The Infinite Monkey Cage - The Infinite Monkey’s Guide to... Infinity

Episode Date: November 1, 2023

Endless inflation seems to be everywhere at the moment, including on this episode examining the nature of infinity. Brian and Robin dive through the back catalogue to discover there might be no limit to the number of parallel universes that exist. This leads to an argument between astronomer royal Lord Rees and comedy producer John Lloyd, who says the whole suggestion is total speculation. Even cosmologist Carlos Frenk can’t get his head round the idea, as he contemplates the suggestion that new big bangs may be happening all the time.Episodes featured: Series 10: Before the Big Bang Series 6: Parallel Universes Series 21: Quantum Worlds Series 9: To Infinity and Beyond Series 10: Numbers Numbers EverywhereNew episodes will be released on Wednesdays, but if you’re in the UK, listen to new episodes, a week early, first on BBC Sounds: bbc.in/3K3JzyProducer: Marijke Peters Executive Producer: Alexandra Feachem

This is the first radio ad you can smell. The new Cinnabon pull-apart only at Wendy's. It's ooey, gooey and just five bucks for the small coffee all day long. Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. BBC Sounds. Music, radio, podcasts. Hello, I'm Brian Cox. I'm Robert Ince and this is the Infinite Monkeys Guide 2. Every now and again our show has moments of furious confusion. Quite often for you.

No, not furious confusion. My confusion is just a la-la-la-la, haven't got a clue what he's talking about. Is that what that look is? La-la-la-la-la. You know what I'm nodding? I've been looking at this face for the last more than a decade and furious confusion, I think, defines that look beautifully. That's what it is.

I'm very much confusion in a hammock. Just kind of, ooh, yeah. But sometimes we have had guests who've not had as much time to get into the hammock of confusion and are in the conflagration of confusion because our brains are big enough to fit in the simple symbol for infinity but when it comes to actually contemplating the infiniteness of infinity or infinities then we do start to get a little bit dizzy from cosmological vertigo

do you ever get cosmological vertigo no there must be something which you've contemplated that has just made you have you know that kind of yeah joke. I mean, the idea that two trillion galaxies, by some measures, it's an estimate, of course, of how many galaxies there are in the observable universe, the part of the universe we can see. And then you think one of those galaxies, the Milky Way, our galaxy, 400 billion suns, give or take, our galaxy, 400 billion suns, give or take, takes light around 100,000 years to cross it. And that's one of the many hundreds of billions,

even thousands of billions of galaxies that we can see in the sky. Yes, I agree. You know that bit when you're putting together the picture in your head and then suddenly it becomes so massive and you just think, oh, I'm slightly off kilter now. 400,000 million suns in one galaxy. It is impossible to picture. Every day you need to make that noise that Keanu Reeves makes in the first Matrix movie, that bit where he goes,

whoa, that kind of just noise is very required. When we first did a show about Infinity, I found that, I think it's a New Yorker cartoon, I think it's one of the greatest cartoons of all time. It's the number eight at the therapist, and the therapist says, just lie down on the couch, and he goes, if I lie down, we're going to be here forever. Well, here is the great cosmologist,

hugely popular guest on the show, Carlos Frank, contemplating infinity. Infinity always kind of gives me the desire to scratch my head. Infinity is big. Big, big, big. So I worry about infinity. It's much bigger than my brain, I'm sure, of that. So it turns out, sadly for me,

and I hope for most of you, that if these ideas of inflation are correct, then because inflation is associated with these quantum things and quantum things fluctuate all the time, then it may well be that once the mother of all big banks happened and inflation then followed, that as part of inflation there were more quantum fluctuations that created a new universe distinct from ours which inflated as well and because there was still some leftover of this vacuum energy i was talking about before it would fluctuate again and again and again and again and again and we could be in a situation where there isn't one universe or two or three

or any number i can count but an infinite number of universes but that's bad enough trouble is if these ideas are correct there are an infinite number of universes being born all the time right now we need to deal with this so brian how many infinities are there i know i know there's a kind of infinity you have between say say, one and two, where there's an infinite number of fractions. What are the others? It's one of the most counterintuitive ideas that there are different sorts of infinity.

It goes back to the great mathematician Cantor. It was those others that led to a heated debate, which is unusual among the case, isn't it? A heated debate. When legendary comedy producer John Lloyd met legendary astronomer royal Lord Martin Rees. And John Lloyd became affronted to discover that there are so many infinities. But first, they had to deal with an infinite number of Big Bangs, leading to an infinite number of universes. and that's before they got on to the infinite

number of potentially infinities is your head hurting yet if it's not hurting yet you're not listening properly so here they are martin reese and john lloyd debating the idea that there should be different types of infinity martin has said before that it's slightly embarrassing in science that 95% of the universe that we're in is unaccounted for. Only 5% we know something about. And the other 95% is two made-up-y things called dark matter and dark energy. So, I mean, it could be anything, couldn't it? Brian? Well, they're not made-up-y in the sense that we've observed their influence on the universe. Well, no, I'm just saying that we don't know what they do

or where they are, and therefore, what other theory... You know, if I produced a comedy show that was only 5% funny, I think I probably wouldn't be sitting here now. Why should everything shine? Most things in the universe, most things in this room don't shine. So why should it in the universe? No, I'm just saying that... Most things are dark in the universe, most things in this room don't shine. So why should it be in the universe? No, I'm just saying that... Most things are dark in the universe, just like the Earth.

My point was that I thought that maybe the 95% that we don't know about is where all the parallel universes are. But that would only allow for 20 of them, which isn't enough to cover the very large numbers that Martin's talking about. It's an interesting point, actually, because, Martin, I believe there have been theories where the influence of maybe extra dimensions in the universe are causing those deviations from Newtonian gravity.

Well, extra dimensions are, of course, fascinating. Most people suspect that if we were to divide up space very finely indeed, on a scale much, much smaller than atoms, chop it up very small then what we think of as empty space becomes very complicated. What we think of as a point in our space may even be a sort of tightly wrapped origami in five

extra dimensions. This is what string theorists think about. But some people think that there may be some of these dimensions which aren't wound up so tightly and it may be that we see some evidence for them in accelerators. But more spectacularly, it could be that there are some that aren't wound up at all. And if that's the case, then there could indeed be another universe which is alongside ours,

but separated by a small distance in a fourth dimension, and we're not aware of it. Just like if you imagine a whole lot of ants crawling around on a sheet of paper. That's like their two-dimensional universe. They might be unaware of another population of ants crawling around on a parallel sheet of paper. It could be that we are in our three-dimensional world

and we are in a space-time that's embedded in some extra dimension and there are other space-times also embedded in it. This is really fabulous, but it is, you know, it's science fiction and fun. It's speculative science. It's speculative science. Somebody said there is speculation, there is wild speculation, and then there's cosmology. Isn't that right?

50 years ago, we didn't know if there was a Big Bang at all. We knew nothing about cosmology. Now we can talk with confidence about back to when the universe was a nanosecond all. We knew nothing about cosmology. Now we can talk with confidence about back to when the universe was a nanosecond old. That's huge progress. And if we think of that progress we've made in the last 50 years,

then 50 years from now, I suspect we will have got back far enough to be able to understand the Big Bang well enough to say whether it was the only one, whether it was one of many, and whether the other Big Bangs cooled down to be governed by the same laws as ours or not. I should mention that there is an idea called eternal inflation,

which is the idea that our Big Bang started with some very rapid expansion called inflation, but that these Big Bangs keep popping off all the time in some infinite substratum that goes on forever. So it's rather like the old steady-state universe, but on a much grander scale. This I love, because I've been saying, I'm going to really step out of line here, I've been saying for ten years that the big bang theory will not stand out,

will not be here in its current state in ten years' time. And you've already mentioned there might be some other big bangs, and this eternal expansion thing, and there's a thing called quantum fluctuation, isn't there, as well, which is quite interesting. And it's starting to come apart at the seams, this big bang thing, because there are a lot of...

No, that's not true at all. It's just... But are you saying the steady state? I like the steady state here. I like Fred Hoyle, and I think that... Well, it was completely wrong in the form that he proposed it. Yes. But it's coming back to deciding that there's...

No, it's coming back on a quite different scale. The point is that in science, what happens is that there are speculative questions, and as they get settled, new issues come into focus, and new questions which you couldn't have posed before. So we've settled most of the questions we debated 40 years ago, but we are now addressing questions that couldn't have been posed then.

And 40 years from now, it'll be another set of questions. That's the nature of science. New science doesn't sort of overthrow the old, it transcends the old. Now, Brian often wonders what an infinite universe would actually look like. Well, I know, because our universe could well be infinite, and I know what it looks like. Well, you know a bit of what it looks like. You haven't got the full picture.

No, that's true. If you have got the full picture, start showing it to us. You'll probably win a prize. But you also like to be drawn into ecumenical matters, and that is how we ended up discussing how a universe without a beginning may affect religious faith with screenwriter and theologian Katie Brand. If, for example, it is shown through doing physics

that the universe is eternal, for example, does not have a beginning in time, what do you think it would mean to people who think about religion? As in, there was no point at which the universe didn't exist and therefore there can't really be a creator. Yeah, well, does that follow? Well, I mean, I'm not now religious and in fact i became an atheist uh on a pilgrimage to rome uh now it's supposed to work yes and i did

meet the pope at the end and it felt like the closer i got to the pope the more atheist i became is what i originally so it was embarrassing when i did finally meet him but i so i can't answer from a personal point of view because i would just find it very exciting because i'm now an atheist and i would just find it fascinating because i find all of this fascinating but i do think you know a lot of christians have have tried to combine the idea of evolution with the idea of guided evolution and that you know all of these scientific discoveries have been kind of folded into religion for the more open-minded or intellectual perhaps people who have religious beliefs so personally I would think that what would happen I'm sorry to disappoint anyone who's a very militant atheist is that religious people would simply find a way to fold

that into their existing story and I think probably a lot of humans would be comforted by that. But I think it's hard to know, because what I'm trying to understand is, how radical would it be for humans, just sort of at a layperson's level, like me, if you did discover the theory of everything? Or would it just be sort of felt to be, you know, a kind of another layer of very complicated physics that most people don't really engage with? Or would it

be sort of front page news like as if an alien had landed in someone's back garden in richmond when you say front page news when we look back einstein was front page news and there were in in the 20th century in the first half science often was front page news and there's still science going on that should be front page news but unfortunately our media has decided that that is not as immediately kind of tacky and sticky and so it's all out there so i think that's part of it as well is to say there are brilliant and wonderful ideas and this is far more interesting than your particular attack on you know harry and megan or whatever it might be but it's also it's interesting isn't it how harry and megan can be both royal and not royal now quite often we've heard that mathematics is a pursuit that can turn people quite mad uh and indeed there is a rich history of people who trying to

comprehend a world of numbers just eventually that was almost very funny did you say can turn i thought you said can't oh can't yeah can't or people quite i thought that's an extremely if we get to that level of pun which i think we may well have done again by chance then uh perhaps we've we've finished our work here can't had the very famous concept of different infinities um had long long discussions with david hilbert the great mathematician and again one of my favorite things that we've discussed in Monkey Cage, Hilbert's Hotel. Yeah, the finest thing that we put into that book we did was the Trip Advisor's review of Hilbert's Hotel and the various issues with continually having to get out of the room that you'd booked and move to the next door. It's the idea that you can have a hotel with an

infinite number of guests and not be full. It's a parable. 21st century Britain. But if it is full, then what happens is someone turns up and then as long as you move one more room, it turns out there is another room. Is that roughly? Yeah. And not surprisingly, John Lloyd... He disagreed with mathematician Simon Singh.

My argument about infinity is this, Simon. Infinity is a word that belongs to the wordy people like me and Robin. The word creatures. And not to the numbery people. Oh, you can have two as well then. Two's a word. No, no, Simon. Infinity is a word. That belongs to the wordy people like me and Robin. The word creatures. And not to the numbery people. You can have two as well then. Two's a word. No, no, no. Two is a numeral. But the point is, you cannot place a numerical

value on infinity and therefore you cannot have a plus one to it or a minus one. No, it was just proved that you could, so we can stop this. It's been proved. That's not proved. Is it a problem with you that's just good it's just wordplay it's gameplay but you have to take infinity as something which

is you know could be bigger but you're right you're you're right in that when whenever i say no he's not no no no he's right in as much as whenever i say so i'm going to talk about the number infinity somebody always corrects me and absolutely right to correct me, that infinity is not a number. It's a concept. And we can play with that concept using mathematical ideas and so on. But as you say, in a concrete way, it's not a number. There are either an infinite number of numbers or there aren't. There are.

I don't see where the problem is. No, there aren't. There aren't an infinite number of numbers, right? Because you can always have more than infinity, and therefore infinity is a meaningless concept. See, I'm annoyed now, because I'm thinking about the infinite number of monkeys, and you get them all together,

and then you go, what have they written? And you go, they've written the Jew of Malta. But that's by Marlow. We didn't have enough monkeys. You know, the whole kind of thing is a disaster. And now to ensure that this show is a Mobius strip, we find ourselves back to roughly where we began. Just how many infinities are there?

Here's mathematician Vicky Neill talking big, big numbers. What's the difference between a big number and a big, big number? Well, it's much like infinity. You know, there's big, and then there's biggie big, and then there's bigness big, and then there's the notorious B.I.G. Is there a number so big that you can't fit it in an infinite cage? How big is your infinite cage? What kind of infinity do you want to find?

No, we're not doing that again. No, no, no. I refer you to series nine for that argument. What about the smallest infinity? The smallest infinity is the real numbers. Is that the smallest? No, no, no. Whole numbers.

Whole numbers. Real numbers. Whole numbers. There are loads of whole numbers, but there are loads and loads of real numbers. Like, loads. Oh, yes. So if I had a cage that was just big enough

to fit the infinity of real numbers in it... That would be huge. That would be huge. That would be huge. Yeah, like massive. But whole numbers then I could, it wouldn't fit the real numbers. That would just be quite big. It wouldn't fit the real numbers. Real numbers aren't that huge because you can quite easily, there are infinite number infinities that are even bigger than that. Yeah. So the infinite cage is really

yeah, problematic. If we were a bit small, treating the numbers humanely, could we make it smaller? The Infinite Monkey Cage episodes we took all of these clips from are available on BBC Sounds and the Infinite Monkey Cage back catalogue. Now, next week, you're in charge of the show. So you've sent us a long list, wonderful emails

about the things you found most surprising over 15 years of The Infinite Monkey Cage. Sadly enough, the main thing that I've seen on the list is the fact that I have aged at an incredible rate and you haven't changed one bit. Apart from the fact you're a bit thinner. Which is hard, really, to contemplate because it's a radio show, so I don't know how they know this stuff. I just think they hear my old beard all filled with like kind of blackbirds that live in it rustling against the microphone every now and again and they hear the tightness of your skin

sometimes ping. Yeah you are morphing into a kind of a Alan Moore. Somewhere between Alan Moore and the subject of a limerick. The Naughty Monkey In the Infinite Monkey Cage Without your trousers In the Infinite Monkey Cage Turned out nice again. We hope you enjoyed that.

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