But then Pauli came to the United States, where various people worked on him—including Dick Feynman, and including me. Many of us talked to Pauli and said, “Look, you shouldn’t associate yourself with this. It’s all rubbish, and you have your reputation to consider.” Pauli agreed, and he wrote a letter to Heisenberg saying something like: “I quit. This is all nonsense. There’s nothing to it. Take my name off.” In another letter, Pauli drew a rectangle on the page, and next to it he wrote: “This is to show the world that I can paint like Titian. Only technical details are missing. W. Pauli.” In other words, Heisenberg had provided only a frame, with no picture. I knew Pauli fairly well. I knew Paul Dirac [another founder of quantum mechanics]. He was a remarkably eccentric person.
Of course I knew these people when they were old, not when they were young and carrying on their most important activities. But still, I knew them. And those were the people we were supposed to admire. I didn’t think the people around me were going to be so special. I guess, looking back now, the era does look exciting.
There’s a big difference, though, that my teacher Victor Weiskopf kept pointing out. And that is that the people who were working out the consequences of quantum mechanics, shortly after quantum mechanics was discovered in 1924 and ’25, began to understand how atoms and molecules really worked, and they asked elementary questions about the world that even ordinary people might ask. For example, Victor used to say, one question is, Why can’t I push one finger through the other finger? Well, ultimately it comes down to the exclusion principle [which shows that two particles cannot occupy the same space at the same time]. And so on. Whereas now you have to be sophisticated to even ask the questions that we’re answering.
One of your best-known interactions was with Richard Feynman at Caltech. What was that like?
We had offices essentially next door to each other for 33 years. I was very, very enthusiastic about Feynman when I arrived at Caltech. He was much taken with me, and I thought he was terrific. I got a huge kick out of working with him. He was funny, amusing, brilliant.
What about the stories that you two had big problems with each other?
Oh, we argued all the time. When we were very friendly, we argued. And then later, when I was less enthusiastic about him, we argued also. At one point he was doing some pretty good work—not terribly deep, but it was very important—on the structure of protons and neutrons. In that work he referred to quarks, antiquarks, and gluons, of which they were made, but he didn’t call them quarks, antiquarks, and gluons. He called them “partons,” which is a half-Latin, half-Greek, stupid word. Partons. He said he didn’t care what they were, so he made up a name for them. But that’s what they were: quarks, antiquarks, and gluons, and he could have said that. And then people realized that they were quarks, and so then you had the “quark-parton” model. We finally constructed a theory—I didn’t do it by myself; it was the result of several of us put together. We constructed the right theory, called Quantum Chromodynamics [QCD], which I named. [QCD describes the interactions between quarks and gluons, which bind quarks together.] And Feynman didn’t believe it.
He didn’t believe that the theory was correct?
No. He had some other cuckoo scheme based on his partons. Finally after a couple of years he gave up because he was very bright and realized after a while that we were correct. But he resisted it, and I didn’t understand why he had to be that way. Partons...
Feynman was famously eccentric. Did you guys ever do anything wacky together?
We did lots of playful things. One of his friends was an elderly Armenian painter. My late wife Margaret and I were friendly with him too. He had some important birthday, and Margaret and I dreamed up this idea of giving him a peacock. So we conspired with the Feynmans to do it. They drew his attention somewhere else while Margaret and I got the peacock from the car and put it in his bedroom. A peacock in his bed! It’s a marvelous way to give somebody a present.
Did you find it strange that Feynman became such a celebrity?
Feynman was a peculiar case because he was a very brilliant, terrific, successful scientist, but he was also a clown. He was more of a clown than he was a scientist sometimes.
But you and Feynman could get into really deep conversations about physics. You were well matched, weren’t you?
For some years, and then I got fed up with him. He was just so turned in on himself. Everything was a test of his brilliance. So if in discussing things we came to some interesting conclusion, his interpretation of it was, “Gee, boy, I’m smart.” And it’s just annoying, so after a few years I just wouldn’t work with him.
When you think about people like Feynman or Einstein or some of the other physics legends, do you think of them as geniuses? Is there such a thing?
Einstein was very special—I mean, creating that theory, general relativity [which describes gravity as a product of the geometry of space and time]. To do it today or to do it 34 years ago would be striking, remarkable, an utterly remarkable achievement. But to do it when he did, in 1915, that’s just unbelievable.
When you were at the Institute for Advanced Study, Einstein was also there, although he was near the end of his life. Were you able to absorb anything from him?
I could have. I could have made an appointment with his secretary, the formidable Helen Dukas, and gone in and talked with him. I could have asked him some questions about the old days. If it were today I would do it in a moment. But all I could see then was that he was past it. He didn’t believe in quantum mechanics, didn’t know about the particles that we were studying. And he didn’t know about this and that. If I showed him what I was doing, he wouldn’t make anything of it. And if he showed me what he was doing, I wouldn’t believe it. So I didn’t do anything. I would say: “Hello. Good morning.” And he would say, “Guten morning.” That was about it.
What are you working on today?
Along with several other people around the world, I’m looking to see if there might be alternate ways to mathematically characterize entropy, the measure of disorder of a system. It might be useful to employ alternate formulas for looking at different circumstances such as financial markets or social interactions. Maybe this will turn out to be an extremely flexible tool for handling all kinds of situations. That’s what people hope. Other people think it’s nuts.