EVERY SPOKEN WORD
150 min read · 30,011 words- 0:00 – 1:00
New black-hole breakthroughs: what happens to what falls in?
- G3Guest 3
(drumming music plays) Joe Rogan podcast, check it out!
- HOHost
The Joe Rogan Experience.
- G3Guest 3
Train by day, Joe Rogan podcast by night! All day. (rock music plays) All right. Brian Cox. Good to see you, sir.
- HOHost
Good to see you again.
- G3Guest 3
How's, uh, things in the world of the discovery of the universe? Any-
- HOHost
Exciting-
- G3Guest 3
Yes, very.
- HOHost
... I would say. I, 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, the amount of the progress that's been made in trying to understand how they work, and, 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 simplest question you could possibly ask.
- G3Guest 3
Right.
- HOHost
There's progress being made on that now, which I think is profound and exciting.
- G3Guest 3
How is the progress being made? Like how, how do we... how do we study a black hole?
- 1:00 – 3:47
Photographing the unseeable: Event Horizon Telescope images explained
- HOHost
I mean, it's mainly theoretical. Although, um, we, we have now got photographs of them. So we have two photographs, which are radio telescope photographs.
- G3Guest 3
Right.
- HOHost
One of the, the one in the center of our galaxy, which is a, a little one. It's called Sagittarius A*. A lit- it's a s- it's a little super massive black hole. So it's about six million times the mass of the sun-
- G3Guest 3
(laughs)
- HOHost
... which makes it a little super massive.
- G3Guest 3
(laughs)
- HOHost
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 six billion times the mass of the sun. Can you imagine that? 6,000 million times more massive than our sun.
- G3Guest 3
Is that the largest black hole we've ever discovered?
- HOHost
No. There, there are bigger ones than that, but that's the... (laughs) The, the, that, that's the scale of them. It's a biggish one, that.
- G3Guest 3
Oh.
- HOHost
But if you think about it... I mean, so there's a number, it's called the, the Schwarzschild radius of the thing. So if you, 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, three kilometers, about two miles. So you've got to take this thing, which is-
- G3Guest 3
Wow.
- HOHost
... well, I have to convert from kilometers to miles, don't I? But it's about-
- G3Guest 3
That's okay. Seven hundred... Seven hundred thousand kilometers. So it's about five, five- 500,000 miles radius or something like that, the sun. So it's a... You squash it down till it's about two miles, and then that would form a black hole. Wow.
- HOHost
The... Six billion times the mass of the sun means you multiply that by six billion. So these things, the, the so-called Schwarzschild radius is, I don't know, larger than our solar system basically.
- G3Guest 3
Oh my God.
- HOHost
This thing that, that sits in, in a galaxy. So we've got these two photographs of it.
- G3Guest 3
Larger than our solar system?
- HOHost
Yeah, the Event... Right. (laughs) The, the... There's... You, you... so it's, it's, it's a big structure.
- G3Guest 3
Ah.
- HOHost
That's, um... That's... Now, that's a Chandra X-ray image of...
- G3Guest 3
I was like-
- HOHost
There it is. That's it. So, so the, uh... That one there, that's the M87 black hole. So what, 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. It's, it's a flat disk, by the way. So y- you think, 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, uh, from Einstein's theory basically. He published it in 1915. And you can predict that that's one... what one should look like. 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.
- G3Guest 3
Wow.
- HOHost
So it's a remarkable thing.
- G3Guest 3
How phenomenal is that?
- 3:47 – 5:40
Gravitational waves: detecting a “storm in time” with LIGO
- HOHost
Yeah. So we've got... 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, that event... that, that process ripples space time. So it sends ripples out in the fabric of the universe, space and time. And actually Kip Thorne, who's a... I, I, 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, 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. So they... (laughs) as, as they go through. And we can detect that now. So we have detectors that can pick that up. And so we've seen those collisions as well.
- G3Guest 3
So these collisions, how far away?
- HOHost
Oh, millions of light years away. The, the-
- G3Guest 3
And they're affecting what's happening in this room right now?
- HOHost
Yeah, to a tiny extent. So there's an ex- there's an experiment called LIGO, which is the, uh... What does it stand for? Something like gravitational interferometer... I can't remember exactly what the, the word... (laughs) But there's... So basically it's, uh, laser beams. And there's one in Washington State north of Seattle and one in Louisiana. And they're, they're kind of laser beams, four-kilometer-long laser beams at right angles. And they can detect these very tiny shifts in the... Effectively, you could say, the length of a laser beam. It's a bit more fiddly and complicated. But it, it essentially measures this... the, the, the distortion in space time caused by-
- G3Guest 3
Whoa.
- HOHost
... these ripples. And it's, it's way less than the diameter of an atomic nucleus by the way. Way less. These little sort of-
- G3Guest 3
Oh my God.
- HOHost
And, and so we've, we've started to... We've observed many of those collisions. There it is. There's LIGO.
- G3Guest 3
Wow.
- 5:40 – 11:42
Hawking radiation and the information paradox (why it shook physics)
- HOHost
So it's just basically two laser beams now, but with these ultra-high precision thing. And so we've got data now of the collision of black holes and that... those event horizon pictures with radio telescopes. So that, that's part of it. But the main bit has been theoretical advances in understanding exactly...... it, 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, su-
- G2Guest 2
Right.
- HOHost
... sure, he didn't get his math wrong. But he did, actually, (laughs) in his calcul-... So what he calculated back in 1973, 1974 is that a black hole... So y- y- we picture this thing from which nothing can escape, even light. So when you go in, you're gone, basically. What he calculated is that even though these things are just a distortion in space and time... That's, 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. So they, they emit radiation. It's called Hawking radiation. And so important was that discovery that 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 (laughs) 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. So he disco- he, 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, they're emitting stuff.
- G2Guest 2
Mm-hmm.
- HOHost
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. And his calculations 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 e-... 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. So it's really true that if I got this, this notepad and pen, right, and I, I wrote some things on it and then I set fire to this (laughs) 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, and you could just measure it all, then just in principle, the idea is you could reconstruct the information. So it'll get scrambled up and thrown out into... Uh, in some practice, you can't do it, but in, 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, right? But this calculation that Stephen did said there is no information in that radiation at all. Zero. Uh, just nothing. So it seemed that uniquely in the universe, black holes erase information.
- G2Guest 2
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- HOHost
So, so really, in bits. I mean, the idea is... And it's, um, I should say it's very much in principle, this. I know no one thinks in practice you could reconstruct what I wrote down on this if you set fire (laughs) to it. But in principle-
- G2Guest 2
Well, maybe some time in the future.
- HOHost
Yeah.
- G2Guest 2
Maybe a million years from now.
- HOHost
Yeah, in principle, y- y- you could just collect everything.
- G2Guest 2
Well-
- HOHost
Then somewhere in that, in that, in that... All that radiation and ashes and light that's come off the thing is the information. It's, 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. And by the way, the... It's kind of easy to see why actually, because this radiation, this Hawking radiation that comes off the black hole,
- 11:42 – 16:51
Event horizons and singularities: ‘the end of time’ inside a black hole
- HOHost
it's coming from the horizon of the black hole. So I should say what the horizon is, maybe. So it's...
- G2Guest 2
Okay.
- HOHost
If you l- remember I said that the, the sun, if you squashed it down within three kilometers of radius, you, you, you'd, you'd get this kind of distortion in space and time from which if you went in-... across this region, three kilometers, you went inside it, you couldn't get out. So that's called the event horizon. So you wouldn't notice if you fell through the, the horizon of the black hole in a, in the Milky Way galaxy, if you went into that one. You, 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, and ultimately, in a few hours in, in that case, w- time would end for us. So we just go... you go to the end of time. We could talk about that. I got... there's a picture of that, maybe I should talk about. (laughs) This is getting quite complicated already, isn't it? So we wouldn't know, but let's- We didn't, we didn't start in a relaxing way, did we? I don't know. (laughs) That's fine. No need to. Uh, no need to. Let's get right into it. (laughs) So, we wouldn't notice... (laughs) Not for the big black holes. So, so yeah, so these supermassive black holes, you, you, we could fall across this horizon. It's just like being in empty space for us. Uh, so we'd just... we'd, w- we would just be talking now and we could've been talking on the outside of the horizon. 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, the thing we would notice ultimately is you go inexorably, w- you, nothing you can do, 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. So it's, it... one way of picturing what's happened here, it's so distorted, this 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, in a real sense, they kind of flip over. They, they get mixed up. And so this, 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 it's more correctly to be seen as the end of time, 'cause everything's gotten mixed up. So you go to the end of time and it's just like saying, eh, the, the... why can't I escape that thing? It's like, why can't we escape tomorrow? Right? So we are going to tomorrow. Right. And if I said to you, let's run away from tomorrow, you'd go, uh... (laughs) I can't run away from tomorrow. So, so- Is, is it the end of time because all information is being erased so there's nothing? Yeah. I mean, if you- Is that the idea? If you draw the thing, you can draw a map of it and it just... literally time ends accor-... just purely, in Einstein's theory, this is 1915 this theory- Wow. ... general relativity, you just get a line there, a line that says there's no future beyond this line. It just stops. (laughs) Okay. So, I mean, admittedly that's not... we, we think it's... there's more, a lot more to it than that, but- It's just we haven't figured the rest of it out yet? Well, that's the thing. So we're starting to get hints about what might happen, which is- Wow. ... which is leading us... so to, to backtrack a bit, why, why does this calculation Stephen did, why has it got no informat-... why does it say there's no information in this radiation? The thing is, it's coming from the horizon. So it's all... one... there's loads of ways to think about it, but o- one way is that th- this, 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. Whereas if you think about the thing that I throw in, if I throw this, 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's not... this thing is not set on fire or something like that. It's, it's gone to the end of time and just whatever's happened to it has happened to it. So, so this radiation's got nothing to do with ev- anything that falls in, at first sight at least. And so that was the paradox. It's called the black hole information paradox. It's like it... 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. So that's why everyone got interested in it (laughs) in the '80s, 'cause it's interesting. So when,
- 16:51 – 21:45
Black holes in galaxies, eclipses, and the perspective shift of a dark sky
- HOHost
when we're looking at the structure of the universe, o- o- obviously there's so much still to learn just about what's out there, you know, but what role do we think... like what is the... is there a purpose, is that the right term, like for a black hole? Like what, what... obviously we know... is it still the, the... do they still believe that in the center of every galaxy there's a supermassive black hole that's, what is it, one half of 1% of the mass of the galaxy? Is that what it is? Yeah, something like... yeah. And, and that's... there's occasionally a galaxy, I think one was discovered where we said maybe we can't see evidence of a black hole, but I think- Oh, really? Yeah. I... but, yeah- So- ... there probably is one. I, I think it's- What do you think that thing's doing there? Like what is that? What's the pro- what is the struc-... the structure is so insanely complex and so immense and you see these things everywhere. And so what purpose do you think they serve in the universe? So (laughs) I mean- Is that a right... it might not even be the right term. Well, so I think we don't... I think I'm right in saying we don't fully understand why all galaxies, as you said-... maybe there's an exception, but w- m- all galaxies have a black hole, a super massive 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. So, that's what, one of the reasons that telescope is up there. So, so w- it's, it's cutting edge research. We're trying to understand how the galaxies form. But I, I, clearly, you're right, that there, it has something to do with the way the galaxies form-
And it's-
... in the early universe.
... pulling in stars.
Well, they, they, they do pull in material.
Right.
But they, i- if you've got stuff orbiting around them, it stays orbiting around it.
Oh.
So, the, the, the way we first detected the one in the Milky Way, before we could, w- p- 'cause that image is very new that we have of it, is it's the stars orbiting it very close to it, and they're called the S stars, that whiz around in these orbits very close to the black hole. So, so if you just-
Imagine that view.
... orbiting around a thing, you go-
Imagine that view.
Yeah, 'cause you don't-
You think it's weird to look at the moon? Imagine if there was a super massive black hole above our head.
It'd be so cool.
(laughs) It would be so cool.
I, I'd love to see one. I, I don't even-
Well, the moon's so cool. Uh, the eclipse was wild. We had the eclipse here in Texas.
Did you see it?
Oh, yeah. It was incredible. It's so strange. The whole day turns into night, all the birds stop chirping, and you're like staring up at this perfect eclipse. It was incredible.
D- did you get this? 'Cause I, I saw one in India, and I got this feeling that I was l- living on a ball of rock.
Right.
Because, uh, and it must have been, just 'cause the night just falls.
Right.
And suddenly you see the universe comes much more quickly.
I went to the Keck Observatory once in Hawaii. I've been a few times, but one time I went on the perfect night with no moon, and it was sensational.
Yeah.
It was the most incr- ... It was such a vivid image of the inc- entire Milky Way, and ev- the enti- every inch of the sky was covered in stars.
Yeah.
It was so phenomenal, and it made me a little upset, because I was like, this is above our head every day, and this would radically shape the way human beings feel about our place in the universe.
- 21:45 – 24:14
UAP talk meets the Fermi Paradox: the Great Silence and life’s rarity
- HOHost
Now we're getting into my subjects. What d- what is your take on all this UAP disclosure stuff? Do you give it any mind at all, or are you busy with like real stuff?
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. Yes.
Which is, and the paradox is that if, 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, there are, we now know, we didn't when Fermi first posed it, by the way. We now know there are so many planets out there. So, let's say trillions of planets in the Milky Way. Milky Way's been there for over 13 billion years, pretty much the age of the universe. 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, as, as, as Elon talks about, multi-planetary civilization. W- 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.
Hmm. Right.
So, the question is, the paradox is, why does it appear nobody has done that? So, the first thing to say is, I, I would not be surprised, right? If a UFO landed here now in the parking lot, I'd actually, not only would I not be surprised, I'd be relieved, actually.
(laughs)
Because I'd be like, "Ah, this is good," 'cause it'd be a weight off my shoulders, 'cause I'm worried-
Right, that we're the only ones.
... that w- we're the only ones, and that-
That's a terrifying scenario.
And we're gonna make a mess of it.
Yeah.
And so I, I'm worried that we could talk about that.
But isn't it bizarre? Like, the, one of the things that's fascinating about looking into the night sky is 'cause it's so humbling, 'cause it's so immense, it kind of puts everything into perspective, and it just gives you this like different view of the world. So, the universe is so vast and so spectacular. Why is it so important that we exist? To us, it's so important that we exist. And if we make a mess of this and we wind up dying, the universe is so big. If we were the only intelligent life in the universe and it didn't matter, we blew ourselves up, like w- i- it's just a weird aberration that's attached to a survival instinct.
So-
Like s-
... we're a weird biological aberration. So, so the, i- if you th- think about it, let's assume, so we di- we didn't finish the UAP thing, so-
Yeah, we'll get there.
So, I was just saying, yeah, so-
We'll circle around.
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, in, in our galaxy, let's say.
Yeah. Okay.
- 24:14 – 30:31
Meaning in an indifferent cosmos: responsibility, climate, and ‘islands of meaning’
- HOHost
Then I would argue...... that. So, there's a question I ask in, 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.
- G3Guest 3
Yeah. That's sort of the question.
- HOHost
What does it mean to live (inaudible) ?
- G3Guest 3
Right.
- HOHost
The, the first thing to say is meaning, right? What does it mean? Mea- that, that doesn't sound like a scientific concept in a way. Meaning, right?
- G3Guest 3
Right.
- HOHost
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. We, we, e- everyone who's listening to this knows that the, 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, right, at, at our level, then it follows, it's the only place where meaning currently exists in a galaxy of 400 billion suns. And therefore, I would argue just for that very basic point that we have a tremendous responsibility in some sense. Because if I, I... By the way, I gave a talk, a little video thing at the, one of the climate summit, the COP Climate Summit in Glasgow in, in the UK a few years ago. And they asked me to do a little video, uh, to the world leaders, and I think they thought I'd say, you know, "Welcome to Glasgow. Have a nice meeting." But I, 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, 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. 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," (laughs) was my intro to Glasgow.
- G3Guest 3
(laughs)
- HOHost
Now, and we can all argue, 'cause people will be listening to this going, "This is nonsense, how can it be." We, we can all argue about whether that's true. Uh, w- what I would say is, given the... As f- as far as I'm aware, we don't have any good evidence to the contrary, that... 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, it... Yeah, if someone lands tomorrow, as I said-
- G3Guest 3
Right.
- HOHost
... I'd be very delighted because then what I just said would be false, and we could relax a bit and go, "It doesn't really matter if we destroy ourselves to some extent." (laughs)
- G3Guest 3
Mm-hmm.
- HOHost
But s- so I think it, it, it's worth taking seriously the idea that civilizations are very rare. Now... And by the way, I used to say, so I... probably last time I was on actually, I used to say that in, in the far future, then the complex life will cease to exist. 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.
- G3Guest 3
I don't believe I have.
- HOHost
He's one of the, um-
- G3Guest 3
No.
- HOHost
... founders of quantum computing and, and so-
- G3Guest 3
Okay.
- HOHost
... he's a big figure in quantum computing, in particular. He's a great thinker. And he th- he... 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. It is possible that life can get so advanced in the universe that it can start to manipulate the universe itself. So... Or at least stars. You could ima- he said you could imagine, for example, just imagine-
- G3Guest 3
Hmm.
- HOHost
... really 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-
- G3Guest 3
Right.
- HOHost
... you know, whatever. So I... We, we don't know how to do that or if it's possible, but imagine it could. Then the evolution of stars would... 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's... And it reminded me, actually. There's another great book by John Barrow and Frank Tipler called The Anthropic Cosmological Principle from the 1980s. 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.
- G3Guest 3
Mm-hmm.
- HOHost
Then suddenly-
- G3Guest 3
It's gone.
- HOHost
... you can't make predictions about the far future-
- G3Guest 3
Yeah.
- HOHost
... un- unless you consider the possible impact of life on the universe. And, and whilst this is... I should say it's wi- wildly speculative, but it's actually logically, it's quite an interesting point. So, 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, it, it bring these brief like flickering candles of meaning, and then they go out again. But it, but it's, it's worth considering it might not necessarily be true, that. If y- if you really think... I mean, just to say, I mean, it s- it must sound to many people listening just nonsense, right? Science fiction. But if you think our civilization has been around for, what, 10,000 years at best really, g- give or take. And in that time, we've sent stuff out of the solar system. We've... Al- although we don't yet, we're way away from being able to manipulate stars, we can manipulate planets. So we, we are changing the way this planet operates. Life has changed it. The, the oxygen in the atmosphere before we appeared, the oxygen in the atmosphere is a products of life. So life already we know changes planets. And so that, that specu- I like that speculation that possi- just possibly-... it's not just a temporary little phenomena that flickers in and out and then disappears again. It could drop a, a real bearing on the future of the universe.
- 30:31 – 1:10:32
AI, curiosity, and godlike futures: would post-biological minds still explore?
- HOHost
And you could also make the argument that intelligent life might be the universe's way to force change, that intelligent life seems to inevit- ... Like, intelligence itself m- must come out of curiosity, because otherwise there's no reason to seek information. So intelligent life consistently seeks information and then it constantly demands innovation. Like, intelligent life is not satisfied with the iPhone 14, it wants the 15, it wants the 16, it wants to keep going-
(laughs)
... forever and ever and ever. Well, if you scale that up, you get this current dilemma that we're in, which is artificial intelligence, and the concept of sentient artificial intelligence, and then quantum computing. And you get, you get insane amounts of computing power powered by nuclear reactors that are essentially a life form. Well, if that thing says, "You guys are doing it all wrong, I got a better way," and it starts making better versions-
(laughs)
... of itself 'cause it's sentient, if you scale up a thousand years from now, you could imagine it becoming God. The ... Like, a godlike property. Like, an unstoppable force that has access to every element in known space.
Uh, I'm, I'm really interested in these kind of arguments. You, you put it really well, actually, be-
It's fascinating, right? Because it scales up-
... 'cause it really is.
... if you go from ... Look, just in the time that human ... Like, in the 4 billion years, which is a blip in the universe, right? And I wanted to ask you about that too. We'll get to that, the, the actual ... The James Webb Telescope's-
Mm-hmm.
... latest, uh ... But if ... Just take that. Okay, life has been around for what? 4 billion years?
Yeah.
That's not that long. So 4 billion years, we've gone some single-celled organisms to the James Webb Telescope.
Hm.
We've gone to ... We have Starlink, we have electric cars. It's like bananas.
Yeah.
You could imagine, if we had another 10 billion years to exist.
Uh, well, exactly. And this is the point that David Deutsch made in the, in the book I've just been reading, and, and John Barry and Frank Tipler made before that. That y- i- it ... Although it sounds insane-
Right.
... th- as you said, uh, and, and that 4 billion years, there's a lot to say about that, by the way, because for, for 3 billion-plus years of that, on this planet, it was just single cells. And so, uh, 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, of the time, were just single-celled things.
That's even crazier.
So wh- which is one of the reasons that many people think civilizations might be rare, because i- if you just t- ... The only evidence we have is this planet.
Right.
And the evidence on this planet is that single-celled life is, is sort of the way that things are for most, most of the history. And then, so it seems like a, a, a f- ... An accident, in a way, that happened late on in the history of life on Earth-
(laughs)
... that produced multicellular life. And, and now, whether ... Is that typical? W- we don't know. Maybe it was ... Took a longer time here than it m- might do somewhere else. But if it's typical, I mean, 4 billion years, you said it, it's not a long time, it is a third of the age of the universe. So here, it took-
When you put it that way, it's a long time. (laughs)
... a thir- one-third of the age of the universe to go from the origin of life to a civilization.
Mm-hmm.
And, and so what was required here on Earth was that that br- unbroken chain of life remained unbroken for a third of the age of the universe in a violent universe. I mean, we ... You know, we, we know there are impacts from space. Many stars are significantly more active than the sun. So the sun's kind of a, quite a boring little star that just ticks along. It's very nice to us. Uh, 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, 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. But-
- 1:10:32 – 1:20:57
Cosmic origins: Penrose, inflation, and what we do (and don’t) know about the Big Bang
- HOHost
... then you're right. From, from some point that we don't understand, by the way, we d- ... the, 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 Roger Penrose's pr- ... he has-
He has a infinite cyclical universe.
Yes.
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. 'Cause-
So, his model is an infinite contraction and expansion?
It doesn't recontract. See, it kind of ... it's called a, what's it called, conformal cosmology or cyclical conformal cosmology or something. So, it's essentially the ... and, and I don't fully understand it, and I have asked him about it, uh, with some colleagues actually. We haven't ... none of us understand-
If you can't understand it, we're fucked. (laughs)
... what he was talk- ... no, no. No, I don't think many of us understand what he-
(laughs)
Roger, uh, I mean, Roger Penrose is one of the greats, right?
Yeah.
So you listen to him and take him very seriously. But I've, I haven't met anyone who quite understands what he, what he's talking about in that.
(laughs)
But, um, but it's, it's ... it doesn't recontract. It's not one of those models where the universe expands and then s- ... and then recontracts and, and bounces like that. It's not one of those. 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, and I can't really fully explain it because I don't really understand what he's trying to say, right? And I'm- Wow. ... I'm ... so-
So, it's not a, a contraction. It's an infinite expansion?
It's... yeah.
And then some sort of a metamorphosis?
Yeah, it kinda looks like ... conformal means there are no, um, 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, 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.
Yeah. So, it ... but it, what it does tell you is that we don't know why or, or how the universe got into this 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 them 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 and the universe is expanding extremely fast, which is ca- ... it's called inflation. And then that period draws to a close, and that expansion sort of slows down and almost collapses and changes. And the energy that was driving the expansion gets sort of dumped into space and changes and ultimately makes the particles out of which we are made. So that, that's, that's actually the standard model of cosmology now. So, so we do have an idea that-... we, we, 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.
Oh, boy.
And, and then you get the question, what is inflation? Did, did, did that have a beginning? And the answer is that in Einstein's theory alone, then yes. 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. And so Stephen Hawking had a thing called the no boundary proposal. There's all sorts. Uh, 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, is the correct statement as we are at the moment. It's p- part of the reason why, by the way, getting back to the black holes, they're important and interesting, 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, so we don't know how it emerges. It's a very strange thing, but it, but it emerges from this collection of atoms, right? Uh, in, 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 ... The one way to describe it is just a quantum theory. So it's, uh, in quantum computing terms, it would be just qubits. 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. 'Cause in order to talk about the origin of time, you have to know what it is.
(laughs)
And we don't actually know what it is, which is, you know ... And that's kind of ... Uh, 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, uh, almost a joke, because he, you assume in Einstein's theory, there's a thing that the watch measures. But what actually it is at the deepest level is a good question. So, but it's funny. It's interesting that study of black holes is forcing us towards these theories. It's not that we had the theory of space and time emerging from something and found ... And decided we could check it by thinking about black holes. It's come the other way round, really. Um, so, so it's, it's interesting. But that, that almost makes the universe look, in some ways, like a, a giant quantum computer, which is not to say that we live in a simulation (laughs) , right? Before you ask.
(laughs)
Uh, but, but it just looks like ... There's a description of the universe that looks like a quantum computer type description. Now, that doesn't have the concept of space or time in it.
Is it possible that that is what it is, and that the universe was created? And that-
Episode duration: 2:55:32
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Transcript of episode Rc7OHXJtWco
