To listen to more of Freeman Dyson’s stories, go to the playlist: • Freeman Dyson (Scientist)
Freeman Dyson (1923-2020), who was born in England, moved to Cornell University after graduating from Cambridge University with a BA in Mathematics. He subsequently became a professor and worked on nuclear reactors, solid state physics, ferromagnetism, astrophysics and biology. He published several books and, among other honours, was awarded the Heineman Prize and the Royal Society's Hughes Medal. [Listener: Sam Schweber; date recorded:1998]
TRANSCRIPT: I immediately heard people talking about Dick. I mean Dick was - everybody called him Dick, 'What did Dick say?' and 'What did Dick think of that?' and so on and so it very quickly became clear that this was somebody noteworthy. And then, the first time I actually got to know him was we went to a seminar at Rochester. At that time the Rochester Department was led by Marshak, and Weisskopf I think was also there, maybe at that time, I'm not sure.
[SS] I think he was at MIT already.
No, maybe he was - yes, it was Marshak was at Rochester... anyway. So every second week we had a seminar at Rochester and then a seminar at Cornell and people would drive back and forth. So I drove up with Feynman to the Rochester seminar one day, and that was when I first got a real chance to talk with him and it was very exciting in both the conversation, and the driving. He was a reckless driver and I was...
[SS] Scared?
Well. I was wondering whether we'd get there alive. I don't know that I was actually scared because I had faith in Feynman, but... Anyway, and he talked, of course, a lot about Los Alamos and about the things he had done with his life. He loved to talk, and he was also interested in me and on what was going on in England. So we hit it off right from the beginning. And then, as the year went by, I became a sort of just an interested spectator, watching him work out his version of quantum electrodynamics, as he was in the middle of that and he was just getting it together and struggling himself to understand what was going on. He had these amazing ways of calculating with diagrams, where you didn't have to have equations but you simply wrote down the answers, and instead of solving equations the way other people did, he just wrote down the answers by looking at the pictures. So it was all very incomprehensible, but it gave the right answers. So that was a big challenge for me, and I decided fairly soon that this was the most interesting thing that I could be doing - was to make sense of Feynman.
[SS] And your own way of doing mathematics and physics was not visual up to that point?
It never was, and I mean I was always analytical in my style, and of course quantum field theory is highly non-visual too. I mean quantum field theory is purely analytical. So I came to Feynman definitely like an anthropologist trying to see what the natives were doing. I mean, I was clearly not his kind of animal.
[SS] And the language was strange.
It was totally strange, and of course, but I found it all very fascinating and the amazing thing was that it gave the right answers. It had some physical basis. I mean, it came originally from Dirac, his style of doing things, but of course he had transformed it totally. Dirac never had pictures in the way he did. He didn't understand it himself, at that time. I mean it all became systematised fairly soon afterwards, but he was still making up the rules as he went along, and was sort of guided by the answers. And one of the big questions which he never really settled was closed loops. When you had diagrams involving electrons going around in circles and coming back on their own tails, what do you do with those? So he had rules for doing that, but there was essentially an ambiguity in whether they should be plus or minus, and so he made up rules so that the answers would come out right, but without any real physical motivation. So we talked a lot about these questions. The general rule was if Feynman was sitting in his office he would keep the door open and anybody could walk in, and then if he wanted to talk he would say, 'Fine, let's talk.' And if he didn't want to talk he'd say, 'Get out!' But you didn't take it personally. No, you never took it personally, and the nice thing was then, if he said, 'Let's come and talk,' you knew he meant it and, and wasn't just being polite. So we got along.
[SS] And he didn't know any field theory either?
He wasn't even interested in learning. He said, right away, you know, he said, 'That stuff isn't for me. That's a hard way of doing it, but I can't do it that way.' He knew his way was better.