20: Sir Roger Penrose - Plotting the Twist of Einstein’s Legacy: Difference between revisions

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|link4=[https://player.theportal.dev/?ep=20:_Sir_Roger_Penrose_-_Plotting_the_Twist_of_Einstein%E2%80%99s_Legacy Link]

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[[Sir Roger Penrose]] is arguably the most important living descendant of [[Albert Einstein]]’s school of geometric physics. In this episode of [[The Portal Podcast|The Portal]], we avoid the usual questions put to Roger about quantum foundations and quantum consciousness. Instead we go back to ask about the current status of his thinking on what would have been called “Unified Field Theory” before it fell out of fashion a couple of generations ago. In particular, Roger is the dean of one of the only rival schools of thought to have survived the “String Theory wars” of the 1980s-2000s. We discuss his view of this [[Twistor Theory]] and its prospects for unification. Instead of spoon feeding the audience, however, the material is presented as it might occur between colleagues in neighboring fields so that the Portal audience might glimpse something closer to scientific communication rather than made for TV performance pedagogy. We hope you enjoy our conversation with Professor Penrose.

[https://theportal.group/20-roger-penrose-plotting-the-twist-of-einsteins-legacy/ Full transcript available here]

 

The second piece of housekeeping surrounds today's episode with Roger Penrose. Now, I know what I'm supposed to do. I'm supposed to talk about quantum consciousness and The Emperor's New Mind, maybe ask Roger about the many-worlds interpretation of Quantum Mechanics, or the weirdness of quantum entanglement. I'm actually not that interested. I also don't want to go back to his earliest work on singularities and General Relativity with Stephen Hawking.

What I instead want to do is to remind you of what Roger is in fact famous for. He is one of the greatest geometric physicists now living. He's perhaps the best descendant of Albert Einstein currently still working in Theoretical Physics in this particular line of thought. I also think he's a great example of what the UK does well: he has a very idiosyncratic approach to trying to solve the deepest problems in Theoretical Physics called Twistor Theory. I'm not expert in it, and I can't always follow it, so if you're not following everything in today's episode, instead of deciding that the episode has somehow failed you, try to remember that people who are working in Mathematics and Theoretical Physics spend most of their time listening to colleagues completely lost as to what their colleagues are saying. So, if you start to feel that you're being left behind by some line of thinking, what we do is, in general, wait to see if another line of thinking opens up that we can try to catch. You're not going to get all of the waves, and in fact the same thing is happening to me while I'm interviewing Roger. He's not understanding everything I'm saying. I'm not understanding everything he's saying. And in fact, this is normal.  

You know, there's a Leonard Cohen quote, from a song called The Future where he says, "You don't know me from the wind, you never will, you never did. But I'm the little Jew that wrote the Bible." And I have what I consider to be the bible right here, which is a book you wrote called The Road to Reality which, there's no getting away from, may be, in my opinion, the most important modern book of our time, because what it tries to do is to summarize what we know about the nature of all of this at the deepest level. And I think what I want to do is to introduce you to our audience, which has been habituated, over perhaps 16 or so interviews, not to expect to understand everything. They want to work, they want to hear conversations unlike any they've heard, and so we'll do some combination of explaining things, but [also] some combination of allowing them to look up things in their own free time, if you're game. Should we talk about The Road to Reality?

'''Sir Roger Penrose:''' You see, I have a proposal, which I didn't have—I mean, it's new since the book. It's not all that new because it's about 15 years old, but it's new since I wrote that book.

'''Eric Weinstein:''' Okay, you got a chance to live through, if not the original General Relativistic and Quantum revolutions, their consequences. In particular, you were able to take classes from people like Paul Dirac, who scarcely seems like a human being, sometimes more like a god.

'''Sir Roger Penrose:''' Oh yeah, that was an experience. Yes. When I was at Cambridge as a graduate student—You see I did my undergraduate work at London University, University College. And then I went to Cambridge as [a] graduate student, and I went to do Algebraic Geometry, so I wasn't trying to do Physics at all. And I, I'd encountered a friend of my brother's, Dennis Sciama, when I think I was at University College as an undergraduate. And he had given a series of talks on Cosmology—well it started with the Earth, and then he sort of worked his way out, and then talked about what was then referred to as the Steady-state Theory. Where the galaxies—the universe expands and expands and expands, but it doesn't change, because all the time there is new matter created—hydrogen—and the universe expands and then you get new material, and it keeps replenishing what gets lost.  

And I thought it was quite an intriguing, I mean, Dennis was a great fan of this model, and so I was really taken by it. So that, well the story was that I was in Cambridge visiting my brother, my older brother Oliver, who did Statistical Mechanics. And he was actually much more precocious than I was, he was two years ahead. And he was, I think, finishing his research there. But I had been listening to these talks by Fred Hoyle, and he was talking, I think in his last talk, about how in the Steady-state Model, the galaxies expanded away, expanded away, and then when they reach the speed of light, they disappear. And I thought that can't be quite right, and I started drawing pictures with light cones and things like this. And I thought, well, they would fade, gradually fade, but they wouldn't just disappear.  

'''Eric Weinstein:''' So you were simultaneously under the great geometer Hodge, as well as Dennis Sciama?

'''Sir Roger Penrose:''' Hodge was my supervisor, originally, until he threw me out, and Todd became my supervisor. That's another little story. But Dennis just wanted to get me interested, and do working Cosmology. This was it. I never, he wanted me to change my subject. I learned an awful lot from Dennis about Physics, because Dennis sort of knew everything and everybody. And he had a real knack of getting, if he thought two people should meet each other, he got, made sure they did meet each other. In one case, it was Stephen Hawking. But, Dennis was actually—well you mentioned Dirac—Dennis was actually the last graduate, at the time he was the only graduate student of Dirac's.  

'''Eric Weinstein:''' Dirac was famously sort of difficult. I think that, you know, in recent years, this book came out of Graham Farmelo, The Strangest Man, that puts Dirac's bizarreness, in line with—  

'''Eric Weinstein:''' Well his, and this gets to a very odd issue, which is that you have wielded taste and beauty as a weapon your entire life. Your drawings are among the most compelling—I remember the first time—one of the things I've done, using our friend Joe Rogan's program, is to push out discussion of the Hopf fibration, because it's the only non-trivial principal bundle that can be visually seen. And since the world seems to be about principal bundles, it's a bit odd that the general population doesn't know that stuff of which we are.

'''Sir Roger Penrose:''' Yes. Well the, the Hopf fibration, or the Clifford parallels, was instrumental in the subject of Twistor Theory.

'''Sir Roger Penrose:''' Well, when I went to the... you see Dirac gave a course of lectures in Quantum Mechanics, and the first course was sort of basic Quantum Mechanics. And the second course was on Quantum Field Theory, but also spinors. And there's an interesting story about that, which I don't know the answer to. In the second course, he deviated from his normal course of lectures. Now, I understood when I talked to Graham Farmelo, who wrote this biography of Dirac, I understood from Graham Farmelo that, when I described that Dirac deviated from his normal course to give two or three lectures on two-component spinors, which for me were absolutely what I needed. You see, I'd learned from my work on Algebraic Geometry, which ended up by trying to understand tensor systems as abstract systems, and things which you can't represent in terms of components.

'''Eric Weinstein:''' Spinors in general. I mean, he brought them into Physics, they'd been previously found inside of Mathematics, I think by people like Killing and Lie, I'm not sure who.

'''Sir Roger Penrose:''' Cartan is the one.

'''Eric Weinstein:''' But that, you know, I asked you before about your favorite film, you said 2001. You could make an argument that spinors are, in Mathematics and Physics, like the monolith. It's always encountered, nobody ever understands exactly what it means, but it always grabs your attention, because it seems so absolutely bizarre and highly conserved.

'''Eric Weinstein:''' Well that won't make any sense to anyone. But if—I mean one way of looking at that is if you have a Klein bottle—

'''Eric Weinstein:''' And for those of—some people will be listening to this on audio, some watching it in video. A Klein bottle, in a certain sense that can be made precise, has a square root that would be a torus: that is a double cover. So it seems like a very weird thing to take a square root of a strange topological mobius-like object, but there you are.  

'''Sir Roger Penrose:''' Well I think this was a mystery. I mean, I understood that a spinor was the square root of a vector, you see, and I couldn't make head or tail of that idea. And it was when I went to Dirac's course it did become clear. And he made, he gave this very impressive illustration, which I thought was due to Dirac, I learned later it was due to Hermann Weyl, that you imagine a cone, circular cone—  

'''Eric Weinstein:''' Well, I think with a, with a pulley system and a wheel, we don't have any trouble imagining a wheel that rotates twice as fast, half as fast, not at all hooked up to one particular crank wheel, right?  

'''Eric Weinstein:''' Have you seen this video called Air on the Dirac String, which illustrates this in video format?

'''Eric Weinstein:''' I would highly recommend it because it shows this off as the similarity to the belt trick, to the Philippine wineglass dance—  

'''Sir Roger Penrose:''' Yeah, I suppose the difference between the fermions and bosons, so the particles which have a spin which is half an odd number—

'''Eric Weinstein:''' Well, it could be Grand Unified Theory, Supersymmetry, Technicolor. It could be Asymptotic Safety. It could be any one of a number of speculative theories from Loop Quantum Gravity, Reggie Calculus, String Theory. It's like the kitchen sink, we've tried a million different things that don't—

'''Sir Roger Penrose:''' Yeah, yeah. I mean, these ideas come back again in a different form, but certainly in the, I guess the 19th century, people were playing with, well, I guess you can go back further than that... Phlogiston.

'''Sir Roger Penrose:''' Well some people do. But the general public don't know about Maxwell. But Maxwell's equations completely change our way of looking at the world. And we live off it without thinking, you know, you've got these lights here. Well, these are visible lights, so we, we know, you knew about visible light, but we didn't know anything about x-rays. X-rays, radio waves, they're all part of the same scheme. Electromagnetism, dynam—well, some of this goes back to Faraday just before Maxwell.

'''Eric Weinstein:''' But even Max, you know, I'm very partial to this book on orchids that followed Darwin's Origin of Species.

'''Eric Weinstein:''' That was the book he wrote—the title is, and I always, I love reciting it, it's On the Various Contrivances by which British and Foreign Orchids are Fertilized by Insects. And so you think, well, why would you write a damn fool book like that after Origin of Species? And the answer is he wanted to test whether he understood his own theory. And in fact, it's revealed that he didn't understand the full implications. I would say that the same thing is true of Maxwell's equations, which is, this is perhaps the best dress rehearsal for unification we've ever seen, you know, full unification, and on the other hand, it's not until the late 50s that we actually unpack the last trivial consequence of the theory with this bizarre effect of passing an electron beam around an insulated wire.

'''Eric Weinstein:''' Yeah, in fact we had dinner last night, we asked Yakir Aharonov if he wanted to come but he's in Israel, and he sends his regards.  

'''Eric Weinstein:''' Well, you know, this etching called Ascending and Descending.

'''Sir Roger Penrose:''' You see when I was a graduate student in Cambridge, I think it was in my second year, when the International Congress of Mathematicians took place in Amsterdam. And so I and a few friends decided we would go to this meeting, and I remember... I think I was just about to get on the bus or tram or something, and Sean Wiley—who is a lecturer in in Algebraic Topology—he's just about to get off the bus, I was getting on, and he had this catalog in his hand of an exhibition in the Van Gogh Museum. And this was a picture... The one called Night and Day with birds flying off into the day and the night, and the birds changed into the spaces between the birds [unintelligible], and I just look at this and I think 'Oh that's amazing what is that? Where on earth did that come from?'  

So I played around with this. And then I sort of whittled it down to the triangle, which people refer to as a tribar. So it's a triangle which is locally a completely consistent picture, but as a whole, it's impossible. And I showed this to my father. And then he started drawing impossible buildings, and then he came up with this staircase. So we decided we'd like to write a paper together on this. And we had no idea what the subject was, I mean, what, who do you send a paper like this to, what journal? So he decided since he knew the editor of the British Journal of Psychology, and he thought he'd be able to get it through, we decided the subject was Psychology.  

'''Eric Weinstein:''' So you saw the movie Inception, of course, where they, they realized this actually?

'''Eric Weinstein:''' But that effect is the soul of the Aharonov-Bohm effect, which surprised the world in the late 50s because it was discovered so late into the game.

'''Sir Roger Penrose:''' It is a comm—same sort of thing. That's right. Well, of course like so many things, people point out that this Oscar Reutersvärd, who is a Swedish artist who'd drawn things like this before. I think roundabout the year I was born, he had a picture which is all, with cubes going around. It wasn't exactly the same, but it was.

'''Eric Weinstein:''' So, what I want to get at is, I think also that we have this very funny thing that happened, recently, starting from the early 70s, where we started mis-telling our own Physics history, because of the needs of the community to look like we were succeeding when we weren't, or we were succeeding at something different than we were trying to succeed at. And, in part, one of the reasons that I want to use this podcast to discuss science is to give alternate versions of what's happened. And I want to explore one or two of them with you. Now, you and I have a very funny relationship which, we don't really know each other. But you were quite close to Michael Atiyah at various points. And I was—

'''Eric Weinstein:''' In Geometry more generally, and Analysis, I mean, just incredible, and Algebra. I mean, he wrote a book on on Commutative Algebra. Now he had a partner for much of his career, Isadore Singer, who I was quite close to for a period of time. And Is was, again, another one of these figures that if I'd never met one, I wouldn't know that the human mind was capable of that level of repeated insight. And they came up with something called the Atiyah-Singer Index Theorem, which governs worlds in which there are no time dimensions, but only space dimensions, or no space dimensions and only time dimensions, but there's no—

'''Sir Roger Penrose:''' Well I can say if I've used the theorem. In at least two different contexts, yes, maybe more. So, I mean, I'm not an expert in that area at all. And it was mainly when I was trying to solve a particular problem... I don't know how much detail you want to go into these things. But it had to do with how to make Twistor Theory work in curved spaces. But I ran up into a question, which had to do, it has to do with Complex Geometry.

'''Eric Weinstein:''' Well if you, I know you're hot on the trail of this, but just to leaven something in, Roman Jackiw at MIT once beautifully said, and I don't think he wrote it down, he said, "We didn't understand the partnership that was possible between Mathematics and Physics, because we the physicists used to talk to the analysts." And he said, "The analysts either told us things that were absolutely trivial and irrelevant, or things that we already understood." He said, "When we talked to the geometers, we started to learn new things that we'd never considered."

'''Eric Weinstein:''' It was just called the Schwarzschild singularity?

'''Eric Weinstein:''' From Princeton, Norman Steenrod.

To say this in a simple way, suppose I happen to see a configuration of stars that happened to be on a circle. Suppose they were concyclic. And then this astronaut passing by me would also see these in a circle. Even though the transformation would not be a rotation of the spheres, the sky would be squashed up more on one end and stretched out at the other end. But the thing about that transformation, it's something which I knew about from my Complex Analysis days. Do you think of the, what's called the Riemann sphere? This is the plane of points, you see it's the complex plane, or the vessel plane: the points represent the complex numbers. So zero is in the middle if you like, and then you've got one, and then you've got minus one, and i and minus i, they're all on a circle, and you go out and infinity is way out to infinity. But the Riemann sphere folds all this up into a sphere. So infinity is now a point.

'''Eric Weinstein:''' But, if I understand correctly, and maybe I don't, we have another mutual acquaintance, or friend, Raul Bott, and he showed us that the world seems to repeat every eight dimensions in a certain way. But during the first cycle of what you might call Bott Periodicity, from zero to seven, or one to eight, depending on how you like to count, you get these things called low-dimensional coincidences. And so, that they don't recur because of your point earlier about spinors, that spinors grow exponentially, whereas vectors grow linearly. And, but during the first period, where these things are of comparable strength, you get all of these objects where, depending upon, you define in two different contexts you turn out to be the same object. Are you making use of that here?

'''Sir Roger Penrose:''' It is that, it's the, well the Lorentz group—

'''Eric Weinstein:''' What you're really talking about is a very important fork in the road for Physics: Do you wed yourself to the world that we're actually given? And you know, Mach was famous for having said this phrase, "The world is given only once." And so we happen to know that there does exist a world that appears to be well modeled by three spatial and one temporal dimension. And then the key question is, do you wish to have a more general theory, which works in all dimensions, or which works for all different divisions between how many spatial and how many temporal dimensions, and what I see you as having done, which I think is incredibly noble, brave, and scientifically valid, is to work with Mathematics that are really particularizing themselves to the world we're given rather than sort of keeping some kind of, I mean, like you're getting married to the world we live in, in a way that other people are just dating it and wishing to keep their options open.

'''Eric Weinstein:''' So, very early in this new stagnation post the Standard Model, people like Glashow and Georgi, and Pati and Salaam, put forward these unifying symmetries that remain very odd, because they're so attractive and powerful, the prettiest of them being something called Spin-10, which physicists persist in calling SO(10) for reasons that escape me.  

'''Sir Roger Penrose:''' I was at the time at the University of Texas for a year, and this Alfred Schild had put a lot of people together who were General Relativity experts, hoping that something would come out of it, I guess. And I had an office, next to Engelbert Schücking, whom I learned a lot from. And on the other side, I had an office, that was Roy Kerr's office, and Ray Sachs was a little way down. And, I have to backtrack, because the question is, where did Twistor Theory come from?  

And so I had a nice, silent drive coming back, and I started to think about these constructions that Ivor Robinson—he was in Dallas at the time, an English fellow who lived in Dallas—and he constructed these solutions of the Maxwell equations, which had this curious twist to them. And I had understood these things, and I realized that they were described by, as you talked about, the Hopf map or the Clifford parallels, these are, you can think of a sphere in four dimensions, three-dimensional sphere in four dimensions, and you have these circles, which fill the whole space, no two intersect, and every two link. Beautiful configuration.  

'''Eric Weinstein:''' And this is, look, I want to tie this into a bigger thread, which I think is fascinating. I am not a devotee of String Theory, nor am I of Loop Quantum Gravity. I think that most of what has been said about Supersymmetry has been overbearing and wrong.  

So we had a first revolution around the mid 1970s with what's called the Wu-Yang dictionary, where a particular geometer, who becomes the most successful hedge fund manager in human history meets arguably the most accomplished theoretical physicist, if it's not Weinberg it might be Yang in terms of what has been proven of his contributions. They have an unbelievable interaction which shows that the Classical Theory underneath Particle Physics is as or more geometric than the theory of Einstein using Steenrod's fiber bundles and Ehresmann's connections, or vector potentials or what have you. Then you have a second revolution, again involving—so that was the first one that Is Singer takes from Stony Brook to Oxford—and you have another one, which is the geometric quantization revolution with your colleague Nick Woodhouse writing the bible there, in which Heisenberg's Uncertainty Relations strangely come out of curvature rather than just being some sort of weird—  

You guys figure out that this weird grab bag that was called Quantum Field Theory, which is this thing above Quantum Mechanics that is needed for if you're going to have particles that change—regimes in which the number of particles changes like something emits a photon, you need Quantum Field Theory, you can't do it in Quantum Mechanics. So that world was a grab bag that made absolutely no effing sense pedagogically to anybody coming from outside of the discipline. And what they taught us, and this is coming from the 1980s on, is that Quantum Field Theory would have been discovered by topologists and geometers, even if the physical world had never used it, because it was actually a naturally occurring augmentation of what's called Bordism Theory, which is an enhancement of what you previously referred to as cohomology.  

'''Sir Roger Penrose:''' Yes. Well it's very interesting, partly from a personal point of view, because when I first heard about it, and a lot of it was on Conformal Supersymmetry, and I could see there was a lot of connection with Twistor Theory. The only thing I didn't like was you were led to these algebras which didn't commute and, well, the square of something was zero or something, whatever. I mean, they weren't the kind of Algebra that you needed in Twistor Theory, you needed Complex Analysis. But anyway, I visited Zumino at one point, and I was most intrigued because I could—

'''Sir Roger Penrose:''' You're thinking of the Lagrangian, yes.  

'''Eric Weinstein:''' Well, that's, well, but the Oxford system, I mean, I don't have to make it so peculiar to Oxford, but you know, even if I think about, like a Nigel Hitchin, or Mason, I guess, has been in that system.

'''Eric Weinstein:''' Let me just... One final thing. Have you been to the courtyard of the Simons Center for Geometry and Physics at Stony Brook, which is tiled with Penrose tiles?

''''''Eric Weinstein:'''''' All right. You've been through The Portal with Sir Roger Penrose, hope you've enjoyed it. Please subscribe to us wherever you listen to podcasts. And if you are the sort of person who views podcasts, navigate over to our YouTube channel. Make sure that you subscribe and click the bell so you'll be informed the next time our next episode drops. Be well.

 

<!-- == Participants ==

* [https://en.wikipedia.org/wiki/Eric_Weinstein Eric Weinstein] (WEIN)

* [https://en.wikipedia.org/wiki/Roger_Penrose Roger Penrose] (PEN)

== Housekeeping ==

WEIN - Hello, this is Eric. 2 pieces of housekeeping:

# On today’s guest. Eric mentions;

* Penrose’s early work, for example with Hawking (eg; [[https://en.wikipedia.org/wiki/Penrose–Hawking_singularity_theorems|the Penrose-Hawking Singularity Theorems]]).

1:00 = Roger is famous for being one of the greatest [https://en.wikipedia.org/wiki/Geometry#Physics Geometric Physicists] now living and perhaps the best descendent of [https://en.wikipedia.org/wiki/Albert_Einstein Albert Einstein] currently still working in [https://en.wikipedia.org/wiki/Theoretical_physics Theoretical Physics] in this particular line of thought. Also, he is an example of what the UK does well.

([https://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#Don't_Panic Don’t Panic!])

1:30 = …if you start to feel as though you are being left behind by one line of thinking, what we do in general is wait to see if a different line of thinking opens up… …this is normal.

2:30 = welcome Roger

3:00 = WEIN - “I know you as one of the most important people at the nexus of Geometry and Physics”

Lyrics from the Leonard Cohen song, “[https://www.youtube.com/watch?v=AKwr3DDvFpw The Future]” (“You don’t know me from the wind, you never will, you never did, but I’m the little jew who wrote the bible”)

Book: [https://www.amazon.com.au/Road-Reality-Complete-Guide-Universe/dp/0679776311 The Road to Reality], by Roger Penrose (this appears to be easily accessible online as a pdf)

4:00 = WEIN - “Where are we in the history of coming to understand what this place is in which we find ourselves? What we are made of? And what we know about our own context?”

PEN - “I now feel I should re-write part of it (the Road to Reality) because since I wrote it things have changed in one important way” *

PEN - “A lot has not changed - the thing that has changed… …is to do with Cosmology.”

PEN - I have a proposal… which is new since I wrote that book

[NOTE: I’m not sure if he ever gets back to saying what this proposal is. It looks like it might be “Conformal Cyclic Cosmology”, see eg; [https://physicsworld.com/a/new-evidence-for-cyclic-universe-claimed-by-roger-penrose-and-colleagues/ Physics World], [https://physicsworld.com/a/inside-penroses-universe/ ibid], his own book, [https://en.wikipedia.org/wiki/Cycles_of_Time Cycles of Time]]

== Penrose brief biography. ==

* Took classes from [https://en.wikipedia.org/wiki/Paul_Dirac Paul Dirac]

* Was undergraduate at [https://www.ucl.ac.uk/ UCL]

* Went to [https://www.cam.ac.uk/ Cambridge] for graduate studies.

* Went to study [http://mathworld.wolfram.com/AlgebraicGeometry.html Algebraic Geometry], not Physics

PEN - “I’d encountered a friend of my brothers, [https://en.wikipedia.org/wiki/Dennis_W._Sciama Dennis Sciama].” * (see also the note below)

Sciama gave lectures on Cosmology and talked about [https://en.wikipedia.org/wiki/Steady-state_model steady state theories] in which the Universe expands but doesn’t change because it’s continually ‘replenished’ by the creation of new matter.

Penrose’s older brother, [https://en.wikipedia.org/wiki/Oliver_Penrose Oliver Penrose] who was studying [https://en.wikipedia.org/wiki/Statistical_mechanics Statistical Mechanics] was the precocious one (of the two brothers).

Penrose had also been listening to talks by[https://en.wikipedia.org/wiki/Fred_Hoyle Fred Hoyle] who suggested that when the matter in the accelerating expansion reaches the speed of light it disappears.

Penrose didn’t think that was quite right and started drawing pictures with [https://en.wikipedia.org/wiki/Light_cone Light Cones] and thought they would gradually fade, but not disappear.

8:00 = Talking to his brother in the Kingswood Restaurant, Cambridge *, Roger expressed his doubts and was referred to Dennis.

[NOTE: I tried to find a link for this restaurant, which appears to no longer exist, and came across this really interesting paper by Professor Penrose and [https://en.wikipedia.org/wiki/George_F._R._Ellis George Ellis], which is a kind of “scientific eulogy”* for Dennis Sciama, in which the same anecdote is recalled, amongst others: https://royalsocietypublishing.org/doi/pdf/10.1098/rsbm.2009.0023 (pdf) ]

&lt;&lt;&lt;There’s probably a better term for this, right?

&lt;&lt;&lt;When I search for ‘“the kingswood restaurant” cambridge’ I don’t turn up anything that seems relevant and when I add the word “remember” to that search I start to turn up links to Sir Roger himself.Possibly it was called by a different name. Also possible that no trace of it has made it onto the internet other than his telling.

Dennis Sciama was impressed! Later, when Roger came up, he took him under his wing.

Penrose’s supervisor was Hodge - [https://en.wikipedia.org/wiki/W._V._D._Hodge W.V.D Hodge]

But later he threw Roger out and Todd became his supervisor - [https://en.wikipedia.org/wiki/J._A._Todd J.A Todd] *

9:00 = advert for a watches. Masculinity, something, something….

10:00 = advert for lamps. Mention of [https://en.wikipedia.org/wiki/Matrimandir the Matrimandir] (looks nice, might buy a lamp)

([https://en.wikipedia.org/wiki/Dennis_W._Sciama Dennis Sciama])

11:00 = Dennis wanted Roger to be a Cosmologist

Dennis had a knack of making sure people met each other. In one case it was [https://en.wikipedia.org/wiki/Stephen_Hawking Stephen Hawking]

Dennis was the last (at the time the only) graduate student of [https://en.wikipedia.org/wiki/Paul_Dirac Paul Dirac].

Book: [https://www.amazon.com/Strangest-Man-Hidden-Dirac-Mystic/dp/0465022103 The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom] by [https://en.wikipedia.org/wiki/Graham_Farmelo Graham Farmelo]

PEN - Dirac was hard to get to know.

WEIN - Dirac would be neck and neck with [https://en.wikipedia.org/wiki/Albert_Einstein Einstein] for greatest 20th Century Physicist.

Eric imputes that Dirac’s hair was not as good as Einstein’s.

PEN - Dirac was the one who put QM in order

== Taste and Beauty ==

The Hopf Fibration ([https://en.wikipedia.org/wiki/Hopf_fibration#/media/File:Hopf_Fibration.png source],[https://nilesjohnson.net/hopf.html gif])

WEIN - “you have wielded taste and beauty as a weapon your entire life, your drawings are among the most compelling”

13:00 = “Our friend Joe Rogan” *

Joe Rogan * is a prominent Podcaster and Cage-fighting Commentator

&lt;&lt;&lt;Roger Penrose and Eric Weinstein are friends with the guy who does the commentary for the cage fighting. It’s quite a time to be alive.

&lt;&lt;&lt;If you have ever been on Joe Rogan’s Podcast and now have your own podcast, you are contractually obliged to mention his name at least every 2.5 episodes

WEIN - The hopf fibration is the only non-trivial principal bundle that can be visually seen

PEN - The “[https://en.wikipedia.org/wiki/Hopf_fibration Hopf fibration]”, or the “[https://en.wikipedia.org/wiki/Clifford_parallel Clifford Parallels]” was instrumental in the subject of Twistor Theory.

14:00 = Penrose’s diagram

There were three versions. The third version is in The Road to Reality. He thinks the second version is probably the best.

(I think they are talking about the diagram of the Hopf Fibration ?? as seen at the link above )

I '''think''' this is the one from “The Road to Reality”, which would make it Version 3: * **

And there’s this diagram, which I found at this link ( http://users.ox.ac.uk/~tweb/00001/ ) which is an HTML presentation of “On the Origins of Twistor Theory” - Roger Penrose, 1987

[NOTE: these latter two might be Versions 1 and 2? Or later reproductions.]

Penrose thinks Version 2 was the best.

WEIN - Dirac famously brought in these bizarre objects called Spinors, which are a prerequisite to getting to Twistors.

15:00 = Dirac gave a course (2 courses) of lectures on Quantum Mechanics