Andrei Rodin

0:00 I'm sure, I will take it anyway, it may be enough, it may be enough, if it's enough, if it's not, that may well be enough, it's not an urgent problem, but I can't lie to you, thank you very much again. I gave a talk at the book, at least. Yes, I know, which I was about to do. What I can say. It's available in written series of ideas. If you want to read it. I mean, it's a subject which I think I'm familiar with. I made the talk, I mean, I made the talk into two images. But I did not explain on the... Two is to have slides. It's what I call glimpses of the scenery, glimpses of the scenery. And then you can at least give the illusion of understanding. But I've decided it's time to understand the meaning of what... Well, no, I do, I have studied a little bit about group points. In fact, as a matter of fact, this conference in Greece, which I went to record earlier this month, in honor of Albert Koch, Koch gave an extremely nice talk about categories of group points. and about sense theory. It was really about stacks, rather about stacking. And the shift between, you know, group points and the strategy of categorization. And it was a very interesting book because it outlined, it made clear for me, something which I've always wanted to understand. Somebody once said to me, his pronouncements are just like a fairy tale. You would have to be a scholar of Indian mysticism to really follow him. Maybe the seventh or eighth or ninth time around. Especially when I'm listening to you or to Colin, I get it, but when you just said this, it's just like, why he, well, it's a little sweet to say reject, but why he really thinks there's a whole program of empathy, but also very bright people like the young man, Jeff O'Furley, are now doing that generalization of what we want to do. It's complete generalization. Well, after understanding how, essentially, what I did.

2:30 His view of descent theory, and particularly in the context of the way one should think of stacks of group lines, made his, my understanding of his objections to any category by, you know, the, what these people really want is a purely geometric map of it. That was always the underlying motive, I think. So it's pretty interesting. I'd love to understand more of that one day, how much of this, of this perspective, all of this data is true. I suspect a great deal. Incidentally, on the subject of gravity, did anything occur? Not really. We haven't decided. We haven't decided. We haven't decided. We haven't decided. First of all, I vote for you. Now you have made public comments. For a long time, it was a secret. I knew it, but I told myself. But you promised not to report. And now, of course, you vote for me. And I'm going on sending a letter. Every day, every day, there will be... I'm concerned, too. There will be, there will be people giving...

5:00 Have you considered asking George to do a talk on topos in mathematics, aren't there? I just wondered, I could slant the idea. It might not be a bad idea. Not least because he would of course have quite close relations with the professor even in the 80s. I mean, it would make a lot of sense to ask him to give the talk on topos there, or one of the talks. I should mention this, just so you know, but I went back now. The party and this young man in Nansu, Rob Palmer, and they and three or four other people now have an application for a meeting on, over the course of having this kind of growth in the year, or year number. And they have asked for a one-week meeting on the history of the Catholic Theatre, which they were not given for this year, but which they are probably going to have for February. You'll receive a message either February or March. It would just be obviously good to make sure that that doesn't overlap with the dates of what is happening here. I mean, I'm in touch with them pretty well all the time. They consist of statistics of two hours and four or five hours. And the dates are more or less the same. Yes, yes, sure. I mean, it usually comes in the week. And so, I've a... And the perfect balance...

7:30 Because the perfect combination, which is something very perfect, and with a lot of people, and with too much, shall I say, you know... Or make an impression. No, it's much... But this plan of hell, I think, sounds excellent. But I think the people... Clair was a... Clair was a... No, no, no. I've met Spencer Block. No, no, no. No, no, no. Dispatchable. Thank you very much for your time, and I hope to see you again very soon. But I would like to part the feed of that suggestion to talk about Thomas Thierry, because I think he would be enormously honoured by it. He would be enormously honoured. This local meeting in Greece, in honour of Andrew's cop's 70th birthday, had some very nice talks. And Joao, Miradijk, and Gonzalo Reyes, in fact all of the cops for that, except sadly for Bill himself, who had to cancel at the last moment. But apart from Kopp's own thought on the sense theory, which I found fascinating, there was a lovely talk by, you may know him, a young researcher called Tom Leinster, he's one of the best young categoricians around, and he gave a lovely talk on Schanuel's work. Beautiful paper. I think it's really a gem. It's an incredible tool of Chaniel's. I'm trying to remember where it appeared in one of his Spring of the Earth lectures. It's called What is the Length of a Potato. What is the Length of a Potato? From Chaniel, yes. It's about 20 years now. I think it may be Spring of the Earth at 753, but I could even easily look it up. You could just Google it. I may be wrong about that. But if you Google, oh, I'm not sure. It must be about 1980.

10:00 But the paper, it presents this beautiful way of generalizing the notion of measure, not in the sense of measure theory. I want to think of the Euler characteristic as a kind of generalization of cardinality. He's connected very much with wrote as well. In fact, Rota and Shanyuel actually wrote the paper. Shanyuel wrote the paper together with Rota on this. But Shanyuel, I have to say, Shanyuel's... But Schaniel, I think, had the more purely geometrical insight of what was going on with this. This is a beautiful idea of how one really ought to think of carbonality. And Schaniel, who's always, as a saint, and probably else, he's one of the few people who can really get the best out of Laubir. He said at the end of this talk, I think I have now convinced you, that Euler did more for our understanding of numbers than Euler. Which is the problem with the rocket. Great, great man. Anyway, very, very interesting talk. I've had this firmly planted, so I'll stay in touch with you about that. I'll stay in touch with you about that. I'm not aware of the initial use of that old file that I received as an official. And that would be... Well, at the moment, yeah, it would be marvellous if it was. But the only thing at the moment is that, well, unless something's happened in the last two or three weeks, I don't think they have dates settled yet. I know about either February or May, which is actually quite good, because it would be better to have it. So it's going to be either, I think, February the 9th to the 16th or, I forget the other day, so either February or May. You know all about mathematics. The other thing I was going to tell you, I tend to... Unfortunately, well, I know what you mean. I had the same experience when my mother was in my family for four years. I thought, well, I'm so happy to have my grandson. Amen. And two weeks from now, my grandson will be 12 years old.

12:30 My very oldest friend, their son, just celebrated his birthday today. No, no, it's tomorrow. Today's the first. He's 12 tomorrow. And I have to go to, well, I can't go to England for that, but I do have to make sure that I send. The first time you're aware of it when you're very young is probably the most, well I would say that's the most significant moment of your life. What taught my grandmother was that I was already quite aware of all these things. No, but I mean when your first awareness... The other thing, I mean, it's the whole two major... That's looking at it in fair sight, but a little bit externally and biologically. But it also, of course, makes something whole, alive. I mean, it gives contours. It makes alive what Aristotle called a plethos or ismenon. I said it's not so much a plethos... When people ask me whether I... If there was no horizon to our being, it would become a liberal art form. I believe in something after that. I say, well, I don't know anything now. No, I don't. That's for the moment. But you have to take the best of what is and are in. Absolutely. And if there is something after, for the best. OK, would you want to take something? No, not at all. No, I agree. It's always pleasant to hear that. No, no, but you are... No, no, I was... Well, no, no, just simply that I was rereading Momande's work. Just two, three days ago. And, well, I think this will probably keep for the next time. We wouldn't have a longer talk. But there were three or four very interesting remarks that you made that I wanted to ask you a little bit more about. Did you by any chance see this blog discussion in Caulfield's blog on N-categories about YARH?

15:00 Well, it's headed for questions. And there's now been a correspondence of about eight or nine contributions to it, but nobody seems to have actually followed to ask you the question. It's to do with fibre functions and to do with whether there is some kind of spectral construction in the background in connection with... Gosh, I'm sorry, I've forgotten the exact context, but something a little analogous to the... I'm amazed that none of them thinks to actually ask you when your name is cited in the discussion. It's weird. People have a strange fear of asking, can I say, particularly when people are very distinguished in their field, people seem to have an absolute terror of actually asking them questions. It's very strange, but it's illogical. I will let you let you get some lunch. I want to ask you one other thing very quickly though, about you mentioned Jean-Pierre d'Augignon and I noticed the poster for the last year for his 60th birthday. Did they ever put this online? They said they were going to, but I don't think they did. They promised, but I don't think anything's happened. And also, this is a little phone I have, which might be possible. And they also promised in March of last year, when they had the Colloquium for Comte's 16th birthday, at the, well, it was only for one day here at the IHES, the other days were at the IHK, but they also promised that that was going to be... And they had these guys, you know, making a film about all these things, and I've never, I've since written to them, they've been kind of like this, four times, and I got one reply saying, oh, well, we'll get back to you. It's now a year, and nothing has happened, but it must exist, because there was, there were two people who had told me, and they said they had to get some sort of grant in order to put it on the website, but nothing has happened.

17:30 Speaking with my kind of artist, my kind of professor, it might be worth just dropping a line. I know him. What we know is very well. Yes, yes, he's very good. It's just probably a question of putting the right little bit of pressure on the right person. But they do promise quite categorically. Okay, okay, I will mention mine. And while I hold this discussion... At the moment, I mean, all our staff was very busy with the 50s, I mean, of course, so I can appreciate that, but I didn't mean to, I didn't mean to sort of start off with it, it's just I know that these things are put on the back burner, as they say, for too long, they just tend to fall off the bottom of the agenda, on the agenda, but I don't know exactly where it is, because, I mean, our staff has been overwhelmed with events, I can imagine, especially with the 50s coming up, and it's just the beginning of the road, one way or the other. The most important things are coming. I mean, so my conference on mathematics, one on physics, and one on biology is here, and then a conference on quantum mechanics. Well, I do stay in touch with the website. You'll certainly come to the conference on mathematics. Okay, I will put questions. Okay, don't put questions. But if you can just put a gentle reminder. You just hired someone to take care of us. I must talk to them. On the subject of my own archive, I want to tell you something very quickly. I couldn't help noticing your marvellous collection of papers, of colloquium course, and these from the market. I've now formed my archive, which now has, God help me, 26,000 recordings in it since 1971, of which I would think past 20% is some real scientific importance. I didn't record them all myself, of course. A lot of them were recorded by other people that came. Like, for instance, John Stakeshaw has given me these wonderful set of recordings that he made back in 1971 of Descartes and Wigner and Wheeler. And then I've got all these conversations which I recorded with Atiyah and Penrose when Penrose was working on...

20:00 And then, of course, the discussions which were 200 hours of other conversations with Lorvius. And even this most recently. I just want to give you a copy of the deed which we've now drawn up, the deed of trust, just so you can have a look at it. It will take a long time to look through it, it's not complete yet. This is a pretty simple document. But that gives us sort of more of a background on what it is. And Penrose used to be the chairman. So I'm hoping that when that is, when the archive, when the catalogue... We have a good website. We, I hope, might be able to approach, to get some funding, at least small seed court funding of a few hundred euros, to start putting the recordings themselves into huge archives that involve a lot of sophisticated software for digitizing. But I'll send you more details. I always check whether it's this part of it or that part of it. Don't worry. No, seriously, Pierre, it's very kind of you. But I wouldn't want to disturb you.

22:30 There's nowhere in town, but it's okay. I happen, in fact, to go to the new Paris-Pétienne. This afternoon, I'm supposed to see Mark Lashley as Ray, and a couple of people there, so I can just get the bike on the way back to town. No, no, I would love to come to London, but I don't want to... Okay, so you've got everything, and yes, you've got that. You gave me... Yes, and you gave... was there something you gave me? Thank you for your attention. Have you ever been in the embarrassing position of asking and then they say no because I wasn't trying to do it? Well, I was... No, no, I won't, I won't. I would like to know. Penrose may be coming here next, in two weeks' time, because there is, these strange Russians that I told you about, you know, the people who argue, are coming here to talk to Gromov, and they have sent me a message to say that Penrose is going to come as well. I'm not sure if that's correct. And could I get hold of somebody, because their translator, apparently, he's a very good man I know called Siparo, but he can't come because his mother has been taken to hospital for the stroke, so they're asking me, could I ask somebody at the IACS to act as a translator, and I know you have lots of Russian speakers here, but I noticed that there's one young man, an algebraic geometer, who...

25:00 He's actually from the State, the Bauman Technical University in Moscow, which is where these people are from. Do you know his, um, so, I made a note of it, I can just run back and check. Okay. No, the best thing is... I'm just wondering whether he would be able to... You send me an email. Okay. You send me an email and I'll... I'll send an email for him, and if you could have a word with him, I think it's probably going to be out the 14th or 15th of April. Okay, thanks again for your time. Take care. It's always good to see you. I am happy that you are in the discussion. Thanks. Take care. I'll see you again soon. Thank you for watching. Thank you for your attention. Thank you for your attention.

27:30 Thank you for your attention. There were four or five others. Is there a question? In terms of having a special class, it's very problematic. I don't know whether he tried to come up with it or not. He did sort of put it and build it up as a kind of, you know, random distribution. And it's got an answer in that context. You know Arnold. He said, I'll denote the way to build it. But no, twistor was actually not that interesting. It was a very interesting, very complicated... Thank you for your attention.