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Well, good evening, ladies and gentlemen, and welcome to the Science Museum.

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I'm Roger Highfield.

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I'm one of the directors of the museum and we're thrilled to host this event for the University of Oxford's Mathematical Institute.

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It's a huge honour to welcome Sir Roger Penrose, Emeritus Transport Professor of Mathematics.

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He's used a combination of maths, art and bestselling books to reveal the unity between mathematics and the physical world.

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Sir Roger will be joined by Hannah Fry, Associate Professor in the Mathematics of Cities at University College London,

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who's actually best known as a broadcaster and writer and has just released her latest book, Hello World.

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A good friend of the museum, Hannah, is also among our latest crop of trustees.

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In fact, she's been taking selfies in front of her name for half the evening.

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Mathematics provides the fabric of modern society, and it's really important to the museum and appears in all sorts of guises.

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We've got our patent pod aimed at younger children, which is inspired in part by Sir Roger's ideas.

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The equations of aerodynamics were crystallised by Dame Zaha Hadid into the sensuous physical forms of our mathematics gallery.

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We're doing a citizen science experiment with Redding University, which aims to improve space weather predictions.

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And that's for our new exhibition About the Sun. And of course, there are lots of events like this one,

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and mathematics shows that we've developed for hundreds of thousands of schoolchildren each year.

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So when it comes to our future projects, you'll find mathematics in an exhibition that we're developing with HQ and all sorts of guises

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in our new or our forthcoming medicine galleries such as epidemiology and in a new gallery,

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our forthcoming gallery, Science City, which is going to tell the story of how London became a global scientific and technological hub.

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And now I'd like to introduce Mike Giles, professor of Scientific Computing and the Oxford Mathematical Institute.

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Over to you, Mike. Thank you, Roger.

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It's a real pleasure to introduce the second Oxford Mathematics London Public Lecture following last year's successful lecture with Andrew Wiles.

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I would like to thank the Science Museum for generously hosting the lecture and a special thanks to execs markets.

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Sponsors of the Oxford Mathematics Public Lecture Series and X Markets are a

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leading quantitative driven electronic market maker with offices in London,

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Singapore and New York. And it's a real pleasure to have so many of their team here tonight.

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It's very important for us in Oxford Mathematics to get out of Oxford and spread the word about our subject to as wide an audience as possible.

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And our public lectures are our flagship vehicle for doing this.

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If for future events, you're not able to come in person, they are all broadcast live and they're also available subsequently on our YouTube channel.

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And so to our speakers, as Roger Highfield says, Roger Penrose needs no introduction, a true mathematical polymath.

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But is he really a mathematician or a physicist?

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Tonight we'll find out. And Hannah Fry also needs no introduction.

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All I will add to what Roger has said is that her latest TV series, Magic Numbers,

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is also available on iPlayer, and she will be signing copies of her book after the lecture.

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So without more ado, let me please present Sir Roger Penrose.

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Well, thank you very much for that introduction. I suppose you want to know the answer to the question about whether a mathematician or a physicist.

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One of my physicist friends keeps worrying me about that, and sometimes people ask me.

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So I think the answer to it is that mathematics I find absolutely wonderful and huge pleasure, and that's what I do.

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But it's the physics which drives what I do.

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So I'm interested in physics as and what's what are the answers to the way the world works and that sort of thing.

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So I say the big drives come from physics, but what I actually do in detail is usually mathematics.

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So I'm both, I suppose. I hope I'm both anyway. Anyway, I want to give a little talk, which is to do with things I've been doing extremely recently.

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In fact, some of these things are really just about last week or so, so it's really up to date.

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So let me explain. I'm going to talk about cosmology.

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And so perhaps we could have the first picture. No, that's.

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That's the first picture. Thank you. Now, you see this. I like when my mathematics.

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I very much like geometry, although I can do a bit of algebra too, but geometry.

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And I like to draw pictures of things. So these are pictures of mine, which I'll show you.

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I often show them on a an overhead projector or something, but this is a nice way of doing it.

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You get nice big pictures here, and this is a picture of the universe.

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I should explain various things about it. Time is going up.

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So you think of any one moment, if you like, of the section through this.

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And one thing I should point out, if you look right at the top, you see look a little bit strange and there's that frilly part of the back.

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That's because I want not to be prejudiced as to whether the universe especially open or closed in my goes all the way round,

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or it might decide to do something else in the very great distance.

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So that's really what that's for.

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So I have a fairly bit at the back, just so I don't care this from the point of this talk whether the universe especially open or closed.

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Now right at the bottom you have this thing called the Big Bang, and that expanded out, the universe expanded out from that.

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And this expansion, I should say, is very much in accordance with Einstein's general theory of relativity,

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which you introduce in whatever it was, 1915. And there is this exponential expansion that you see.

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If you go up, it's it expands out a bit, slows down a bit, and then starts to do this what's called an exponential or self similar expansion,

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which has been observed for looking at distant supernovae, stars and so on.

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But I'd saied's equations require what's called the cosmological constant.

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It's usually called lambda. These days people call it dark energy.

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I don't like the term very much because it's neither dark nor energy in the sense it's pushes rather than pulls energy and gravity pulls things in,

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says a strange the terminology, never mind. Anyway, that's the dark energy, and it causes the universe to expand and expand and expand.

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And this behaviour is in all the cosmology books.

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If you put in this lambda the cosmological constant and when it's positive that's what it does.

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So that's pretty well a picture of the universe as we now believe it to be,

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except people usually think right at the beginning there is something called inflation.

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And I might be asked, why haven't I put inflation in the picture?

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Well, there are two reasons. One is maybe I have, because inflation would be right tucked in at the little black spot at the bottom.

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You wouldn't even see it in the picture.

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This inflation was supposed to have taken part in the universe's activities in the first about ten to the -30 2 seconds.

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So think of one followed by 32 zeroes, one over that.

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That fraction of a second, in fact, is supposed to have been within the time that the inflation took place.

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Now, if you wanted to see what inflation is supposed to look like, we need a pretty good magnifying glass to look at that little point at the bottom.

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So let's have the next slide, please. And there's the magnifying glass.

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When I use overheads, I put that one on top of the previous picture, but I'm not doing that here.

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What I'm going to do is show you what you would see with this very powerful magnifying glass.

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And I have the next picture, please. And well, the thing at the top, I should say, is just the handle, the magnifying glass.

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So that's not something funny about the universe. Forget about that.

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But the you see, this expansion looks very much like what we see now as this exponential expansion of the universe,

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which is observed now from the observation of distant supernova stars and all sorts of other things which fit together to get the picture,

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that that's probably what the universe is doing now. But this view is that within these first elements, 32 seconds,

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it did this other exponential expansion and expanded by some huge amount in that tiny little point.

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Now, I never like this partly because it doesn't fit in with Einstein's equations very happily,

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partly because, well, it didn't do half the things they're supposed to do.

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It's supposed to smooth out the universe, and it doesn't do that. However, it does do something.

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It does a couple of things which are important in cosmology.

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I'm not going to say much about that, except that they are important and that if we don't have inflation, you've got to have something a bit like it.

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So I'll come to that shortly before that.

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Let me describe something about infinity.

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You see, the universe does is expansion, and then it's going to go expanding and expanding and expanding right to infinity.

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At least that's what Einstein's equations tell us. So infinity is a nice thing to talk about in mathematics, and it's very important in mathematics.

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People say you can't really understand infinity, can you? Well, you can in mathematics.

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That's just what you can understand. So let me have the next picture.

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Now, that's a very nice illustration of infinity, and it's also a very nice piece of geometry.

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I am very attracted by this picture. It's an Escher picture.

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If he was told about this kind of geometry by Cocteau, who is a very distinguished mathematical geometry,

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and he said to Escher, Why don't you use this representation of what's called the hyperbolic geometry?

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So you have to imagine that these fish, I think they're fish, are all really the same size and shape.

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But when you get round the edge, they're squashed down. And the way they're squashed down is according to what's called a conformal map.

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Conformal means where small shapes are preserved, they might be bigger or smaller, but they're not squashed one way or the other.

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If they're squashed, they're squashed always in the same way, to the same degree.

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So it's what's called conformal. That means angles. So you take the angles on the fins or the wings or whatever they are of these fish.

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And those angles are exactly the same, no matter how close to the edge you are.

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So according to the universe that these fish inhabit, which is called, as I say,

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hyperbolic geometry, but this is what's called the it's called the Poincaré disk,

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which is, of course, in mathematics, you often find that the name attached to something is not always the first the right one.

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I mean, it's really Beltrami who is in Italian geometry who for this representation before Poincaré?

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Well, Poincaré made a lot of very important use of it, so it's all right to attach his name.

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Except Beltrami got a rather bad deal out of it.

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There's another well-trod is called The Kline Representation.

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Again, he doesn't get the credit for it, but it's very beautiful.

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And the straight lines in this geometry are really circles. Well, they look like circles in the picture which meet the boundary right angles.

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And if you follow the the fish, the noses of them, and they go nose to tail all the way around, you'll see the circles all over the place.

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Very nice representation. Now, the point I really want to make about this is using this conformal idea.

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So the geometry we don't know about distances, you just know about angles you can represent often, if you're lucky, infinity.

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So this boundary around the edge, you can look at it and you say, well, you could step outside that,

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but these fish think that that's infinity as far as they're concerned.

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So that's the kind of representation which I've been very keen on.

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I've played around with these conformal geometries for a long time before I started doing research in mathematics,

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or at least official research I was supposed to be doing. And my interest in general relativity,

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I found my interest in these things were important and I learned how you could study things asymptotic, things like radiation.

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I mean, what is if you have something radiating and the radiation goes way out to infinity and describe it.

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If you have infinity just sitting there, it's. Very helpful. So I was playing around with these things in the 1970s and so on.

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Okay, now let's think about our cosmological picture.

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I think I want the next slide, please, if I've got it right.

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See here, what I've done is the same trick as we have in the picture applied to the remote future.

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So the remote future goes on and on and on and on.

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And one of my reasons for thinking about this in this conformal way was it seemed to me that the universe.

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Well, I mean, it gets pretty boring for a while when black holes have swallowed pretty well, everything of interest.

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I come to the black holes in a minute and then as we can see, that's I go to the next picture quickly and then I'll go back again if I can do that.

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This is a picture of, again, a space time picture.

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So time is going up and we have some collapsing material at the bottom and then we have the black hole.

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You need a few more dimensions to picture it properly, but the black hole is represent.

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The horizon is where you see that line, the singularities in the middle and the horizon just outside that.

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And then, according to Stephen Hawking, after a while, these black holes disappear.

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Well, I'm pulling with a pop because whatever kind of an explosion it is, it's very,

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very tiny on astrophysical by comparison with other kinds of astrophysical events.

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So this black hole, it can be. Well, you see, our galaxy has a black hole, which is about 4 million times the mass of the sun.

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There are lots of smaller ones undoubtedly going around, but the one at the middle is extremely big.

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And you can see it's quite amazing because the pictures like a movie of these stars going around this thing in the middle,

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you can't see a thing in the middle because the black hole you can't see directly,

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but you can see the stars going around it and this you can see and speeding it up a bit, but it's quite impressive.

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So it's there. Now, what happens to the black holes eventually?

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Well, you see, they evaporate away by hawking evaporation.

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And then when they've all gone. How long does that take? Well, for the really big ones, you have to think of something like a Google.

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Yes. What's a Google? Well, that's one followed by a hundred zeros.

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Not a very scientific term, perhaps, but it was invented by the nephew of, I think, a mathematician.

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And it was a nice name to say if you mean a really big number.

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Now, Google is, I say, 10 to 100 years.

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And that's the sort of time you're going to have to wait before all the black holes have gone.

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The really big ones take the longest to go away, and the smaller ones go much more quickly.

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But after they've all gone now, I thought it was pretty boring before sitting around watching for a black hole to evaporate.

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Whether that's dead boring when they're all gone, that's very boring.

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But then I began to think, who's going to be bored by this?

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Well, photons, probably mainly photons. And it's really hard to borrow a photon.

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It's hard probably for two reasons. One is it probably doesn't experience anything, but the other is from relativity effects.

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Photons. If I could say experience, don't experience time at all.

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The time from creation of that photon or whatever happens to it is nothing for that photon.

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So that it gets right out to infinity. And it's as though this has just happened instantly.

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So as far as the photons or other particles which have no mass are concerned, infinity is right there.

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So I'm going to show you in the next picture. Next one, please.

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No, that's. Is that the next one? I can't remember.

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Perhaps it was the next one. That'll do. These are the cones that you perhaps saw in the previous picture.

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They're very important. They're what I call light cones or now cones, and they represent what light would do.

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So think of the big picture at the bottom.

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And here I've got a couple of clocks, the histories of those clocks, and they're supposed to be identical clocks.

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And this purple, whatever they are, ball shaped surfaces represent the first tick, the second tick, the third tick.

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But the light cone is there. Irrespective of the clocks.

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And it's very important they're sort of sitting there at any point is space time.

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The main structure of that space time is given by those cones.

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It tells you what light would do if there were light there. And you see the photons zipping along like that.

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With the speed of light. That means going along with its word line, going along the cones.

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And you can see if you look back at the previous picture with the black hole right on the horizon,

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the cones are all tipped over so that the light rays are along the horizon.

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But anyway, I want to show you this pic, this picture here, because it illustrates something important about relativity.

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The thing I want to illustrate is that there's a thing called the metric now that defines the structure of space time at every point.

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There's what's called the metric. Now, the metric is a thing which has ten numbers to describe it.

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Nine of those numbers, really, it's the ratio of the ten numbers, nine of those numbers.

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And that in that sense, tell you where that light cone is.

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So that's most of the information. The one other bit of information are the ticking of the clocks.

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Now, in relativity, nowadays we have extremely good clocks, very, very, very precise clocks.

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They're so good, for example.

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But one of the effects that Einstein predicted about clocks is that if you had a clock down here and a clock way up there,

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the clock down here would run just a little bit more slowly than one up there.

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But nowadays, if you had a clock sitting here and the clock ticking there,

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we can now measure the difference between the time rates, very, very precise.

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Now, the fact that we have such precise measurements of time is one of the things that underlies the very precision of Einstein's general relativity.

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Now. The one important reason for that is the two formulae that I have at the top on the left hand side.

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These are the two most important formula of 20th century physics.

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One of them, of course, is Einstein's E equals M.C. squared, which tells you, roughly speaking, that energy and mass are equivalent.

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Okay, you've got C squared, but that's just a constant energy and mass equivalent.

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The other formula is Max Planck equals H new.

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I think people call it F. Often these days that's the frequency E is again the energy.

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And Planck tells us that energy and frequency are equivalent.

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Okay, you've got another constant, which is Planck's constant, but that's a constant.

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So we have these two formulae, both telling you energy is something and one tells you it's equal to mass,

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the other something, even the frequency apart from constants.

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So that tells you that mass and frequency are equivalent.

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So if you have a stable, massive particle, that particle is a clock.

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It's a clock of incredible precision. It's not something that you could necessarily measure.

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You can't use it on your wrist or something. You have to have some way of of.

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So scaling it down does extremely high frequency. But that's what these essentially these very, very good clocks depend upon,

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is the fundamental fact that energy and frequency are equivalent in physics.

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Now, suppose you have no mass.

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Photons don't have mass. They aren't any good of being clocks and they zip along the cone.

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They never hit the first of these [INAUDIBLE] surfaces so that that first tick never happens.

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Those clocks don't experience time at all. So suppose you had a situation in the universe where there weren't any massive things around then.

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It's really the geometry of the cones that you're interested in, and that is in relativity and space time structure, the conformal structure.

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I said angles. That's the conformal structure. Well, here it's the light cones and that's the same thing.

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So if you only have the. If you don't have any mass, you've just got things without mass.

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Then they're not really interested in the metric. They're only interested in the conformal structure.

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So now you can apply the trick, which I just illustrated in the estimate Escher illustrated,

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and the picture I just showed you a moment ago with this infinity of that geometry being represented by a nice boundary, a nice smooth boundary.

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That trick can be used for the whole universe. Now, can I have the next picture?

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I hope it's the right one. I think the picture has gone missing.

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This one. Can we go back to. Back to back.

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Another one. Back another one. That's it?

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Yes. Did we have that picture? I can't remember.

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Anyway, you see the tricks here. Right in the remote future.

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That's the trick I'm talking about. We've squashed down infinity to become a nice, smooth future boundary.

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And as far as the photons are concerned, they zip along and they get to the boundary.

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So if you had nothing left but things of that mass, this is a problem about electrons.

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And so you need to do have a scheme which gets rid of that problem, which is probably the mass phase out in the very remote future.

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But let's not go into that issue. It is important for this scheme, but let's suppose you have nothing left but photons.

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Then you can do that trick. What about the other trick?

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This is the opposite trick. You see, we have this nasty big bang at the beginning.

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How do we talk about that? Well, again, you can play a trick.

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This is the other direction where you stretch it out.

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Now, here, the reason you can get away with that is because things get hotter and hotter and hotter than when you get the big bang.

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Then the nearer the, the higher the temperature gets.

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And when the temperature is extremely high, that means each particle has an extraordinary high energy,

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far higher than the mass energy that, according to the Einstein equals M.C. squared is.

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So you get an energy, which means that the mass becomes completely irrelevant.

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The closer to the Big Bang you get, the more irrelevant the mass gets.

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And so therefore, this trick makes physical sense. Now, I should say that the future one applies very, very generally.

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There's a theorem due to Helmut Friedrich, which tells you that you can get away with this very big general case of irregular universes.

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In the other direction, it's completely the opposite. It's a very, very strong restriction on the world that the Big Bang can be treated in this way.

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I kept worrying for a long time because we know there is a very big restriction.

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It goes down to a thing called the second law of thermodynamics. I can't spend time talking about all these things.

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Then a colleague of mine, Paul Todd, who was a student of mine, and he had a much better way of describing that.

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The very, very, very strong restriction that the Big Bang had satisfied is that you can stretch it out that make it something nice and smooth.

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So here we have a nice representation. Nothing outrageous with regard to cosmology.

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You can squashed an infinity stretched out the big bang. The squashed down infinity looks like the same as the stretch.

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That big bang, you might say, isn't the big bang very, very hot. Yes, it was.

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But then you stretch it out, it gets colder again and you squashed an infinity.

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It gets hotter. So they look pretty much the same. Okay, now let's have the picture with that.

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We I think the last one, if you can rattle along to the last one.

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Great. Now, this is what's outrageous. The one I had before.

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Okay. It requires maybe people have to agree with me.

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It's okay. But now this is outrageous. Our Big Bang, according to what I'm saying, was the conformal continuation of somebody else's infinity.

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Now I'm calling these individual things on the left.

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I looked up in my dictionary to see how long an Ian was, and I was glad to see there was no definite length of time.

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So I'm going to call it the entire history of the universe is one Ian.

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Now our remote future then because there's nothing left with any mass, becomes equivalent to a big bang of the next.

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Ian And it's nicely smoothed out in just the way you want to have the signal of feminine dynamics and all that stuff in the right form.

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So it really works very nicely. Of course, not only in the cosmology community like this idea because they're being brought up with inflation.

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And where's inflation in this picture?

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Well, actually, you could see it because if you take the one in the middle to be our Ian, then the one before it,

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rather than having to have a big magnifying glass to see that exponential expansion, you can see it in the previous Aeon.

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Now this is an idea which is a bit like an idea that that was an Italian physicist called Veneziano had his model was a bit different from mine,

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but I'm not claiming originality for that particular concept because Veneziano had it in his model.

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But okay. Anyway, that's that's the conception I have with consult conformal cyclic cosmology and I find it rather attractive.

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It makes nice mathematical sense. So that's why I like it, if you like.

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When I'm a mathematician, does it make physical sense? Well,

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I gave lectures about this for many years and I was quite happy to give the lectures because

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I thought nobody is ever going to be able to do an observation which will prove it's wrong.

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So I'm nice and happy. Then I started thinking like. You can find the evidence for it.

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And the thing I thought of was the collision between supermassive black holes, which would produce the huge gravitational wave signal.

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You see, we have this 4 million solid mass black hole in our centre.

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We are on a collision course with the Andromeda Galaxy, which has one inch, about 30 times bigger than or something like that.

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And so there will be one walloping explosion when they hit each other and swallow each other up.

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We won't be around to see that, but people may be in the aeon beyond us might see the effects.

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Now, what I'm saying is that we might see this kind of thing happening in the Aeon prior to us.

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Well, I'm not going to talk about that because this is all very controversial.

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Do we see these things? I think we do, but we get into all sorts of trouble.

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Me and my colleagues, my Armenian colleague and my Polish colleagues who seem to have some decent papers on this,

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seem to giving good evidence for that, but nobody's picked up on it.

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More recently, we've had another idea. This is very appropriate in a way, because it has to do with Stephen Hawking.

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Now, I showed you that evaporation of a black hole.

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And Stephen was very worried that his prediction of black hole evaporation was never going to be seen.

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He hoped it would be seen by little black holes in the in the big bang.

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And and but nobody saw it. But what I'm claiming.

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Just think about it for a minute. That black hole, although the radiation coming from it, is very, very weak, extremely low frequency,

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all that energy in that black hole is finally dumped into this photon, mainly photons.

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So that by the time of the crossover. Let's talk about the previous aeon, though, the one below, the one in the middle.

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Think of a black hole in there. It's been sitting around and right tucked up.

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I talked about the Google years.

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Where is the Google Earth in this picture is you could hardly tell it from the crossover surface to the next one is right up there.

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But all the energy in that black hole is contained in that.

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And where does it go? Well, it bursts through into the next aeon.

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Now, my colleagues, Christoph Meissner, Polish colleague, and Daniel Ann,

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who is a Korean who works in New York, have been analysing the cosmic microwave background.

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That's the radiation coming from well, is it the Big Bang where it's coming from about 380,000 years after the Big Bang.

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But still, it's pretty close to the big bang on the cosmological scale.

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And what we claim is happening is that the energy from the black supermassive black hole in the previous aeon burst through to that crossover surface.

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And in the 380,000 years, it spreads out to a distance, which is about eight times the diameter of the moon.

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That sort of cosmological scale is actually pretty small. The moon looks quite big to us, but that's because I don't know.

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From the home sky it's really quite small. And this is the what we call hawking points.

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Now, the evidence for these things, the analysis, not all of which has appeared.

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Yes, we have an article on the on the archive, but the new one we don't have on the archive yet.

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The confidence that we can give, gives to the signal by the usual tests that people use in cosmology would be one part in the well.

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In about one of one ones in about 50,000.

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Now 5000. Yes. Because you do a lot of tests to see whether they random skies that you construct.

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Do you see this feature? So the feature is about confidence levels, about 99.98% confidence.

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So it's a pretty impressive thing whether anybody is going to believe it.

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After that, I'm not sure. But all they have to do is look.

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So thank you very much. Thank you very much.

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Actually, first I say so. Okay. I sort of want to make sure that I've understood that in terms of the cyclic cosmology.

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So is the idea for our current universe then? Is the idea that will get gobbled up by black holes?

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Oh, no, no, we don't get gobbled up. They sit there, I the universe does what I showed in the picture.

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It goes expanding out and out and out the black holes as a whole.

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I mean that big. But they're totally from the point of view of the universe as a whole.

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So. So they're very small in the picture. If I drew a black hole.

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Just be a line going up. You wouldn't see the diameter of it's tall.

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So how has this gone down in the community? How have cosmologists is that?

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Very badly, from my point of view, very badly.

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Yes. Well, you see, the the old idea about the.

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I think collision and the gravitational waves. Would cause a signal which to independent groups.

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I have a person who collaborated with Ms.

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Vargas again, who is who's an Armenian, and he initially did a bit of analysis, which people it was a bit unconventional people,

324
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but the paper we finally published on this, we have a way of showing that this is not random,

325
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mainly because you see this sense that you should see circles in the sky.

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And these circles are very concentrated in certain regions.

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It's clearly not random, but nobody believes it because it goes against the conventional view.

328
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And then Christoph Meissner and this is the first paper they had was to two Poles,

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Pavel Neurovascular and Daniel and finally get they published the paper published in the monthly notices of the Royal Astronomical Society.

330
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After having many, many referees coming back say, look, this is no good, you must do this test and must do this.

331
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They did. The more they did, absolutely everything reversed. And finally, the editor wrote to them to say more or less, well,

332
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I suppose we're going to have to accept your paper wasn't quite in those words, but it was more or less death.

333
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And they said, we'll accept it on condition that in the first paragraph you say this might be a chance effect,

334
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but it could be a chance if they're like anything and they give a chance.

335
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The chance is about 124 to 1, that it's a real effect.

336
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Nobody pays any attention. I asked Christoph what responses you have.

337
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Zero. And so we've had zero. And so it's not like, you know, all sorts of angry people saying that on this wrong and that's wrong.

338
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And how can you do this? And sure, it contradicts this deathless silence.

339
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That's what we had. And now we have the thing on the archive.

340
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We had a paper rejected already big from somebody complaining that this thing says this this this result is unbelievable.

341
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They haven't checked to see that. It's really they're just unbelievable.

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It is unbelievable if you believe these effects come in from inflation, because for inflation it would have to be the very last point of inflation.

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Otherwise you wouldn't see a thing like this. And that's what they call a graceful exit.

344
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They have a problem of getting rid of the how do you turn it off? How do you sell off?

345
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Everywhere all at once? Pretty well all at once. That's a big challenge.

346
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That was one of the reasons I had trouble believing it from the start.

347
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So it contradicts that view. So that's why they say, I suppose this is unbelievable.

348
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It's unbelievable on the basis of current cosmology.

349
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But I guess picking up on that point more generally,

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there are there have been times in the past where there was sort of conventional wisdom in physics that eventually,

351
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as David said, do you think more generally there are other areas of physics that are currently being misconceived?

352
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Yeah. I would say the main man is quantum mechanics.

353
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Now, quantum mechanics, people say, is the most well-tested theory in physics.

354
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I'm not sure if that's quite true.

355
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You have to compare it with general relativity, the two big revolutions of 20th century physics, quantum mechanics, general relativity.

356
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They're both extremely precisely tested with, you know, let's not make a comparison.

357
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It's a bit different in each case. Extremely well tested.

358
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Now, people normally think I think I'm just guessing, but they think, well, quantum mechanics is the physics of the small.

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Big things are made of small things. Therefore, the physics of the small rules.

360
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And therefore, if you have conflict between the two areas, you've got to get into quantum mechanics.

361
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That would be fine if it weren't for the fact that quantum mechanics is self inconsistent.

362
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Now I'm putting this in a rather strong way.

363
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I mean, Einstein said it's incomplete. That was he was much more polite, as I say, was incomplete.

364
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Schrödinger agreed with him. People may be familiar with the Schrödinger cat.

365
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Schrödinger's cat was given by running as a demonstration.

366
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Of what's wrong with quantum mechanics is more or less saying, look, an absurd thing like this is what my that's Schrödinger's equation predicts.

367
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His own equation predicts that you could have a dead and alive cat, which is dead or alive at the same time.

368
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Now, you never see such things. And people would say, Well, it's hard to make the coherence and environmental decoherence,

369
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all that kind of stuff, but it never really solves the problem.

370
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So where people are led correctly is that to what these rather many worlds kind of interpretation?

371
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Okay, the cat is the dead one and the live one coexists in two separate worlds.

372
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And we are led to believe that that's what quantum mechanics tell us.

373
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Well, it is what quantum mechanics tells us. If you believe that this linear Schrödinger equation, evolution or unitary.

374
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Yes, people call. Is absolutely universal.

375
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Now, when I when I had my phase of going through many works myself, but I, I came to the conclusion that that's probably wrong and that the,

376
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the unitary evolution which says the superpositions of these is quantum mechanics,

377
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says that that you can have a particle which is here and here at the same time and you get.

378
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That's true. I mean, you get two slits and it seems to go through with at once very strange.

379
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And then I say, well, what's the limit to that? Could cricket balls me here, in here at the same time?

380
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Well, according to quantum mechanics, yes. But you never see that.

381
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So why don't you see that? Well, there's all sorts of things.

382
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Well, they can't mess up with the decoherence and the atmosphere and all sorts of stuff, but that doesn't really explain it.

383
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So I never was happy with that. I say never. That's wrong because I did have one time in my life and I believe the other thing.

384
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But the thing is that when you start thinking about general relativity, you realise that there is a serious conflict between these superpositions,

385
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that there's a problem with the very fundamental basis of general relativity,

386
00:39:14,590 --> 00:39:21,069
which is principle of equivalence, the things that fall into that big, big mass and the small mass of all together,

387
00:39:21,070 --> 00:39:27,610
Galileo, whoever it was, the astronaut who dropped these things on on the moon that fell together.

388
00:39:27,670 --> 00:39:36,790
People expect that fundamental principle, which drove Einstein to his amazing theory, is inconsistent with quantum mechanics.

389
00:39:37,270 --> 00:39:47,170
And so I was developing that idea, and that gives you a limit to when these quantum superpositions will persist.

390
00:39:47,890 --> 00:39:52,920
And these are experiments which are. Being trying.

391
00:39:52,930 --> 00:40:00,580
Well, some of them have been going on for several decades, I would say, and not yet with an answer.

392
00:40:00,790 --> 00:40:04,750
So they've kind of borderline, but one can actually do with current technology.

393
00:40:05,560 --> 00:40:09,370
But I guess this is something that you have done quite a number of times in your career.

394
00:40:09,430 --> 00:40:14,620
It really is in terms of challenging conventional understanding of various areas of physics.

395
00:40:14,980 --> 00:40:20,350
What sort of a frame of mind do you have to have to sort of the bravery to be able to do that?

396
00:40:20,860 --> 00:40:25,510
Because in this program, I don't know if some.

397
00:40:27,270 --> 00:40:31,229
Partly, I think, not worrying about what people are going to think about it,

398
00:40:31,230 --> 00:40:41,670
which is public and not realising what people are going to think and thinking, okay, it's alright too and not realising what people's reactions are.

399
00:40:42,630 --> 00:40:46,920
And I feel a little bit of happy about this. Quantum mechanics one because Einstein.

400
00:40:46,920 --> 00:40:48,149
Yeah, I've got Einstein on my side.

401
00:40:48,150 --> 00:40:56,850
Well, he was there a long time before me and Schrodinger, the boy, a little more surprisingly, Dirac was a to find a quote from there.

402
00:40:56,850 --> 00:41:01,260
I can say yes, he. If you find the right quote, you can see he thought the same thing.

403
00:41:01,650 --> 00:41:06,780
Quantum mechanics is a provisional theory. Hmm. Because of problems like this and other problems.

404
00:41:07,110 --> 00:41:11,940
Okay. It works beautifully. Brilliantly. It must be pretty correct.

405
00:41:12,690 --> 00:41:20,550
You have these experiments now, which it used to be, that quantum entanglements, this things happening here and here,

406
00:41:20,940 --> 00:41:28,620
really know about each other, in a sense, and quantum entanglements, whether I think the record a few years ago was 173 kilometres or something.

407
00:41:29,010 --> 00:41:32,970
Now it's, I don't know, thousands of kilometres.

408
00:41:33,510 --> 00:41:38,490
It's experiments with satellites and so on. So quantum effects stretch over those distances.

409
00:41:39,360 --> 00:41:44,340
I'm really glad they do because not that's not where I think things go wrong.

410
00:41:44,370 --> 00:41:47,430
If they went wrong, they're my ideas would be wrong to say.

411
00:41:47,850 --> 00:41:51,880
So it's it's it's got to be mass displacement.

412
00:41:51,910 --> 00:41:56,040
You see, when you have a bit of mass doesn't have to be much a bit of mass displaced.

413
00:41:57,860 --> 00:42:02,720
And it's here and here at the same time, but there's too much mass doing that. Then you're in trouble with general relativity.

414
00:42:03,110 --> 00:42:07,610
And so that's where I think you're liable to see a difference.

415
00:42:08,390 --> 00:42:12,530
But people say, Oh, we're quantum mechanics so beautifully tested, but they've never tested it this level.

416
00:42:12,810 --> 00:42:17,980
Mm hmm. But you ask me, why do I. I think it's because it didn't.

417
00:42:21,080 --> 00:42:25,310
Don't necessarily. I don't know. I think my father was a bit like that.

418
00:42:25,730 --> 00:42:29,660
So he certainly had you know, he just thought what he thought.

419
00:42:30,500 --> 00:42:34,430
And if it was against the current beliefs, that was all right.

420
00:42:35,420 --> 00:42:39,710
So you sort of joked there about being big headed, but you're not afraid to change your mind either.

421
00:42:39,740 --> 00:42:43,220
I mean, there's been several times where you've you've you've gone against what you've said in the past.

422
00:42:43,230 --> 00:42:46,370
You were one of them. Was the the big bang thing?

423
00:42:47,150 --> 00:42:54,740
Yeah. No, it was it was strange because I was quite early on Stephen Sacco but I don't know what he got wind of it.

424
00:42:54,740 --> 00:42:57,950
And somewhere I went and was interviewed by him and this is Hardtalk.

425
00:42:57,950 --> 00:43:03,319
BBC Hardtalk. Yeah, that's right. Absolutely. And so, you know, I went into the cinema and he went to the beginning.

426
00:43:03,320 --> 00:43:08,540
He said to talk to me quietly. He said, Well, look, it's my job to be rude about people.

427
00:43:08,540 --> 00:43:13,470
You see, usually I talk to politicians, but I'm afraid I'm going to have to be a bit rude.

428
00:43:13,490 --> 00:43:19,550
Is that all right? So that's a person right by me. So at one point you said you said, why did you change your mind?

429
00:43:20,130 --> 00:43:24,680
Say, because I used to believe the big bang was the beginning. And I'm saying it's not the beginning.

430
00:43:24,890 --> 00:43:32,690
I had these theorems with Stephen Hawking, these theorems about singularities, and they had the same very general circumstances.

431
00:43:32,930 --> 00:43:37,490
If you believe Einstein's theory, you've got to run in the singular state where things, things go wrong.

432
00:43:37,970 --> 00:43:42,620
So that's the beginning. So, well, you have to have your way around that.

433
00:43:43,190 --> 00:43:46,700
And I thought the reasons against it were, I mean,

434
00:43:46,730 --> 00:43:52,880
against it just being the beginning were much stronger and the previous reasons I had for believing in it.

435
00:43:52,910 --> 00:43:57,470
So yes, changing your mind is path. I think I said in the interview.

436
00:43:57,830 --> 00:44:03,530
Well, I think being a scientist, I'm allowed to change my mind if the evidence starts to point the other way.

437
00:44:03,600 --> 00:44:08,929
Hmm. Very true. I mean, you do have these quite bold ideas, I think it's fair to say.

438
00:44:08,930 --> 00:44:11,810
I mean, I think you've you've described them as crazy ideas, actually, yourself.

439
00:44:12,230 --> 00:44:17,000
How can you tell the difference between a good crazy idea and just a crazy idea?

440
00:44:18,950 --> 00:44:23,010
Which is true with the thing I conformal cyclic cosmology.

441
00:44:23,270 --> 00:44:28,730
See if you see that scheme. When I talked about, I used to call it outrageous or crazy.

442
00:44:29,210 --> 00:44:36,110
Mainly because I wanted to get in there first because before other people started saying It's crazy, but it is a crazy idea.

443
00:44:36,200 --> 00:44:40,099
But then so is inflation, you see. So, so. Okay, one crazy idea, I guess.

444
00:44:40,100 --> 00:44:44,390
Another crazy idea. But there's something pretty crazy about the big bang.

445
00:44:45,470 --> 00:44:49,570
And Einstein already at the early stages. He thought it was pretty crazy already.

446
00:44:49,580 --> 00:44:53,490
He thought that and. Uh.

447
00:44:54,750 --> 00:45:03,270
All these people who will later, I guess, and other people who'd got some of the equations Freedman and Lamantia solved in science equations said,

448
00:45:03,270 --> 00:45:06,630
Look, there's this singularity at the end. And I said, Look, that's bad physics.

449
00:45:07,320 --> 00:45:11,010
Then eventually had to be convinced that this made sense in the equations.

450
00:45:11,760 --> 00:45:19,530
So he had to change his mind there. There's also a funny thing about the cosmological constant, you see,

451
00:45:19,530 --> 00:45:24,540
because as I introduced it for the wrong reason, he wanted the universe static to expand.

452
00:45:24,540 --> 00:45:27,679
And then people said, well, Hubble shows the universe expanding.

453
00:45:27,680 --> 00:45:31,690
Woops. So I signed, retracted and said, Oh, it's the worst mistake I've ever made.

454
00:45:31,710 --> 00:45:37,980
You see that cosmology. But it turns out to be true. See? Sorry, I going to say something else.

455
00:45:38,820 --> 00:45:42,260
Yeah, I don't know.

456
00:45:42,370 --> 00:45:48,779
I think. I think it probably was my father because he he he had the same sort of attitude,

457
00:45:48,780 --> 00:45:51,820
and he didn't mind whether things were unconventional or what other people did.

458
00:45:52,170 --> 00:45:59,580
As long as he had good reason for thinking what he thought. So do you think you can you can teach someone to challenge the status quo.

459
00:46:01,710 --> 00:46:06,970
You have to be careful at the same time when there's a huge amount of evidence.

460
00:46:07,190 --> 00:46:13,630
I get letters from people mails these days, from all sorts of people who put forward and they think,

461
00:46:13,650 --> 00:46:16,740
you know, I be very sympathetic with them because I've done this sort of things.

462
00:46:16,740 --> 00:46:21,720
You say that I would be sympathetic with their ideas, which are just about as crazy as mine.

463
00:46:22,560 --> 00:46:28,290
But the trouble is that so often they come into conflict with well-established things.

464
00:46:28,800 --> 00:46:37,050
And so it's all right to be crazy, but you got to be careful that they're not in conflict with well-established physical facts.

465
00:46:37,470 --> 00:46:42,060
And I think that's a lot of people don't take that part of it into into consideration.

466
00:46:42,360 --> 00:46:45,630
A difficult line to tread. It's yeah, it is difficult.

467
00:46:46,240 --> 00:46:50,760
Now, we've spoken so far about mainly your ideas in physics.

468
00:46:50,760 --> 00:46:53,010
Basically, you've had quite a big impact in a number of different fields.

469
00:46:53,010 --> 00:46:57,780
I mean, computer science, artificial intelligence, but also in the art world.

470
00:46:58,110 --> 00:47:03,960
So tell us, if you would, a little bit about your your collaboration or your work with Escher.

471
00:47:04,680 --> 00:47:06,450
Yeah, well, this went back to,

472
00:47:07,110 --> 00:47:16,680
I think in my second year as a graduate student when I was at Cambridge and the International Congress of Mathematicians was being held in Amsterdam.

473
00:47:16,980 --> 00:47:20,750
And so I decided with some friends of mine, Oh, that'd be fun.

474
00:47:20,760 --> 00:47:26,370
So I went to Amsterdam here, the great German violin, great figures there talking about mathematics.

475
00:47:27,090 --> 00:47:36,719
And I remember seeing getting onto a bus at the point where Sean Wylie, who is a lecturer in topology,

476
00:47:36,720 --> 00:47:44,220
told me when I was at Cambridge and he holding in his hand was this catalogue with this very strange looking picture.

477
00:47:44,550 --> 00:47:51,510
You open it up. And there were these. It was just night and day with the birds flying one way, and they'd become birds flying the other way.

478
00:47:51,690 --> 00:47:56,220
And one is night and the other day. And the spaces between the birds and the birds going the other way.

479
00:47:56,720 --> 00:48:04,590
Oh, my God. What's that? And he said, Well, there's this exhibition going on in the Van Gogh Museum, and you I'm sure you'd be interested in that.

480
00:48:04,590 --> 00:48:09,390
So I went to see this and I was absolutely blown off my feet.

481
00:48:09,900 --> 00:48:14,400
And about these amazing pictures, particularly I remember the one called relativity,

482
00:48:14,400 --> 00:48:19,650
where the people got staircases pointing at right angles to each other and so on on the other side of the stairs.

483
00:48:20,160 --> 00:48:26,310
And I thought that was incredible. So I went away and I thought, Can I do something a little bit different?

484
00:48:26,320 --> 00:48:32,670
What I've seen, which is impossible. So I started drawing pictures of bridges and rivers and all of that,

485
00:48:32,670 --> 00:48:38,220
which went over each other in an impossible way and finally came up with this Triborough Bridge.

486
00:48:38,340 --> 00:48:42,360
So I think we have a picture of this sort of pictures. I think navigate. This is your original drawing, I think.

487
00:48:42,360 --> 00:48:45,390
Is it? Yes, I think that's the one. This in our article.

488
00:48:45,870 --> 00:48:54,059
Yes. You see, I showed that to my father and he showed it to all his colleagues and they all got made the paper thought they made them feel.

489
00:48:54,060 --> 00:48:57,830
You know, it's interesting, when chimpanzees apparently shown this, they also feel ill.

490
00:48:57,870 --> 00:49:01,010
Really? Apparently, yes. I was told about this.

491
00:49:01,020 --> 00:49:04,709
Yes. It's not just humans. How can you tell if a chimpanzee feels it?

492
00:49:04,710 --> 00:49:08,070
I'm not sure. But I was told there were experiments that showed this.

493
00:49:08,120 --> 00:49:15,090
Wow. Yeah, that's interesting. Apparently, they felt very uncomfortable saying these things, but I think.

494
00:49:15,240 --> 00:49:22,890
Yeah, anyway, you see. So then my father started drawing buildings, which were impossible, and then he produced a staircase going round and round.

495
00:49:23,220 --> 00:49:26,040
Neither of us were aware of Oscar rides.

496
00:49:26,040 --> 00:49:36,150
His father had played with these things earlier, or in fact, people the bright bridle pictures and things which use these impossible structures.

497
00:49:36,420 --> 00:49:43,860
In fact, she knew about some of them, too, but we decided we'd write an article on this, which we did with the triangle in the staircase.

498
00:49:44,400 --> 00:49:48,480
And then we thought, Well, what journal will accept this? What's what's that subject?

499
00:49:48,990 --> 00:49:54,030
So my father said, Well, I happened to know the editor of the British Journal of Psychology.

500
00:49:54,030 --> 00:49:58,700
I'm pretty sure he would take it in. So we decided it was psychology.

501
00:49:59,520 --> 00:50:06,690
So we decided this psychology. In fact, he did get it accepted for British Journal of Psychology and it's become psychology.

502
00:50:06,690 --> 00:50:14,010
I've seen this in psychology books, but we sent a copy to ESA and gave credit to the Escher exhibition.

503
00:50:14,580 --> 00:50:22,140
And then my father had a correspondence with Escher and then somewhat later I actually visited Escher

504
00:50:22,710 --> 00:50:31,020
and he got I had some these puzzle pieces which I left with him and he gave me one of his prints,

505
00:50:31,020 --> 00:50:37,409
which was a great honour to get one of these from him. But he eventually started including the triangle in his own words.

506
00:50:37,410 --> 00:50:44,550
Yes. Where he from our article, the first thing he put in was the staircase and he had this one called ascending and he said,

507
00:50:44,600 --> 00:50:47,940
I think we've got that as well. Actually, I've got that. Yes. That's the one. Yes.

508
00:50:47,940 --> 00:50:52,950
That's this one of the monks going around in two directions. That's right. Now, that's an amazing picture.

509
00:50:52,980 --> 00:50:55,980
Yeah. And then this one came later.

510
00:50:56,080 --> 00:50:59,550
The worst of the waterfall came a bit later. Yes, that's based on the triangle.

511
00:50:59,790 --> 00:51:09,059
But he, in the meantime had produced over dairy, which uses the same type of idea so that he goes was stimulated by these things and

512
00:51:09,060 --> 00:51:13,800
I got stimulated by him also with sort of some of his repeating pictures and so on.

513
00:51:13,980 --> 00:51:18,360
Hmm. And talking of repeating, it's like that link those two things.

514
00:51:18,420 --> 00:51:20,969
Yeah. So this isn't a one off.

515
00:51:20,970 --> 00:51:27,450
You're sort of, you know, playing around with these kind of shapes because, of course, many people will know about Penrose tiling.

516
00:51:28,320 --> 00:51:32,010
Well, I used to fiddle around with just periodic ones a lot.

517
00:51:32,160 --> 00:51:37,450
And as we have a picture as well as lots of. Oh, well, this is yes this is the come to that missing.

518
00:51:37,500 --> 00:51:44,610
Okay. But the I just I used to draw in my notebooks, little complicated ones which have more and more complicated ways of repeating.

519
00:51:44,610 --> 00:51:50,580
But they were repeating one. And these so these are shapes that have shapes that tile a plane with.

520
00:51:50,670 --> 00:51:54,360
Yeah. And you're trying to make it so that you never repeat yourself. Well that came.

521
00:51:54,360 --> 00:51:58,800
Yes. You see? Yes, that came a bit later, you see.

522
00:51:59,670 --> 00:52:07,500
Unfortunately, it came just after Aysha died and my father died, both of whom would be very fascinated by these things.

523
00:52:07,810 --> 00:52:16,020
It was a great shame. I mean, Aysha, I was a bit slow off the mark, I'm afraid, because she would appreciate it if she had.

524
00:52:16,080 --> 00:52:24,270
First of all, I don't a pattern. I think it was I was trying to answer a letter and I couldn't bring myself to but there was a logo in the corner,

525
00:52:24,270 --> 00:52:27,389
which was Pentagram with six pentagons inside.

526
00:52:27,390 --> 00:52:29,500
And I thought, Well, suppose you repeat that several times.

527
00:52:29,500 --> 00:52:37,530
And I thought of a rule for doing this, and I made a big picture and I sent that to a friend of mine who was in hospital just to cheer up a bit.

528
00:52:37,950 --> 00:52:46,980
And then a little bit later I looked at this thing and I thought, Is there some way of forcing this picture with a jigsaw puzzle arrangement?

529
00:52:47,310 --> 00:52:53,070
I don't know why I had that thought, but I suppose that's one of these things you might say a gas or something,

530
00:52:53,070 --> 00:52:56,130
which I was giving it about 50% chance that that was.

531
00:52:56,370 --> 00:53:03,659
And then I tried those things. I'm sure you could. So I needed about six different shapes there with four shapes.

532
00:53:03,660 --> 00:53:08,220
And I needed three of the Pentagon's and one of the promises system and of the other shapes.

533
00:53:08,850 --> 00:53:12,870
And, and then I could do it with six shapes.

534
00:53:13,320 --> 00:53:22,200
And then I had a conversation with, with an American mathematician son in Cochin who was visiting in Oxford,

535
00:53:22,260 --> 00:53:29,790
and he was talking about Rafael Robinson had six shapes, which would only tile the plane, no repeating way.

536
00:53:30,780 --> 00:53:35,010
And he said, Rafa Robinson, somebody likes to get down to the smallest number possible.

537
00:53:35,490 --> 00:53:39,690
So I said, Well, I can do it with five because I knew I had the six and I could.

538
00:53:39,840 --> 00:53:42,870
I knew there was a way I could glued to the pieces together and I could do with five.

539
00:53:43,980 --> 00:53:49,170
So I thought I could do with five. So I went home and I started thinking about it for a bit and I thought I got it down to four.

540
00:53:49,170 --> 00:53:53,730
That's nice. Then I thought a bit more and I thought, Oh, I can do with two.

541
00:53:54,870 --> 00:53:58,650
And I'll tell you my reaction to that. People ask me what was my reaction? I tell you what my reaction was.

542
00:53:58,830 --> 00:54:02,790
Disappointment because this is just ridiculous.

543
00:54:03,300 --> 00:54:10,140
It's it's suit. It's so simple. It must be, you know, Islamic designs or something.

544
00:54:10,140 --> 00:54:15,810
They must have it. I mean, purely surely that's not new, but apparently it was new.

545
00:54:16,470 --> 00:54:24,480
I mean, nobody has found it in Islamic designs. So you can see here what you have to do is have the two shapes that you can see.

546
00:54:24,660 --> 00:54:28,950
They're both rhombus damaged shapes and they're slightly different.

547
00:54:28,950 --> 00:54:34,770
There's a dark one and a light one. The light one is the thin rhombus and the fat rhombus is the dark one.

548
00:54:35,130 --> 00:54:40,830
Now, each one has two stainless steel arcs on it.

549
00:54:41,640 --> 00:54:47,430
And the thing is, you have to match the arcs. I was done with the arcs that nobody else has done this yet anywhere else, as far as I know.

550
00:54:47,880 --> 00:54:51,209
But the originally I just put little arrows on the shape.

551
00:54:51,210 --> 00:54:54,990
So you had to match the arrows and they would be non periodic.

552
00:54:55,020 --> 00:55:02,610
The only way you can tile the entire plane right up to infinity is with a non-repeating pattern.

553
00:55:03,360 --> 00:55:09,060
And each of these that one nice feature about it is if you go out to infinity and you take any finite subset of it,

554
00:55:09,270 --> 00:55:13,860
that appears infinitely many times in all the others. So this is true here.

555
00:55:14,460 --> 00:55:17,040
And instead of putting little arrows, you have to match the arcs.

556
00:55:17,550 --> 00:55:21,630
And I like that because it brings out these circular features and nice things to look at.

557
00:55:22,200 --> 00:55:29,399
So we have this low in the front of our building and and people might say, is this a special picture?

558
00:55:29,400 --> 00:55:36,840
Well, any way of tiling with these patterns right out to infinity, we'll have that exact pattern in front of our building infinitely many times.

559
00:55:38,340 --> 00:55:45,479
I quite like that you came up with this idea when you were looking at a stamp on a letter.

560
00:55:45,480 --> 00:55:50,340
Were you essentially procrastinating, which I this I was definitely procrastinating, I tell you.

561
00:55:50,340 --> 00:55:55,319
Yes. So do you make a distinction then between the the sort of the math that you do when

562
00:55:55,320 --> 00:55:59,130
you're playing around procrastinating and the math that you do very seriously?

563
00:55:59,820 --> 00:56:07,040
No. I mean, it's a good question because as you say, I would be doing some problem,

564
00:56:07,040 --> 00:56:15,829
like when I was doing my Ph.D. and beating my head against the problem, which I'd never properly solved, and I'd keep coming back to that.

565
00:56:15,830 --> 00:56:20,030
But then, you know, I say, Well, let's fiddle around with something else, which is fun, you see.

566
00:56:20,450 --> 00:56:27,620
And then I go back to that problem. So I give you like that's that's the difference between procrastinating and doing what I'm supposed to be doing.

567
00:56:28,460 --> 00:56:32,360
And maybe the procrastinating was in some ways more fruitful.

568
00:56:32,420 --> 00:56:38,060
I don't know. That's an interesting question. I'm not sure the answer to that, but it certainly has been fruitful.

569
00:56:38,570 --> 00:56:44,330
Yes, that's true. I think I think it probably was more.

570
00:56:46,400 --> 00:56:55,490
I don't know. I'd have to go back through my old notebooks and see how many with the results of procrastination and how many were deliberate thought.

571
00:56:55,660 --> 00:57:00,780
But I think you see, you can think along the route, you see you have a clear kind of route to say, well, that's the obvious thing follows.

572
00:57:00,800 --> 00:57:03,910
Let's follow. And then you say about, well, let's try something else.

573
00:57:03,920 --> 00:57:09,380
It's not something that comes back into the same old thing that's trying before I betray that already.

574
00:57:09,440 --> 00:57:18,319
How about this though? It comes back against the same old thing, so it's not often you think something which is really different and that does

575
00:57:18,320 --> 00:57:22,760
usually require a bit of maybe not thinking deliberately about the problem,

576
00:57:22,760 --> 00:57:26,000
something else which suggests a connection. Oh, that's a little bit like that.

577
00:57:26,570 --> 00:57:28,520
Oh, maybe it is something like that.

578
00:57:29,390 --> 00:57:37,820
And it may be a little bit of thinking outside the box is that's what people say play I guess as well, just sort of playing with things.

579
00:57:37,850 --> 00:57:41,300
Yeah, yeah. I'm okay. I'm going to come to the audience in just a second.

580
00:57:41,810 --> 00:57:45,170
So if you have questions that you'd like to ask to Roger, then please think of them.

581
00:57:45,410 --> 00:57:48,710
But I wanted to ask you just in the last couple of minutes I have with you,

582
00:57:48,980 --> 00:57:56,000
I just wanted to ask you about your experience of maths at school, because I heard that you were moved down a class.

583
00:57:56,000 --> 00:58:01,940
Roger I was moved down to class. Yes, I was a I think it's when I was eight years old.

584
00:58:01,940 --> 00:58:03,230
I miss it a little while back.

585
00:58:03,590 --> 00:58:12,170
This bit is a class in Canada, was school in Canada and the teacher there was one teacher who had what was called high grade,

586
00:58:12,920 --> 00:58:21,950
high grade two and low grade three. I was in low grade three and she used to have us do sort of mental arithmetic.

587
00:58:21,950 --> 00:58:26,149
You had to add multiple things and she was too quick for me. I just couldn't keep up with it.

588
00:58:26,150 --> 00:58:30,890
So I was considered to be pretty stupid. I wasn't very good at arithmetic anyway.

589
00:58:30,980 --> 00:58:37,879
I was very slow at it. So I always got lost and I don't know if it was that or not, but she considers I was too stupid.

590
00:58:37,880 --> 00:58:47,220
And she moved me down to high grades to. After a few days, she thought maybe it was a little easier for me and I agreed to.

591
00:58:48,090 --> 00:58:50,800
So she we we never got on.

592
00:58:50,820 --> 00:58:59,880
I may say at one point there was a moment much later when a number of people, not just me, got moved up to Hybrid three instead.

593
00:58:59,910 --> 00:59:05,219
I think she's just getting rid of me. I think she just thought I was too stupid to be able to be dealt with.

594
00:59:05,220 --> 00:59:11,520
So she's very to get rid of me by moving into hybrid theory instead, which I found that I got on with the teacher better.

595
00:59:12,330 --> 00:59:16,350
But then there was a I think it was a bit later there was a teacher who I thought

596
00:59:16,350 --> 00:59:21,510
was pretty insightful because I didn't do all that well in the maths tests.

597
00:59:22,440 --> 00:59:26,790
But he said, Look, I'm going to let you have as long as you like.

598
00:59:27,590 --> 00:59:30,800
It was supposed to take the period at the end of the period people to have the papers.

599
00:59:30,810 --> 00:59:34,950
It says, take you so long as you like. Don't consider that's the end of the test.

600
00:59:34,980 --> 00:59:39,660
People go out and it was the play period after that looking longingly out of the window to see them playing around.

601
00:59:39,660 --> 00:59:44,760
But I would keep going. I would keep going. Sometimes even the period after that, I was still going strong.

602
00:59:45,360 --> 00:59:50,820
Then I'd do well. I'd get into the high nineties, you see, on 99, 100 or something on the, on these tests.

603
00:59:51,570 --> 01:00:01,680
So I thought that was pretty good of him because he realised I was just too slow and it was partly because I wasn't very good at remembering things,

604
01:00:01,680 --> 01:00:04,800
you know, times, tables, maybe I had to work it out each time.

605
01:00:05,970 --> 01:00:09,630
So that was pretty slow. Obviously I had the idea.

606
01:00:10,610 --> 01:00:15,709
But I didn't know how to do it quickly. And this this was with me for quite a long time.

607
01:00:15,710 --> 01:00:18,980
I speeded up a bit after the years, but I was always pretty slow.

608
01:00:19,100 --> 01:00:25,840
Yes. So in terms of if you could have a chat with your 17 year old self then or well,

609
01:00:25,860 --> 01:00:30,170
I guess maybe more a message to people who are 17 now and kind of coming through the school system.

610
01:00:30,280 --> 01:00:35,180
Yeah, but they do have to sit these times exams and more generally, what advice would you would you give them?

611
01:00:35,300 --> 01:00:41,570
It has to be now, I think, rather than me then other people at that time, because maybe I've given them the same advice.

612
01:00:42,080 --> 01:00:46,340
I'm not sure what advice. Spin off. Ask me that and I really don't know what advice to get people.

613
01:00:46,820 --> 01:00:51,530
I think it's much more difficult now because of the horrendously competitive.

614
01:00:53,470 --> 01:01:02,230
The way that schools are and schools and universities are tremendously competitive and you have this horrible conflict because on the one hand,

615
01:01:02,230 --> 01:01:06,160
you've got to be objective. And how do you how are you objective?

616
01:01:06,160 --> 01:01:08,650
Where do you make a test? Which is objective?

617
01:01:09,460 --> 01:01:17,080
And then people, you know, they then they, you know, you can make up things which are new and which people have seen before, but that's pretty hard.

618
01:01:17,440 --> 01:01:26,830
He's trying to make up a test. It's the right level and it's extremely hard to test without favouring those who've learnt by rote.

619
01:01:28,030 --> 01:01:36,489
And so I think that the rote learning as opposed to the free thinking, unfortunately, I don't know,

620
01:01:36,490 --> 01:01:45,160
is that whether it necessarily wins out at the level of exams for university, but it's it certainly gives people a great advantage.

621
01:01:45,940 --> 01:01:53,860
So I think it's much harder now for people who just like to think on their own and not worry about exams too much and so on,

622
01:01:54,100 --> 01:01:58,060
because it's become much more competitive. I don't know how to do with that question.

623
01:01:58,390 --> 01:02:07,270
So maybe the answer is just to procrastinate more. Yeah, that's the well, that is when they have this need, give people extra time.

624
01:02:07,630 --> 01:02:11,920
Let me say my 18 year old son benefits from that.

625
01:02:12,400 --> 01:02:20,230
He also suffers from a big bit slow, too, but having a bit of extra time to do it was this was to his advantage in that.

626
01:02:20,260 --> 01:02:25,810
Yeah. Okay. I think we'll come to the audience, though. We have got I'm going to say about 10 minutes or so.

627
01:02:25,990 --> 01:02:29,890
Who would like to. Oh I've lots has going up. So anyway so we have microphones going round.

628
01:02:30,160 --> 01:02:37,930
He may just have to. Oh there's a case on that. Any other microphones request.

629
01:02:39,070 --> 01:02:43,850
First of all are you and I do. Oh, is that the question?

630
01:02:44,870 --> 01:02:50,550
Yeah, I think so. I call myself an atheist, although some people worry about that.

631
01:02:50,580 --> 01:02:56,040
Yes, you're right. Good question.

632
01:02:56,670 --> 01:02:59,760
Is. Would you sign your book for me?

633
01:03:01,980 --> 01:03:05,460
If you can find me? Yeah. Okay, let's.

634
01:03:05,640 --> 01:03:10,140
Let's get a microphone. One just down here on the front verification.

635
01:03:10,320 --> 01:03:14,700
We'll go one and then we'll come to you straight after. And then we'll go over the other side afterwards.

636
01:03:16,760 --> 01:03:20,780
Go and shout, shout for us. So Jim Archuleta gave a very interesting.

637
01:03:21,340 --> 01:03:25,950
Talk to us a lot about the idea of. Potentially.

638
01:03:25,950 --> 01:03:29,550
I am saying quantum entanglement is wormholes. Do you have any thoughts on that?

639
01:03:29,880 --> 01:03:33,120
Wormholes. You mean quantum entanglement?

640
01:03:33,390 --> 01:03:38,280
I don't think wormholes are going to be any use, I'm afraid. Despite the film.

641
01:03:38,550 --> 01:03:41,550
What was it? Interstellar. Yeah.

642
01:03:41,910 --> 01:03:47,400
No, I. You see, if you really think about general relativity and you try to.

643
01:03:48,330 --> 01:03:52,110
I think I'm partly responsible for wormholes. I'm afraid so.

644
01:03:52,110 --> 01:03:59,310
Because I had a theorem which I proved that black holes produce singularities under very general circumstances.

645
01:03:59,550 --> 01:04:03,210
And one of the conditions I had is that universe suddenly didn't.

646
01:04:03,600 --> 01:04:07,830
Well, is that technically that you had what's called a quasi surface.

647
01:04:08,190 --> 01:04:13,260
And if you want to put that in the ordinary language, you somehow the universe doesn't join on to another universe or something like that.

648
01:04:13,860 --> 01:04:16,170
And so what had to settle that rather loose form?

649
01:04:16,260 --> 01:04:20,280
And then some people picked up on that said, Oh, Penrose says, you might join under another universe.

650
01:04:20,280 --> 01:04:26,309
And that's the answer. I disown it, so I don't think it makes much sense.

651
01:04:26,310 --> 01:04:32,560
These things are not stable. And how on earth can you make a wormhole which is aimed where you want to go to?

652
01:04:32,580 --> 01:04:37,600
I don't understand that at all. But it's quantum entanglement.

653
01:04:37,620 --> 01:04:40,260
No, I don't think there's some nonlocality.

654
01:04:40,890 --> 01:04:49,470
No, I mean, fascinating feature of quantum mechanics that you have separated objects which somehow know something about each other,

655
01:04:50,610 --> 01:04:53,130
not enough that they can communicate with each other.

656
01:04:53,340 --> 01:05:00,870
It's a very subtle thing, but more than them being independent, it's between that sort of gap of being independent.

657
01:05:00,870 --> 01:05:03,569
They're not independent the slightly to do with each other,

658
01:05:03,570 --> 01:05:08,340
but just not enough that they can send each other a signal, which is a pretty subtle thing.

659
01:05:08,340 --> 01:05:16,169
But quantum mechanics exhibits this phenomenon. I think it tells you something quite different, and that is that space, time structure.

660
01:05:16,170 --> 01:05:19,800
There's something much deeper going on in the physics,

661
01:05:20,220 --> 01:05:27,330
which is a non-local description which gives you space time as a sort of approximation at a certain level.

662
01:05:27,660 --> 01:05:32,520
But we don't have that yet. Okay. We have our second question very high.

663
01:05:32,520 --> 01:05:40,500
So Paris, I'm wondering if you know about Sasha's recent work, about fine structure coefficient and what do you think about it?

664
01:05:41,100 --> 01:05:50,280
If you know, fine structure, constant and so, so much so recently, Sartre has made a mark of it here.

665
01:05:50,520 --> 01:05:55,410
Yeah, yeah. Some classes that he saw had all that out.

666
01:05:55,680 --> 01:05:58,680
I prefer not to comment to that because I've never seen it. I have.

667
01:05:59,130 --> 01:06:04,180
Yes, I've had I've heard this because I wasn't sure that he wasn't making this.

668
01:06:04,180 --> 01:06:08,549
There's a claim that he didn't necessarily believe, but he says he's an old man.

669
01:06:08,550 --> 01:06:11,680
He's allowed to do things like this. So quite right, too.

670
01:06:11,760 --> 01:06:15,930
He has a lot of these amazing things in his history.

671
01:06:16,230 --> 01:06:19,380
And so he's allowed to play around with things which might be a bit controversial.

672
01:06:19,500 --> 01:06:24,090
I do not know. I've not seen it, so I can't comment on that. Okay, let's go over here.

673
01:06:24,270 --> 01:06:27,929
One do do you have any female questioners? Would be nice.

674
01:06:27,930 --> 01:06:31,080
Says no. Even one. There we go. Okay.

675
01:06:31,380 --> 01:06:34,500
Can we go there? And then I'll come over that scientist. Yeah. Okay, good. Thank you.

676
01:06:37,900 --> 01:06:39,850
The question was what would a model look like?

677
01:06:39,940 --> 01:06:47,830
Infinite time where you see, if it's my cosmology, cosmology model, expansion of time, it's just this boundary.

678
01:06:48,880 --> 01:06:52,960
I mean, this is where you have to do the mathematics, you see. I've got this model with this.

679
01:06:53,740 --> 01:07:00,040
It's you squash infinity down, and then you stretch the big bang of the next iron out and it joins together.

680
01:07:00,160 --> 01:07:06,610
Now, does that make sense? You rather have equations which govern this transition from one to the other.

681
01:07:06,970 --> 01:07:15,490
So if you ask me that question, what's it like? Well, I got some equations which tell you what it looks like, but I am not going to write the data.

682
01:07:15,880 --> 01:07:17,620
I don't have a nice place to write them down.

683
01:07:17,980 --> 01:07:28,120
But you can use the point of view really is there's a way of looking at what happens in between, which means different things are important.

684
01:07:28,990 --> 01:07:34,170
It's hard to say, but. I used to worry about this, you see.

685
01:07:34,170 --> 01:07:39,090
Suppose you had a time capsule and you had people that said this is so strong that people

686
01:07:39,090 --> 01:07:43,530
could keep in it and it would would survive right out to infinity or something like that.

687
01:07:43,950 --> 01:07:51,540
But then in the model I have, the trouble with that is that the matter in it would gradually lose its mass and it would

688
01:07:51,540 --> 01:07:55,840
stop and whatever images of it would evaporate away and it wouldn't hold itself together.

689
01:07:56,580 --> 01:08:00,270
So somehow everything in the limit becomes without mass.

690
01:08:00,930 --> 01:08:06,510
And so it doesn't know what it feels like to be. But still, I don't know.

691
01:08:06,690 --> 01:08:11,930
How do I know? Okay, let's go over here.

692
01:08:11,940 --> 01:08:15,059
So we could go. Well, your nearest microphone. That's okay.

693
01:08:15,060 --> 01:08:18,750
First to you and then will come to you after. Hi. Oh, you.

694
01:08:19,620 --> 01:08:23,400
I've asked lots of people this question and no one since your to give me an answer.

695
01:08:23,850 --> 01:08:29,850
So doing. Do we know the answer is, is gravity a force or an effect?

696
01:08:30,450 --> 01:08:35,400
No one seems to know the answer. No one's been able to answer that question to me. And I'm I am not a scientist.

697
01:08:35,520 --> 01:08:40,860
Well, I can tell you what your current view on that is partly depends on which community you're in.

698
01:08:42,900 --> 01:08:50,280
It's a very ironic thing. You see, according to Einstein's general theory of relativity, gravity is not a force.

699
01:08:51,390 --> 01:09:01,330
It's the irony is, you see, how did the notion of force come by while Newton had his notions of force and all that stuff,

700
01:09:01,330 --> 01:09:09,090
his second ball and whatever it was and all these things and the notion of force was real and the main candidate was gravity.

701
01:09:09,480 --> 01:09:13,140
And you see, look, it works so beautifully. You get these orbits and you get everything.

702
01:09:13,560 --> 01:09:21,030
Beautiful theory. And then Newton also thought, well, there must be other forces with different laws, maybe not inverse square learners.

703
01:09:21,030 --> 01:09:25,770
And he looked at this in his principle, his study of different kinds of ways, of different kinds of attracted.

704
01:09:26,400 --> 01:09:35,010
And now we have other kinds of forces in physics, strong force, the weak force and the electromagnetic force, the charged electric force.

705
01:09:35,670 --> 01:09:38,700
And all these things are what we now call forces.

706
01:09:39,390 --> 01:09:44,730
But when you go back to gravity and you say, well, you just fall freely and you and it goes on.

707
01:09:45,900 --> 01:09:50,430
So it's not a force in the technical sense, all these other things.

708
01:09:50,880 --> 01:09:57,540
There is a difference which I can't go into. There's a technical difference, which means that gravity is something a bit different.

709
01:09:58,110 --> 01:10:05,750
And in order for it, the principle of equivalence, this is things falling together that the gravity they gather,

710
01:10:05,760 --> 01:10:12,360
their thing of a big mass of little mass falling together is something which holds only for gravity.

711
01:10:13,110 --> 01:10:16,469
If you had an electric charge or to electric charges,

712
01:10:16,470 --> 01:10:22,650
and that you had gravity as air and electric charge at one end of the other, they would fall completely differently.

713
01:10:22,920 --> 01:10:30,030
It's only for gravity in which you have this principle equivalent, so it's not a force in this refined way of looking.

714
01:10:30,210 --> 01:10:35,250
However, you can treat it as a force, and often people do.

715
01:10:36,120 --> 01:10:40,319
So the answer is a bit slippery out. So in a way that's a yeah.

716
01:10:40,320 --> 01:10:42,990
You treat it as a force, you do your Newtonian mechanics,

717
01:10:42,990 --> 01:10:50,640
which is works extremely well and you often don't think it's in the general relativity way and you treat it as a force just like every other force.

718
01:10:50,940 --> 01:10:56,460
Quantum mechanics you probably put a term in the Hamiltonian is do with any other force and you get away with it.

719
01:10:56,610 --> 01:11:00,870
So you get away with it being a force, but it's not really.

720
01:11:01,930 --> 01:11:07,059
How about that? I think that's a bit. I think I think there's actually a gentleman in front of you last time.

721
01:11:07,060 --> 01:11:11,540
So if I gave you that. And then. And then you. Hi, Roger. I've got two questions.

722
01:11:11,560 --> 01:11:16,160
If I know you. We're running short on time, so you gotta think your best one and the two.

723
01:11:16,690 --> 01:11:22,550
All right. You mentioned that you didn't like the term dark energy for cosmological constant.

724
01:11:22,570 --> 01:11:26,860
If you had a a free hand to put a new name out there, a popular name, what would it be?

725
01:11:27,550 --> 01:11:31,900
The trouble with cosmological constant got all the syllables to it. Dark energy.

726
01:11:32,140 --> 01:11:38,830
Dark energy. Well, that's. It's for cosmological constant.

727
01:11:38,850 --> 01:11:42,630
Yes, that's a bit longer. Lambda, how about that, lambda lambda.

728
01:11:42,810 --> 01:11:47,390
That's only two syllables. Call it lambda. It's this capital inside.

729
01:11:47,420 --> 01:11:50,670
Einstein had a little lambda, but the Capital One is what they use now.

730
01:11:50,730 --> 01:11:54,990
How about lambda? It's lambda. Yeah, I think that's.

731
01:11:54,990 --> 01:11:58,860
That's another bad name. Um, dark energy.

732
01:11:58,860 --> 01:12:03,720
Just maybe it was this other question. Let me just answer. You see, there are two dark things.

733
01:12:03,990 --> 01:12:10,950
This dark energy and this dark matter. Now, I don't like either of those terms because they're not dark.

734
01:12:11,040 --> 01:12:16,890
That's transparent. You can see through them there is dust and that's dark.

735
01:12:17,310 --> 01:12:20,400
And you can see pictures of the galaxies with a dark st right across the middle.

736
01:12:20,760 --> 01:12:23,910
That's dark. But dark matter and dark energy.

737
01:12:24,690 --> 01:12:28,410
No, they're not dark and transparent, but dark is a nice short word. So that's why it's.

738
01:12:28,420 --> 01:12:31,950
See, I suppose. Is that how is this pick words for things.

739
01:12:31,950 --> 01:12:39,300
Just the shortness of its the shortness with how it is. So if you had to say cosmological constant all the time, it's a bit of a mouthful, but lambda.

740
01:12:39,570 --> 01:12:42,830
Yeah. Okay. From here on and from here on in. Okay.

741
01:12:42,840 --> 01:12:47,129
I think we have one question here and then I'm going to ask one more. So who really will go?

742
01:12:47,130 --> 01:12:49,860
We're going to first and then, you know, the rest of you have to fight.

743
01:12:53,990 --> 01:13:00,950
And can you tell us a little about what motivated you to come up with the very elegant ideas behind Twister Theory?

744
01:13:01,190 --> 01:13:05,150
And are you still working in that area? Oh, gosh.

745
01:13:07,460 --> 01:13:10,640
I have the second question. That was two questions. Can I ask this?

746
01:13:10,850 --> 01:13:16,700
The second one is yes, I am still working on it on that one, but it has been stuck for about 40 years and a certain problem.

747
01:13:17,360 --> 01:13:20,210
But I think now you see there is me being big headed again.

748
01:13:20,510 --> 01:13:26,000
I think we have the answer to the problem that's sticking as it was think called the Google problem,

749
01:13:26,600 --> 01:13:30,530
which I think I know the way to do it, but it's pretty difficult to do so.

750
01:13:30,680 --> 01:13:36,200
I need some spare time or a good graduate student or about six graduate students actually to work on that.

751
01:13:36,980 --> 01:13:42,620
Elegance. Yes. Elegance was important. And it. But it's a complicated story.

752
01:13:42,830 --> 01:13:46,320
I can't really go into this. It wasn't just one thing.

753
01:13:46,370 --> 01:13:52,849
You see, there were if I could locate this page somewhere in one of my notebooks, I could remember what it is.

754
01:13:52,850 --> 01:13:59,990
But I remember having a big page full of all sorts of connections between things, which seemed to me needed some unifying idea.

755
01:14:01,040 --> 01:14:05,180
And that was what underlay twisted theory.

756
01:14:05,990 --> 01:14:09,980
But that came about from. Okay.

757
01:14:10,550 --> 01:14:19,690
The thing which. Really was the trigger was something very elegant in mathematics, which I knew which was Clifford Parallels.

758
01:14:20,860 --> 01:14:25,810
People know about spheres. They're not so familiar, perhaps with spheres in four dimensions.

759
01:14:26,350 --> 01:14:33,640
Known for dimensions, you have the analogue sphere. It's a three dimensional space, goes up and closes up on itself.

760
01:14:33,950 --> 01:14:41,020
But there's a practice you can get a feeling for this thing. But Clifford described these things, which people refer to as Clifford Parallels.

761
01:14:41,290 --> 01:14:45,459
So you have two things which are parallel. Well, they're parallel.

762
01:14:45,460 --> 01:14:48,130
They never meet, you say, but you're going to have kinds of geometries,

763
01:14:48,130 --> 01:14:52,430
like the Beltrami pictured of hyperbolic geometry where the parallels don't meet.

764
01:14:52,450 --> 01:14:56,170
They get from further apart. You can have a geometry where they come and they do meet.

765
01:14:56,410 --> 01:15:01,840
So if you have a an ordinary spherical surface and you try to make two lines, straight lines, what do they have to be?

766
01:15:01,840 --> 01:15:09,070
Great circles. They gradually come and meet now in the sphere in three, a three sphere in four dimensions.

767
01:15:09,760 --> 01:15:13,510
You can trust them a little bit so they don't meet. They just restrained each other.

768
01:15:14,140 --> 01:15:15,490
And you can make them all circles.

769
01:15:15,490 --> 01:15:23,170
And you fill the whole space with these circles and they twist around in this very, very beautiful way, which is known as Clifford PAGELS.

770
01:15:23,470 --> 01:15:28,780
And I known about these things for a long time and they're very, very elegant mathematical structure.

771
01:15:29,440 --> 01:15:34,989
So when I realised that this thing in physics which to do with, I can't go into it,

772
01:15:34,990 --> 01:15:40,540
but there was these solutions of the maximus equations which also do the same thing,

773
01:15:41,080 --> 01:15:45,520
and I realised that that was what I was looking for, to work, to see why they were.

774
01:15:45,520 --> 01:15:51,850
That was what I was looking for. I'd have to go into something too complicated to explain here, but it was a revelation.

775
01:15:52,120 --> 01:15:56,409
But I thought, gosh, and only because these are solutions of Maxwell's equations,

776
01:15:56,410 --> 01:16:00,700
which overall Robinson, a colleague of mine, had been studying and he knew these things.

777
01:16:00,700 --> 01:16:07,040
They were. Yeah, that's it. If I had to go back to back home and and work it out.

778
01:16:07,040 --> 01:16:17,220
And it was it was. But then it took God back decades, decades to realise that did various things that he was supposed to do with great difficulty.

779
01:16:17,240 --> 01:16:21,100
I'm still thinking on it now. Yes. Okay.

780
01:16:21,140 --> 01:16:24,940
I realise I've gone horribly over time. So the last one has to be a really quick question.

781
01:16:25,100 --> 01:16:28,640
Got a quick question? Okay, let's go.

782
01:16:28,650 --> 01:16:39,440
Let's go for you there. Say if you could shout out the. Do you think it's going to be constrained further or.

783
01:16:40,970 --> 01:16:41,980
Let me just repeat the question.

784
01:16:41,980 --> 01:16:46,880
Questions they put the fact that it was the half life of a proton has been constrained to something like 10 to 30 years.

785
01:16:47,180 --> 01:16:50,240
And then the last bit was, do you think that constrains?

786
01:16:51,560 --> 01:17:00,860
Okay. Let me address that question. The thing I need for this scheme, is it out to the 30 years you might say, okay,

787
01:17:00,860 --> 01:17:04,330
that's nothing compared with 10 to 100 years, which is what you need for the back house.

788
01:17:04,700 --> 01:17:09,290
But the thing is, where the protons go, well, they go if that's what happens to them,

789
01:17:09,710 --> 01:17:16,370
they decay into into positrons and something that the electric charge has to be preserved.

790
01:17:16,790 --> 01:17:23,480
So even if they decay into less massive particles, which very possibly they do, it depends on your particle physics theory.

791
01:17:23,810 --> 01:17:27,469
I'm quite prepared to believe they do decay in general years. I don't know.

792
01:17:27,470 --> 01:17:34,040
I don't have a view on that. But they would decay because of and charge conservation into a charged particle.

793
01:17:34,550 --> 01:17:40,700
So the problem I have is not so much with protons, but with these charged smallest mass particles.

794
01:17:40,700 --> 01:17:44,390
We have the electron and the positron.

795
01:17:44,660 --> 01:17:48,290
Now, what about neutrinos where they don't have charge? So I don't care too much about them.

796
01:17:48,800 --> 01:17:52,100
They could they could be masses where they actually couldn't for a technical point.

797
01:17:52,100 --> 01:17:56,750
But but it's really the the the positrons which are the problem.

798
01:17:57,560 --> 01:18:00,710
Now, I'm not saying they decay because they've got nowhere to go.

799
01:18:01,430 --> 01:18:11,630
What I am saying is that the very notion of mass fades out and that fade out comes about in this scheme.

800
01:18:11,840 --> 01:18:16,760
It's not fully worked out, but it comes about in this scheme because of Lambda.

801
01:18:17,330 --> 01:18:20,040
Now you see in particle physics people,

802
01:18:20,060 --> 01:18:27,020
one of the first things they do in particle physics is to classify particles according to what's called the Poincaré group,

803
01:18:27,590 --> 01:18:30,350
and this has what's called to Casimir.

804
01:18:30,370 --> 01:18:37,200
Often I'm using technical jargon here, but it has these two very important things called Casimir operations, which commute.

805
01:18:37,220 --> 01:18:44,500
Well, that's another technical term with all the other operators of the group, which means they have to be absolutely conserved.

806
01:18:44,510 --> 01:18:47,870
What are they? Their mass and spin.

807
01:18:48,290 --> 01:18:54,860
Now, mass, that means is a fundamental thing, which must if you have a stable particle, it must change.

808
01:18:55,250 --> 01:18:58,640
But when you put lambda in, it changes the game.

809
01:18:59,000 --> 01:19:06,979
It introduces something, a tiny little effect, which means what are the Casimir properties where they're not mass and spin?

810
01:19:06,980 --> 01:19:11,060
I suppose spin probably is not so, but it's not mass. You find it's corrected.

811
01:19:11,300 --> 01:19:14,420
There's something now. I don't know whether to make this into a good theory or not.

812
01:19:14,720 --> 01:19:20,450
Nobody's done it as far as I know. But there's good reason to believe that when you put Lambda in,

813
01:19:20,960 --> 01:19:28,610
you're going to have a change and that mass is not completely, absolutely constant and over timescales,

814
01:19:29,240 --> 01:19:37,520
like when lambda starts to kick in, as they say that something like the current age of our universe from Big Bang to now,

815
01:19:38,000 --> 01:19:42,500
which is what, about 4000 million years, that kind of time?

816
01:19:42,830 --> 01:19:46,940
When is about the sort of scale when these kind of particles are going to start to?

817
01:19:47,960 --> 01:19:54,880
Lose a bit of their mass. And then finally they would decay gradually and asymptotically become zero.

818
01:19:54,890 --> 01:20:00,020
So that's that's the picture. Just to check when you say lambda there you do you talking about dark energy.

819
01:20:00,890 --> 01:20:07,300
Yes. That's how are calling it that, you see, because it's neither dark nor and it's not necessarily good.

820
01:20:07,490 --> 01:20:10,610
But you see some people use absolutely no. No. For a general public.

821
01:20:10,610 --> 01:20:15,019
Yes. That Ducat is Stockholm. Okay. Unfortunately, I think we have to leave it there.

822
01:20:15,020 --> 01:20:16,190
So a few of you, I think,

823
01:20:16,190 --> 01:20:22,489
have got VIP wristbands and are invited to a drinks reception over in the mass gallery where so much it will be the rest of you.

824
01:20:22,490 --> 01:20:26,480
I'm afraid you're stuck with me. If you come downstairs is the gallery can come and say hi.

825
01:20:26,660 --> 01:20:28,070
But I think all that remains.

826
01:20:28,220 --> 01:20:33,830
Oh, no, I need to say actually first we need to exit first if you give us a few seconds to leave before you eventually follow us.

827
01:20:34,310 --> 01:20:38,180
But all that remains really is to say an enormous thank you, Roger, for joining us.

828
01:20:38,350 --> 01:20:41,390
I think we could have gone on all night, actually. Fascinating. Thank you very much, indeed.

829
01:20:48,580 --> 01:20:49,390
Thank you for that.