The Legendary John Conway (1937-2020)

The thing is that there can be in mathematics, particularly in number theory, there can be theorems about numbers that are tremendously hard to prove and maybe, when you've proved them, you don't feel you've got any insights as to why they're true. I mean, in fact, asking why, although I keep on asking why, I don't understand what it means to ask why. And I don't understand what would count as an answer to that question. That's the voice of John Horton Conway. He died this week at the age of 82.

He wasn't just one of the great mathematicians of his generation, he was also one of the great characters. I interviewed Conway for a series of Numberphile videos back in 2014. You'll hear a few clips from those videos today, including a few that weren't used originally. playing them for the first time here. I'll also be speaking to other people about their thoughts on Conway. First, it's the woman who wrote the book on him, quite literally. Siobhan Roberts was Conway's biographer.

So I first met him when I was writing my biography of Coxeter. So that would have been 2003. I tracked him down at a math camp that he was at for a couple of weeks. Conway was at this math camp. So that was 2003. You know, when you first meet Conway and being a writer, I kind of knew immediately, well, here's a fantastic subject for a book. So I think, you know, for all intents and purposes, that's when I started collecting Conway anecdotes.

When the Coxer book came out in 2006, then I proposed it to John that I could write his biography. And initially he said no, but then when he suffered his first stroke, he sort of felt his own mortality. Soon after that, he reconsidered. So I guess I started in earnest maybe in 2007, and then the book came out in 2015. So all in all, I've been kind of on his trail for...

You know, I was on his trail for more than 10 years, which is a long time. So every day I would walk across town and go and sit with Conway and his alcove at Fine Hall in the math department. And yeah, there were countless. Countless visits. And he was supremely generous with his time. He was at once a biographer's dream come true and worst nightmare because he just loves talking so much. But he is a great storyteller. So, you know.

It was this this wonderful treasure of of information. But, you know, there were pros and cons. And, you know, he was kind of as I came to discover in the fact checking process when I would. at the end, go back and want to nail down certain details. You know, he seemed almost congenitally incapable of answering a yes or no question. So I would have some, you know, very specific question, you know, yes or no. And he would be like,

well, have I ever told you the story of how I came to discover surreal numbers? And I'm like, Yes, John, I've already heard that story a number of times. I did only meet him once. Even from that one meeting, I can tell he would be a really hard guy to pin down. I imagine at times he would have treated you like a... Like he was a cat with a mouse and would enjoy messing with you. Yeah.

I mean, he did like to sort of string people along. And there were a couple times where he told me stories that turned out not to be true. You know, so there were some counterfactuals and some misdirection there. And, you know, I'd have to triangulate a truth. if not the truth. It was fun, but it could be infuriating. He was a giant in a lot of different ways. He did... very important central mathematics. He did any amount of recreational mathematics. He was also a stuntman in various respects.

Quite a remarkable character. David Eisenbud's director of the Mathematical Sciences Research Institute. in Berkeley, California. Oh, he attracted plenty of attention. That was, you know, he famously said that when he went to Cambridge for university, he decided to transfer from being an introvert to an extrovert. But his... His notion of being an extrovert was to do stunts. So he could roll his tongue in more ways than you're supposed to be able to do. Or he could calculate the...

day of the week of a given date, within two seconds. He loved that kind of thing and was extremely good at it, too. I mean, very talented person in a lot of different ways. He wanted to stand out, and that was how he had figured out to do so, I think. Why did you become a mathematician? Why didn't you become a runner? or a bricklayer? I became a mathematician in some sense before the age of four. So doesn't that excuse me from answering the question why? You know, it's more than 70 years ago.

I did go through a period when I was at high school in England of possibly being more of a scientist or a physicist or something. But mathematics always seemed to be it somehow. Here's the answer, really. There are some things, I call them parochial. Well, let's say parochial really means, depending on where you live, you know, I live in the parish or somewhere. I'm going back to...

you know, the 16th or 17th century, you know, I live in the parish of so-and-so. There, parochial matters are just relevant to people who live in this particular little district, you know. And I'm not really terribly interested in parochial things. They're just local. And if you move to another parish in the same county, they're not, you know, you have a different... set of values and so on. In a larger sense, if I'm interested in sort of British history, well American history is different.

And so British history is parochial and so is American history, you know. And then you can go up to world history and geography. They're still parochial. And when finally we meet some people I'll call the Martians, but they're not really Martians, who've been educated in a totally different way and maybe discovered fantastically interesting things, then what they're saying is less parochial.

With mathematics, I suspect that these people I'm calling Martians, perhaps Aliens would be a better name, would still be interested in mathematics. So it was the most non-parochial subject. I used to think like that at the age of 14, maybe. That was my reason for... really concentrating on mathematics, I suppose. At least that was my rationalisation of why I thought about mathematics. And in a way it still is. You know, am I interested in the history of the Ottoman Empire?

Well, there's possibly a good reason to be interested in this if I'm Turkish, which I'm not, you know. Or if I'm Greek, because Greek was subjected to Ottoman rule. No, I'm not too good. Well, I actually am interested. I like to think in everything. But I'm less interested in those than in the things which will be of interest to the aliens when they come to visit us.

Someone who's dying in the street of starvation doesn't care about the symmetry of objects in 24-dimensional space. Nothing matters less. I agree. Listen, I'm not going to go up to that person. kneel down and try and interest him in 24-dimensional space. I might very well try and produce some food or some warmth or some lodging and so on. I'm not entirely without human feeling, although I think human feelings are parochial.

I mean, I came to be very fond of him, which is kind of a funny thing as a journalist. You know, you're supposed to keep your distance from your subject. But since I did spend so much time with him, you know, I did find him to be a very endearing. fellow you know he was a vulnerable soul in a lot of ways yeah but at once you know an egomaniac as he used to say you know modesty is my only vice if i weren't so modest i'd be perfect

And yeah, he just had this, you know, obviously this massive curiosity. I think he would write Martin Gardner letters in the 60s and 70s telling him about all his, you know, games and things that he was inventing and what he was thinking about. One time Martin wrote back and, you know, commented on the kaleidoscopic profusion of ideas that Conway had sent him. So he was just, you know, he had this treasure trove of things going on in his brain. And it was.

such a joy to sort of try and tap that and understand it even in a very superficial way as far as I was concerned, I think. Well, he was rather different from the average mathematician. Colin Mulcahy is a mathematician at Spelman College. He's also vice president. of the Gathering for Gardener. He didn't have errors of graces. He wasn't particularly impressed by credentials. He was interested in ideas. He would talk to anybody on the street. And in fact, he was one of those people whom...

people sometimes thought was a man on the street. He could be mistaken for a hobo in later life because he didn't wear a suit or comb his hair very often. But he just was an infectious man with a tremendous passion and effectiveness for communicating and getting people interested in mathematics.

So, you know, I mean, anybody who ever went to a talk would never forget it. And I had the good fortune to see him probably a dozen times in the last 20 or 30 years. And just amazing. Amazing, Kai. I think he really... valued simplicity. You know, mathematicians talk about elegance and beauty and simplicity, and so he really did always want the simplest, clearest explanation, whether it be...

in words or in a theorem, you know, that was another funny thing about writing the book. He was, he, he read parts of it towards the end. And so he was constantly, you know, questioning my word choice. So I think he just had, you know, he just had really fine taste in all things intellectual and sort of that quest for knowledge and wanting to know how things work and how the world works.

Just trying to find these little moments that... spark your spark your brain and then get to the bottom of things so what was john conway like in person then if you would have a coffee with him or when he wasn't like you know playing the room he was never not playing the room he was a he was a born performer and it was Absolutely charming to be with him. I mean, if you like that kind of thing, and I do, you know, it was a laugh a minute. It was kind of a new trick, a new thing that he did.

told you or could do all the time. Let's see, when we invited him to come and give a talk, you know, we have these Museon dinners, rather formal dinners, fancy catering. This particular one was at Will Hurst's offices. in a high-rise building in San Francisco, and we had nice cocktails, and there was music, and then we went down to hear Conway talk. And Conway had come wearing a tie.

which was extremely unusual for Conway. But he saw that Will Hurst was not wearing a tie. Of course, I was wearing a tie. But Will Hurst was not wearing a tie. So as he began his talk, he commented on this, and he said since Will was not wearing a tie, he wasn't going to either. But that wasn't...

You know, that's not enough for Conway. So he took off his tie while he was standing at the podium and threw it on the floor and jumped up and down on it. So that was the sort of... way canway would do things he had a card trick which was his own extension of a classic principle and he did it with a rigged deck so he would set up the entire deck but the deck could be shuffled once could be given one

so-called gilbert shuffle where you deal off some into a pile there by reversing their order so he had a setup where he could set up the deck and take it out and do a few false shuffles and then do this genuine shuffle and convince people the deck was very randomized

And then he would do trick after trick. He had a little sequence with his own kind of... slight you know his own slant on it and uh it was very entertaining so having seen him do it a few times i begged him to tell me what was going on because i was starting to get interested in card tricks myself this would have been the late 90s i guess

And he did actually give me the inside secrets. And like all inside secrets, once you hear it, you go, oh, is that all there is to it? But of course, when you don't know that, it's quite an impressive trick. But the fun part was I would then, when I would meet him at conferences, I'd always have a deck ready in the Conway order. and um i would i would give it to i you know he would he would spot me and once once he understood he would um

he would say to somebody, oh, does anybody have a deck of cards by any chance? And I'd say, oh, I have one here, John, I think. Yeah. Thank you very much. And you take it from me. And off you go, because he knew I had set it up in the right order. Physicist Tony Padilla's a regular on Numberphile.

and like John Conway, was born in Liverpool and went on to study at Cambridge. He's a bit of an inspiration, really, because, of course, you know, he's a mathematician, one of the world's greatest mathematicians, and he just happens to come from the... the same city of me as me you know so he's the boy from liverpool who went on to be be one of the world's greatest mathematicians and it's natural that for me that makes me an inspiration

It also always made me feel a little bit inadequate, to be honest. You know, you think you come from the same place, you think maybe you've got the same similar starts in life, even though he's obviously quite a bit older than me. And he's just gone on to do sort of things that I could only dream of. He's kind of like lived the...

Yeah, life gone from Liverpool to Cambridge. And then he's just done everything that I've tried to do in my career, but he's just done it so much better. Do scousers know who he is? Like, is he identified as a famous scouser? No, I don't think so. So we're talking about, you know, one of the world's greatest mathematicians here, and he comes from our city.

We're not just talking about some ordinary mathematician, we're talking about an absolute great here. And I think, you know, we should be super proud of him in the way that we're proud of our musicians and our footballers. Have you ever dipped into his actual mathematics or was it not really something that's crossed your path?

so obviously the whole monstrous moonshine thing is of course related to string theory um so that's that's something where you know you hear the name crop up and i'll tell you where i've really sort of started you know come across it more and more obviously we make a lot of videos Brady on on big numbers and I think Conway his name crops up again and again and when I'm sort of doing a bit of digging on these sorts of things you know the

The arrow notation, comma arrow notation, for example, is something that we haven't really discussed, but I keep saying and thinking, oh, maybe that's something that we should do a bit more on. I don't know if you've actually discussed it with him. But, you know, it's just seen his name keeps cropping up in that area. And I was also, you know, reading some stuff up about symmetries and whatnot.

learning about his magic theorem so you just I think a lot in the recreational side of maths is where I would sort of perhaps see more of him doing the things that we do together. You obviously spend loads of time with lots of mathematicians. Do you have any idea what it was about him that... made him different to the others? Well, I think he wasn't interested in what was fashionable. So he really did go his own way. He wasn't governed by, you know, kind of ordinary propriety. And so that...

gave him a certain freedom maybe in his, you know, I call it his promiscuity of curiosity. He would, he really, at some point, you know, he had this period in his life where he was quite down and wasn't happy with. how he was progressing as a mathematician and then he had his his annus mirabilis when he invented the game of life and discovered surreal numbers and his conway constellation of

And then after that, he really decided not to worry what anybody else thought. And he would just pursue whatever interested him and go his own way. And I think that's somewhat unique.

I have never really been worried about whether something was trivial or not. Well, no, that's not true. I was worried. You know, in my early twenties, let's say, people always thought that I would, you know, be a great mathematician and be good at various things and so on. And in my late 20s I hadn't achieved any of the things that people were predicting. And so I call it my black period.

I started to wonder, you know, whether it was all nonsense, whether I was not a good mathematician after all and so on. And then I made a certain discovery and was shot into international prominence as a mathematician. When you become a prominent mathematician in that sense, it doesn't mean that many people know your name. It means that

Many mathematicians know your name, and there aren't many mathematicians in the world anyway, you know, so it doesn't count very much. But it suddenly released me from feeling that I had to live up to my promise. I had lived up to my promise. I remember I was lecturing on it in various mathematical capitals. I lectured in Paris, in Göttingen.

and then flew to New York, gave a 20-minute talk and flew back again. That's all in the space of about two weeks. And I was in the mathematical jet set for a time. And that stopped me from worrying. as to whether I was good enough. I sort of made a vow to myself. It was so nice not worrying anymore that I thought I'm not going to worry anymore ever again.

I was going to study whatever I thought was interesting and not worry whether this was serious enough. Most of the time I've kept to that vow. And what has that resulted in for you? What has that made you... better or more successful or just happier? What's the result of taking that attitude? Well, it made me happier. Yes, it made me happy is the only one of those different things. You know, I sit.

in a corridor in the mathematics department in Princeton, and I think about things. I imagine that the young graduate students there think, oh, this guy's a loony, he did something good once. And I don't care. I really don't care. I've been released from worrying about what other people think about me. And in a way he did do something interesting once.

You know, if I may say that. As far as I'm concerned, I'm doing something interesting right now. I don't mean talking to you. I'm sorry, that's really boring. Forgive me for saying that. But no, I find some problem. I try and solve it and I don't care whether it's a problem that will advance my reputation or not. I mean, I really don't. Do you care about advancing knowledge, advancing mathematics?

Yes, I suppose I do, but less than I did before because, you know, I'm pretty old now. And so if I advance mathematics and I'm not around to see the result of that advancement, then what do I care? I don't know. I don't like thinking of my impending death. You know, I haven't got all that many years left. I don't quite know how many. But I do still like doing mathematical things, so I do.

He was phenomenally fast. He could make calculations in his head very accurately and very quickly. You know, he had this system for telling the day of the week on which a given date had fallen. So you would say the 9th of March. 1564 and he would tell you instantly the day of the week.

And he was right. I mean, he had a whole system for doing this. He practiced incessantly. His computer wouldn't let him log on until he had solved one of these puzzles. I asked him about checking his email, and this was in the mid-90s. He was already up to speed on email.

But he said to me, you know, I can't get in. It takes me so long. And I said, what do you mean? And he said, well, I make myself identify the day of the week for 10 random days of the week. I've programmed the computer to throw at me 10 random days of the year.

in history so it might say the 4th of july 1827 and i have to type in a three if it's tuesday or whatever yeah instantly and i have to do 10 of these and i said how long does it take you and he said oh i'm very slow these days it's very embarrassing

It takes me about eight or nine seconds to do 10 of them in a row. And the computer would lock him out if he didn't do it within 10 seconds flat. You know, at Cambridge, there was the John Horton Conway Appreciation Society. I think his students were always... quite agog with him you know he would come in seeming to not know what he was doing and totally confused and disorganized and then

Either by the end of the lecture, he would have pulled some rabbit out of a hat, or by the end of the term, they would come to see that he had this sort of brilliant thread going all the way through. And he was a sort of showman. on various levels in that way like he really did sort of seem to be pulling at the strings and he had a grander idea in mind well the first thing is it was nice when he actually showed up

And there were times that a couple of rather important national talks in the U.S. where he forgot to show up in his later years. And that was embarrassing because, you know. If you have 400 people in the room to see the great John Conway and he's not there and nobody even remembers having seen him at the meeting and it turns out that he'd forgotten to show up or had forgotten his plane ticket or whatever.

That was not good. But on the occasions when he showed up, which was most of the time, in fairness, he was very unconventional. For instance, he came and talked to my students about 25 years ago and I couldn't get him pinned down on.

what the topic was going to be, which had me a little worried. But he said, don't worry, I've got various things I can speak about. So he walked into the room and he wrote up on the board about eight or nine topics. And he described them briefly and said to the students, which of these would you like to hear a talk on?

They were just flabbergasted because that's not the way most of us, you know, you have to lecture, prepare very carefully and get your slides or your thoughts organized. And they voted. And democracy won, and he launched forth with great passion on one of them. And in fact, one of the talks he gave, he gave a few talks. One was on Can You Hear the Shape of a Drum, which he gave to an applied mathematics class.

which was supposed to last for 50 minutes. And he went on for, I think, a little over two hours. And it happened that there was no class afterwards, so he didn't need the room. And the students didn't want to leave. They were just fascinated because he brought them into this deep... result that people had proven a few years earlier and he had simplified the proof. That was one of his geniuses was for simplifying things.

streamlining, making it seem obvious in hindsight. So he did it in such a way that these undergraduate students were with him all the way. And I just kept looking at my watch thinking they're going to bolt any minute, but they didn't. And they talked about him till they graduated.

They still remember that visit? He had an office. I think at one point he had two offices, which just got overrun with stuff like models and papers and books and so forth. At one point, his son Gareth strung hazard tape.

around his office because it was just such a tip yeah and so i think partly it was it just became slightly inhabitable so he would park himself in the common room so there was there were windows lining the hallway and there were these nooks sort of one nook per window and there were two armchairs and a chalkboard so along one wall there was two armchairs facing a chalkboard.

on the other wall so he sort of um would always be in one of these alcoves and you know even in in cambridge he would spend a lot of time in the common room so i think it must have been his just preferred modus operandi to sort of be out there and

have people coming by him and talking. I didn't get the impression he was a super tidy man. No, no. I mean, in the alcove, there was his, under his, I think, probably under a couple of different... armchairs and various all clothes he would stuff papers under the seat cushion so that's where he kept all his notes yeah and then he would stash chalk in the radiators beside the beside the window so he always knew where some chalk was

So, you know, he created a little ecosystem for himself. His work was extremely deep and broad and extended over many decades. But was marked by this free-spirited, fun-loving and playful approach to everything, which distinguished him from, you know, some other big shots who also did very serious mathematics. He had a flair and a passion.

which is unique, but he did contribute to group theory, coding theory, knot theory, geometry, quadratic forms, and two fields that he largely founded or played significant roles in founding. That would be cellular automata, I think the game of life, his most famous creation, and combinatorial game theory. And sadly, within a year and a few days, we lost the three creators of combinatorial game theory, Elwin Berlekamp.

A year ago, Richard Guy, about a month ago, and now John, a few days ago. So, you know, it's very much the passing of an era. He and Elwin were not friends at the end, I'm afraid, but their disagreement, which was passionate. was the kind that only mathematicians could possibly have. Namely, Conway thought that infinite games were important too, and Elwin only thought that finite games were important.

And they locked horns over this. And I think in some way it stopped progress for a while on their big book. And at one point Elwynn threatened to sue Conway for non-delivery of... of the manuscript, so to speak. It never came to that. Well, I guess I simply came to see him as just being human. I can remember one of the first times I visited him, I was staying with... john and his wife diana at their house and i remember being horrified that he was eating

jello pops of some kind i'm like oh my god he's he's you know he's a genius and he's eating jello pops like this can't be right he must have you know some more sophisticated snack which was you know silly but you know just realizing that Yeah, he's just a guy and he likes jello pops. And in the end, you know, he has his foibles. He's definitely not perfect. In the book, I say, you know, he's a sweetheart and an asshole. And he was fine with me saying that.

So, yeah, I just, you know, I just got to know him on a more granular level, if you will. And, you know, came to like him all the more, really. When you say he was a bit of an asshole. I think it probably ran the spectrum. You know, he.

He had his moods. He could be a little, you know, there was maybe, although he was often insecure and self-deprecating, he could also be kind of hoity-toity and, you know, maybe he... didn't give everybody the attention they deserved, whether it's, you know, an interested. student here and there or his family and his life. You know, he was just, he could be an asshole like anybody else can be an asshole. He was once asked, possibly in an interview in a student magazine in recent years, how

he made progress on stuff and how he attacked difficult problems. And one of the things he said, which actually resonated with me, and I've kind of tried to take it on board, is he said he never worked on a single problem at a time. He always had.

you know, five or six different pots simmering away. And if he got stuck on one, he would switch gears and try another. And then he might be on the fourth one and he suddenly realized something from the second problem might help him or be relevant. So we said, don't be too narrow in your focus. you know, have broad interests even within your discipline and be pursuing different theorems or lines of engagement or whatever.

And there might be some synergy between them. And he's a classic example of that. A lot of people have very narrow focuses, I think, in research. And, you know, it works for some people. And it may be the only thing that works for most of us. When your mind is as original and effective as his was, and I can't begin to fathom how he functioned, he made good use of, you know, multitasking and working on five different theorems at the same time.

What was his crowning achievement in his mind, do you think? He was definitely proudest of the surreal numbers. Yeah? Yeah. He really thought that was his greatest achievement, and I think he had hoped to sort of see them... take on another life or find their way. And anybody I spoke to said they will eventually, you know, whether it's in physics or in another field. Yeah, he was definitely proudest of this real numbers. I think he also...

was still really curious about the monster group, and he wished that he understood why the monster group existed, and that was something he was after. He wanted to understand why before he died, and he would say, you know, I... I fear I'm not going to understand. Do you feel like he was happy with where he was towards the end? Like, was he satisfied? I think he was.

reasonably satisfied. I mean, I think just the nature of who he was always wanting to understand things and be curious, he was still wanting to do that. And I think at the end it was increasingly difficult and that frustrated him definitely. You know, his brain was not working the way it used to and the way he wanted it to. I think that pained him. All in all, I visited him in January, and he still had his sense of humor, and he was still making plays on words and talking about...

you know, the game of life. And he came to love life again, which was nice to see that he came around to love the game of life after hating it for so long. He made his peace with it, did he? I think he did. Yes, finally. I felt like whenever my name was mentioned in respect of some mathematics, it was always the game of life. And I don't think the game of life was very, very interesting.

I don't think it was worth all that. I've done lots of other mathematical things. So I found the game of life was sort of overshadowing much more important things and I did not like it. Now... Well, I'm getting old. My capacity for hatred is getting less, I suppose. And it was an achievement, and I'm quite proud of it. I just want...

Don't want to talk about it all the time. I'm sorry. That's all right. Do you ever feel frustration that you won't see where things are going to be in 50 years or the next breakthrough? Do you worry about the things you'll miss? No, I don't think I do. I mean, you see, a whole series of things have happened. You know, when I was a kid, I mean a sort of late teenager, and learnt about all these unsolved problems.

It really did seem – there were about four of them – there was the Four Colour Map Theorem, there's Fermin's Lust Theorem, the Riemann Hypothesis, the Continuum Hypothesis, okay. It all lasted at least a hundred years and it looked as though they were going to last another few hundred years. Then they've mostly been solved in some sense. Continuum hypothesis.

solved in a way. Four-colour-map theorem, definitely solved. The human hypothesis, still unsolved. I've forgotten what the fourth one was. Fermat solved, yes, of course. So, three out of the four. was solved or should we say two and a half out of the four because the solution of the continuum hypothesis is a bit different from the others but there's a very definite sense in which it is solved and that may be the only sense in which

one can live with it, so to speak. But they had all lasted at least 100 years. Now, when something lasts 100 years, you're unlikely to be in it at the beginning and at the end of it. That demands that you're at least 117 years old, provided you're pretty bright at the age of 17. So essentially nobody is in at the beginning and the end. And so we're accustomed really in mathematics to have these problems that you don't expect to see solved in your lifetime. There's nothing you can do about that.

You can wail and moan and say you know something I've heard people say that if they are granted the thing to come back in a few hundred years you know what's the first question you'd ask some of them say has the so-and-so problem been solved you know but really

there's nothing you can do. You can try desperately to solve it, but if it hasn't been solved for a hundred years, you probably aren't going to. You know, it's only given to one person, so to speak, to solve a particular one of these problems. So we're used to it. And here's an atmosphere of resignation, you know. There's also a thing that we don't really know quite often, whether a problem can be solved. Okay, that's that. I mean...

I have to ask you then, if you come back in a few hundred years and get one question, what's your question then? Yeah, interesting. This is not original. I mean, I'd like to know. whether the agreement hypothesis has been solved and so on, and perhaps a few more technical details about it. Do you have unfinished business? I don't know that I have.

I mean, I have unfinished business in a way, things I'd like to do, but I'm not going to do them. I'm not going to solve them. There's one thing I would really like to know. Yes, perhaps if I hark back to the question you asked a little bit ago. There's a thing called the monster group, which is a beautiful, very large, symmetrical thing. And I would just like to know what it's all about, you know, why it's there.

I've often said, I've said for 25 or 30 years, that the one thing I'd really like to know before I die is why the monster group exists. I'm resigned now to not learning it before I die. I might just. Every now and then I've taken it out, so to speak, thought about it for a time. It's about every five years. But usually when I've taken it out, dusted it and thought about it for a time, I've made some progress.

But I don't think I will learn what it's all about before I die. Well, he did leave us a great body of work. I mean, the big... group atlas and you know game of life which people are still playing and many other things sphere packing and so on but he I think, you know, his originality, his original approach and spirit. I mean, there's very few people in the last 50 years. I can only think of one or two who.

developed a following, if you like, almost a Rothstar-like following the way he did. I mean, the other obvious one would be the Hungarian itinerant mathematician Paul Erdős, who was about 20 years ahead of him. Ehrlich traveled the world and met people. And Conway did that, too, in a different sense. But he did, you know, with 25 years in Britain, his home country, and another 25 or 30 in the States.

He covered a lot of ground and met a lot of people and made a lot of friends and had a heck of an influence. Erdos was a real character, a special, special person. Conway was a real character. I don't think I know anybody in that. category who's alive today. He certainly added colour to the scene anywhere he was in his shaggy way. That's all from us today.

I'll be putting plenty of links in today's show notes, including Siobhan's excellent biography of Conway. It's called Genius at Play. And also there among the links, I'll put all the videos we did with John Conway, including, of course, a couple about the game of life. There's also a lot of stuff there about the monster group and a look and say sequence that was a lot of fun too. I'm Brady Harron and you've been listening to the Numberphile podcast.

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