum mechanics, you are allowed to have a little bit of negative energy, but not enough to have a wormhole that would allow you to travel faster than the speed of light. So those types of science fiction wormholes are not allowed, according to... the laws of physics as we know them and this is not something that depends on the detailed structure of the standard model but it's something that depends on relativistic quantum field theory so the principles of relativity which are

the principles on which this whole picture of space time is based and the principles of quantum mechanics, they they do not allow uh such a thing. I think this is a beautiful consistency condition between the two theories, for because the

th this issue with this this wormholes, which is some property of general relativity, they depend on some quantum property of matter. If qua quantum matter didn't obey this property then you would be allowed to violate the you would be able to send signals faster than the speed of light. Right.

creating these wormholes. So those are not allowed and we this is a nice uh theoretical result, uh important theoretical result. But this does not forbid wormholes that where it would take longer for you to go. Right. So so you you could imagine a non-trivial topology where there are two holes and they're connected by a long tube and it takes you longer to go through the tube, at least I've seen from somewhere outside, than the time it takes to go between the two mouths.

And recently it's became possible to construct some solutions that that are of this kind. So they require cer certain types of matter and in particular charge fermions which are massless and so on. So they could exist as solutions at very microscopic scales where you can approximate the fermions of nature as being massless. Though those would be very tiny. Or you could say

Well, I have some very special type of dark matter that um is this is uh dark matter specially designed to make wormholes. And then you could have a very, very big wormhole, uh that could be humanly traversable that the person can traverse. Meter scale, right? Yeah, well for to to make them this way you need them to be actually much bigger than meterscale. And the the reason is is kind of interesting. It's it's because um so these are structures where there is some space time curvature.

We we are quite sensitive to tidal forces. So you need them to be roughly the size of the earth for it not to kill you when you're traveling. We could transport whole planets, you know. Why stop at astronauts when you can have all people? I just saw that the curvature is small enough that they would not kill you. Ah, right. I see. Yeah. If you and Einstein were together in nineteen thirteen, you know, or nineteen eleven, say.

after his happiest thought about, you know, falling on an elevator and and uh uh experiencing no gravitational field. And you gave him an L M and a G P T and a and a GPU and you had the most powerful system Do you think he could have come to or you guys together could do stuff that you couldn't do without an AI? In other words, someone, you know, operating at the highest levels of theoretical physics. What level of I mean, I use A L L Ms all the time, but

I don't see them creating new physics any time soon. Well, we'll see. We'll never say never. The field is advancing quickly and we'll see we'll see what happens. Yeah. I was uh an altar boy in the Catholic Church in um Westchester County, actually in Chappaqua, New York, where the Clintons now live, uh as it turns out. And uh I loved it. I thought it was awesome. It was nineteen eighty four, nineteen eighty-five. And

Then the uh Pope John Paul II, who was, you know, in my opinion, the greatest pope in history, maybe. I I loved him. They came out with a decision that Galileo was right, but they never really forgave him. And I understand that you remember the Catholic Scientist Society.

How do you reconcile? Like, do you feel like there's a tension? I always thought they should just say he's he was right, he was part of it. How do you reconcile the the so-called, you know, kind of tension between science and religion? I think yeah, the Galileo was a very Galileo thing was a very unfortunate I mean uh unfortunate case. Uh but there are well, there are many other cases of uh, you know, scientists that reconcile their their faith with their

And we're talking about cosmology, for example, the Lemaitre who was one of the people who created the Big Bang Theory, he was a priest and he reconciled. So I think th there isn't a uh a fundamental issue but but uh you know as science progresses we'll have to change what how we understand religion or we and also religion can illuminate some some

scientific well not not some scientific questions but some issues, some that arise because of science. Right. Yeah. I know we have uh now very powerful weapons and, you know, what uh that have some responsibilities that uh you know, are very very important, very moral responsibilities that are Yeah, and how to adapt. You know, people are so obsessed with artificial intelligence, but I kind of feel like we need artificial wisdom. Like

Intelligence is f plentiful, but somehow it's more important to get wisdom and I don't see science providing wisdom. It provides knowledge. I mean that's what science means in Latin, right? But it doesn't mean wisdom, so Yeah, from my perspective, they can be partners, you know, science and religion. I don't see them as foes or in in opposition. But yeah, people that try to derive one from the other, like prove that the Big Bang happened using the Torah, the you know, using the Bible.

I think that's not not great. when the cosmic microwave background was detected. So the Pope wanted to say said actually that uh now we saw the you know the the beginning of the universe, the hand of God and so on and and Lemaitre told him don don't don't wade into this, just don't don't say anything because Yeah.

Yeah, that's right. It could it could change. And back then they thought the earth was, you know, younger uh older than the universe, right? That was uh quite embarrassing. Well, let's see, we gotta get you to your talk. But before we do, I have a gift for you. Not a Nobel prize, but uh It's called the Keating Prize. It's not too arrogant of me. So it has uh Arthur C. Clarke on the front, because the podcast comes from him and it says, uh, the Keating Prize for Impossibly Good Imagination.

And and then a meteorite, which is a a fragment of the early solar system that somehow magnetically attaches to the monolith on the back and has your name on the side. Juan Maldissana, thank you so much for coming to San Diego. I hope you enjoyed. Right. Yeah. And then you'll add it when you win the Nobel Prize you can add them together. Right. Great. Thank you so much for being on and stay tuned to watch the lecture on black hole entropy and thermodynamics coming up next.

Juan told us today that he thinks the structure of space-time is built out of quantum entanglement, and that the deepest problem in physics isn't black holes, it's the Big Bang. Now, if that changes how you think about reality, hit subscribe and turn on notifications. Drop a comment. Let me know what problem you think Einstein would most like to see solved if he came back. And you'll want to go deeper and check out Juan's two-part lecture on my second channel, Keating Experiments.

I'll link that here. And if you want to go deeper, you're going to want to watch my conversation with Leonard Suskin, talking about the Black Hole Wars using the language that he and Juan invented. The link is right here. Don't forget to like, comment, and subscribe, and I'll see you next time. Drömmer du om en strand villa på Maldiverna? Ett potikhotell på Marin. Eller en gömd ö i Grekland. Globter tar dig till exklusiva resmål och handplockade hotell. Världen över. Boka digitalt.

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