One gets the sense that Freeman Dyson has seen everything. It’s not just that at 92 he’s had a front row seat on scientific breakthroughs for the past century, or that he’s been friends and colleagues with many of the giants of 20th-century physics, from Hans Bethe and Wolfgang Pauli to Robert Oppenheimer and Richard Feynman. Dyson is one of the great sages of the science world. If you want to get a sense of where science has come from and where it might be headed, Dyson is your man.
Dyson grew up in England with a gift for numbers and calculating. During World War II, he worked with the British Royal Air Force to pinpoint bombing targets in Germany. After the war, he moved to the United States where he got to know many of the physicists who’d built the atomic bomb. Like a lot of scientists from that era, excitement over the bomb helped launch his career in physics, and later he dreamed of building a fleet of spaceships that would travel around the solar system, powered by nuclear bombs. Perhaps it’s no accident that Dyson became an outspoken critic of nuclear weapons during the Cold War.
For more than six decades, Princeton’s Institute for Advanced Study has been his intellectual home. Dyson has described himself as a fox rather than a hedgehog. He says scientists who jump from one project to the next have more fun. Though no longer an active scientist, he continues to track developments in science and technology. Dyson seems to be happy living in a universe filled with answered questions, and he likes the fact that physics has so far failed to unify the classical world of stars and the quantum world of atoms.
When I approached Dyson about an interview on the idea of the heroic in science, he responded, “I prefer telling stories to talking philosophy.” In the end, I got both stories and big ideas. Dyson isn’t shy about making sweeping pronouncements—whether on the archaic requirements of the Ph.D. system or the pitfalls of Big Science—but his manner is understated and his dry sense of humor is always just below the surface.
Growing up, did you know you would become a scientist or mathematician?
Yes. It was more mathematics than science, but I read a lot of science and there were lots of good, popular science books. I read [Arthur] Eddington and [James] Jeans and of course H.G. Wells. They made science enticing. What I remember most vividly was Jules Verne. I must have been about 8 years old when I read his book Hector Servadac about an expedition to a planet. I thought it was all true and it came as a big disappointment when I discovered it was just a story.
Why did you go into physics once you got to college? Why not stay in mathematics?
It was partly because of the bomb. I was in England all through the war. We knew nothing about nuclear bombs and then suddenly, Hiroshima, and the war was over. We were just hugely grateful to these physicists who had somehow brought the war to an end, and I thought it would be interesting to get to know those people and find out what they’d been doing.
Were there scientists who were your heroes?
Oh, yes. One was [J.B.S.] Haldane, the biologist who wrote excellent popular books. He was also a man of very wide interests. The people in Cambridge whom I got to know personally—Hardy and Littlewood and Besicovitch—were all great mathematicians. The joke was they spent most of their time playing billiards. Besicovitch had a wonderful billiard table. I was very lucky because my father had bought a billiard table when I was a child. So I immediately fit into this coterie in Cambridge. If I wanted to talk to the big mathematicians, I would just start playing billiards and then the conversation would turn to mathematics.
Feynman would just write down the solutions without ever writing the equations. It seemed like a sort of magic.
After the war, you went to Cornell as a graduate student in the late ’40s, and you ended up working with one of the towering figures in physics, Hans Bethe. Did he become your mentor?
Yes, very much so, an extraordinarily good one. He was amazing with students. He had a lot of students and he always found the right problem for each student, just difficult enough but not too difficult. He was an ideal person to have as a mentor. I owe a tremendous amount to him.
What was the right problem for you?
It concerned quantum molecular dynamics, which was bursting open at that time. There was a group of experimenters at Columbia who had been looking at the hydrogen atom with tools they developed during the war. Microwaves were invented for military purposes—for radar—and microwaves were just what you needed to study quantum mechanics with great accuracy. Willis Lamb was the chief experimenter, and he was tickling the hydrogen atom, measuring very precisely the energy levels of hydrogen. It turned out the standard quantum theory gave the wrong answers, so something new was needed and Bethe understood what it was. If you put the reaction of the atom’s radiation field onto its mechanics, it gave the right kind of behavior. Bethe had this extraordinary ability to do simple calculations which were quite sloppy but gave roughly the right answer. Then he gave me the problem of doing the same calculation, which I did much more accurately.
Then you met Richard Feynman and you ended up working with him on quantum electrodynamics.
I never worked with Feynman, but I learned a tremendous lot from him. He was a young professor and I was just a student, so I listened to Feynman, and of course he was a genius. He was also a clown and loved to perform, so he always needed an audience. I was very happy to be the audience.
What made Feynman different from other scientists?
He was extremely original. He had his own way of doing science, which was different from everybody else. That’s why he had a hard time communicating. He never wrote down equations. Most people in physics write down an equation and then find the solutions, but that wasn’t the way Feynman did it. Feynman would just write down the solutions without ever writing the equations. It seemed like a sort of magic because he thought in terms of pictures instead of equations. He had these little pictures in his head and he scribbled little pictures on paper and nobody understood what they meant. My job was to translate Feynman into language other people could understand.
You never actually got your Ph.D., did you?
No. I was so lucky. I slipped through the cracks.
You didn’t want a Ph.D.?
No, I hate the Ph.D. I think it destroys people’s lives. I had actually three tragedies which I witnessed with people who came to work with me and came to grief. One of them committed suicide and two ended up in mental institutions. I blame the Ph.D. system for that. I think it really was a disaster for many people.
Why? Because the Ph.D. system grinds people down?
Yes, and it’s completely inappropriate for what most people need. It was designed for German academics in the 19th century and it was fine for that. But for any other kind of life, it’s totally wrong. It takes far too long. It forces you to pretend to be a researcher when most people don’t want to be researchers. It’s become a union card and I think it’s highly disruptive, particularly bad for women. For women to waste five or 10 years of their lives is more of a disaster than it is for men.
Because they might have family responsibilities as well?
Yes, because there’s a biological clock. It’s ticking much more for them.
Everybody was scared of Wolfgang Pauli. He had nasty things to say about almost everybody.
There were many famous scientists at Princeton when you got there, including Albert Einstein. Did you ever get to know him?
No, and he didn’t encourage young people to get to know him. He never came to seminars, never came to lunch. We always saw him walk by every day. He was tremendously busy with affairs of the world, so he was very much in demand. People came every day. Important people came to visit, so he just didn’t have time for saying hello to the kids.
But it sounds like he didn’t want to say hello. Was it simply not part of his makeup to talk with the up-and-coming generation?
That was true. He didn’t enjoy teaching. There were two important things for him. There was his own work, which he always continued, and there was his public activity as a politician, which he did extremely well. He was a really serious player in the international game and actually had a good effect.
In matters of war and peace?
Yes. And especially civil liberties.
When you were first at Princeton, what did you think of Einstein?
I admired him tremendously, of course, both as a scientist and a public figure. We all knew he was a great man, but we also considered him sort of out of it. He wasn’t interested in the things that were going on in science. As far as we were concerned, we didn’t have anything to learn from him and he probably felt the same way about us.
Had his time in science come and gone?
That was certainly true. He missed the bus on the physics that was going on after the war.
Niels Bohr often visited the Institute for Advanced Study. Did you get to know him?
Yes, he was totally different. Bohr was about the same age as Einstein, but much more in touch. He talked to everybody. He was interested in everything and was well-informed and he gave us good advice. He was definitely part of the community. He came to seminars. He also came to lunch. We had a lot of interaction with him.
There were other prominent physicists who came through Princeton. Did you know Wolfgang Pauli?
I knew him very well, but of course I’d been with him in Switzerland. He was the chief professor in Zurich. I was living in Zurich for half a year, so I saw him every day. We became good friends. He liked to go for a walk after lunch and he would usually invite me along, so I had many conversations with him. He was full of stories and he was a great joker, too. He was keeping up with the young people.
Did you talk about science or life in general on those walks?
Oh, everything. He was particularly interested in psychology. He was a personal friend of Jung. He had been analyzed by Jung and so he talked a lot about that.
There are fascinating stories about his friendship with Carl Jung. Jung believed in various psychic phenomena and so did Pauli.
Oh yes. He had lots of weird ideas, but he also had a great sense of humor. He never took himself too seriously.
What set Pauli apart as a scientist?
What distinguished him mostly was his sharp tongue. Everybody was scared of him. He had nasty things to say about almost everybody. I remember the very first time I met him at a conference in Zurich. He was talking with a whole group of people about Julian Schwinger, who had just come to Switzerland. Schwinger was a brilliant young American who had done some very fine work. He was a rival of Feynman; they were the two geniuses then. Pauli was saying that Schwinger told us all this stuff that actually made sense, not like that nonsense Dyson has been writing. At that point I came walking up with a friend of mine, Markus Fierz, who was also a Swiss scientist. With a twinkle in his eye, Fierz came up to Pauli and said, “Please allow me to introduce you to my friend, Freeman Dyson.” Pauli said, “Oh that doesn’t matter. He doesn’t understand German.” Which of course I did. That was a good beginning and we were friends right from the very first day.
The middle-age crisis is when you suddenly become aware of the fact that you’re not as smart as your students.
You also knew Robert Oppenheimer, who came to Princeton shortly after his work at Los Alamos. I’ve heard he was a truly gifted leader, at least while he was running the Manhattan Project, and probably a better administrator than scientist. Was that true?
I don’t know whether that’s true. He did one really important thing in science, which was the theory of black holes. He really discovered black holes, which turned out to be extremely important. That was done in 1939 with his student [Hartland Snyder]. They developed this theory of why black holes exist, how they are formed, and he got everything right. Essentially, he was the originator of black holes as a concept and it was a prediction that turned out to be true.
The sad thing was that this paper was published on the first of September, 1939—actually the day that Hitler walked into Poland. So the whole world was looking at Poland and not at Oppenheimer. That piece of work somehow got forgotten and Oppenheimer himself lost interest in it and he never went back to it later. It went out of his life and that was a shame. He could have done a lot more with it, so it all had to be redone 20 years later. He was a big scientist. The strange thing is, the really great thing that he did was not what he wanted to do. He wanted to do particle physics and wasn’t interested in astronomy. Anyway, that’s the way the ball bounces. You never know what you end up being famous for.
You must have known Oppenheimer once he took over the Institute for Advanced Study at Princeton. What did you think of him?
I had very mixed feelings. He was my boss. He was a very temperamental, unpredictable kind of character. He would suddenly blow hot or cold and you never knew which one you had to deal with. He could be extremely generous and friendly or he could be very harsh. I had family problems when I came to the Institute and he was very helpful and generous on a personal level. He was a very good friend. On the other hand, he could be unreasonably brutal on scientific questions. He was very quick to judge and decide that somebody was no good, and then that was final. There were some bad cases of that.
Leon Cooper was a young kid who came to the Institute at Princeton, and he had this crazy idea that he could understand superconductivity, which was one of the big unsolved problems of that time. Cooper had this idea that superconductivity had something to do with pairs of electrons and Oppenheimer said that was total rubbish. Cooper tried to give a talk about his theory of superconductivity and Oppenheimer would just interrupt all the time and tell him why it was nonsense. He decided Cooper was no good, so Cooper left the Institute and went to Illinois, where he met Bardeen and Schrieffer, and the three of them produced the correct theory of superconductivity, which was in fact Cooper’s idea. They all got the Nobel Prize and Cooper got his revenge.
You’re talking about the giants of modern physics—some of the founders of the physics we know today. This seems like a golden age of science—what I would call a heroic age—when major discoveries about the nature of reality were revealed. Do you see it that way?
Yes. Of course, the real golden age was the 1920s, when quantum mechanics was developed. Quantum mechanics was a much bigger revolution in the ’20s than what happened in the ’50s, when I was involved. Ours was sort of a silver age, but still it was a good time to do physics. It was a time when most bright kids went into physics. It was a very exciting time for young people. There were plenty of jobs and the field was expanding fast. Any second-rate physicist could do first-rate work. That’s the best time to be active. A third-rate physicist could do second-rate work.
This was also a time when certain scientists were true heroes. Einstein above all, but you also had people like Feynman. Do we still have those kinds of heroes in science today?
I would say they mostly are going into biology now. Biology is moving very fast and so the same kind of people who became physicists in those days now tend to become biologists. Theoretical biology is now becoming much more of a real subject than it used to be, so a lot of people who are really computer scientists are doing biology. The line between mathematics and biology is not so sharp anymore. I would say that’s where the young people are. They’re having the same good times now that we had 50 years ago.
We still don’t have a unified theory in physics. There’s the classical world of stars and planets, and then the quantum world of atoms and electrons. Does it trouble you that no one’s been able to bring those two realities together in one theoretical model?
For some people it does. For me, it’s something to rejoice in. I like it better to have two universes rather than one. I think the classical world is real and the quantum world is real, too. The beautiful thing is how well they fit together even though they are so totally different. I like the difference. I always hope they won’t be unified, but of course nature will decide in the end.
You’ve known many great scientists over the years. Are there certain personal or intellectual attributes that make a great scientist?
It’s never easy to define. They’re all different. I would say they had a tendency to become a bit crazy when they get old. They lose a sense of proportion. That’s what made Bohr unusual. He kept his sense of proportion right up to the end.
Do you need to be willing to risk your reputation and pursue crazy ideas? Is that what leads to great breakthroughs?
First of all, it helps to be ignorant. The time when I did my best work was when I was most ignorant. Knowing too much is a great handicap. Especially if you’ve been teaching for some years, things get so fixed in your mind and it’s impossible to think outside the box. I was in the lucky position of jumping into physics without ever having taken any courses in physics. I’d only been a pure mathematician up to that point.
Is the great scientist also naturally subversive?
Yes, undoubtedly. You’ve got to destroy what exists in order to build something new. You need good taste, of course. If you destroy indiscriminately, it doesn’t help at all. That’s where intuition comes in—what parts of the old building should be taken down.
Is physics a young person’s game? It seems that most great discoveries are made by people under 40 or even under 30.
That is true in theoretical physics. Experimenters can keep going much longer and sometimes stay very productive into old age. That’s a very different game. For theoretical physics, I suppose you need to be ignorant. After a while, you get so attached to things as they are.
I thought you’d say we have more brain power when we’re young. But you’re suggesting the problem is we get too set in our ways.
I would say so. Of course, I don’t know how to measure brain power. I certainly am slowing down and that’s quite noticeable. I can’t measure how much brighter I used to be than I am now.
Was there a certain point in your own career when you stopped doing the kind of mathematical physics you had once done, when you decided to go in a different direction?
Yes. The turning point was around the age of 45. The middle-age crisis is when you suddenly become aware of the fact that you’re not as smart as your students. At that point, I decided to spend the second half of my life mostly writing books rather than doing calculations, which was a wise choice. Most people become administrators or do something else then. You have to find another line of work rather than just thinking.
You’ve written about a wide range of subjects—not just science but also literature, the humanities, and even God. You’ve described yourself as a practicing Christian, though not a believer. Do you have a metaphysical frame of mind?
No, not at all metaphysical, but I have a very strong social personality. I like friends. I like to be a part of a community. It’s not metaphysics, it’s something very practical. Religion to me involves going to church, having friends who go to church, singing the music and listening to the words. It’s something you do together with people. I don’t go to church anymore, but I’m very happy with my daughter, who’s a Presbyterian minister. I value her as my contact with that world.
How does the perception of scientists today compare to when you were starting out as a scientist in the 1930s and ’40s?
Well, it goes around in circles. When I grew up in the ’30s, science was really unpopular. Science was responsible for the horrors of World War I, especially chemical warfare. That was so horrible and was very much on people’s minds. When I was in high school, only the dumb kids would take science. If you were really capable, you’d do Latin and Greek. If you were second-rate, you would do French and German. If you were third-rate, you would do science. In some ways times have changed. I think there’s a low opinion of science just due to the technological abuses. Now it’s nuclear weapons rather than chemical weapons. The public is also very distrustful of genetics.
You knew a lot of people who worked on the atomic bomb. Many of those people at Los Alamos said that was the most exciting time of their lives. Yet there’s a deep irony. Their work produced the most devastation we’ve ever seen.
That’s all true. Those people were my friends. I’ve been trying all my life to deal with problems of war and peace. When I’m not doing science, I’m worrying about problems of war and peace. Of course, that’s a perennial problem. It was particularly bad in the ’30s when I was a teenager because we had to deal with Hitler, which was worse than anything we have at the moment. It goes up and down. There’s definitely a huge problem with the world divided into nations. We’re all murdering each other. But I also find it very good that the whole basis of our society is having a variety of cultures and languages. This variety is what makes the human species so creative. It’s a question of how you can reconcile those two aspects.
Are you fundamentally an optimist about the human species?
Yes. It comes from having grown up in the 1930s. In so many ways, things were black in the 1930s, far worse than they are today. People don’t remember, but everything in England was covered with soot. When I would go to London for the day, the color in my shirt would turn black because there was so much soot in the air. England is much cleaner now than it was then. The United States is much cleaner now. Los Angeles was full of smog when I first came there. Economic problems were much worse in the ’30s than they are today. Above all, we had World War II to look forward to. We were all quite aware of Hitler and the fact that we were going to have to fight him, and that we probably wouldn’t survive. That was what I grew up with. That was far worse than the kind of wars we have today.
Steve Paulson is the executive producer of Wisconsin Public Radio’s nationally syndicated show To the Best of Our Knowledge. He’s the author of Atoms and Eden: Conversations on Religion and Science. You can subscribe to TTBOOK’s podcast here.