When Julian Schwinger came to the Columbia Graduate School of Physics in 1935 at the age of seventeen—five years younger than the youngest of us—he was shy and pudgy, with a schoolboy’s broken complexion; but he had already gone through the most advanced treatises on theoretical physics, quantum theory, and relativity all by himself, as easily and avidly as the rest of us had once gone through Two Years Before the Mast. By comparison, we were illiterates. There was even a rumor that he had published his first scientific paper in the Physical Review at fifteen when he was at Townsend Harris High School. He was at once so obviously in a class by himself that no one bothered to envy him. One thing, each of us assured the others: eventually he would earn a Nobel Prize.
When I say “we,” I mean the group of about a dozen graduate students studying and doing research toward our doctorates, along with a handful of postdoctoral fellows and instructors also in their early or middle twenties. We made up the laboratory population of the department. As it turned out, we were right about Julian. In 1965, he was awarded the Nobel Prize for work in quantum electrodynamics. Also, as it turned out, we proved to have been very poor judges of Nobel Prize material. Sitting right there among us all the time, taking part in our talk and gossip, were three other whom we had passed over completely. The first was one of our research chiefs, I. I. Rabi, who was to win a Nobel Prize in 1944. The second was Polycarp Kusch, a young experimentalist from the Middle West, with large angular movements and a loud assertive voice. He was the Nobel laureate in 1955. The third was Willis Lamb, a tall, thin Californian with a slight squint and a quiet erudition, both in physics and out. In the thirties, Lamb considered himself only as a theoretician—although certainly no then in Schwinger’s class, as far as anyone thought.
Four Nobel laureates out of a group as small as that, at a time when the world population of physicists was over ten thousand, was a remarkably high proportion indeed. All these prizes, though, were still decades in the future. We didn’t know what a genuine Nobel Prizewinner looked like, or even what he did once he had been awarded the prize. From time to time, a few such exalted beings as Harold Urey, Arthur Compton, and Robert Millikan would drop in on us for a public evening lecture, but then they took off again with their radiance unpenetrated.
Our first real contact—certainly my first contact—with a living, breathing, close-enough-to-touch Nobel laureate came in 1938 when Enrico Fermi left Italy with his family, ostensibly to go to Sweden to receive the prize for his work in artificial radioactivity. Instead of returning to Mussolini’s Rome, he kept on going until he came to us at Columbia. He was in his middle thirties at the time. I hoped only that when he’d start giving his lecture on atomic and nuclear physics I wouldn’t open my mouth and make a fool of myself in his seminars. I glimpsed him with awe as he hurried through the Pupin corridors, labs, and offices: a short, quick, long-armed man. His gray eyes looked patient, when they were really only polite. To me, he was already half a god.
About a week after Fermi’s arrival, I was called to Rabi’s office. In those days, Rabi liked to whittle at a small piece of wood as he talked. I had recently finished an apprentice research for him in his molecular-beam techniques, and had passed all my qualifying exams. I came, hoping that he was finally going to put me to work on my doctoral assignment. Instead, he told me he was releasing me from his research group so that I could be free to become Fermi’s assistant. It was as if I had been told I was to report to heaven to sit at the right hand of God. But there was also a nightmare side to all this splendor and that was my feeling that at that particular point of my career I was no more capable of carrying on research physics on the Fermi level and up to the Fermi standard than I was able to walk onstage at the Metropolitan Opera House in the middle of a performance of Tannhäuser and take over the main role. It was the greatest opportunity I had ever had; it was also the most appalling invitation to disaster.
Fermi got to the point the moment I appeared in his office. He asked me what I knew about cosmic rays. I said I knew nothing. He said, no matter, neither did anyone else. He went to the blackboard then and outlined the theory of the experiment he wanted performed, that he wanted us to perform. For the first few minutes, he was remarkably clear. How marvelous it felt to be one of the talented people up here At the Top where life shone! Then everything darkened. He was speaking brilliantly, lucidly, but really to himself, because I no longer understood anything. I kept nodding though; it never occurred to me to ask him to repeat any of the points that I lost. At last, he finished with theory and began to discuss the apparatus I would have to build: pulse-counting circuits, giant Geiger tubes, and appropriate vacuum systems. I felt a little better. I had never made any of the things he asked for, but I knew that I would be able to find out how. Physics had always come more easily to my hands than to my head.
Fermi turned out to be the most active, the most competitive man I have ever known, not only intellectually but physically as well, even with men twice his size and half his age. If it was a matter of mountain climbing, he had to be the one in the lead. If it was swimming, he proved to be the one with the greatest endurance. As his tennis partner, I never had anything to do but hold my racket and squint against the sun. He played both courts, the net and the backcourt as well. Shortly after his arrival in America, he bought a long shining black Packard with part of his prize money. When a minor adjustment had to be made one Sunday, he insisted on doing it himself—and lost a piece of his finger. In the laboratory, sometimes I literally had to wrestle pieces of equipment out of his hand, because while I never saw him lose his temper or even show impatience, he wanted things done his way, by him. I was freed of his furious energy only when the news of nuclear fission came along, and he threw himself into that.
The discovery of nuclear fission was a direct personal challenge to Fermi. In the early 1930s, Fermi had remarked to his old professor in Rome, Carponi, that even though it might take another fifty years to work out all the details of the wave theory of atomic structure, the main outlines were already clear. It was time he moved on to where the next big questions were. Then he and his young Italian co-workers plunged into research on neutron-induced artificial radioactivity, and ranged like wolves through the entire periodic table of elements, and beyond—to the so-called “transuranic” elements, those made heavier than uranium by the nuclear capture of the bombarding neutrons. In 1938, once again Fermi found himself in a field where the general outlines had been cleared. The next advanced position for him to attack was the question of the nature of the very high energy particles found in cosmic rays; and this is what he planned to be doing in America.