Feynman loved doing physics. I think what he loved most was the process of it. Of calculating. Of figuring things out. It didn’t seem to matter to him so much if what came out was big and important. Or esoteric and weird. What mattered to him was the process of finding it. And he was often quite competitive about it.
Some scientists (myself probably included) are driven by the ambition to build grand intellectual edifices. I think Feynman — at least in the years I knew him — was much more driven by the pure pleasure of actually doing the science. He seemed to like best to spend his time figuring things out, and calculating. And he was a great calculator. All around perhaps the best human calculator there’s ever been.
Here’s a page from my files: quintessential Feynman. Calculating a Feynman diagram:
It’s kind of interesting to look at. His style was always very much the same. He always just used regular calculus and things. Essentially nineteenth-century mathematics. He never trusted much else. But wherever one could go with that, Feynman could go. Like no one else.
I always found it incredible. He would start with some problem, and fill up pages with calculations. And at the end of it, he would actually get the right answer! But he usually wasn’t satisfied with that. Once he’d gotten the answer, he’d go back and try to figure out why it was obvious. And often he’d come up with one of those classic Feynman straightforward-sounding explanations. And he’d never tell people about all the calculations behind it. Sometimes it was kind of a game for him: having people be flabbergasted by his seemingly instant physical intuition, not knowing that really it was based on some long, hard calculation he’d done.
Feynman and Wolfram had very different problem-solving styles:
Typically, Feynman would do some calculation. With me continually protesting that we should just go and use a computer. Eventually I’d do that. Then I’d get some results. And he’d get some results. And then we’d have an argument about whose intuition about the results was better.
The way he grappled with Wolfram’s rule 30 exemplified this (I’ve omitted a bunch of pictures, you can check them out in the article):
You know, I remember a time — it must have been the summer of 1985 — when I’d just discovered a thing called rule 30. That’s probably my own all-time favorite scientific discovery. And that’s what launched a lot of the whole new kind of science that I’ve spent 20 years building (and wrote about in my bookA New Kind of Science). …
Well, Feynman and I were both visiting Boston, and we’d spent much of an afternoon talking about rule 30. About how it manages to go from that little black square at the top to make all this complicated stuff. And about what that means for physics and so on.
Well, we’d just been crawling around the floor — with help from some other people — trying to use meter rules to measure some feature of a giant printout of it. And Feynman took me aside, rather conspiratorially, and said, “Look, I just want to ask you one thing: how did you know rule 30 would do all this crazy stuff?” “You know me,” I said. “I didn’t. I just had a computer try all the possible rules. And I found it.” “Ah,” he said, “now I feel much better. I was worried you had some way to figure it out.”
Feynman and I talked a bunch more about rule 30. He really wanted to get an intuition for how it worked. He tried bashing it with all his usual tools. Like he tried to work out what the slope of the line between order and chaos is. And he calculated. Using all his usual calculus and so on. He and his son Carl even spent a bunch of time trying to crack rule 30 using a computer.
And one day he calls me and says, “OK, Wolfram, I can’t crack it. I think you’re on to something.” Which was very encouraging.
Nice reminiscence from Stephen Wolfram on his time with Richard Feynman:
Feynman and Wolfram had very different problem-solving styles:
The way he grappled with Wolfram’s rule 30 exemplified this (I’ve omitted a bunch of pictures, you can check them out in the article):