The Infinite Monkey Cage - Black Holes

Episode Date: August 13, 2022

Brian Cox and Robin Ince are joined by Monty Python's Eric Idle, and cosmologists Dr Netta Engelhardt and Dr Janna Levin as they tackle one of the biggest challenges in cosmology. What happens when you throw something (Robin!) into a black hole? Is the information about Robin lost forever, or is there a chance, sometime in the far future, a super intelligent alien civilisation could piece back some key information to discover proof he ever existed? Are Robin and his cardigans lost for all eternity? Executive Producer: Alexandra Feachem

This is the BBC. This podcast is supported by advertising outside the UK. All day long. Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. BBC Sounds. Music, radio, podcasts. Hello, welcome to the Infinite Monkey Cage. I'm Professor Brian Cox, Royal Society Michael Faraday Prize winner 2012. And I'm Robin Innes, Tufty Club Affiliation Certificate 1975 and 1976. Ask a scientist if you could die in any way possible in the universe, what would you choose? Well, many scientists always choose the same answer. Have you actually asked anyone that? It sounds a bit like a threat.

Well, I do feel that quite often there may be a reason that there's quite a few people who've turned down it, because I tried to do it in a friendly way. You know, I didn't do a kind of like James Bond, you know, kind of movie where we go, ah, Roger Penrose. So how would you like to die? The particle accelerator or the black hole? It was very much more of a kind of upbeat, you know, how would you like to die? Like a Quaker assassin.

I'm assuming this is why every time we do cosmology, we do it via Zoom with people on different continents. Yeah, they aren't taking a risk with me. I mean, the truth of it is that I really have asked loads of scientists when I was researching something how they would most like to die. And the number one answer was by falling into a black hole. And I think it's possible that today we're going to find out a little bit more about why that was the answer. We will indeed, Robin, because we are discussing perhaps the most profound question in theoretical physics, the so-called black hole information paradox. Put simply, if I throw Robin into a black hole, will he be erased from the universe forever? Or would some sort of omniscient, omnipotent super being in the far future be able to reconstruct his cardigan using a quantum computer?

Oh, they'd find it hard to, but these cardigans are a cotton wool mix. They're cheap, but they're sturdy. Rather like Robin. Cheap, but sturdy. Joining us on a journey into and perhaps out of a black hole are two eminent professors of theoretical physics and one eminent crooner of cosmological ballads and they are hello i'm janna levin i'm a professor of physics and astronomy at barnard college of columbia university what i would most like to retrieve from a black hole is whether or not there's actually a whole big bang on the inside,

whether there's a universe on the inside, whether a black hole's much bigger on the inside than it is on the outside. Doctor Who. Doctor Who. It's a TARDIS. Hello, my name is Netta Engelhardt, and I'm a professor of physics at MIT. The information I would most like to extract from a black hole is rather pedestrian. It's all the information that my computer lost the last time I upgraded the operating system. Including the setting on the spam filter. Hello, my name is Eric Idle.

I am an expert on spam filters. I am an expert on spam filters. And I have been asked by my Twitter followers to ask for information leading to the retrieval of their socks. And this is our panel. Netta, we should start at the beginning. What is the information paradox? Well, there are many answers to that question, depending on how deep you want to go. But at the sort of 60,000 foot view of what the information paradox is, it's a conflict in the predictions between two theories, both of which seem to describe our universe extremely well. So it's a conflict between the predictions of general relativity, which describes the very massive objects in our

universe extremely well and has been tested many times, and the predictions of quantum mechanics, which describes the universe at extremely small scales, protons, electrons, subatomic world, and also been tested many times. Now, you might, of course, say, well, you know, one describes stuff like galaxies and stars, and one describes things like electrons and protons. So how is there a situation where those two theories could possibly conflict one another, given that they obviously apply to two very different types of phenomena? And the answer, of course, are black holes, which take an incredible amount of mass

and concentrate it into an incredibly small space, where we expect both gravity, general relativity to be applicable. And on the other hand, we expect quantum mechanics that describes really small stuff to be applicable as well. And so we need a theory that describes both of them. And so this is the 60,000 foot view that doesn't tell you what information is being lost and what's really happening, but just tells you, why is it that we are interested in a conflict between a theory that describes really massive stuff and a theory that describes really, really tiny things? Jana, in what sense is there a conflict? In terms of information itself, what is the central problem? is the central problem? Yeah, so before Hawking, there really wasn't a problem. So your very own Sir Roger Penrose realized in the 60s that collapse to forming a black hole was inevitable

if it was unhindered, meaning what he really was showing was that there would become a region where space-time was so curved that not even light can escape. We all know that that's called the event horizon. But then he continues to show that the star itself, which is just one way to make a black hole, has to continue to fall. So the star leaves behind an empty nothingness at the event horizon, like a kind of archaeological imprint. logical imprint. And all of the information of suppose it's a star and something else didn't fall in, might, we have no idea really what happens to it once it's inside, might be tossed out as we were kind of joking in the beginning into a new Big Bang or fall out in a singularity. Even Roger Penrose in that first paper in the 60s said, ah, that's probably just because we don't understand quantum mechanics. So that wasn't a problem. The information was kind of lost,

meaning the information content of the star that Ned is describing, but it was hidden behind the event horizon. So that was fine, right? As long as it's never revealed to us that the information is gone, it's kind of tolerable. So it's in there. So the idea was it's kind of in there. It's kind of in there.

But what happened with Hawking is he realized that if you add to the theory of gravity, the general theory of relativity, even a little smidge of quantum mechanics in the empty space-time around the event horizon, even the tiniest fluctuations, that the black hole can steal from that empty space-time and also simultaneously radiate away in a way that it evaporates. And when it evaporates, it's as though the event horizon's yanked up, you know, the curtain's yanked up. And so the crisis comes there because then you really have to say, oh, is that like a news alert, breaking news alert?

We have a thing that basically the BBC, whenever you say the word crisis, a jingle is played, which suggests something ominous. You'll find there's other words you use as well. And just every now and again, the BBC has a list of possibly 12,000 jingles for different words. I would really like it if that followed me around in life. So breaking news, the curtains yanked up of the black hole. And then there's a real problem because now information has been lost out of the universe. And that's against the entire paradigm of knowing the universe that flies in the face of the entire success of physics, which is that we can know things about the world. It literally

violates something very foundational. And so that irked a lot of people. And it's been, it has been a crisis. Where's my, where's my jingle? Ever since. No, you only get it once. You get the, being the BBC, the jingle can be only used once every three years. But before I ask you why we care that information might be erased from the universe,

I wanted to just go to Eric, because Eric, I know that you knew Stephen and it's all Stephen's fault. I'm prepared to blame him. Actually, Brian and I had the great fortune of going to Cambridge one day and shooting a comedy joke with Stephen, where Brian was complaining about the lyrics of my song, a Galaxy song, it was inaccurate.

And Stephen appeared behind him in his wheelchair and ran him over. And it was the most wonderful day of my life. I got to see one professor running over another professor on the backs of Cambridge. It was just great. And he called me pedantic. Yes, he also ad-libbed. Way too pedantic. He ad-libbed. Way too pedantic. He ad-libbed when we were with him.

I was abused and then run over. That really is the two cultures in action, isn't it? I think, Eric, what you've done there to bring science and art together and bring it eventually to violence, which is what people always like most. Violence and slapstick. That's where the two cultures come together.

I mean, it's interesting, Eric, because really of everyone on the panel, you've probably worked most closely with Stephen Hawking, haven't you? But only in comedy. Well, isn't that what the whole universe is? Isn't that what we've worked out from physics? It's absurd enough. I did say to him after he came to the O2, I said,

I think you, me and Brian ought to go on the road, because we'd be a great comedy trio. And he seemed rather interested in that. Well, you did. I mean, we do have a clip, actually, because you sang a duet with him as well. We haven't got a clip of the duet. We've got a clip of just Stephen singing. Just remember that you're standing on a planet that's evolving

and revolving at 900 miles an hour. That's orbiting at 19 miles a second. So it's reckoned. The sun that is the source of all our power. The sun and you and me and all the stars that we can see. I still think the lyrics are inaccurate, even though Stephen's singing it. By the way, Brian, next time I would get him to sing, sit on my face so you could shut up. By the way, Brian, next time I would get him to sing, sit on my face so you could shut up.

But I love the fact, Eric, that you basically, because you love writing songs about science, you've now got a whole team of people who peer review your lyrics, which is just this, you know, or even end of the peer review your lyrics. Oh, thank you very much. But that's a fantastic thing that you write a song and you go, hang on a minute, it's not accurate enough yet, I'd better send it to the universities. Only about 30 years later is the actual truth

of the matter. And everybody's peer-reviewed them in an entirely negative way, I should say. Entire highly inaccurate. The issue in Circular Orbits, for example, in the Galaxy Song, it's horrendous. They're elliptical. It was written in 1981, Brian.

That's before bloody Penrose got a knighthood. That was Newton. Bloody Roger Penrose. Thanks, sir, Roger. Netta, bringing this back, I was going to say down to earth, but it's not. Why do we care if information is destroyed in a black hole? Why is that a fundamental problem? So one of the fundamental things that we want to do in physics, one of the goals of physics, is to actually be

able to predict the future, if you believe it or not. Given some information about the universe right now, we would like to predict what happens moving forward. And so in particular, that also means that given the information about the universe right now, we would like to be able to post-dict what happened in the past. So for example, if you're sitting in a room and the temperature is sort of cranked up to a certain temperature, but it hasn't quite reached that temperature, but you know how much electricity has gone into it, then you can say, oh, okay, I know that two hours ago it was this cold in this room. So you want to be able to post-dict as well as predict. What happens when information is lost is that we lose our ability to do that. And not

just that we lose our ability to do that, but it is simply impossible in principle to actually make predictions or postdictions. So for instance, if Brian were to take Robin and throw Robin into a black hole, and then that black hole were to evaporate and lose all of that information, hole were to evaporate and lose all of that information, then there would be no trace at all that Robin existed in this universe. Nobody would be able to track down the crime. But my question was fundamentally, why do we care about that? And you've made it even more vivid. Very good. So suppose that we have two different stars that have formed black holes. And one of those stars, they were different from the other star. They formed black holes and those black holes evaporated.

And now we have no way of looking at what was left over, at the radiation, and actually telling that those were two different stars. The radiation looks completely identical. We are unable, given the state of the universe today, to say where it came from and how it evolved. Now, that's one reason to care about the information paradox. Another reason to care about the information paradox is that, as physicists, we love paradoxes.

And the reason we love paradoxes is because nature thinks just happen. A paradox means that there's some fundamental misunderstanding in our pillars of physics. In this case, quantum mechanics and general relativity. And we would really like to have a good understanding of quantum gravity, the theory that unifies the two. What the information paradox can do for us is it can tell us

what is the pillar that we're getting wrong, that we need to understand better. And maybe if we resolve it, then we'll have much better understanding of quantum gravity, which can tell us things like what was the Big Bang, what happened before the Big Bang, all the fundamental building blocks of our universe. So Jana, I mean, that question, for instance, the Big Bang, is the problem, all right, saying that that first 10 to the minus 38 of a second, that quantum mechanics and whatever, if we're for the time being saying gravity, at that point they have to be together and they cannot be together. Is that basically the simple way of looking at it,

that we cannot get them to fit together when you get to that very, very small universe, that tiny amount? Yeah, and it's both the Big Bang and black holes. But the black hole is just a particular terrain on which to explore something very similar. But yes, the very extreme curvatures of the Big Bang and black hole acts like a kind of magnifying glass making the quantum scale important. And you can't just glibly say, I'm going to ignore quantum mechanics and still try to fundamentally understand the Big Bang or black holes. See, I love this stuff because I don't know if you've had this, Eric, when sometimes when you're trying to explain something to someone,

I'd been chatting with some scientists. He said, basically, you've got quantum mechanics, you've got gravity. They don't seem to really seem to work together. And it looked to the scientists, I suspect, they said, it's gravity that's going to have to be got rid of. That's the thing that's going to happen. And I said that to someone and they looked absolutely panicked. And then I said, oh, no, no, no, you'll still stick to the Earth. It doesn't mean that, but it was a beautiful moment of panic,

and I realised how badly I'd explained it and why I have to work with Brian all the time. Well, I'm glad you asked me, because I'm completely fluent in absolute stupidity, and I know nothing at all about this. Well, can I ask you though because that's it because you've got so you know your interest in science and you've written you know novel that kind of explored different ideas about consciousness many things yeah is there a point

where you go ah there was one day when I still thought I nearly knew it all and then I read this book of science and I went oh man am I lost, it was the day I first read a book on science. Well, I have been trying to catch up, but I really, it's so complicated and it's very confusing, and I do, but I think people are really interested in it, and I know from my Twitter feed that people are really interested by black holes and they have many interesting things to say,

none of which I understand. Netta, recently, so this is 2019, 2020, we talk about the black hole information paradox. In a sense, in the last few years, it's not been solved, but the answer, I think, is widely agreed upon now, which sounds kind of trivial. Yes, the information comes out. So ultimately, all the information of everything that fell into the black hole comes out in the Hawking radiation at some point in the far future. So the question is, how? The simple question. That is the question.

How does it get out? Robin's cardigan becomes imprinted in radiation. How does it become imprinted? So yes, the answer appears to be that the information comes out and the crime will be found. Now, we would like to understand that better. I'll put a disclaimer there, which is that the information paradox isn't solved, even though we understand that the information comes out, because even though we've made a lot of progress over the last three years, we still don't quite have a complete understanding of how the information comes out. Now, why do I say that we've made a lot of progress over the last three years if we still don't know how the information comes out.

And the answer is that we have understood how to use gravity and quantum mechanics at the event horizon of a black hole in order to actually do calculations that are consistent with information not being lost. So let me break that down a little bit. Before 2019, we really thought that with the conventional wisdom, the consensus was that if you wanted to see that information was not lost, you would have to do some really complicated quantum gravity calculation in some theory that we don't know and we don't understand, and we have no clue why that theory is even important. Now, what we've seen in 2019, what we've understood since then is that actually, we can do calculations in just ordinary gravity, a little bit of quantum mechanics, that little bit that Hawking used, and never need this quantum theory of gravity that's really wild animal that

we don't understand. we don't need it in order to see that information is conserved because here's the really weird thing so let's use robin i like using robin as an example so robin this is like an episode of colombo isn't it ever since net said that thing and you can't totally cover up the crime i'm just all i can see is peter falk finally capturing patrick mcguin because of the Hawking radiation, which I hope eventually exists on NBC. I do have bad news for you, Robin, which is that according to our current calculations, it will take an

exponential amount of time to actually tell that the information got out. I love suspense. We're talking about, yeah, 10 to the 60 odd years in the future. Can I ask you a question? Just from a layman, does the adventure horizon presumably gets wider

as more information goes in? Is that correct? The black hole grows, right? So presumably if you could take a picture of the past, you could see something would be different from the current, although it probably take a long time. That's actually a really interesting point about black holes is they're featureless. They hide all of their secrets. It's inside the event.

So you can't really take a picture of a black hole from the outside and have any kind of deep insight into what happened inside. And that's really the meaning of the event horizon. All you can tell is how wide it is. That's quite true. So the black hole. That changes too, right? Right. But it'll change whether we threw Robin in or we threw Brian in.

If we were the same mass. Vote now. We're not the same mass. Because I know we talked about this last time you were on, Jana, as well, but this interesting thing that we talk about being inside a black hole, but also we talked about the fact that the black hole itself is only surface as well. So it's really counter-instinctual, you know, all of these things, especially for non-scientists, I think.

It feels like you're dealing with trying to understand it from the dimensions that we experience the world, and then trying to go into that black hole or lying on top of that black hole. It's a big leap to make, isn't it? Yeah, I mean, it is a big leap to make. But I think you're also pointing out that everything about the black hole is actually understood from looking at the event horizon to some extent that's that's something we call holography and you know you were discussing being two-dimensional netta's working in two dimensions on our blackboard and eric i don't know i suggested he was actually two-dimensional

i'm actually what i'm actually one dimensional i thought you were very three-dimensional in Nuns on the Run. I think it's an insult from... There's a great insult from... I think it's Eddington who described some kind of... You know, someone who works for the local council who was bothering him with parking tickets or something. And he said he was a Euclidean point,

someone with position but no magnitude. That's a great insult. Well, I think the idea of a hologram is that information is packed on a two-dimensional surface, and it projects a three-dimensional image, but it's an illusion, that three-dimensional image. It's really no more information than you can pack on the flat surface, the 2D surface. And so in the case of a black hole, we're saying that there's no more information that you can pack in the black hole that you can pack on the surface of the event horizon. So if we take that really seriously, if we say black holes are

foundational, that they're telling us something about the underlying law of physics, it's telling us maybe that the entire universe is really two-dimensional and that the three-dimensional projection is an illusion. So you are two-dimensional, Eric. Let's expand on that because this is one of the questions that I get asked a lot. In fact, you got asked it. I've got it here. You got asked it on, I believe, this morning on ITV, which led to the Daily Star headline, front-page news, Brian Cox, you've been talking out of Uranus. That's the front-page headline.

Space boff fears everything we know about the universe could be wrong and we could actually all be holograms. It is very rare that holographic principle makes it to the front page of any newspaper and the fact that the Daily Star got there before The Guardian, The Times, The Observer. So I don't think they understood the subtlety of what I was trying to say. But maybe, Netta, since we've started talking about this, one of the deep messages from this physics seems to be that, as Jana said,

that you can picture all this information that falls into a black hole in some sense being stored on the surface of the event horizon, even though, again, as Jana said, the event horizon isn't there in some sense. It's just space. It's a fascinating idea. The general understanding previously was that in some sense, the information should be stored on the event horizon of a black hole. But our more precise understanding now is that actually the information is stored at infinity. And in particular, what we mean by that is it's stored an infinite distance away. So if you imagine that you have a ball and you have something going on inside the ball, the information is stored on the boundary of that ball on the outside. But then take

that boundary of the ball, take its radius and make it infinite. Then the information about everything that happens in there is stored at this sort of infinite radius sphere. But are we really claiming that in some sense, the pattern that is Eric Idle is actually, in some sense, some kind of information processing on a surface infinitely far away? Are we going that far? So are we really going that far? Are we really saying the information only lives out there? And the answer is no, we don't expect that. The idea behind this relation, the holographic principle, what it tells us is it gives us another way of doing the same calculation. We can either do it at infinity without worrying about gravity, or we can do it in the gravitational universe where the black hole is.

Given that we see information is not lost in this non-gravitational theory at the boundary of infinity, well, it's better not be lost when we look at the black hole. Well, can I ask you, because we've heard a lot of discussions about information. When does the universe, from a human perspective, become information? Because that's the thing, is we have it thrown around, the information that makes Eric, the information that makes my cardigans, all of those things. And I know we were talking earlier on today, Brian,

about John Wheeler had that great line where he talked about, he said, when I started, the universe was particles, then it became fields, and now it's information. What level of cosmological understanding means that we now have to define the experience of the universe as information? Well, I think it's been creeping up on us for a while, starting with quantum mechanics and then going to thinking about, you know, mathematics in general, like, what does it mean to say, what is an electron, for instance, if it's a fundamental particle, and it might not be because it might be really a little loop of string, but whatever is fundamental, what does it mean to be

an electron, it means you have a certain charge, a certain mass, a certain spin, certain list of information. And that's it. That's all it means to be an electron. There's there's nothing else to the meaning of being an electron than that list of information. And you realize that a lot of how we conceive of the world and conceptualize it is illusory. Like I know, for instance, that you're mostly empty space because you're made of atoms. And I'm sure you're gonna have a good joke about that. No, I accept it. I think yet again, I've proved on this show that there's more empty space in me than most yeah nature abhors a vacuum but it made an exception for me

but you know I see you I perceive you as being solid just because of the way your atoms interact with light and the light interacts with my eyes and I'm perfectly comfortable with the fact that that's an illusion and ultimately all that there really is is information do you find I mean this is for in fact for all of you really for Netta, Jana and Eric that that idea that when when people first hear these ideas and maybe for quite a while it cannot help but also really hit you psychologically it cannot help that to to feel to feel that possibility of the existential anxiety. I remember Brian once explaining something, and then at the end of it he said, you know, a bit of existential anxiety is good for the soul.

And then later on I said to him, have you ever had existential anxiety? And he went, no. You know, he's one of those kind of particle physicists who can manage to just avoid that messiness of philosophy. So I just, you know, do you find that when you tell people those things, that there is a reaction, a gut reaction to it? So I'll start with you, Jana. Yeah, I think that there's, it's existential, but it's not necessarily dread. There's also a profound sense of meaning and connection with the world.

And I think that's what physicists search for. You know, this quote of Laplace's when I think it was Napoleon asked him what he thought about the existence of God. He said... It was Louis XIV. It was Louis XIV?

Am I totally... It wasn't Napoleon. It was before Napoleon. Centuries ago? It was Louis XVI, yeah, something. But it was Laplace, anyway. 17th century. Give the quote.

You'll probably do it better than I do. He said, Michel Laplace, why is there no mention of God? And he said, I did not require that hypothesis. Exactly. To explain it. And in the original medieval frame?

That's not medieval, Brian. No, it's not medieval, is it? I guess my history is a little shaky. So in that sense, it's a way of deriving meaning and actually pushing existential dread off. Can we be very specific? So let's stick with Robin falling into the black hole because we can all imagine that.

It's a good way of losing weight as well that's spaghettification i am gonna look look at those cheekbones but for a very small amount of time wait this is spaghettification this is okay so is there any form other form of pastification i mean can can you be resotified, for example, if you fall into a black hole? So we follow Robin in. I'm going to keep going on that. I want to throw him in. In he goes. In the very far future, the black hole has evaporated away and all that's left is Hawking radiation, which is basically photons and some other stuff, gravitons and things, right? It's there.

In what sense is Robin reconstructable from all that information? You gather it together. What do you do to get him back? How is he encoded in that radiation? So that's an excellent question. And it is a question that we are in the process of working out, but I can tell you what we've got so far. So if you imagine you're flying around the radiation of a black hole that's evaporated

that once upon a time contained Robin, and you have a bunch of beam splitters and mirrors, and you collect every single last photon, and then you say, okay, what do I do with all of this to tell if a crime was committed and Robin was actually thrown in? And you have to ask, what do I need to do? So you need an extremely powerful quantum computer to process that data in order to basically read the radiation to see what fell into the black hole. Now, the million-dollar question is, what is the quantum circuit that you have to build that you can take all of that radiation and put it through that exact quantum circuit?

And what comes out at the end of the day is a picture of everything that fell in. And so far, we've learned some things. What we do know is it requires an incredibly complex quantum circuit. That idea, and as you were talking about the fact that, you know, enormous lengths of time. But if we look forward to a future civilization, be it billions and billions of years ahead, there could be the possibility of a civilization that creates a technology with quantum computers that says we go to the nearest black hole and from there we start reading what civilizations, what has existed before, and we rebuild the history of the universe through the information. The black hole is the worst case scenario. Essentially, no information is lost, you know, in a normal situation. So like if you burn up Netta's computer in a fire

and she's lost all her data, which she wants to retrieve, it's actually a lot easier to retrieve it just from the fire and the smoke and everything it did into the room and the soot. And that's obviously like an incredibly daunting task to actually add to that, that maybe you threw it into a black hole as well,

is making your life just like that much harder. So the idea is that even if I set a dictionary on fire, the dictionary that tells you how to understand the world, that I should be able to recover that information as long as it doesn't fall into a black hole. Eric, can I ask, the last time we had you on, we dealt with the end of the universe. And I thought this one was going to be possibly more upbeat. What's your general reaction to what you've heard during this show? I would say that the only thing I could take from today's talk is I don't understand most of it. But I found it fascinating.

And I find the whole thing about the actual edge of the event horizon, because I love the picture of the end of the universe when all these black holes start to leak, and finally the last black hole leaks away, and that's the picture of the end of the universe, as we seem to know. It just keeps going on and on, leaking and leaking away. So I have nothing really to contribute except I did have just a tweet from Steve Martin who was interested in black holes and he

wants to ask what is the price of a used one and he said is it only in black it does feel like this there's always at least one show in this in a series where a lot of people get in contact say i didn't really understand it but i thoroughly enjoyed listening to people who i think did and i think that's one of those lovely things that you know that's for me yes yeah and that's how i feel sometimes is go i'm not sure how much i actually

understood but what a joy to see minds that are in action dealing with these things, which are beyond me and my cardigans and all of those things. But there are people working out these things. people using ideas like the holographic principle in what I would consider maybe sometimes pseudoscientific ways and in the same way that quantum is often attached to many different products in the idea of saying this must be very sciencey because we've called it quantum chicken and so I kind of how should we react and I'll ask both Jana and Netta this should this change the way that we live our lives or merely the way that we understand the universe and for the time being let's just live as three-dimensional creatures yeah i think in practice we live as three-dimensional creatures but i i think that sometimes the consequences of that culturally and in terms of how internationally we move ahead as a species is often affected by

these ideas and these ramifications in ways that we don't immediately understand. I mean, if you think about Copernicus displacing us from the center of the solar system, it wasn't just a scientific discovery. And it wasn't like it changed anyone's daily lives. What it did is it radically altered our understanding of our place in the world. And it was huge, and you couldn't peel it back once it happened. And I feel like the physics is like that for us. But hadn't that already happened? Didn't Lucretius already tell us everything was atoms and floated around? That was the Greeks, you know, so maybe we just keep recycling these ideas and stupidity comes in again. I think we just get so much better at it and that it is fair to say we get incredibly

better at. We're not just talking about atoms as a kind of vague hypothesis. It's the most successfully tested theory in the history of human thinking. And we build things and we're on Zoom now because of it. And we're able to talk to each other in different countries because of it. now because of it. And we're able to talk to each other in different countries because of it. And that they couldn't do. So it's not all on the same level. So Netta, does your work, do you find that affects you philosophically in a kind of pragmatic way? So I think there's a sense in which discoveries about the basic building blocks and fundamentals of the universe, discoveries like holographyy and quantum mechanics affect us in two ways, really. And I think both of those can be thought of as affecting our daily lives. And the first of those ways is a little bit more abstract and a bit more

aspirational in the sense that human beings have sort of always been driven as a species to understand the world around us better. This was a drive and an impulse that dates back to basically as long as we have recorded history, to try to understand better what makes the world around us tick. And honestly, just understanding it is already impacting our lives simply because we have striven for so long and so far and so hard to understand it better. So that is the first sense. And then there's a second sense in which we can ask, well, do you expect new technologies? Do you expect something that I can have in my living room while I'm watching TV out of the information paradox? And I don't have anything for you right now. I mean, there certainly is in my living room,

there's lots of papers on information paradox. It's definitely pragmatic for me. But on a sort of more visionary level, you know, the GPS in your phone works because of general relativity. And of course, when Einstein came up with it, he didn't think about GPSs. That took a long time for the GPS to actually be developed. So what will we come up with, with quantum gravity? I don't know. But I certainly am looking forward to finding out. I love that idea that, you know, the idea that Einstein, it all started when he went, yet again, I'm lost in Munich. I really need to come up with a system. And then he put a grant proposal to say, what are the likely spin-offs of general relativity?

I love some of the stuff. I've got a book, this book, The Holographic Universe, which you might know, which kind of plays around with some of these ideas. I don't know it. Sometimes I read these to Brian just to annoy him, just these things like, you know, the holographic principle may explain near-death studies. Nothing more than shifting of a person's consciousness from one level of the hologram of reality to another. I love doing this to him. Eric, stop him. Oh, lucid dreaming as well. You don't want

to know about lucid dreaming and how that went into a different universe where I exist for a while, but now I'm back. After working with John Cleese and Graham Chapman and all the others for so many years, how do you stop a comedian talking? You must know. You show him how much he's actually getting paid. Oh, OK.

You need more than the holographic principle. Yes. I'm afraid it is the misinformation highway. Right, we have asked our audience a question. We said if you could throw anything into a black hole, what would it be? We asked that on Twitter, by the way, and most of the answers were your least favourite politician.

So think of a politician you don't like. 99% of the answers were that. What the people on Twitter didn't know is that, as we've just shown, that politician will re-emerge in the far future as a pattern in the radiation. And so, unfortunately or fortunately, the black hole will not erase them from the universe. Somebody suggested they should throw in Houdini to see if he could get out.

Yeah. We've got... Barge says, My Christmas lights. If the complex gravitational forces could disentangle them, great. We've got Front Barge says, My Christmas lights. If the complex gravitational forces could disentangle them, great. Otherwise, they'd never be the best kind of light to not escape anyway. Time I'll never get back.

I like this one from Gavin Jamie or Jamie Gavin. He said, Robin Ince, bear with me here. As we see him forever, never ageing on the event horizon, he might one day look younger than Brian Cox. Gonna take a while. Gonna take a while. Brian Blessed's voice to disprove the theory that nothing can escape from a black hole. So the idea...

Hawking radiation? No way! Come on! I'll take you on, supermassive, tiny little thing! Just an ink spot! I love the idea you could still hear him. You could still hear him inside there. Let me out! Jacob would like to throw in a string of spaghetti just to see what happens when it's spaghettified.

Jacob is 11 years old, and I think you have a good future in cosmology. Sorry, Eric. He should throw in tomatoes then afterwards, really, shouldn't he? Someone here at Richard said, the actor Brian Cox, because life is too confusing. Just get rid of one of them. Right, so thank you very much to our panel,

Netta Englehart, Jan Eleven and Eric Idle. Now, usually at this point, I say what's going to happen next week on the Infinite Monkey Cage, but notwithstanding the fact that the universe evolves deterministically, as we've seen, we don't actually know what we're doing next week because Robin's quantum computer really isn't up to the job Yeah to be honest the quantum computer I've come up with basically what I did was I just sellotaped two egg boxes and an abacus to the side

of a cat and I put it in a box and all I've actually created is a rattly cat it's just not that impressive Bye It's just not that impressive. Bye. Bye. In the infinite monkey cage Out you travel In the infinite monkey cage Turned out nice again.

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