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Brian Cox

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The Joe Rogan Experience

#2217 - Brian Cox

10002.217

But it's still in principle there. But the question is, how does it get out? How is it getting out? How is the information that is you ending up outside again?

The Joe Rogan Experience

#2217 - Brian Cox

10012.574

And the physical picture is not really understood, but the link is that one of the pictures that people are beginning to suggest to have is that there is some kind of wormholes, in a sense, some kind of wormhole that connects the inside of the black hole to the outside. And so a picture...

The Joe Rogan Experience

#2217 - Brian Cox

10033.639

is that your atoms and everything, your bits get scrambled up and go basically through the wormholes and come out again. But they're funny kind of wormholes. So people don't really understand this. But mathematically, it looks like maybe. So it looks like maybe there's some role for wormholes.

The Joe Rogan Experience

#2217 - Brian Cox

10052.768

these things, the science fiction things, after a fashion, some kind of, there's some role for it in the way the universe works. So it's really cool. The last thing I'll say, because I think we're going to, is there's a thing called ER equals EPR, which is, so EPR was the spooky action at a distance. So we may have talked about that before.

The Joe Rogan Experience

#2217 - Brian Cox

10072.061

You know, in quantum mechanics, there's this entanglement thing where something can be separated by a million light years. But if you do something to it, it seems like this thing responds, right? Not in a way that you can transmit information, but it responds. So entanglement. There's a picture of that.

The Joe Rogan Experience

#2217 - Brian Cox

10088.931

So that's Einstein, Podolsky and Rosen, EPL, they wrote a paper on this saying, we don't like this. There must be something wrong with quantum mechanics. We don't think there is now. This is the basis of quantum computers. So we build things that rely on this effect. ER is Einstein-Rosen, which is Einstein-Rosen bridge, which is wormhole.

The Joe Rogan Experience

#2217 - Brian Cox

1009.367

And if I said to you, let's run away from tomorrow, you'd go, I can't run away from tomorrow.

The Joe Rogan Experience

#2217 - Brian Cox

10109.481

So they also published a paper about wormholes, Einstein and Rosen, in the 30s. And so the idea is that you could picture that somehow as being a kind of wormhole that connects the entangled particles together. So that's how this entanglement works. Another description of quantum entanglement is a wormhole kind of geometry.

The Joe Rogan Experience

#2217 - Brian Cox

10131.289

And this is part of the cutting edge of research into black holes, but also the structure of space and time and quantum entanglement and how quantum entanglement might produce space and time. And it's related to the way that quantum computers work. So it's become a really hot topic because people are trying to build quantum computers and program quantum computers.

The Joe Rogan Experience

#2217 - Brian Cox

10153.096

And these are the kind of problems you have to face about quantum entanglement and how you maintain it and what it means. And there was a paper. which is quite a controversial paper, but I think it was the Google quantum computer, which is one of the best ones. And it's not using it as a computer.

The Joe Rogan Experience

#2217 - Brian Cox

10170.582

It's using it just as these qubits, these little quantum systems that are kind of very stable, that are the basis of quantum computing. And it's using those qubits and setting them up in such a way that something that looks like a kind of a wormhole is created in the quantum computer. It's kind of a one-dimensional wormhole, and it's a bit kind of technical and everything.

The Joe Rogan Experience

#2217 - Brian Cox

10193.751

But it looks like it might be the first hint of how you build space from qubits. And so that paper was published recently. There it is. That's it. A holographic wormhole. It's important to say that wormhole is what's called a hologram. It's not really in our universe. It's kind of a different thing.

The Joe Rogan Experience

#2217 - Brian Cox

1021.276

Is that the idea? If you draw the thing, you can draw a map of it, and it just literally time ends, just purely in Einstein's theory. This is 1915, his theory of general relativity. You just get a line there, a line that says there's no future beyond this line. It just stops. Okay. So, I mean, admittedly, that's not... We think there's a lot more to it than that.

The Joe Rogan Experience

#2217 - Brian Cox

10216.145

Because that's the last thing I'll say, because I've got to blow your mind because your mind looks... It's blown! These theories... The hologram thing is quite well established now. And it's coming from a thing that you may have talked about with other people on the show, the ADS-CFT conjecture, the great physical Maldacena. So the idea is that you can have a quantum theory living on a boundary.

The Joe Rogan Experience

#2217 - Brian Cox

10239.781

So you could imagine, picture a sphere with a quantum theory living on the surface. And there's a completely equivalent description of whatever's going on, the physics, in the interior of the sphere. So it's almost as if the interior of the space is a hologram of the theory that lives on the surface. And it's kind of not accepted, but many physicists think our universe is like that.

The Joe Rogan Experience

#2217 - Brian Cox

10269.255

So what we're saying is that we're having this conversation now and there's an equivalent description of this somehow in a theory that does not contain space and time. There's a completely equivalent description that lives in fewer dimensions on a surface somehow that's surrounding us. And it's really woolly and hand-wavy because we don't fully know what it means.

The Joe Rogan Experience

#2217 - Brian Cox

10292.554

But it would mean that we're holograms. So this is a hologram of this other dual theory. That's what that thing was, the holographic wormhole thing. So it's all very the beginnings of this work. But that's an example of how it could become an experimental science because quantum computers now exist. And they allow you to do those experiments to try to build filaments.

The Joe Rogan Experience

#2217 - Brian Cox

103.527

No, there are bigger ones than that, but that's the scale of them. It's a big-ish one, that. But if you think about it, I mean, so there's a number. It's called the Schwarzschild radius of the thing.

The Joe Rogan Experience

#2217 - Brian Cox

10321.215

It's almost like a filament of space, a holographic filament of space that you're building from these qubits, which is just. And by the way, that word is a bit weird. It's just something like an electron. It's not that they're more complicated, but an electron would be an example of one. So it's a physical thing that we have in the lab. There is a quantum system that's a quantum bit.

The Joe Rogan Experience

#2217 - Brian Cox

10342.021

So you build it in the different ways of building them. And that's what a quantum computer is. But it's amazing, isn't it, that we're beginning to use those things not for computing yet because they're really hard to program. But we do. Physicists have gone, this is great because Google and Microsoft have spent billions of dollars building these things because they want to build these computers.

The Joe Rogan Experience

#2217 - Brian Cox

10361.027

But they're perfect laboratories for quantum mechanics. So you can do abstract research into quantum mechanics on them, which I find fascinating.

The Joe Rogan Experience

#2217 - Brian Cox

10375.775

Yeah, it's kind of, you know, factoring large numbers, it's kind of boring. But building wormholes, which is, and I caution, it's a complicated thing, but it looks like the beginnings of...

The Joe Rogan Experience

#2217 - Brian Cox

10427.999

So it's visualized to entangled particles in real time.

The Joe Rogan Experience

#2217 - Brian Cox

10437.836

Yeah, I mean, I hadn't seen that, but it looks to me like it's another example of trying to visualize. Entanglement looks fundamental. Let me put it that way. So it does look as if this idea of entanglement, which is, as I said, perhaps producing space and time itself,

The Joe Rogan Experience

#2217 - Brian Cox

10463.943

But also is the way that quantum computers work and the way that you – we didn't talk about this, but the way that you can – one way of picturing what this does is allow you access to multiple universes. It's the many worlds interpretation of quantum mechanics. You mentioned it, breaking people's encryption codes, right?

The Joe Rogan Experience

#2217 - Brian Cox

10482.578

What are you actually doing there? You've got an algorithm. You run a quantum computer. Yeah. And how does it factor these? What it's doing is finding the prime numbers that you multiply together to make a very big number. So it's very easy to multiply two big numbers together to get a really big number. It's very hard to take a very big number and factor it.

The Joe Rogan Experience

#2217 - Brian Cox

10505.788

So find out what the numbers were that got multiplied together to make it. That takes much longer than the current age of the universe for big numbers with any conceivable classical computer. But the quantum computer can do it in a second or something.

The Joe Rogan Experience

#2217 - Brian Cox

1051.622

Well, that's the thing. So we're starting to get hints about what might happen, which is leading us. So to backtrack a bit, why does this calculation Stephen did, why does it say there's no information in this radiation? The thing is, it's coming from the horizon. So there's loads of ways to think about it.

The Joe Rogan Experience

#2217 - Brian Cox

10526.187

But the explanation for how it's doing it, a picture, which many people in the field, not everyone, many people would say is the correct, is what it's doing is the calculations in multiple universes.

The Joe Rogan Experience

#2217 - Brian Cox

10537.685

So it's accessing the fact that actually there's an interpretation of quantum mechanics called the many worlds interpretation, where you're to imagine these, you know, infinite pretty much sea of universes. And the computer kind of goes and does the calculation in parallel and then brings them back together again at the end.

The Joe Rogan Experience

#2217 - Brian Cox

10557.73

And I mentioned David Deutsch earlier, who's a fascinating writer in this field and the instigator of many of these algorithms. early on, who would say that. He would say, this is what is happening. There is no other explanation. How do you explain the fact that this quantum computer can do something that no classical computer can ever do? How do you explain it? Where is it doing the math?

The Joe Rogan Experience

#2217 - Brian Cox

10584.581

And he would say, he would say, it's doing it in the multiple universes.

The Joe Rogan Experience

#2217 - Brian Cox

10591.847

Well, I don't fully understand that. I feel so much better.

The Joe Rogan Experience

#2217 - Brian Cox

10615.104

It is a photograph of, in a real sense, that the photons are arriving and you're detecting them. So it's a photograph of... So that's what it actually looks like. If you think about what, I think what must be happening is you're getting these photons. It is true to say that, again, this many worlds interpretation of quantum mechanics would be that these entangled photons...

The Joe Rogan Experience

#2217 - Brian Cox

10635.235

If you send them on a path, then they, going back to Feynman, if you calculate, the way you calculate how a photon goes from A to B or an electron, whatever it is, it just formally is you allow it to take all possible paths. That's one way of calculating the probability it will go from one place to another. And when you get entanglement, it gets more complicated.

The Joe Rogan Experience

#2217 - Brian Cox

10658.192

But you're essentially, you are mathematically saying I allow it to go on all paths. And so really there you're seeing what an interference pattern is, is you're seeing the result of the fact that these particles can go on all loads of paths and interfere with each other and make a pattern you can see. And I think that's what that is.

The Joe Rogan Experience

#2217 - Brian Cox

10682.635

It is beautiful, isn't it?

The Joe Rogan Experience

#2217 - Brian Cox

10695.906

I'm going to do some. Yeah, I've been doing this tour for a long time now, actually. I ended up doing it for about two and a half years, and it's changed a lot. We've done it to over 400,000 people, I was told, the other day around the world. Wow. And I thought just to finish it, because I want to finish it and write another one, I'd come back to the U.S. We did a few in the U.S.

The Joe Rogan Experience

#2217 - Brian Cox

10714.517

So coming back in April and May and doing these quite relatively small issues. I saw the one you did years ago. That was ages ago, wasn't it? Yeah. So this is, you know, it explores many of these questions, actually, particularly black holes. And just to round it off, I'm doing a few. So if you go and look on the web, you'll find some. We're doing some LA, New York, Chicago, around.

The Joe Rogan Experience

#2217 - Brian Cox

10734.263

I hope we do in Austin, actually. I hope you do in Austin.

The Joe Rogan Experience

#2217 - Brian Cox

10737.805

Yeah, please. If it's not in there, we couldn't do Austin. Please come. Yeah, so that's what I'm up to.

The Joe Rogan Experience

#2217 - Brian Cox

1076.929

But one way is that this weird place, this point of no return in space that you can fall through, but it's a point of no return. It sort of shakes. It almost disrupts the vacuum of space and sort of almost shakes particles out of the vacuum. That's one way of thinking about it. But this radiation is coming from the vacuum. It's coming from empty space.

The Joe Rogan Experience

#2217 - Brian Cox

1100.121

Whereas if you think about the thing that I throw in, if I throw this notepad into the thing, then that goes to the singularity. It's got nothing to do, the radiation's got nothing to do with this thing. This thing is not set on fire or something like that. It's gone to the end of time and just whatever's happened to it has happened to it.

The Joe Rogan Experience

#2217 - Brian Cox

1120.61

So this radiation has got nothing to do with having anything that falls in at first sight, at least. And so that was the paradox. It's called the black hole information paradox. One way to put it is the laws of nature that we use to calculate what happens tell us that information is never destroyed. And when you calculate what happens, it tells us that information is destroyed.

The Joe Rogan Experience

#2217 - Brian Cox

114.477

So if you took our sun, which you can fit a million Earths inside, and collapsed it down to make a black hole, it would form a black hole when it shrunk within a radius of three kilometers, about two miles. So you've got to take this thing, which is what I have to convert from kilometers to miles. That's okay. 700,000 kilometers. It's about 500,000 miles radius or something like that, the sun.

The Joe Rogan Experience

#2217 - Brian Cox

1143.445

So that's why everyone got interested in it in the 80s, because it's interesting.

The Joe Rogan Experience

#2217 - Brian Cox

1180.221

Yeah, something like that. There's occasionally a galaxy. I think one was discovered where we said maybe we can't see evidence of a black hole.

The Joe Rogan Experience

#2217 - Brian Cox

1210.918

Well... So I think I'm right in saying we don't fully understand why all galaxies, as you said, maybe there's an exception, but all galaxies have a black hole, a supermassive black hole in the center. It's obviously got something to do with the way they form. And one of the purposes, by the way, of the James Webb Space Telescope is to try to look at the formation of the first galaxies.

The Joe Rogan Experience

#2217 - Brian Cox

1237.883

So that's one of the reasons that telescope is up there. So it's cutting-edge research. We're trying to understand how the galaxies form. But clearly, you're right, that it has something to do with the way the galaxies form in the early universe. And it's pulling in stars. Well, they... They do pull in material. Right. But if you've got stuff orbiting around them, it stays orbiting around it. Oh.

The Joe Rogan Experience

#2217 - Brian Cox

1263.582

So the way we first detected the one in the Milky Way, because that image is very new that we have of it, is the stars orbiting it very close to it. They call the S stars that whiz around in these orbits very close to the black hole.

The Joe Rogan Experience

#2217 - Brian Cox

1285.64

It'd be so cool. I'd love to see one.

The Joe Rogan Experience

#2217 - Brian Cox

1293.909

Yeah, did you see it?

The Joe Rogan Experience

#2217 - Brian Cox

1304.439

Did you get this? Because I saw one in India. And I got this feeling that I was living on a ball of rock. Right. And it must have been just because the night just falls. Right. And suddenly you see the universe comes much more quickly. Yeah.

The Joe Rogan Experience

#2217 - Brian Cox

1385.416

Yeah, because, you know, these questions we have about our place. And as you said, it can be easy to be myopic, can't it? You said if you look at our screens, it's Earth that we think about at most. And most of us don't really think about Earth. You think about your country or your city or your town. Or your neighborhood. Yeah, even think about the Earth. But you're right.

The Joe Rogan Experience

#2217 - Brian Cox

139.079

So you squash it down until it's about two miles, and then that would form a black hole. Wow. Six billion times the mass of the sun means you multiply that by six billion. So these things, the so-called Schwarzschild radius is, I don't know, larger than our solar system, basically. Oh, my God. This thing that sits in a galaxy. So we've got these two photographs. Larger than our solar system.

The Joe Rogan Experience

#2217 - Brian Cox

1407.508

If you know, when you look at that arc of stars, and as you said, when you see it in a truly dark sky, it's powerful. It's incredible. 400 billion suns, give or take. 400,000 million suns. That's just words. You know what I'm saying? It's impossible to picture.

The Joe Rogan Experience

#2217 - Brian Cox

1432.056

It's so abstract. And most of them, I think the best guess would be all of them have planets. So pretty much. So you're talking about trillions of planets.

The Joe Rogan Experience

#2217 - Brian Cox

1452.754

No, I mean, the thing is, there's a thing called the Fermi paradox. Yes. Which I think we talked about before on the show. Yes. And the paradox is that if we haven't seen it, let's assume we haven't seen any evidence of anything. That's a paradox because, as I said, we now know. We didn't when Fermi first posed it, by the way. We now know there are so many planets out there.

The Joe Rogan Experience

#2217 - Brian Cox

1473.825

So let's say trillions of planets in the Milky Way. The Milky Way has been there for over 13 billion years, pretty much the age of the universe. Yes. So if there's no one else out there, then the question is why? Because there's been so much time and so many places for civilizations to become space-faring civilizations. Right. As Elon talks about, multi-planetary civilization.

The Joe Rogan Experience

#2217 - Brian Cox

1496.867

We're very close to becoming a multi-planetary civilization. And once you have become a multi-planetary and multi-stellar civilization, if you become that, you're immortal, basically, essentially. So the question is, the paradox is, why does it appear nobody has done that? So the first thing to say is, I would not be surprised if a UFO landed here now in the parking lot.

The Joe Rogan Experience

#2217 - Brian Cox

1522.641

I'd actually, not only would I not be surprised, I'd be relieved, actually. I'd be like... This is good because it would be a weight off my shoulders because I'm worried that we're the only ones. That's a terrifying scenario. And we're going to make a mess of it. Yeah. And so I'm worried that we could talk about that.

The Joe Rogan Experience

#2217 - Brian Cox

1576.636

So if you think about it, let's assume. So we didn't finish the UAP thing. Yeah, we'll get to that. So I don't know about that. But anyway, let's assume just for the purposes of this that we're the only ones in our galaxy, let's say.

The Joe Rogan Experience

#2217 - Brian Cox

1593.028

Then I would argue... So there's a question I ask in these live shows that I do. I start with a question which is kind of a joke in a way, which is what does it mean to live a finite, fragile life in an infinite, eternal universe? Which is a good question, right? That's what you're asking, right? What does it mean to live a finite life? The first thing to say is meaning, right? What does it mean?

The Joe Rogan Experience

#2217 - Brian Cox

1615.616

That doesn't sound like a scientific concept in a way. Meaning, right? Right. I would argue that whatever it is, it self-evidently exists because the universe means something to us. I would argue that it's a property of complex biological systems. So whatever it is, it's something that emerges, in this case, from human brains... It self-evidently exists.

The Joe Rogan Experience

#2217 - Brian Cox

163.954

Yeah, the event. So it's a big structure. Now, that's a Chandra X-ray image of... There it is. That's it. So that one there, that's the M87 black hole. So what you're seeing there is the emission from the material that's swirling around it. It's called the accretion disk. So you have material that's orbiting very fast, emitting a lot of radiation. And that's what you see.

The Joe Rogan Experience

#2217 - Brian Cox

1638.837

Everyone who's listening to this knows that the world means something to them. So I would argue that if this planet is the only planet in our galaxy where complex biological systems exist at our level, then it follows. It's the only place where meaning currently exists in a galaxy of 400 billion suns. And therefore...

The Joe Rogan Experience

#2217 - Brian Cox

1662.984

I would argue just for that very basic point that we have a tremendous responsibility in some sense. Because, by the way, I gave a talk, a little video thing at one of the climate summit, the COP climate summit in Glasgow in the UK a few years ago. And they asked me to do a little video to the world leaders. And I think they thought I'd say, you know, welcome to Glasgow, have a nice meeting.

The Joe Rogan Experience

#2217 - Brian Cox

1685.71

But I made this little argument as fast as I could. I said, it's possible, at least, that this is the only place where complex biology has emerged in our galaxy. If that's true, this is the only island of meaning in a galaxy of 400 billion suns. And you are responsible for it because you are the world leaders.

The Joe Rogan Experience

#2217 - Brian Cox

1702.644

Therefore, if you destroy it through deliberate action or inaction, then each of you would be personally responsible for destroying meaning in a galaxy of 400 billion suns, potentially forever. Now go and discuss that, was my intro to Glasgow. Now, we can all argue, because people will be listening to this going... Nonsense. How can it be? We can all argue about whether that's true.

The Joe Rogan Experience

#2217 - Brian Cox

1725.223

What I would say is, given that, as far as I'm aware, we don't have any good evidence to the contrary, which goes back to your previous question, it's a reasonable working assumption. So why don't we just operate on that basis? And then, you know, yeah, if someone lands tomorrow, as I said, I'd be very delighted because then what I just said would be false.

The Joe Rogan Experience

#2217 - Brian Cox

1746.491

And we could relax a bit and go, it doesn't really matter if we destroy ourselves to some extent. But so I think it's worth taking seriously the idea that civilizations are very rare. Now, and by the way, I used to say, so probably last time I was on, actually, I used to say that in the far future, then the complex life will cease to exist.

The Joe Rogan Experience

#2217 - Brian Cox

1770.901

So it probably doesn't matter on a global scale, but it matters locally because of this idea that meaning emerges from complex biological systems. So if you don't care about that, what do you care about? But actually, I read a book. Have you had David Deutsch on the show? David Deutsch is a really interesting physicist. I don't believe I have. He's one of the founders of quantum computing.

The Joe Rogan Experience

#2217 - Brian Cox

1790.613

And so he's a big figure in quantum computing in particular. But he's a great thinker. And I was reading some stuff he wrote recently. And he pointed out that it's not necessarily true that life is temporary. Because you could imagine a situation as you go into the far future. Let's imagine that we continue for a million years or a billion years as a civilization. Imagine what we could do.

The Joe Rogan Experience

#2217 - Brian Cox

1818.232

It is possible that life can get so advanced in the universe that it can start to manipulate the universe itself. Or at least stars. He said you could imagine, for example, just imagine. Wild speculation. But imagine life gets so advanced that it can start to change the destiny of a star. Maybe it could start to add material into the star or something, you know, whatever.

The Joe Rogan Experience

#2217 - Brian Cox

1843.467

So we don't know how to do that or if it's possible, but imagine it could. Then the evolution of stars... life would matter in the sense that it could start to change the way that the universe behaves on a large scale in the future. And so it reminded me, actually, there's another great book by John Barrow and Frank Tipler called The Anthropic Cosmological Principle from the 1980s.

The Joe Rogan Experience

#2217 - Brian Cox

1866.604

It's one of my favorite books, actually. And I remembered it. And in there, they speculate about this life in the far, far future. And if it became powerful enough to manipulate the whole universe or the observable universe, then suddenly you can't make predictions about the far future unless you consider the possible impact of life on the universe.

The Joe Rogan Experience

#2217 - Brian Cox

1888.355

And whilst this is, I should say, it's wildly speculative, but it's actually logically it's quite an interesting point. So I kind of disagree with myself a few years ago where I would have said that life is extremely valuable because it brings meaning to the universe, but temporarily. And so it brings these brief like flickering candles of meaning and then they go out again.

The Joe Rogan Experience

#2217 - Brian Cox

19.578

Exciting, I would say. I've been doing some work on black holes recently, which I hadn't started last time I saw you, actually. So I got interested in it. And the amount of the progress that's been made in trying to understand how they work. And a question that was posed by Stephen Hawking a long time ago, really 1970s, early 1980s, which is what happens to stuff that falls in?

The Joe Rogan Experience

#2217 - Brian Cox

1912.729

But it's worth considering. It might not necessarily be true that if you really think. I mean, just to say, I mean, it must sound to many people listening just nonsense, right? Science fiction. But if you think our civilization has been around for 10,000 years at best, really, give or take. And in that time, we've sent stuff out of the solar system.

The Joe Rogan Experience

#2217 - Brian Cox

193.828

It's a flat disk, by the way. So you think Saturn's rings. So this material is very flat. But what you're seeing in that photograph is the light rays being bent around the black hole from that flat disk. So that was a prediction from Einstein's theory, basically. He published it in 1915. And you can predict that that's what one should look like.

The Joe Rogan Experience

#2217 - Brian Cox

1936.313

Although we're way away from being able to manipulate stars, we can manipulate planets. So we are changing the way this planet operates. Life has changed it. The oxygen in the atmosphere, before we appeared, the oxygen in the atmosphere is a product of life. So life already... We know change is planets.

The Joe Rogan Experience

#2217 - Brian Cox

1957.221

And so I like that speculation that just possibly it's not just a temporary little phenomena that flickers in and out and then disappears again. It could have a real bearing on the future of the universe.

The Joe Rogan Experience

#2217 - Brian Cox

2126.991

I'm really interested in these kind of arguments. You put it really well, actually. It's fascinating, right?

The Joe Rogan Experience

#2217 - Brian Cox

215.942

And then just about, what was that, four years ago now, maybe five years ago, for the first time in history, we get an image of one. And it looks like the prediction. So it's a remarkable thing. How phenomenal is that?

The Joe Rogan Experience

#2217 - Brian Cox

2164.953

Well, exactly. And this is the point that David Deutsch made in the book I've just been reading and John Baron Frank Tifler made before that. Although it sounds insane, as you said, and that four billion years, there's a lot to say about that, by the way. Because for 3 billion plus years of that on this planet, it was just single cells.

The Joe Rogan Experience

#2217 - Brian Cox

2186.707

And so it's only in the last, let's say, a billion years, but actually a bit less, that we've had multicellular organisms. So three quarters of it at the time were just single celled. That's even crazier. Which is one of the reasons that many people think civilizations might be rare. Because the only evidence we have is this planet.

The Joe Rogan Experience

#2217 - Brian Cox

2208.526

And the evidence on this planet is that single-celled life is sort of the way that things are for most of the history. And then so it seems like an accident in a way that happened late on in the history of life on Earth that produced multicellular life. Now, is that typical? We don't know. Maybe it took a longer time here than it might do somewhere else.

The Joe Rogan Experience

#2217 - Brian Cox

2231.799

But if it's typical, I mean, 4 billion years, you said it's not a long time. It is a third of the age of the universe. So here... You put it that way, it's a long time. One third of the age of the universe to go from the origin of life to a civilization. And so what was required here on Earth was that that unbroken chain of life

The Joe Rogan Experience

#2217 - Brian Cox

2252.546

remained unbroken for a third of the age of the universe in a violent universe. We know there are impacts from space. Many stars are significantly more active than the sun. So the sun's kind of quite a boring little star that just ticks along. It's very nice to us. We're also on the edge of the galaxy, by the way. We're not close in. If you go into this region where that black hole is,

The Joe Rogan Experience

#2217 - Brian Cox

227.75

So we've had those two photographs. The other thing we've had is so-called gravitational wave detections. So these are colliding black holes, and they collide and merge together. And obviously that's quite a violent event in the universe. And so that event, that process ripples space-time. So it sends ripples out in the fabric of the universe, space and time.

The Joe Rogan Experience

#2217 - Brian Cox

2277.304

There are a lot of stars around. There are supernova explosions and all sorts of stuff going on. So it's violent in there. So maybe you can only get unbroken chains of life for billions of years on the outskirts of a galaxy. So there are fewer stars and planets out there. And maybe even then you need to be fortunate.

The Joe Rogan Experience

#2217 - Brian Cox

2299.206

The moon is big, and so it stabilizes the spin. So the spin axis, Mars, I think, if I'm right, I think the spin axis is wobbled around by something like 60 degrees or something over its history. Imagine that. Imagine Earth was – the pole was wobbling around and everything was falling over. You wouldn't imagine that complex life like us would emerge on a planet like that.

The Joe Rogan Experience

#2217 - Brian Cox

2383.207

Yeah, an evolutionary biologist would say the counter-argument. is that what life does, what evolution does, is produce organisms that are well-fit to their environment. They fit niches in the environment. But there's no drive to complexity. There's no law that says that the more complex you are, the more likely you are to survive and flourish.

The Joe Rogan Experience

#2217 - Brian Cox

2406.193

And the example of life on Earth probably backs that up. Biologically. Yes, three billion years of single cells. What that means is that the single-celled organisms were just doing very well. Right. And so it's not obvious. It's not a given that just because you suddenly get more complicated, you're better than the single-celled things. Right.

The Joe Rogan Experience

#2217 - Brian Cox

2431.101

Earth was almost that. Right. So you go back one billion years from now and Earth was that planet. So the interesting things that happened, photosynthesis, complex biochemistry. But as far as we can tell, nothing more complex than a single cell. So as most of the history of life on Earth. So that might suggest that that's the way that things are usually. And that this is an aberration.

The Joe Rogan Experience

#2217 - Brian Cox

2457.587

And again, emphasize we don't know. Right. But we've got one example. The other observation, though, it goes back to your first question. It is true that we do look sort of systematically for signals or evidence of civilizations out there. There's the Breakthrough Listen Project and there's SETI, as it's called. So we do. And we haven't seen anything, I would say.

The Joe Rogan Experience

#2217 - Brian Cox

2483.403

And I know that if you go onto the web and things on the internet, people say, we have, we've seen stuff, and I've seen stuff. But just the basic point, as far as I know, scientifically speaking, we haven't seen anything at all compelling. No. Basically nothing. Basically nothing. And so astronomers have a name for it. They call it the Great Silence. The great silence.

The Joe Rogan Experience

#2217 - Brian Cox

2507.961

And it's a tremendous mystery, as I said earlier. But it does seem that the universe is quiet, as far as we can tell.

The Joe Rogan Experience

#2217 - Brian Cox

252.811

And actually, Kip Thorne, I've spoken to him several times. He's one of the greats, right, won the Nobel Prize for this. And he calls it a storm in time. So you get a time storm. So really, we're to think, as we speak now, there will be these very tiny ripples from violent cosmic events passing through this room. And they're changing the rate that time passes as they go through.

The Joe Rogan Experience

#2217 - Brian Cox

2521.553

Yeah, there are different. So the counter arguments when we say we've seen nothing, therefore, as far as we can tell, there's nothing out there. You could say, well, what if the civilization that evolved is far ahead of us? What if the space probes are the size of an iPhone?

The Joe Rogan Experience

#2217 - Brian Cox

2541.008

Well, it's kind of a reasonable thing to say, actually.

The Joe Rogan Experience

#2217 - Brian Cox

2543.51

Because why would you not, if you can build a little thing, it's easier to send around the galaxy than a big thing.

The Joe Rogan Experience

#2217 - Brian Cox

2549.616

So why would you not, as you said, these hyper, ultra intelligent quantum computers, why would they not be tiny? Right. So you could say that. You could say, well, maybe they are. Maybe they're all over the solar system, but they're the size of phones and we wouldn't have seen them.

The Joe Rogan Experience

#2217 - Brian Cox

2563.729

Yeah. Okay. You would have to concede that. So we're just saying that the way that we've looked for energy signatures, for example, of civilizations, you tend to look for big things because that's all we can see. And we don't see any big things. We don't see any big structures. We don't see any evidence of spacecraft and all that kind of stuff.

The Joe Rogan Experience

#2217 - Brian Cox

2583.321

But I could make an argument that, well, why would the spacecraft be big? Right. Because as you said, it's another thing you said, actually. It's interesting that we're on the verge now of creating things, artificially intelligent things, which are smarter than us. So I think everyone agrees that we're on the verge of doing that. Artificial general intelligence.

The Joe Rogan Experience

#2217 - Brian Cox

2608.372

Some people might think it's further away than others. You probably had people on the show said it's five years away or two years away or 50 years away. But it's probably not 10,000 years away, right? So that which is the blink of an eye. Once you've done that, and once you've got those things...

The Joe Rogan Experience

#2217 - Brian Cox

2626.377

I find it hard to believe that if we get that far as a civilization, we won't begin to send those things out to the planets and ultimately to the stars. So we'll begin that process if we survive long enough. Sure. And it shouldn't be too much longer. Might be 100 years, might be 10,000 years, but we should do it. So it becomes a powerful question. Why does it appear that nobody's done that before?

The Joe Rogan Experience

#2217 - Brian Cox

2651.97

And my guess, in the absence of other evidence, would be biology. It's just that maybe the number of places where biology becomes complex enough to do that is on average one, maybe on average zero per galaxy. Maybe just civilizations are very, very, very rare in the universe. Maybe that's an answer. But that's a guess.

The Joe Rogan Experience

#2217 - Brian Cox

276.235

And we can detect that now. So we have detectors that can pick that up. And so we've seen those collisions as well.

The Joe Rogan Experience

#2217 - Brian Cox

2780.369

There's a lot of points in there. So you're right. What you're arguing, I suppose, is whether intelligence... is integral to the structure, the biological structure, or whether it is a separate thing. And I think, so again, I think the answer is it's not known. You could argue either way, but the counter argument would be The brain, these things, are just computers, ultimately.

The Joe Rogan Experience

#2217 - Brian Cox

2810.96

There's nothing magical in there. It is connected to a body, and so there are these sensations. But it doesn't seem to me impossible that a silicon-based life form or whatever it is, obviously it has sensors, it has access to the environment, it exists, it thinks. I don't see any fundamental difference between an intelligence,

The Joe Rogan Experience

#2217 - Brian Cox

2838.359

based on silicon, let's say, or a quantum computer or whatever it is, and this intelligence here. So I know that many researchers in this area do say that it's not a brain. They call it a brain in a jar, don't they? And say, well, that's not right. It needs to be connected to all this. This is part of our intelligence. And that's surely true as well. Sure. So it's a very good question.

The Joe Rogan Experience

#2217 - Brian Cox

284.497

Oh, millions of light years away.

The Joe Rogan Experience

#2217 - Brian Cox

2861.958

But I suppose if you say it's not obvious to me that a different kind of intelligence in a different structure running on a computer or whatever it is, would necessarily have different motivations to us.

The Joe Rogan Experience

#2217 - Brian Cox

2876.258

I mean, you could equally well argue that these motivations to survive and curiosity, those ideas, the desire to explore, you could argue those are fundamental properties of intelligence and not of biology.

The Joe Rogan Experience

#2217 - Brian Cox

288.32

Yeah, to a tiny extent. So there's an experiment called LIGO, which stands for something like gravitational interferometer. I can't remember exactly what the word is. So basically, it's laser beams. And there's one in Washington State, north of Seattle, and one in Louisiana. And they're laser beams, four-kilometer-long laser beams at right angles.

The Joe Rogan Experience

#2217 - Brian Cox

2984.559

It's a wonderful argument, isn't it, that our humanity... Because part of the thing that you described, this desire to create things and build things and explore and expand, is almost the definition of being human, isn't it? Yes. And so the idea that if you remove all threat and you essentially become immortal... Yes. then you're almost saying, what's the point? It's my T-shirt. It's existence.

The Joe Rogan Experience

#2217 - Brian Cox

3011.67

What does it matter, right? By the way, this T-shirt, I've got to say, was designed by a friend of mine, Peter Saville, who's a great designer who designed the Joy Division Unknown Pleasures album cover, amongst other things. Oh, wow. That's cool. That's a great shirt. It's a Joy Division.

The Joe Rogan Experience

#2217 - Brian Cox

3026.174

It probably is, but I'm not going to do that because it's vulgar, isn't it? No, no, no.

The Joe Rogan Experience

#2217 - Brian Cox

3030.596

That's why I asked. He made it for, we did these gigs, I talk about them later, called Symphonic Horizons, which were the, shows with cosmology, but also symphony orchestra. And he was exploring these issues, actually. But most of the music was Strauss's Zarathustra, which is based on Nietzsche's book. So it's kind of exploring these questions, actually, of what's the point of existence.

The Joe Rogan Experience

#2217 - Brian Cox

3053.124

And I do have some sympathy with that idea that A great deal of our humanity comes from our fragility. And so your question, I think, is fascinating. What happens when you become godlike? You said it earlier.

The Joe Rogan Experience

#2217 - Brian Cox

3066.212

If you acquire so much knowledge that you're essentially a god by any description and so much power and you become effectively immortal, which is what our descendants in the far future could be, as you said, these AI descendants. Right. What's the point of living?

The Joe Rogan Experience

#2217 - Brian Cox

312.197

And they can detect these very tiny shifts in the, effectively, you could say the length of the laser beam. It's a bit more fiddly and complicated. It essentially measures the distortion in space-time caused by these ripples. And it's way less than the diameter of an atomic nucleus, by the way. Way less. These little sort of... Oh, my God.

The Joe Rogan Experience

#2217 - Brian Cox

3232.055

I mean, I thought this a while ago. I remembered I was talking to someone and they said, yeah, I'm not worried about this. I'm not worried about the fact that AI could become more intelligent than us. What was it going to be like when we're not the smartest things on the planet? This might be just a few years.

The Joe Rogan Experience

#2217 - Brian Cox

3248.14

And I again, I might be quite relieved because I'm not sure they could fuck it up. The level that we are backing it up.

The Joe Rogan Experience

#2217 - Brian Cox

3327.919

Honestly, I've had the same thought. That's the utopian view. Yeah. And so I have thought, how could it be worse? In fact, it could be significantly better. Yeah.

The Joe Rogan Experience

#2217 - Brian Cox

334.397

And so we've started to... We've observed many of those... There it is. There's LIGO. So it's just basically two laser beams, that, but these ultra high precision thing. And so we've got data now of the collision of black holes and those event horizon pictures with radio telescopes. So that's part of it. But the main bit has been theoretical advances in understanding exactly...

The Joe Rogan Experience

#2217 - Brian Cox

3398.113

You can decide exactly... And as you said, the definition of what is best is a moral decision that we make.

The Joe Rogan Experience

#2217 - Brian Cox

3442.765

Well, that's one of the arguments. I spoke to Robert Zubrin, who wrote these wonderful books about colonizing space. And so he's a fascinating character. And I spoke to him once, and he made this very simple argument that, as you said, one of the problems we have is competition for resources. And of course, the competition for resources is now so extreme that it's not only wars that

The Joe Rogan Experience

#2217 - Brian Cox

3466.88

that it creates and always has. But it's also, of course, we damage the planet if we over-exploit the resources and so on, right? So you've got this problem about resources. And he's right. He would say this is the number one motivation for going up because there are, in fact, infinite resources out there. And so once you begin to have access to the asteroids and access to Mars and beyond...

The Joe Rogan Experience

#2217 - Brian Cox

3492.463

You can imagine a world where you alleviate that pressure.

The Joe Rogan Experience

#2217 - Brian Cox

3512.205

Yeah, and I think it's Neptune or Uranus that we think has diamonds in it. Oh, my goodness.

The Joe Rogan Experience

#2217 - Brian Cox

3527.036

They're good for drill bits as well. But we can make them for jewelry.

The Joe Rogan Experience

#2217 - Brian Cox

3536.148

No, they want the real ones.

The Joe Rogan Experience

#2217 - Brian Cox

3539.352

It's the way that we value things. Gold. Yes. Gold is another example, right? It's valuable because there isn't very much of it.

The Joe Rogan Experience

#2217 - Brian Cox

3547.64

Yeah. A football field of gold in the whole world. You know, by the way, that we were talking about the gravitational wave detectors earlier and the collision between black holes that we detect with them. We also detected a collision between neutron stars using the gravitational wave detector. And we pointed optical telescopes at that collision and saw the signature of gold being manufactured.

The Joe Rogan Experience

#2217 - Brian Cox

3570.567

And it was always a question. We used to just think, well, it comes from supernova explosions. But it also seems now that it comes from the collision between neutron stars. So one of the reasons that it's very rare is because it takes rare processes in the universe to actually make it. Which makes it all the more wonderful when you think about it.

The Joe Rogan Experience

#2217 - Brian Cox

3589.646

If you look at the gold, your wedding ring or your watch or whatever it is, some of those nuclei, some of those elements clearly came from the collision between neutron stars at some point before our solar system was formed, which makes it more wonderful.

The Joe Rogan Experience

#2217 - Brian Cox

3609.721

Yeah, as Carl Sagan said, star stuff.

The Joe Rogan Experience

#2217 - Brian Cox

361.103

In a sense, it was what's wrong with Stephen Hawking's calculation, which is a weird thing to say sometimes because people think Stephen Hawking, sure, he didn't get his math wrong. But he did actually. So what he calculated back in 1973, 1974. is that a black hole, so we picture this thing from which nothing can escape, even light. So when you go in, you're gone, basically.

The Joe Rogan Experience

#2217 - Brian Cox

3617.417

It's a remarkable thing. I want to go back to something you said actually about the – I've been thinking about this. You said this godlike intelligence that we might create. And kind of what's the point? What would be the point of existence if you were immortal and you knew everything? Wouldn't it be incredibly dull? Well, you said it's almost like a meditative state.

The Joe Rogan Experience

#2217 - Brian Cox

3643.904

So we strive for this peace, you know, essentially.

The Joe Rogan Experience

#2217 - Brian Cox

3800.988

So you've already achieved nirvana then. You don't need to go any further. It's fascinating.

The Joe Rogan Experience

#2217 - Brian Cox

3808.333

I would argue, I think, imagine that you had access to, as you said, essentially infinite knowledge. Imagine you're one of these beings in the future. Maybe the things that we created that essentially know almost everything there is to know in some sense. Right. I think that they would feel there was no point in existing at all.

The Joe Rogan Experience

#2217 - Brian Cox

384.759

What he calculated is that even though these things are just a distortion in space and time, that's the description of them. So it's almost as if there's nothing there apart from a distortion in space and time. He calculated that they glow, so they have a temperature of... So they emit radiation. It's called Hawking radiation. And so important was that discovery.

The Joe Rogan Experience

#2217 - Brian Cox

3915.769

If you think about some of the things that make us... The most important things that make us human so one of them would be hope for example right for the future or indeed Fear or that those emotions that are connected with not knowing Not knowing what's around the next corner as you said even exploration, right? So if you remove that if you remove

The Joe Rogan Experience

#2217 - Brian Cox

3942.742

any sense of not knowing what the future will be, you do remove hope as well as fear. So you could argue that some of the best, the essence of being human, some of the things that we value the most and make us most valuable in the universe in this sense, some of those things come from incomplete knowledge. I mean, surely hope does.

The Joe Rogan Experience

#2217 - Brian Cox

3964.77

How could you have hope and excitement about what's going to happen tomorrow if you know

The Joe Rogan Experience

#2217 - Brian Cox

3979.298

It's like you said when you're growing up, you said like, you know, when you're in high school or when you're young, Christmas, for example. Right. You know when you're at Christmas Eve?

The Joe Rogan Experience

#2217 - Brian Cox

3986.523

And you go, what am I going to get tomorrow? Yeah. It's one of the most wonderful feelings, isn't it? One of the most wonderful, like, oh, God, in the presence of God. That's incredible. None of that would exist if you were one of these super beings. Right. But that's just for us.

The Joe Rogan Experience

#2217 - Brian Cox

4037.379

I think what I'm getting to, is it purely biological?

The Joe Rogan Experience

#2217 - Brian Cox

4043.445

But it's only us. Or is it just a property of intelligence? I mean, you're arguing, and it's a good argument, that many of these desires come from our biological fragility. Yes. And also the fragility of our planet, as you said. But it could be. that these ideas of meaning, of what it means to exist, of what is the point of existence, maybe that's a general prophecy of any intelligent system.

The Joe Rogan Experience

#2217 - Brian Cox

4076.291

Well, it seems like it's imperative for survival.

The Joe Rogan Experience

#2217 - Brian Cox

408.671

If you go to Westminster Abbey in London, look on the floor of the abbey on his memorial stone, and he's in there next to Newton and Shakespeare and all these people, and he's there. And chiseled in stone on the floor of Westminster Abbey is his equation for the temperature of a black hole. So it was this tremendously important discovery.

The Joe Rogan Experience

#2217 - Brian Cox

4095.325

Is there such a thing as... contentment, though, for anyone.

The Joe Rogan Experience

#2217 - Brian Cox

4118.039

So that's what I'm kind of interested that God... A godlike being might be so bored and so devoid of all excitement because those things like hope and curiosity. Curiosity is one of the most foundational things. It's one of the most incredible. We both share that idea.

The Joe Rogan Experience

#2217 - Brian Cox

4138.723

So if you know... So much. Right. Maybe what happens in a world where your curiosity is not there. You've got nothing to be curious about. Wouldn't that be horrendous?

The Joe Rogan Experience

#2217 - Brian Cox

4173.822

You linked hope to anxiety. Is that right?

The Joe Rogan Experience

#2217 - Brian Cox

4179.705

I hope.

The Joe Rogan Experience

#2217 - Brian Cox

4186.069

I have hope. I think I was using it in a different way, though. I was imagining hope as like, I don't know, excitement for what's beyond the horizon. Sure. So not driven by... This actually gets to the heart of what I think a scientist is, by the way, the difference between not only a scientist, but let's say, what is a scientist? Or somebody just researching anything, really.

The Joe Rogan Experience

#2217 - Brian Cox

4209.99

Somebody who creates things. They're people who like to stand on the edge of the known. So they find it exhilarating but interesting. Almost in the context we're talking, it's almost one of the things that drives our existence. Yes. Is to stand on the edge of the known and peer into the unknown with excitement and curiosity because you can go over the horizon.

The Joe Rogan Experience

#2217 - Brian Cox

4234.013

And so that's the sense in which I'm using these terms. I'm saying that's one of the fundamentally most valuable things of being human. Yes. That there is an edge of the known. Yes. And so I would find it, I think, more terrifying to imagine that there was no edge of the known. that everything was known, then I would think existence is pointless. I personally would not find that.

The Joe Rogan Experience

#2217 - Brian Cox

4260.383

I wouldn't think I'd achieved nirvana. I would think there's no point.

The Joe Rogan Experience

#2217 - Brian Cox

427.996

So he discovers these things glow, and he calculates how they glow. They're very low temperature, but they emit things, which means that they shrink because they're emitting stuff, and so they're shrinking. So that means they have a lifetime. So first of all, one day they'll be gone. So that means that you have to address this question of what happened to all the stuff that fell in.

The Joe Rogan Experience

#2217 - Brian Cox

4346.892

I think we're trying to imagine what it's like to be God, aren't we?

The Joe Rogan Experience

#2217 - Brian Cox

4453.902

I mean, it is in some technical sense. It has to be.

The Joe Rogan Experience

#2217 - Brian Cox

4457.164

The universe is everything, including God, if God is a real thing. If you define God as the creator, then you're right. From some point that we don't understand, by the way, the Big Bang, we don't even understand whether that was the origin of the universe, by the way. We understand that something interesting happened. What is Sir Roger Penrose's... He has an infinite cyclical universe. Yes.

The Joe Rogan Experience

#2217 - Brian Cox

4479.755

And he's trying to answer... Questions about the very special state of the early universe and why it was the way that it was.

The Joe Rogan Experience

#2217 - Brian Cox

449.74

And his calculation said that there's no record at all of anything that fell in, in all this radiation that's come off the black hole. So it's purely information-less radiation. So what that means is that black holes destroy information, according to that calculation. And that's a big deal because nowhere else in all of physics does anything erase information from the universe.

The Joe Rogan Experience

#2217 - Brian Cox

4491.961

It doesn't recontract. It's called, what's it called, conformal cosmology or cyclical conformal cosmology or something. So it's essentially that... And I don't fully understand it. And I have asked him about it with some colleagues, actually. If you can't understand it, we're fucked. No, I don't think many of us understand what he... I mean, Roger Penner is one of the greats, right?

The Joe Rogan Experience

#2217 - Brian Cox

4515.82

So you listen to him and take him very seriously. But I haven't met anyone who quite understands what he's talking about in that. But... But it doesn't recontract. It's not one of those models where the universe expands and then recontracts and bounces like that. It's not one of those.

The Joe Rogan Experience

#2217 - Brian Cox

4532.731

It's somehow, he argues, that when you get to what we usually call the heat death of the universe, where even the black holes have evaporated away. you have conditions that begin to look perhaps like an origin of the universe again. And I can't really fully explain it because I don't really understand what he's trying to say, right?

The Joe Rogan Experience

#2217 - Brian Cox

4563.667

Yeah, it kind of looks like conformal means there are no...

The Joe Rogan Experience

#2217 - Brian Cox

4568.69

sort of distances or time measurements or anything in the universe it kind of loses all sense of scale and then you could you could reimagine that as looking somewhat like the beginning it's something like that that he has in mind but i really couldn't explain to you i don't understand what what he's what he's proposing wow so it but what it does tell you is that we don't know

The Joe Rogan Experience

#2217 - Brian Cox

4595.558

why or how the universe got into the state that we call the big bang so we don't we don't know whether the universe existed before that we have theories that it did theories called inflation which are very popular theories you'll find up in all the textbooks which say that before the universe was hot and dense which we used to call the big bang space and time is still there

The Joe Rogan Experience

#2217 - Brian Cox

46.459

The simplest question you could possibly ask. Right. There's progress being made on that now, which I think is profound and exciting.

The Joe Rogan Experience

#2217 - Brian Cox

4619.893

And the universe is expanding extremely fast. It's called inflation. And then that period draws to a close. And that expansion slows down and almost collapses and changes. And the energy that was driving the expansion gets dumped into space and changes and ultimately makes the particles out of which we are made. So that's actually the standard model of cosmology now.

The Joe Rogan Experience

#2217 - Brian Cox

4644.705

So we do have an idea that we redefine the Big Bang as the hot Big Bang. And it's not the origin of the universe in time. It's the end of inflation. And then you get the question, what is inflation? Did that have a beginning? And the answer is that in Einstein's theory alone, then yes.

The Joe Rogan Experience

#2217 - Brian Cox

4664.727

And Roger Penrose actually and Stephen Hawking proved this a long time ago, that just given Einstein's theory, you have this singularity, just like kind of like the black hole singularity, but at the beginning of time. But we do know that when you put quantum mechanics in and add that in, then it gets messy and we don't really know what that means.

The Joe Rogan Experience

#2217 - Brian Cox

4684.983

And so Stephen Hawking had a thing called the no boundary proposal. Basically the point is we don't know. So we don't know whether the universe had a beginning in time, I would say is the correct statement as we are at the moment. Part of the reason why, by the way, getting back to the black holes, they're important and interesting.

The Joe Rogan Experience

#2217 - Brian Cox

4704.657

Because the study of black holes and this idea of information and how does it get out, that's leading us to suspect that space and time themselves are not fundamental, but they emerge from something else. So just in the way that we've been talking about consciousness. emerging from this physical structure in our heads.

The Joe Rogan Experience

#2217 - Brian Cox

4725.085

So we don't know how it emerges, it's a very strange thing, but it emerges from this collection of atoms in a particular pattern. Well, we think now, from the study of black holes, that space and time emerge from something else, which is kind of... One way to describe it is just a quantum theory. So in quantum computing terms, it would be just qubits

The Joe Rogan Experience

#2217 - Brian Cox

4749.079

So a network of qubits entangled together, just like a quantum computer. Out of that, we suspect that space and time might emerge. So surely we have to understand that process, and we don't really fully understand that, but we have glimpses of it in much more detail to start talking about the origin of time. Because in order to talk about the origin of time, you have to know what it is.

The Joe Rogan Experience

#2217 - Brian Cox

476.415

So it's really true that if I got this notepad and pen, right, and I wrote some things on it, and then I set fire to this, even just incinerated it, put it in a nuclear explosion, whatever. In principle, according to all the laws of nature that we know, if you collected everything that came off, all the radiation, all the bits of ashes and things,

The Joe Rogan Experience

#2217 - Brian Cox

4772.495

And we don't actually know what it is, which is, you know, and that's kind of when you say that it sounds bizarre, doesn't it? Well, how can you not know what time is? I think Einstein once said that it is the thing that you measure on a watch. But he said that as kind of almost a joke, because you assume in Einstein's theory, there's a thing that the watch measures.

The Joe Rogan Experience

#2217 - Brian Cox

4792.953

But what actually it is at the deepest level is a good question. But it's interesting the study of black holes is forcing us towards these theories. It's not that we had the theories face and time emerging from something and decided we could check it by thinking about black holes. It's come the other way around, really. So it's interesting. But that almost makes...

The Joe Rogan Experience

#2217 - Brian Cox

4817.731

the universe look in some ways like a giant quantum computer, which is not to say that we live in a simulation, before you ask. But it just looks like there's a description of the universe that looks like a quantum computer type description. That doesn't have the concept of space or time in it.

The Joe Rogan Experience

#2217 - Brian Cox

4871.079

It is. It's interesting that you're right. And that's a good way of phrasing it. It mimics or looks like a network of qubits. So it looks like some kind of quantum computing description is available to us, to the universe. But I don't think you can infer much from that. I mean, it just passes the question further back.

The Joe Rogan Experience

#2217 - Brian Cox

4894.25

As I said, we have never understood what it means for the universe to have a beginning. So we don't really know that. And so this is the same. I think it's just the same question. It's like, well, you ask, well... If it really is a network of qubits, it could have been there forever, that network of qubits. Actually, in quantum theory, it's more natural for it to be just eternal.

The Joe Rogan Experience

#2217 - Brian Cox

4917.527

And it's an interesting question. I once gave a talk, actually, a conference of bishops. They were Catholic bishops. And they asked me to go and give a talk at their conference about cosmology. And so I gave the talk about cosmology, and they all listened. And we had a question thing afterwards. And I said to them, What happens if we discover the universe has always existed? Because it might have.

The Joe Rogan Experience

#2217 - Brian Cox

4939.519

We know there's a thing called the Big Bang, but it might have been something that happened in a pre-existing universe. Maybe that's eternal. What does that mean for your sort of picture of a creator? Does it? I don't know. I was asking it. It's a genuine question. Right. How would you? And they really didn't. They thought it was a cool question and didn't have an answer. Right. But it but it is.

The Joe Rogan Experience

#2217 - Brian Cox

4962.094

I think the idea that I was the question to you, actually, are we more comfortable with the universe that began or would we be more comfortable with the universe that had always existed?

The Joe Rogan Experience

#2217 - Brian Cox

497.548

and you could just measure it all, then just in principle, the idea is you could reconstruct the information. So it all gets scrambled up and thrown out. And so in practice, you can't do it. But just in principle, the laws of nature say that information is not destroyed. It's just scrambled up in a way that you can't reconstruct.

The Joe Rogan Experience

#2217 - Brian Cox

5042.534

And you're right. You've had Sean Carroll on the show. He always points out that this question, why is there something rather than nothing, presupposes that nothing is more likely than something.

The Joe Rogan Experience

#2217 - Brian Cox

5057.523

Whereas it might be the other way around. Right, right. We don't even know that. Right.

The Joe Rogan Experience

#2217 - Brian Cox

5063.304

That's the big one. The history, I think historically, you have, I think it's right to say that Einstein really felt, I think, that initially that an eternal universe was more natural. But it is also true to say that his theory, general relativity, really doesn't quite rule that out. But it's strongly suggestive of there being a beginning and or an end.

The Joe Rogan Experience

#2217 - Brian Cox

5089.35

So the theory itself, historically speaking, strongly suggests that. And so he changed his mind. And then we saw the universe was expanding. We observed that. And then we've now seen the oldest light in the universe, the cosmic microwave background radiation, which is the afterglow of the Big Bang. So we know that the universe was hot and dense 13.8 billion years ago.

The Joe Rogan Experience

#2217 - Brian Cox

5110.357

We have so much evidence for that, not least that we have a photograph of it 380,000 years after the Big Bang. It's called the cosmic microwave background radiation. Let's see that images of that. That's from the satellite called Planck, a European satellite and also satellite called COBE. So we have these images of the afterglow of the Big Bang.

The Joe Rogan Experience

#2217 - Brian Cox

5127.929

We also have theories that tell us about the abundance of chemical elements in the universe which match this perfectly. So there's multiple lines of evidence that tell us the universe was hot and dense. But none of that tells us that that was the beginning. I think that would be widely accepted. It's a beginning in Einstein's theory.

The Joe Rogan Experience

#2217 - Brian Cox

5148.982

If you just take general relativity, there's a singularity there at the beginning of time. We don't know what it is, but it's there. But it absolutely is true to say that we think that's not complete as a picture. So there it is. So that is light that was emitted about 380,000 years after the Big Bang.

The Joe Rogan Experience

#2217 - Brian Cox

517.333

But this calculation that Stephen did said there is no information in that radiation at all. Zero, just nothing. So it seemed that uniquely in the universe, black holes erase information.

The Joe Rogan Experience

#2217 - Brian Cox

5170.233

And the key thing, there's so many things to say about these images, but one thing is those colours. correspond to regions of very slightly different density that we detected now in the gases of the young universe.

The Joe Rogan Experience

#2217 - Brian Cox

5185.408

Yeah, the reds and blues, all those as well. They're both the same. So that greeny one, well, either that one or the one with the greeny blue, that one, that's from the Planck satellite. So those colors correspond to regions of different density.

The Joe Rogan Experience

#2217 - Brian Cox

5201.839

So in this young universe, 380,000 years after the Big Bang, that's only hydrogen and helium gas, basically, and a bit of lithium, some of the lighter elements, but basically hydrogen and helium. So you've got an almost smooth, almost featureless universe then. But these little density fluctuations are very important because as the universe expanded and cooled, they collapsed to form the galaxies.

The Joe Rogan Experience

#2217 - Brian Cox

5229.818

So without those ripples, without that pattern, we would not exist. Nothing of interest would exist. And so the question is, where did that come from, that pattern? It's fundamentally important.

The Joe Rogan Experience

#2217 - Brian Cox

5242.984

and the theory of inflation that i mentioned earlier that there's this time before the universe got hot and dense that theory predicted that pattern before it was observed so this idea that you've got this very stretch very quickly stretching space by the way so it's so the stretch if i can remember the number is if you consider two points in space during inflation the distance between them was doubling

The Joe Rogan Experience

#2217 - Brian Cox

5269.813

every 10 to the minus 37 seconds, which is 0.0000000000. So it's incredible rate of expansion that draws to a close. And those theories... So there's inflation there. So those theories... predicted slight variations in the rate at which inflation stops.

The Joe Rogan Experience

#2217 - Brian Cox

5303.118

I mean, it is. He doesn't like inflation as a theory. He doesn't? Oh, no. So our universe is accelerating in its expansion at the moment, which is one of the great mysteries that was discovered in the 1990s by a friend of mine, actually. Brian Schmidt got the Nobel Prize for this discovery.

The Joe Rogan Experience

#2217 - Brian Cox

5325.377

He told me once, I don't know if I told you the story before, but he told me that he'd made this measurement and it wasn't really, he was looking at supernova explosions. And he'd seen that the suggestion in the data was that the universe is accelerating in its expansion, not slowing down, but speeding up. in its rate of expansion. And no one was expecting it, so he thought it was just wrong.

The Joe Rogan Experience

#2217 - Brian Cox

5349.268

But he couldn't find anything wrong with his data. So he published it and thought, well, that's the end of my career. Oh, boy. He was quite young. I think he might have even been a postdoc, and he just published it. That's a good scientist, right? I don't think this is right, but I can't see anything wrong with it. I'll publish it. Someone else will tell me where my mistake was.

The Joe Rogan Experience

#2217 - Brian Cox

5366.761

And there was no mistake, and he won the Nobel Prize for that discovery. That's the 1990s. So this idea of the universe is accelerating in its expansion. The way that it does that is really important. Is it going to carry on doing that? Is whatever's driving that expansion going to change in some way, which could actually re-collapse the universe again?

The Joe Rogan Experience

#2217 - Brian Cox

5388.81

We give it a name, by the way, dark energy, this thing. But we don't know what it is. I think it's very fair to say. But it looks a bit like inflation, but it's way slower. So maybe they're linked. Maybe it's the same kind of thing. We don't really know. And so it's one of the great mysteries.

The Joe Rogan Experience

#2217 - Brian Cox

5406.198

But the universe, it looks like the universe is going to continue to expand forever and to continue to accelerate.

The Joe Rogan Experience

#2217 - Brian Cox

5415.919

Yeah, dark matter's in some sense marginally less confusing in the sense that at least we have an idea of what it might be. Whereas dark energy, there are people listening to it, there are people working on it, so there are theories about what it might be. But I think it feels less explicable, given what we know, than dark matter.

The Joe Rogan Experience

#2217 - Brian Cox

5437.976

But we haven't discovered what... We think dark matter might be some kind of particle. that has got certain properties and doesn't interact very strongly. It interacts like neutrinos, basically, that you mentioned earlier. So it really doesn't interact very strongly. But we thought we might have seen those particles. We're looking for them.

The Joe Rogan Experience

#2217 - Brian Cox

5457.369

They would be passing through this room now, and so we could build a detector in here, and we do that, and we look for these particles. We haven't seen them. We thought we might make them at the Large Hadron Collider at CERN. I think many people thought that we'd see the signature of these things, and we haven't done. So it could be that we're not right with that picture.

The Joe Rogan Experience

#2217 - Brian Cox

5479.668

So, yes, it's about 5% matter, about 70% dark energy, and the rest, so 25% dark matter. So we're just less than 5% this. That's crazy. And stuff we can see. So everything we can see in the sky, all the gas and the dust and the galaxies and the stars and the black holes, all those things, less than 5%. According to the standard model of cosmology.

The Joe Rogan Experience

#2217 - Brian Cox

5512.572

Yeah. Wow. But those are models. I mean, it's important to say that it's interesting because until... So we have a hypothesis, which is strongly supported by lots of bits of evidence, that dark matter is some kind of particle. So that's the broadly, that's what you find in the textbooks. But it's true that until you find it, until you see it, then you haven't shown it to be correct.

The Joe Rogan Experience

#2217 - Brian Cox

5539.669

Are there alternative theories? There are. Are they compelling? No, they all have problems. And most of them have problems with that pattern, the CMB, the cosmic microwave background that we just saw. Because that pattern, what you're looking at actually in that pattern is acoustic, it's waves, sound waves essentially in the early universe that go through the plasma of the early universe.

The Joe Rogan Experience

#2217 - Brian Cox

5564.84

And they go out and we know what speed they go through that plasma. So it's almost like you're looking at a pond and you're throwing stones into the pond. And they all land in the pond at the same time and send ripples out, little circular ripples in the pond. And they all overlap. And that's what that pattern is. So we're looking at sound waves going through this plasma. And those theories...

The Joe Rogan Experience

#2217 - Brian Cox

5589.827

uh require the dark matter the dark matter fits well if it's in there in in this plasma in this kind of soup that this subatomic particle soup that's the early universe and the way the sound waves go through it fit that idea so that's one thing but the the the idea also came from looking at galaxies and how they rotate and galaxies and how they bend light and and

The Joe Rogan Experience

#2217 - Brian Cox

5614.407

And deform space and time and how they interact together. So there's loads of different bits of information, observations of the universe from the cosmic microwave background all the way through to galaxies and the formation of galaxies and the theories that we have there that suggest there are these particles around that interact very weakly with light.

The Joe Rogan Experience

#2217 - Brian Cox

5634.036

So they don't really interact with light at all, which is why we don't see them, which is why they're dark. That's just like a neutrino, right? So like heavy neutrinos. And actually there was a theory once that maybe they were heavy neutrinos, but that's kind of disfavored now. And so we have loads of kind of different bits that fit. This is how you do science.

The Joe Rogan Experience

#2217 - Brian Cox

5654.352

You start with a theory and you make a load of observations and you can infer things and you get a consistent picture. But... very importantly, until you find it, until you really find that particle, then you don't know, right? So that's a good question.

The Joe Rogan Experience

#2217 - Brian Cox

5680.131

Yeah. And we've inferred it. So you might say, how do you know it's there? You know, which is a good question, right? I mean, if we have not detected this stuff, how do you know? And it's from Einstein's theory, really. So it's from gravity. It's from looking at the way that galaxies rotate and the way that these sound waves move through the early universe and the way that the universe expands.

The Joe Rogan Experience

#2217 - Brian Cox

5703.881

Because the way the universe expands is related to the stuff that's in the universe. So we can weigh the universe and find out what kind of different things are in there by looking at the way it's expanded and how that expansion history has changed over time. So what you do with science, which is why it's true that you can criticize any one bit of it, and people will.

The Joe Rogan Experience

#2217 - Brian Cox

5729.591

So online you'll see in the comments under this, there'll be people saying, what about this, what about this, what about this? And it's true that you can pluck away and pick away any piece of it. But the way it tends to work is when you have this kind of consensus view of something, it's because you have multiple observations that all fit a particular hypothesis.

The Joe Rogan Experience

#2217 - Brian Cox

5750.424

And by changing one of them, by changing the explanation of one of them, you tend to mess the whole other thing up. You mess the wider description of multiple phenomena up. You mess it all up. So it's quite hard to find other theories at the moment that will fit all of those different observations. I mean, another example would be the age of things.

The Joe Rogan Experience

#2217 - Brian Cox

5775.977

It's interesting that you can look at, we can measure the age of the Earth, right? And you measure it from geological processes, radioactive dating and so on, and you can kind of measure the age of the Earth. You can measure the age of the sun in a different way. You can measure it by looking at what's called helioseismology. So you can measure how much helium is in the core of the sun.

The Joe Rogan Experience

#2217 - Brian Cox

5797.467

And the sun shines by making helium from hydrogen. So by measuring the amount of helium in the core, by looking at basically sound waves, it's like an earthquake that sunquakes. You can measure how much helium is in there so you can get an estimate of the age of the sun. And then you can get an estimate of the age of the universe by measuring how it's expanding and using Einstein's theory.

The Joe Rogan Experience

#2217 - Brian Cox

5816.941

The fact that they all fit with the picture of a universe that's 13.8 billion years old, a sun that's 4.5 billion years old, a planet that's 4.5 billion years old, the fact that it all fits is quite an intricate model. And so you could say, well, I argue with the measurements of the age of the Earth. Maybe I don't like the radioactive dating or something, and people will say that.

The Joe Rogan Experience

#2217 - Brian Cox

5844.401

But the thing is, it's a consistent picture with multiple different observations. And same with dark matter. So the standard model of cosmology is you have, as I said, about 5% matter, 25% dark matter, 70% dark energy. It might be wrong, but it fits loads of different independent observations. So it's a consistent picture.

The Joe Rogan Experience

#2217 - Brian Cox

5881.238

There are theories that people try to build where you modify our theory of gravity. So many of these observations, not all of them, so the cosmic microwave background are different observations, but many of them depend on gravity and how gravity works, Einstein's theory of general relativity. So you could try to modify that theory to say, well, our observation's wrong.

The Joe Rogan Experience

#2217 - Brian Cox

59.852

I mean, it's mainly theoretical, although we have now got photographs of them. So we have two photographs, which are radio telescope photographs. One of the one in the center of our galaxy, which is a little one. It's called Sagittarius A star. It's a little supermassive black hole. So it's about 6 million times the mass of the sun, which makes it a little supermassive.

The Joe Rogan Experience

#2217 - Brian Cox

5907.261

Maybe, because the way we measure how the expansion of the universe is, is to look at light from supernovae is one way, and see how it's stretched over time. Because the light, let's say you have a supernova, and it happened a billion years ago, then the light has been traveling for a billion years across the universe.

The Joe Rogan Experience

#2217 - Brian Cox

5924.952

And so the universe has been expanding for a billion years, so the light will be stretched. And so you can measure how much stretch there is. You just measure the color of the light from the supernova. So you can argue that maybe if you go for light that's been traveling 12 billion years across the universe, then maybe there was something different. Maybe the light was emitted a bit different.

The Joe Rogan Experience

#2217 - Brian Cox

5947.902

Maybe the speed of light changes over time or something. So you can invent theories that would allow you to change the data or the interpretation of the data. But what you always find, I think it would be fair to say, is that you can change a theory and explain one bit, but all the wheels come off the other bits. Got it. So that's why it's quite difficult.

The Joe Rogan Experience

#2217 - Brian Cox

5976.008

Yeah. So it fits. Yeah. But then there are some mysteries. Not least, what is this stuff? Right. And so until you know what it is, you don't have a complete theory.

The Joe Rogan Experience

#2217 - Brian Cox

5991.332

Yeah. Yeah. And so that's what I love about. One of the things I love about science is it often gets presented, you know, because I talk about science a lot in public and it can often seem arrogant. I think it can seem, you know, like these people are saying, well, this is the way the world is. And you might say, well, you know, how are you to say this?

The Joe Rogan Experience

#2217 - Brian Cox

6012.56

The thing I like about it, personally, and the reason for its success, is that really you have to be delighted when you're wrong. It's the key to science. It's been said many times, Richard Feynman, the great physicist, said it. If your goal is to understand nature, so that's what you want to do, So you've not got an ego or anything. You don't want to prove right. You just want to understand.

The Joe Rogan Experience

#2217 - Brian Cox

6043.559

Then being wrong. So if this idea of dark energy and dark matter turns out to be wrong, all scientists or good scientists will be absolutely delighted because it'd be tremendously exciting that we'd ruled out this picture. It'd be great to rule out this picture. So there isn't such a thing as dark matter. And dark energy. It's all nonsense.

The Joe Rogan Experience

#2217 - Brian Cox

6065.118

We were barking up the wrong tree, looking in the wrong direction. It's something else, which should be more wonderful, undoubtedly, than that theory that we have. So I think it's a humble pursuit, ultimately, science. And that's the reason for its success, because you're just trying to understand how things work. You're not trying to, you know, you shouldn't be anyway.

The Joe Rogan Experience

#2217 - Brian Cox

6086.314

Good scientists are not trying to be the person that got it right. You're not trying, you know, you're not trying to do it. There's obviously human failure. Everyone's got fragility and everyone's human, you know, an ego. But ultimately, you're just trying to understand how things work.

The Joe Rogan Experience

#2217 - Brian Cox

6137.134

Yeah. So we had one of the reasons we built that telescope was to what it does, because it can see very distant things and because light travels at a finite speed, the further out into the universe you look, the further back in time you're looking.

The Joe Rogan Experience

#2217 - Brian Cox

6152.944

So because that can see things from which the light has been traveling for over 13 billion years, then you're seeing things as they were in the first billion years or a few hundred thousand years in the history of the universe, right, essentially. So, well, a few hundred million years, sorry, I should have said.

The Joe Rogan Experience

#2217 - Brian Cox

6171.493

So you're seeing the first galaxies form with that telescope, which is one of the reasons it was built. And the reason we wanted to see is because we don't fully understand that process. As I mentioned before, we don't really fully understand why they have black holes in them, and it's something to do with their formation, but we don't understand it very well.

The Joe Rogan Experience

#2217 - Brian Cox

6191.645

So it's not surprising to me that when you build that instrument and collect light from the early universe, you see an early universe that's behaving in a different way to the way that you thought it behaved. And so indeed, yeah, we're seeing... galaxies that you formed earlier than you would have predicted.

The Joe Rogan Experience

#2217 - Brian Cox

6213.061

But that means that your model of the way the universe evolved is not quite right, and that's not a surprise, because we wouldn't have built the thing if we'd known everything. Right, of course. So I think it's fair to say there's nothing there that's absolutely... completely destroys our picture of how the universe evolved from the cosmic microwave background that you saw in those images earlier.

The Joe Rogan Experience

#2217 - Brian Cox

6239.885

Yeah, I would say so. And I'm not an expert in that field, but my understanding is that it's interesting because we're having to refine and develop new models of the way that the galaxy is formed. And indeed, you said that it looks like the stars and the galaxies...

The Joe Rogan Experience

#2217 - Brian Cox

6256.515

present in the universe earlier than we might have expected so it might be it might be that you're seeing a hint of something really profound that we didn't understand or it might be that just the models need a bit of a tweak mmm so galaxies form quicker than we expected yeah that early stages of the universe what are those red dots the red dots that were observed

The Joe Rogan Experience

#2217 - Brian Cox

6282.425

In the images, the James Webb images of the early universe. Yeah, they're distant.

The Joe Rogan Experience

#2217 - Brian Cox

6289.148

I don't know.

The Joe Rogan Experience

#2217 - Brian Cox

6313.882

I don't know. It says there that we don't know. So I'm going to go with that. I mean, I think just speed reading that. It says a class of galaxies that... So I suppose we're looking at a kind of galaxy. It seems we're looking at a kind of galaxy that we don't see today in the universe. Red and compact, visible only during about one billion years of cosmic history.

The Joe Rogan Experience

#2217 - Brian Cox

6342.691

So that would be, as I said, because we don't really understand the formation of the galaxies and these supermassive black holes, that's interesting because what you're seeing in the data is a kind of almost proto-galaxy, I suppose, these little tiny galaxies. That's what it seems to suggest. That's the first time I've seen that.

The Joe Rogan Experience

#2217 - Brian Cox

6361.187

But just so, yeah, I think what we're seeing is that we don't understand how structures formed in the universe. We have a reasonable idea, but we don't understand the detail. And the more things like that you find, the more information you have to build models of how stuff formed.

The Joe Rogan Experience

#2217 - Brian Cox

6388.257

I mean, there are several sort of proposed observatories. And also, by the way, gravitational wave detectors. So we've got LIGO, which is on the ground. There are proposals to put one in space, which is called LISA. One of the proposals is called LISA, which is lasers between satellites. So you can have much bigger things.

The Joe Rogan Experience

#2217 - Brian Cox

6410.956

And the reason that's interesting is because there'll be gravitational waves from the Big Bang, right? So, you know, as you mentioned, neutrinos, you've got neutrino observatories, which can observe neutrinos from the early universe. And you can see things. It's just like light in a way. But it gives you a different view. You mentioned earlier, it's a different way of looking at the universe.

The Joe Rogan Experience

#2217 - Brian Cox

6433.757

So the neutrinos will have information. Gravitational waves will have detailed information about the Big Bang itself. But we can't detect them at the moment because we can't detect those really tiny little ripples in space and time.

The Joe Rogan Experience

#2217 - Brian Cox

6453.53

And we want to know. It's like you said earlier. We're asking very deep questions about why the universe is the way it is. And maybe why there's a universe at all in the sense that did it have a beginning? Right. And if so, what does that mean? What does it mean for something like this to begin? Yeah, I really... I find it... And the most exciting thing of all is that we don't know.

The Joe Rogan Experience

#2217 - Brian Cox

6478.706

And that's so important, by the way. And just to reiterate, I think it's often missed when you're talking about the beauty of science and the value of science. It's almost not the knowledge. It's almost like the opposite of the knowledge. It's just this idea that... I think... It goes back to what we were talking about earlier.

The Joe Rogan Experience

#2217 - Brian Cox

6499.071

I haven't really thought about this connection before, but it's that... I was pushing back on you saying, I don't know I'd like... What would it mean to know everything? I don't think I'd like that. And you were saying maybe you would. Maybe that's what it means. Nirvana, you know, maybe achieving enlightenment.

The Joe Rogan Experience

#2217 - Brian Cox

6513.625

That's what it means. But I find... The most human I feel, I think, is when I'm on the edge of the known. Sure. So it's the fact that there are mysteries in the universe, profound mysteries, to me is one of the things that makes life worth living.

The Joe Rogan Experience

#2217 - Brian Cox

6539.301

Yeah.

The Joe Rogan Experience

#2217 - Brian Cox

6543.695

I'm sure you're right. What if we get past this little blip?

The Joe Rogan Experience

#2217 - Brian Cox

6572.864

We've got loads of problems. Loads of problems, which will all be fixed by AI. Well, there is an exciting future, isn't there? It's always exciting. I feel that we are kind of a fork in the road here because, as you said, there are tremendous challenges that we face, environmental challenges and so on. Competition for resources.

The Joe Rogan Experience

#2217 - Brian Cox

6592.794

Geopolitically, the world looks rather, I think it looks as unstable as it was in the 1930s in some respects. So it's quite terrifying. But we have nuclear weapons now. So it's terrifying. But on the other side, as you said, we have not only AI and quantum computers, which are potentially profoundly powerful things. But also, you know, the rockets that we have now, I mean, reusable rockets.

The Joe Rogan Experience

#2217 - Brian Cox

6619.3

We haven't talked about that, but I think it's an absolute game changer. It is now the case that we have cheap and reliable access to space.

The Joe Rogan Experience

#2217 - Brian Cox

6663.865

Yeah, this is really important. This is so incredible. I think we'll remember that in future generations. We'll remember that.

The Joe Rogan Experience

#2217 - Brian Cox

6684.846

That's the road to the stars that right there, that that moment.

The Joe Rogan Experience

#2217 - Brian Cox

6691.855

It does a bit, doesn't it? That does a lot. That didn't end well, though.

The Joe Rogan Experience

#2217 - Brian Cox

6700.403

And also, of course, Blue Origin are maybe not far behind. Right. I love that.

The Joe Rogan Experience

#2217 - Brian Cox

6712.293

Let's go. Yeah. You know, and I get, you know, I get criticised for this quite a lot and will no doubt after this interview, because I do think our future at some point is beyond Earth. It has to be, right? Obviously, logically it is. But the question is when. And there are two things to say.

The Joe Rogan Experience

#2217 - Brian Cox

6733.503

One thing to emphasize, which I'm sure you'd agree with, is that I don't think anybody is suggesting that what we're able to do now is trash this planet and then move to another one. Right, of course. No one's saying that. That's way in the future.

The Joe Rogan Experience

#2217 - Brian Cox

6751.195

Yeah, well, that's in our control. I mean, we can move those now. Sort of. Well, not quite yet.

The Joe Rogan Experience

#2217 - Brian Cox

6759.441

Not really. That's true. So we need that technology. So we're on the verge of having that technology. That would be nice. It was Carl Sagan, wasn't it, who said that if dinosaurs had a space program, they'd still be around. So it's their fault, in a sense. Which I kind of, you know, they didn't build rockets.

The Joe Rogan Experience

#2217 - Brian Cox

6780.234

Let's just reset.

The Joe Rogan Experience

#2217 - Brian Cox

6784.637

Yeah. But I think that idea, that basic idea, I interviewed Jeff Bezos once and he was fascinating. And he said to me that, first of all, we need infrastructure in space. Because if you think about building Amazon, he said what I needed was two pieces of infrastructure, the postal service and the Internet. And so they were provided and I could build my company.

The Joe Rogan Experience

#2217 - Brian Cox

6808.852

So I want to do that for the next generation of entrepreneurs in space. I don't know what they're going to do in space, but I would like the infrastructure to be there for them to do it. And that's really simple. Yeah. And then he also goes on to say, of course, as we said before, the resources are up there. They're infinite.

The Joe Rogan Experience

#2217 - Brian Cox

6824.039

infinite resources infinite energy effectively up there and so the idea he said to me i want to zone the earth residential and and people say that's ridiculous what are you talking but how ridiculous is it when you see that when you see the fact that for the first time we have launch vehicles that really should be able to launch almost anything we want.

The Joe Rogan Experience

#2217 - Brian Cox

6847.797

So the idea that we can build infrastructure in space and then, of course, build bases on the moon and then ultimately on Mars and then beyond, that's a lot closer now.

The Joe Rogan Experience

#2217 - Brian Cox

6864.767

120-ish, is it?

The Joe Rogan Experience

#2217 - Brian Cox

6896.888

So I think we're on the 1906. We're on the verge of a revolution in many fields. My worry is that we're also seeing increase in political instability. Yes. And so I think most people would agree a very dangerous moment.

The Joe Rogan Experience

#2217 - Brian Cox

6914.796

And the question is how to get to that future. And that future that you talked about, this wonderful future that we have, might be 10 or 20 years away. But it might be an eternity away if we get the next few years wrong. Right. So I'm concerned that this... We don't know how to build a bridge to that future that we should see.

The Joe Rogan Experience

#2217 - Brian Cox

6936.726

In our lifetime, we should see this future beginning to unfold before us. How do we get there?

The Joe Rogan Experience

#2217 - Brian Cox

6969.534

Yeah.

The Joe Rogan Experience

#2217 - Brian Cox

6990.64

And what's interesting to me is I've got interested in Oppenheimer's writing post-war. And I've been interested in it. The BBC asked me to look at... There's a thing called the BBC Reith Lectures that are very famous in the UK. And every year someone gives these lectures after Lord Reith, who founded the BBC. And Oppenheimer did them in 1953, I think it is, 53 or 54.

The Joe Rogan Experience

#2217 - Brian Cox

7015.971

And they were considered a failure because no one understood what he was talking about. But in there, he was concerned with the fact, of course, that he felt he delivered the means by which we would destroy ourselves. And he felt our technology, our scientific know-how, exceeded our wisdom and our political skill, which is arguably true.

The Joe Rogan Experience

#2217 - Brian Cox

7037.526

So he thought in the 50s, he couldn't see how we'd avoid destroying ourselves. But he thought about it a lot, feeling partly personally responsible for it. And he describes this, how if there's any lessons that science teaches us, the exploration of nature teaches us, that we could move into other fields, that we could transfer into politics, for example.

The Joe Rogan Experience

#2217 - Brian Cox

7063.933

And one of them is this picture that complex systems are complicated. So he's talking about looking at quantum mechanics, for example, and it gets complicated. And you say, what is an electron? It's this thing. It's a particle-like, point-like thing or a big extended wavy thing. What is it? It behaves in all these strange ways.

The Joe Rogan Experience

#2217 - Brian Cox

7084.008

We don't really have the language or the mental capacity to picture it. And so he said any attempt to say this thing is this or it is that, it is like this thing, it is doomed. What you have to understand is that you have to develop this rather complex and nuanced picture of the way that nature works. And quantum mechanics is a good example. But he said so it is with human societies.

The Joe Rogan Experience

#2217 - Brian Cox

7109.837

So in a society... And what is it? It is at one level a load of individuals, like little particles. And they have their own needs and desires and they have their views and strongly held views. And so should they, by the way. There's a great quote from, I think, early 60s from Oppenheimer, where he says that to be a person of substance, you need an anchor.

The Joe Rogan Experience

#2217 - Brian Cox

7131.675

So you need to believe things and you need to argue for things. You need to take positions. You have to have a morality. You have to have a politics, right, basically. Otherwise, you're not a person of substance. But he says at the same time, of course, you have to recognize there's a society. So there are lots of people with anchors.

The Joe Rogan Experience

#2217 - Brian Cox

7152.08

And you might strongly disagree with that anchor and they might be wrong. Their anchor might be nonsense. But the challenge of politics is to avoid war. I read somewhere recently, someone said, I can't remember if it was, but said that democracy is a technology challenge. to avoid civil war. That's what it is.

The Joe Rogan Experience

#2217 - Brian Cox

7175.206

So somehow you've got to understand that whilst you have your, and should have, your firmly held position, you have to find a way, and it feels almost contradictory, you have to find a way of understanding that the society as a whole is a complex mixture of all these different little particles with their own anchors and their own positions. And what is the goal? So it is the goal.

The Joe Rogan Experience

#2217 - Brian Cox

7202.659

It often feels to me that politics at the moment, the goal is to win an argument. It often feels like to convince enough people that your view is the right view. And that obviously is part of democracy. It's the way it works. You argue for your position and then you get four or five years to do your thing and then someone else can take over.

The Joe Rogan Experience

#2217 - Brian Cox

7223.444

But also, I think the thing we're missing at the moment is that perhaps more fundamental function of democracy, which is to avoid war. Because if you can avoid war, especially with the power that we have now, you have the time to sort the rest out. But if we can't avoid war, we don't. And I think that – and Oppenheimer wrote – he knew that in the 50s.

The Joe Rogan Experience

#2217 - Brian Cox

7249.497

And it feels to me more that we're back full circle now. It feels to me we've almost forgotten. We seem to have forgotten that the primary – The primary function of democracy is not to ensure that your side wins. The primary function of democracy is to ensure there's a chance for the other side to win at some point in the future.

The Joe Rogan Experience

#2217 - Brian Cox

7277.334

And yeah, that's it really. That's what I would like to say.

The Joe Rogan Experience

#2217 - Brian Cox

7478.633

This just makes sense. What does seem to be generally true is that we haven't, as a society... It says it was just on Facebook.

The Joe Rogan Experience

#2217 - Brian Cox

7501.806

I mean, what I think is generally true is that we haven't yet adapted to the Internet. Yes. Just the Internet. Yes. Because it's only, as you said, in the great sweep of human history. Right. And it's only been used by people for 30 years.

The Joe Rogan Experience

#2217 - Brian Cox

7517.674

Yeah. And it's a couple of decades. It's been influential. Yeah. So I think it feeds. It's another of those problems we face now. This what we talked about, this this bridge to this tremendously bright future that we have. One of the pillars of that bridge that we need to strengthen is how to deal with this thing that we've only had for a couple of decades. Right. It's clear.

The Joe Rogan Experience

#2217 - Brian Cox

7540.644

I think we would – you know, people, again, will be listening to this and they'll have different views on the way that things happen on the Internet and regulation and so on. But I think what everyone would agree on is we haven't got it right yet.

The Joe Rogan Experience

#2217 - Brian Cox

7551.308

So we don't know how – the way that it's influencing our –

The Joe Rogan Experience

#2217 - Brian Cox

7650.598

And I don't know what the answer is. I mean, one answer, I mean, the way I do it, because obviously I'm on Twitter X. And so the way that I do it is you can tell, I think, by someone's timeline usually. Because my basic rule of thumb is that if you look at someone's timeline and it's all political. Right. I just ignore them.

The Joe Rogan Experience

#2217 - Brian Cox

7672.775

Because a normal person's timeline, if I look at your timeline, you look at mine, some of it's just silly stuff. Some of it's retweeting sports stuff or science stuff or whatever it is. I like aeroplanes, so a lot of my stuff is retweeting stuff about aeroplanes, right? Or whatever it is. So I think you can see a real person by seeing a breadth in the things that they retweet or whatever.

The Joe Rogan Experience

#2217 - Brian Cox

7698.616

And so I tend to ignore and mute at the minimum the people who are just single issue. And usually what you find, by the way, is that. They're not a single issue. I can just about understand it if someone's single issue focused on a single thing. But they're just a generic kind of political position. So you'll see an account and all it does is promote divisive issues.

The Joe Rogan Experience

#2217 - Brian Cox

7723.959

You can see them a mile off, I think. So then it comes back to how do you deal with it? And my sense would be your sense. It's hard to legislate around conversation, isn't it? Yeah. So what do you do? I suppose you could argue it's education. Ultimately, ultimately, everything comes back to to education. A democracy requires an educated population. Right. And tools who have the mental tools.

The Joe Rogan Experience

#2217 - Brian Cox

7751.122

to deal with this sort of new world of information.

The Joe Rogan Experience

#2217 - Brian Cox

7831.359

Yeah. Yeah. Isn't it a big problem?

The Joe Rogan Experience

#2217 - Brian Cox

7856.508

But we can be optimistic. Yes. Because we're both optimists, I think, ultimately. Yes, I'm very optimistic. Because of the things we've talked about today.

The Joe Rogan Experience

#2217 - Brian Cox

7908.028

I do understand, though, that you and I, you know, we're in a good position, Mike, personally. Yes. As we have a, you know, this confidence comes with some degree of success and you can put things in perspective. And as you said, you know, when, if you're, I often think, actually, I see people who struggle financially. When they become well-known for the first time, for example.

The Joe Rogan Experience

#2217 - Brian Cox

7933.521

I mean, I remember when I became quite late in life, became well-known as a public figure. I did a series on the BBC in 2009 or 2010 called Wonders of the Solar System. And suddenly I was well-known. And I find it very difficult to navigate. And fortunately, I had the support structures and people around me and I could navigate it and you come to terms with it and you learn how to do it.

The Joe Rogan Experience

#2217 - Brian Cox

794.767

So really in bits, I mean, the idea is, and I should say it's very much in principle this, so no one thinks in practice you could reconstruct what I wrote down on this if you set fire to it. But in principle... Well, maybe sometime in the future. Yeah, in principle, you could just collect everything.

The Joe Rogan Experience

#2217 - Brian Cox

7958.083

But it's a process, isn't it? So I think it's the same. One of the problems, I think, with social media is you can become very well known. Very quickly.

The Joe Rogan Experience

#2217 - Brian Cox

7967.066

Often for something that you kind of said in a clumsy way. Sometimes, you know, it can.

The Joe Rogan Experience

#2217 - Brian Cox

7971.669

And I think it's probably almost impossible to navigate that as just a person who just suddenly is exposed to that glare of publicity and becomes a public figure. Yeah. Sometimes a hate figure. Yes. Overnight.

The Joe Rogan Experience

#2217 - Brian Cox

8005.067

Yeah. And it wasn't in a controversial area. It's about planets and the solar system, astronomy. So but even then, I found it difficult initially to navigate through that world. Yes. And you get used to it eventually.

The Joe Rogan Experience

#2217 - Brian Cox

8049.491

I do, yeah, there's still, I mean, the number of people who, when I, so I did that, the rocket catch, right? The starship, as you said, the most incredible thing. I just retweeted that and said, brilliant engineering. The number of tweets I got back saying that space is, I don't understand what it means. Space is fake. I don't even know what that means. But I got quite a lot of it.

The Joe Rogan Experience

#2217 - Brian Cox

8072.668

You know, it's fake.

The Joe Rogan Experience

#2217 - Brian Cox

8091.48

Oh, it's that.

The Joe Rogan Experience

#2217 - Brian Cox

810.815

Then somewhere in all that radiation and ashes and light that's come off the thing is the information. It's there. So you could reconstruct the book or what I wrote on this page in principle. But the thing about Stephen's calculation was that even in principle, it said there is no information.

The Joe Rogan Experience

#2217 - Brian Cox

8101.348

I love this. You go, okay, so let's assume that's true. Let's assume he's right.

The Joe Rogan Experience

#2217 - Brian Cox

8117.958

But the thing I've never understood, and I've asked this in my early days on Twitter. I made the mistake of asking, you know, sometimes. Now I don't reply at all. Obviously, you learn that. I go, what possible advantage could there be? Right. What's the answer? I think they think that it's just a scam. So, yeah, SpaceX are just like a scam or something.

The Joe Rogan Experience

#2217 - Brian Cox

8143.953

So they're just taking all this money for launching satellites. So, again, it's a very complicated scam because they're getting it off, you know, communications satellites. They should try Starlink.

The Joe Rogan Experience

#2217 - Brian Cox

8183.082

Look at the sky. The fundamental thing as well, the fundamental misconception these people have is they assume that there's a competence...

The Joe Rogan Experience

#2217 - Brian Cox

8191.187

there in government you know anyone who's interacted with government i speak of my own country i've interacted with the government the idea that they're competent enough to do this right tremendously intricate scam they can't even in my country they can't even make the trains run right it's very basic that so i think that is this assumption that there's some kind of

The Joe Rogan Experience

#2217 - Brian Cox

8215.598

underlying competence to the world.

The Joe Rogan Experience

#2217 - Brian Cox

8222.745

Yeah, I just don't think that the world is run by people who are smart enough to do that.

The Joe Rogan Experience

#2217 - Brian Cox

8300.616

I've learned something I didn't know because I didn't know the space is fake thing was linked to that.

The Joe Rogan Experience

#2217 - Brian Cox

832.798

And by the way, it's kind of easy to see why, actually, because this radiation, this Hawking radiation that comes off the black hole, it's coming from the horizon of the black hole. So I should say what the horizon is maybe.

The Joe Rogan Experience

#2217 - Brian Cox

8337.197

Going back to what we said earlier, if that was the way that nature is, we would tell you. I'd love it.

The Joe Rogan Experience

#2217 - Brian Cox

8355.126

Because you become tremendously... I mean, what a great discovery. Amazing.

The Joe Rogan Experience

#2217 - Brian Cox

84.252

And then there's another one, the first photo that was taken. It's a collaboration called Event Horizon. And they took a photo of one in the galaxy M87, 55 million light years away. That thing is around 6 billion times the mass of the sun. I mean, imagine that, 6,000 million times more massive than our sun. Is that the largest black hole we've ever discovered?

The Joe Rogan Experience

#2217 - Brian Cox

8429.304

What is it? It starts with, in the beginning, God created the heaven and the earth, and the earth was that form of void, and darkness was on the face of the deep. I love that. It's a great line. Well, it's amazing.

The Joe Rogan Experience

#2217 - Brian Cox

8442.708

Yeah, and it's the deep. I think I read somewhere that I was talking to a friend of mine who's It seems to come from the Egyptian creation myth, I think. I might be wrong there, but it was very much to do with the Nile and the waters. And you find that in many religions that there's water and things emerge out of the waters. And you see that in Genesis, the echo of it.

The Joe Rogan Experience

#2217 - Brian Cox

8464.179

Darkness was on the face of the deep. And then there's light after that. So I don't know. I'm not a biblical scholar.

The Joe Rogan Experience

#2217 - Brian Cox

848.467

Remember I said that the sun, if you squashed it down within three kilometres of radius, you'd get this kind of distortion in space and time from which if you went in across this region, three kilometres, you went inside it, you couldn't get out. So that's called the event horizon.

The Joe Rogan Experience

#2217 - Brian Cox

8480.588

That's it. That's ultimately it, isn't it?

The Joe Rogan Experience

#2217 - Brian Cox

8483.509

That's what we talked about earlier. To me, that's one of the defining characteristics of being human, trying to make sense of the world. And that's why, by the way, I don't like to get into sort of arguments with people who have different views, different belief systems. My sort of baseline position is if you're curious... And you're interested. And you want to know how things happened.

The Joe Rogan Experience

#2217 - Brian Cox

8512.325

That, to me, is common ground that we can share. The people I don't really understand are people who are not curious. Right. And don't have questions. Because Carl Sagan wrote a great book called The Demon-Haunted World, Signs of the Candle in the Dark.

The Joe Rogan Experience

#2217 - Brian Cox

8526.212

Where he says that story about a taxi driver when he got in the taxi at the start. And he's asking him all these questions about Atlantis or whatever it is. And he realizes... He doesn't think this guy is an idiot. He thinks this guy has a curious mind. He's someone who should be, we can have a wonderful conversation. But he also says that he felt that he'd perhaps been failed.

The Joe Rogan Experience

#2217 - Brian Cox

8550.43

by society, by education, in that his curiosity had not been somehow channeled to the real mysteries. Yes. But it got sidetracked into all this strange stuff.

The Joe Rogan Experience

#2217 - Brian Cox

8571.266

Simpler, simpler things.

The Joe Rogan Experience

#2217 - Brian Cox

8586.496

And by the way, that idea that I think one of the problems we have communicating science and getting young people into science is that idea that you have to somehow be really clever. Yeah. Which is not true at all. It goes back to what I said before, that it's more you have to be comfortable with not knowing. So that's a big step to say I'm not going to guess and I'm OK.

The Joe Rogan Experience

#2217 - Brian Cox

8611.853

If you ask me a question about the origin of the universe, the answer is don't know. So I think it's if, as you said, if you can be comfortable with not having to have a simple, intelligible explanation for something, then you'll make more progress in life. But it's quite difficult. Yes. So it's easy to just go, oh, there's a simpler that thing. Yes. So there's a simpler explanation there.

The Joe Rogan Experience

#2217 - Brian Cox

866.79

So you wouldn't notice if you fell through the horizon of the black hole in the Milky Way galaxy if you went into that one. We could be falling through that horizon now in this room, and we wouldn't notice anything except that we couldn't get out again. And ultimately, in a few hours, in that case, time would end for us. So you go to the end of time. We could talk about that.

The Joe Rogan Experience

#2217 - Brian Cox

8678.843

And in there he says the most valuable thing is scientists bring this transferable skill to life. And it's that you have a great experience with being wrong. So nature is brutal. And most of the time you come up with some really great theory and you're really sure about it. You do the experiment and you're just wrong. And so you get so used to it that you come to enjoy it.

The Joe Rogan Experience

#2217 - Brian Cox

8701.852

Because you're learning. But it's a process. That's why science is so important in schools and experiments are so important. It's not that you just swing a pendulum and there's nothing interesting about that. But it's just that you're learning that there's a gold standard of knowledge, which is nature. And as Feynman said, it doesn't care who you are or what your title is or what your name is.

The Joe Rogan Experience

#2217 - Brian Cox

8727.26

Or you may have been elected with 99% votes in whatever it is. It doesn't matter. Nature just doesn't care. And so the more you interrogate nature, even as a kid at school with a little experiment with a battery and a light or something, you learn that there's a reality and you learn what it takes to acquire reliable knowledge about the world. And reliable knowledge is important. Yeah.

The Joe Rogan Experience

#2217 - Brian Cox

8753.607

How do we how do we form a view of and it can be very important questions. It can be questions like what happens if we carry on putting greenhouse gases into the atmosphere, for example, whatever your politics are. It's a legitimate question, a good question. Right. So are we going to influence the climate if we carry on doing this?

The Joe Rogan Experience

#2217 - Brian Cox

8775.592

and so how do we then address that as a question you can't do it by going back to your political affiliation or your belief system you've got to try and understand this complicated system which is the climate of a planet so you make measurements of the thing and you build some models and computer models and there's a very famous saying that all models are wrong because they're models right so but they're the best you can do so you have a go and

The Joe Rogan Experience

#2217 - Brian Cox

8800.757

You come up with some information and a model that kind of works. And you say, well, this is the best version of our knowledge at the time. And then you can try to act on it and you define the model. And that's the process.

The Joe Rogan Experience

#2217 - Brian Cox

8813.973

But that idea of how can we acquire reliable knowledge that we can trust, which might not be right and is very likely not completely right, but it's the best we can do at the time. That's what my definition of science would be. It's nothing more or less than... The best picture we can manage of how nature works at any given moment. It's not a truth. It's not something by its very nature.

The Joe Rogan Experience

#2217 - Brian Cox

8844.677

The way that science works is it will it may be shown to be incorrect or not particularly great a model tomorrow. Yeah, but I would define it as the best we and by we I mean our civilization the best we can do. And so we act on that. I don't see any other way to act as a civilization other than with the best we can do. It's the best we can do.

The Joe Rogan Experience

#2217 - Brian Cox

891.775

There's a picture of that. Maybe I should talk about it. This is getting quite complicated already, isn't it? We didn't start in a relaxing way, did we?

The Joe Rogan Experience

#2217 - Brian Cox

898.716

No need to. Let's get right into it. So we wouldn't notice anything. Not for the big black holes. So, yes, these supermassive black holes, we could fall across this horizon. It's just like being in empty space for us. So we'd just be talking now when we could have been talking on the outside of the horizon.

The Joe Rogan Experience

#2217 - Brian Cox

8993.843

Oh, the Cuban Missile Crisis?

The Joe Rogan Experience

#2217 - Brian Cox

9056.437

I don't see shit. I think it's best to assume. Carl Sagan again, wasn't it, when he said, no one's coming to save us from ourselves. Let's just assume that.

The Joe Rogan Experience

#2217 - Brian Cox

9096.2

Whatever they have, they're crossing.

The Joe Rogan Experience

#2217 - Brian Cox

9108.465

As I said, I wouldn't be surprised. I'd be relieved. I'd be relieved as well.

The Joe Rogan Experience

#2217 - Brian Cox

921.138

And by the time I finished the sentence, we could be on the inside of the horizon, inside the black hole. And... according to Einstein's theory at least, which is the theory that predicted them initially, we could just do that, we could just go in And we wouldn't notice for a bit. The thing we would notice ultimately is you go inexorably. Nothing you can do.

The Joe Rogan Experience

#2217 - Brian Cox

9236.912

How did we get here?

The Joe Rogan Experience

#2217 - Brian Cox

9290.301

And I think they would be interested in us. This is Star Trek.

The Joe Rogan Experience

#2217 - Brian Cox

9301.448

Yeah, well, don't intervene at all. Don't intervene at all, isn't it?

The Joe Rogan Experience

#2217 - Brian Cox

9321.792

I think you're absolutely right. I mean, the point is I think there's nobody there for a long way.

The Joe Rogan Experience

#2217 - Brian Cox

9340.021

That would be my baseline view.

The Joe Rogan Experience

#2217 - Brian Cox

9350.686

If it's infinite? I mean, we don't know if it's infinite. We have the observable universe. I think the current number is something like two trillion galaxies, depending on how many smaller ones there are.

The Joe Rogan Experience

#2217 - Brian Cox

9377.794

Yeah. But we're talking the distance between the galaxies is, you know, the Andromeda galaxy is two million light years away. Right. Which is the largest and nearest large neighbor. So I think when I when I think about this, I tend to confine it to our galaxy because I can't conceive of travel between galaxies. Too crazy. I think it's too far.

The Joe Rogan Experience

#2217 - Brian Cox

9403.051

Although for now, it is true that the laws of physics do not prevent that. So relativity, I teach relativity at Manchester University for the first years, the 18-year-olds.

The Joe Rogan Experience

#2217 - Brian Cox

9415.062

And the first thing we do in special relativity is talk about the fact that if you travel close to the speed of light, so if you had a spacecraft traveling close to the speed of light, then distances shrink from your perspective.

The Joe Rogan Experience

#2217 - Brian Cox

9429.478

And the one number I always have in my mind is that the Large Hadron Collider at CERN, the protons go around the ring, which is 27 kilometres in circumference, and they go around at 99.999999% the speed of light, so close to the speed of light. At that speed, distances shrink by a factor of 7,000. And so that ring... is something like four meters in diameter to the protons.

The Joe Rogan Experience

#2217 - Brian Cox

943.877

You go to this thing called the singularity once you've crossed the horizon. And you are going to that thing. And then the question arises, what is that thing? And one answer is we don't know. But in Einstein's theory, it's the end of time.

The Joe Rogan Experience

#2217 - Brian Cox

9460.623

So according to laws of physics, if you can build a spacecraft that goes very close to the speed of light, you can shrink the distance to the Andromeda Galaxy and therefore the time it takes to get there by an arbitrary amount, actually. The closer you get to the speed of light, the more you can shrink it. And so you can make those two million light years.

The Joe Rogan Experience

#2217 - Brian Cox

9482.238

You could traverse across that distance in principle in a minute, according to physics. However, the downside... is that you couldn't come back to tell – if you came back to the Earth at that speed to tell everybody what you'd found, at least four million years would have passed on the Earth. Oh, boy. So you can't – so there's kind of a downside to it.

The Joe Rogan Experience

#2217 - Brian Cox

9509.08

We could, in principle, explore the galaxy and beyond. But getting to chat to everybody about what you found is forbidden by the structure of the universe. It's the way that relativity works. That really is essentially a time machine. Well, it's a time machine in the sense that we could go arbitrarily far into the future. by flying around in a rocket very close to the speed of light.

The Joe Rogan Experience

#2217 - Brian Cox

9535.972

So we could come back a million years in the future and look at the Earth and find out what had happened. You can't go back, as far as we can tell. So you can't build a time machine to go backwards. So these are time machines. The world is built such that a time machine...

The Joe Rogan Experience

#2217 - Brian Cox

9554.382

A way to think about it, the way that we teach it in undergraduate physics, is that, so in Einstein's theory, there are events, which are things that happen in space-time. So that would be an event. It's something that happens. Our conversation now is a thing that happens, space-time. And what Einstein's theory tells you is it's about the relationship between events.

The Joe Rogan Experience

#2217 - Brian Cox

9577.559

So let's say that we wanted to come back here tomorrow. That would be another event. We meet again tomorrow. And you can see how much time has passed between those events. In Einstein's theory, the amount of time that has passed... is the length of the path you take over spacetime between the events. So it's just like saying, in a sense, what's the distance between Austin and Dallas, right?

The Joe Rogan Experience

#2217 - Brian Cox

959.87

So one way of picturing what's happened here is so distorted is space and time by the collapse of a star or the collapse of loads of stuff to make these big supermassive black holes. We don't quite know how they form, actually, but it's collapsing stuff. So it distorts space and time so much. that in a real sense, they kind of flip over. They get mixed up.

The Joe Rogan Experience

#2217 - Brian Cox

9601.729

And you'd say, okay, well, it depends what route you go. Well, what's interesting in Einstein's theory, the only complication is the length of the path you take between events is the time measured by a clock that's carried along that path. So that's how much.

The Joe Rogan Experience

#2217 - Brian Cox

9619.622

If you're carrying your watch with you and you go between here and tomorrow, you go this way, you go off and maybe you fly to Dallas and back or something and then come back again. There's a particular length. Someone else can take a different path, obviously. And so a different amount of time will pass for them between those two things that happen. Just because of that one fact.

The Joe Rogan Experience

#2217 - Brian Cox

9641.004

A very infinitely small but measurable amount of time. It's a tiny amount unless you travel, someone goes close to the speed of light or someone goes near a black hole or something where the space time is all distorted. Then you can get big effects. But it's still completely measurable.

The Joe Rogan Experience

#2217 - Brian Cox

9658.14

I mean, they are quite big effects, these, in the sense that for the satellite navigation system, for example, GPS. The clocks on the satellites tick at a different rate to the clocks on the ground. And it's quite a big effect.

The Joe Rogan Experience

#2217 - Brian Cox

9671.609

I think from memory, it's something like over 30,000 nanoseconds per day difference because they're in a weaker gravitational field and they're moving and all sorts of things. It's the same thing. But 30,000 nanoseconds. Light travels one foot per nanosecond, which is great. I always say that God used imperial units because it's 30.8 centimeters. It's one foot, right? It's good.

The Joe Rogan Experience

#2217 - Brian Cox

9696.804

It's one foot per nanosecond. So that's 30,000 feet of position measurement. if you drift your clock out by 30,000 nanoseconds. So it wouldn't work. So it's a big effect for when you start using time to measure distance, which is what we do in satellite navigation, GPS. So we have to correct. So the clocks have to be corrected for that effect.

The Joe Rogan Experience

#2217 - Brian Cox

9720.632

So it's an effect that we can easily measure with atomic clocks, but it doesn't make much difference to us as humans. But just the point is that the laws of nature would allow you to do it if you could go close to the speed of light. By the way, the last thing I'll say is the limiting factor. You might say, well, what happens if you go really close to the speed of light?

The Joe Rogan Experience

#2217 - Brian Cox

9740.062

What happens if you go at the speed of light? Well, special relativity, Einstein's theory, is built such that the distance between any two events in the universe along the path of the beam of light between the events is zero. No time at all. So that's the way that Einstein's theory is built.

The Joe Rogan Experience

#2217 - Brian Cox

9759.777

So he asked the question when he was younger, famously, what would the universe look like if I traveled alongside a beam of light? And the answer is that you wouldn't perceive any time. You can't. The last thing I'll say is that if you've got any mass at all, you can't do that. You can't go at the speed of light.

The Joe Rogan Experience

#2217 - Brian Cox

9779.114

So according to our model, which is a good model and it seems to work, but if you've got no mass, you go at the speed of light. So if you're a photon, you go at the speed of light and no time. So...

The Joe Rogan Experience

#2217 - Brian Cox

9804.308

Yeah, that's called the – I can never pronounce it. It's the albacore – what's it called? The drive. So you can – Einstein's general theory of relativity, general relativity is his theory of gravity. And it's a theory where space and time are distorted by things, anything in the universe, right? Stars and planets. So that's what gravity is. It's the distortion of space and time by mass and energy.

The Joe Rogan Experience

#2217 - Brian Cox

9832.082

It's Einstein's theory. So you can, and it's been done, you can develop... sort of things where you say, well, if we could make this geometry of space and time, if we could distort it in this way, then indeed you can build a warp drive. Right, right, right. But it always turns out, as far as we can tell, that the other question is, but what kind of stuff would you need?

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#2217 - Brian Cox

984.171

And so this singularity, which you might have thought of as the point to which this thing collapsed, this infinitely dense point, you might think. But actually, more correctly to be seen as the end of time. Because everything's got mixed up. So you go to the end of time. And it's just like saying, why can't I escape that thing? It's like, why can't we escape tomorrow? So we are going to tomorrow.

The Joe Rogan Experience

#2217 - Brian Cox

9857.635

What kind of matter or energy or field, whatever it is, what kind of thing would you need to make that geometry? And it always turns out that those things don't appear to exist. So these particular kinds of matter and energy, that if you had them, you'd be able to do that with space and time. We don't think you can have them. And so it's kind of a bummer, right?

The Joe Rogan Experience

#2217 - Brian Cox

9893.731

It's not going to be elements. It's going to be kind of some kind of quantum field, some kind of energy or something. And so you can sort of try to speculate. But Stephen Hawking wrote a very famous paper called The Chronology Protection Conjecture. So conjecture is important. It's a guess, not proved.

The Joe Rogan Experience

#2217 - Brian Cox

9912.896

Where he said that whatever the ultimate laws of physics are, we don't have them at the moment, string theory, whatever it is, then they will be such that you can't do this. Because chronology protection means protect the present from the future. So in other words, you can't build a time machine that goes back in time. Right. So that...

The Joe Rogan Experience

#2217 - Brian Cox

9936.403

But because Einstein's theory allowed you to imagine such a thing, even though you might not be able to build it, it's not been proven beyond doubt that you can't somehow make these kinds of quantum fields or whatever it is that you need to make wormholes, for example, stable wormholes you can go through. And so it's not been proven. So it's just it's suspected that that's going to be the case.

The Joe Rogan Experience

#2217 - Brian Cox

9960.004

By the way, the final thing, this is very neat because it goes right back to what I said at the start, that one of the pictures of how I said there was this thing, the black hole information paradox. And we thought Stephen's calculation was that no information comes out. We now think it comes out. So we now think that black holes do not destroy information. We're pretty sure.

The Joe Rogan Experience

#2217 - Brian Cox

9980.35

So it's been proven mathematically to most people's satisfaction that the information ends up out again. So if you went into a black hole, the information would be out in that Hawking radiation that could reconstruct you, but only in the sense that if a nuclear bomb landed on us now, then in principle the information would be still there in the future and we could be reconstructed, right?