by Ray Monk
Dyson was naturally apprehensive about Oppenheimer’s reaction to this memo, but, in fact, the next time the two met Oppenheimer told him that he was delighted by it and had arranged for Dyson to give a seminar twice a week for the following four weeks, as an opportunity for him to put his views to the other members of the institute. As Dyson discovered at the first seminar in the series, however, Oppenheimer evidently saw these occasions as being an opportunity for him to express his views as well. In the next letter home to his parents, Dyson wrote about how difficult Oppenheimer had made it for him to put across his ideas:
I have been observing rather carefully his behaviour during seminars. If one is saying, for the benefit of the rest of the audience, things that he knows already, he cannot resist hurrying on to something else; then when one says things that he doesn’t know or immediately agree with, he breaks in before the point is fully explained with acute and sometimes devastating criticisms, to which it is impossible to reply adequately even when he is wrong. If one watches him one can see that he is moving around nervously all the time, never stops smoking, and I believe that his impatience is largely beyond his control.
During the second seminar, ‘we had our fiercest public battle so far, when I criticized some unwarrantably pessimistic remarks he had made about the Schwinger theory. He came down on me like a ton of bricks, and conclusively won the argument so far as the public was concerned.’ The following day, Dyson told his parents, he was rescued by Hans Bethe, who came down to talk to the seminar ‘about some calculations he was doing with the Feynman theory’.
He was received in the style to which I am accustomed, with incessant interruptions and confused babbling of voices, and had great difficulty in making even his main point clear; while this was going on he stood very calmly and said nothing, only grinned at me as if to say ‘Now I can see what you are up against.’ After that he began to make openings for me, saying in answer to a question ‘Well I have no doubt Dyson will have told you all about that,’ at which point I was not slow to say in as deliberate a tone as possible, ‘I am afraid I have not got to that yet.’ Finally Bethe made a peroration in which he said explicitly that the Feynman theory is much the best theory and that people must learn it if they want to avoid talking nonsense; things which I had begun saying but in vain.
After the seminar Bethe and Oppenheimer dined together, and during dinner Bethe must have said something about Oppenheimer’s treatment of Dyson, because after that Oppenheimer listened to Dyson without interrupting, and at the end of the last seminar made a short speech saying how much they had all learned from Dyson’s talks. The next morning, Dyson found in his mailbox a short note from Oppenheimer, saying simply ‘Nolo Contendere’, a legal term derived from the Latin for ‘I do not wish to contend.’
By the time these seminars had finished, towards the end of November 1948, Dyson had achieved, simply by word of mouth (his paper would not actually appear in print until February 1949), a reputation, in both America and Europe, as an extremely gifted and promising young physicist, and he was consequently bombarded with job offers. The Commonwealth Fellowship that had allowed him to spend two years in the US stipulated that, when those two years were over, he had to return to either Great Britain or one of the Commonwealth countries. He was therefore unable to accept a position that Rabi offered him at Columbia, which he deeply regretted. ‘It’s a grim prospect,’ he told his parents, ‘to be cut off without more than rumours and months-old reports of what Feynman or Schwinger or Columbia or Berkeley is doing.’
To avoid this ‘grim prospect’ becoming a permanent state of affairs, Oppenheimer made Dyson a generous proposal, based on a very flattering comparison. Both Bohr and Dirac, Oppenheimer told Dyson, had felt compelled to return to their home countries after their visiting fellowships at the institute, but he had made for them an arrangement whereby they could visit the institute every third year so that they could keep in touch with people and developments in the United States. ‘Certainly,’ Oppenheimer told Dyson, ‘we shall be able to do something of the kind for you.’ A short while later, Dyson went to see Oppenheimer to tell him that, among British universities, he had received offers from Birmingham, Bristol and Cambridge, and to ask for advice on choosing between the three. ‘Well,’ said Oppenheimer, ‘Birmingham has much the best theoretical physicist to work with, Peierls; Bristol has much the best experimental physicist, Powell; Cambridge has some excellent architecture.’ Perhaps, by this time, Oppenheimer had broken free of the spell exerted by Dirac. In any case, Dyson chose to go to Birmingham.
Intoxicated by his new-found celebrity, Dyson wrote to his parents: ‘I am really becoming a Big Shot.’ However, as a celebrity, he was nowhere near being in Oppenheimer’s league. On 8 November 1948, in the middle of Dyson’s series of seminars, the cover of Time magazine was taken up with a painting of Oppenheimer, looking thoughtful and troubled, beneath which was the quotation (which, in the context of the Dyson/Oppenheimer exchanges, acquires a rather ironic flavour): ‘What we don’t understand we explain to each other.’ The article heralded by the cover was a long, surprisingly intimate profile of Oppenheimer, who seemed to have taken a liking to the interviewer, to whom he revealed many things about himself that he did not often reveal, even to close friends. Many of his remarks about his childhood that seem to appear in every article or book written about him – that he was an ‘unctuous, repulsively good little boy’, that his life as a child ‘did not prepare me in any way for the fact that there are cruel and bitter things’, that his home offered him ‘no normal, healthy way to be a bastard’, and so on – have their origin in this Time article. His life is told in some detail, using both his words and those of his friends, schoolmates and teachers, including – and here, in the increasingly hysterical anti-communism that was sweeping through the States at the time, he was taking something of a calculated risk – his active involvement in left-wing politics during the 1930s, when, he is quoted as saying, ‘I woke up to a recognition that politics was a part of life.’
I became a real left-winger, joined the Teachers Union, had lots of Communist friends. It was what most people do in college or late high school. The Thomas Committee doesn’t like this, but I’m not ashamed of it; I’m more ashamed of the lateness. Most of what I believed then now seems complete nonsense, but it was an essential part of becoming a whole man. If it hadn’t been for this late but indispensable education, I couldn’t have done the job at Los Alamos at all.
The ‘Thomas Committee’ mentioned by Oppenheimer was the House of Representatives’ Committee on Un-American Activities (HUAC), which, under the chairmanship of J. Parnell Thomas, had been holding hearings throughout the spring and summer of 1948, investigating alleged communist subversion. The most sensational outcome of these hearings came in August 1948, when Whittaker Chambers, a senior editor at Time magazine, accused Alger Hiss, a lawyer and an official in the State Department, of having been a member of a secret communist cell. At the time that Oppenheimer was being interviewed for Time, Hiss was engaged in legal proceedings against Chambers, which, following the revelation by Chambers of fresh evidence against Hiss, were to lead to Hiss’s conviction, and subsequent imprisonment, in 1950 for perjury.
In a letter he had written Frank from Europe, Oppenheimer remarked how hard it had been while he was away ‘to follow in detail what all is up with the Thomas Committee’, and describing the Hiss case as ‘a menacing portent’. Oppenheimer was evidently (and rightly) concerned that HUAC would come gunning for Frank, and advised him to get himself a good lawyer, someone like Herb Marks, who, Oppenheimer told his brother, knew his way round Washington, Congress and the press. Coincidentally, when the Time profile of Oppenheimer came out, among those who wrote to him about it was Herb Marks, who complimented him particularly on the ‘pre-trial’ touch – presumably a reference to Oppenheimer’s open disclosure of his left-wing past. Replying to Marks, Oppenheimer told him that was the only thing he had liked about the article, ‘w
here I saw an opportunity, long solicited, but not before available’.
The Time piece ended with some remarks about the Institute for Advanced Study, which Oppenheimer said he liked to think of as an ‘intellectual hotel’, a ‘place for transient thinkers to rest, recover and refresh themselves before continuing on their way’. He hoped that some people, Oppenheimer told his interviewer, like Dirac and Bohr, would make periodic returns to Princeton, so as not to lose touch with the US. His recent experiences in Birmingham and Brussels had shown him how ‘despairing the life of the intellect had become in postwar Europe’, which had given him a renewed sense of the importance of the institute: ‘Viewed from Princeton, the Institute might have its shortcomings; viewed from Europe, it had something of the special glow of a monastery in the Dark Ages.’
In an earlier interview, this time for the New York Times, published in April 1948, Oppenheimer had apparently given a rather different impression of his role as the institute’s director. Suppose, the reporter had written (in remarks presumably based on things Oppenheimer had said), you had funds based on a $21-million endowment, and:
Suppose you could use this fund to invite as your salaried house-guests the world’s greatest scholars, scientists and creative artists – your favourite poet, the author of the book that interested you so much, the European scientist with whom you would like to mull over some speculations about the nature of the universe. That’s precisely the set-up that Oppenheimer enjoys. He can indulge every interest and curiosity.
The New York Times description actually gives a fairly accurate account of how Oppenheimer used the funds placed at his disposal. In almost every appointment he made, one can see a very personal influence at play. This has already been mentioned in connection with Bohr and Dirac, but it is no less evident in those who came the following year. These included, for example, Oppenheimer’s old friend Francis Fergusson, who, in the many years since he and Oppenheimer had last seen each other, had become an eminent critic and writer on theatre. Fergusson taught at Bennington College, Vermont, where he founded the drama department. During his time at the institute Fergusson wrote The Idea of a Theatre, which was to become his best-known work. Another old friend who arrived at the institute in 1948 was Harold Cherniss, the ancient-Greek scholar whom Oppenheimer had known at Berkeley. No less personal, albeit in a different way, was Oppenheimer’s invitation to the Japanese physicist Hideki Yukawa, whose work had had such a profound influence on Oppenheimer’s and who also arrived in 1948.
Finally there was T.S. Eliot, who had long been both Oppenheimer’s favourite poet and Fergusson’s. Indeed, over the years Fergusson had published many essays about various aspects of Eliot’s work. Eliot, too, came in 1948, arriving while Oppenheimer was still in Europe. Dyson remembers him as being ‘prim and shy’. Eliot, he says, ‘appeared each day in the lounge at teatime, sitting by himself with a newspaper and a teacup’. Neither Dyson nor any of his contemporaries could muster the courage to approach him. ‘None of our gang of young scientists,’ Dyson recalls, ‘succeeded in penetrating the barrier of fame and reserve that surrounded Eliot like a glass case around a mummy.’ Pais says he ‘was dying to have conversations with Eliot but refrained from approaching him, less out of shyness than from an ingrained sense not to bother him with trivia’. He did, however, have one conversation with the great poet, when they happened to share a lift. ‘This is a nice elevator,’ Eliot remarked, to which Pais replied: ‘Yes, this is a nice elevator.’ ‘That,’ Pais writes, ‘was all the conversation with Eliot I ever had.’
Eliot’s biographer Peter Ackroyd says that Eliot ‘felt lonely and homesick’ at Princeton, precisely because ‘he suffered from the fate of many famous men’ – that is, ‘most people were afraid to talk to him’. In November 1948, it was announced that Eliot had won the Nobel Prize in Literature. Consequently, according to Dyson: ‘Newspapermen swarmed around him and he retreated even further into his shell.’ Years later, Dyson asked Oppenheimer what he thought of Eliot. He replied that, though he loved Eliot’s poetry and regarded him as a genius, he was disappointed with his stay at the institute. ‘I invited Eliot here,’ Oppenheimer told Dyson, ‘in the hope that he would produce another masterpiece, and all he did here was to work on The Cocktail Party, the worst thing he ever wrote.’
Dyson’s time at the institute, on the other hand, despite his acrimonious spat with Oppenheimer, was a triumph, and, in fact, Oppenheimer became one of his leading admirers and supporters. Before submitting for publication the report he gave at the Solvay Congress, Oppenheimer rewrote it, adding to it several mentions of Dyson’s paper on Feynman, Schwinger and Tomonaga (which he describes as being ‘in press’) and drawing attention to Dyson’s own original contributions to the theory that – Oppenheimer’s temporary doubts notwithstanding – had so captured the imaginations of physicists during the latter part of 1948. On 30 December, Oppenheimer wrote to Peierls in Birmingham:
One piece of news which you need to know is how very very good Dyson is. He wants to return, and in fact must return, to England for the next years, but we have made a flexible arrangement with him to come back here for as many semesters as he can spare. I think he likes the arrangement and we are all delighted by it.
In January 1949, Dyson went with Oppenheimer to New York to attend the annual meeting of the American Physical Society, of which Oppenheimer had recently been elected president. On the first day of the meeting, Dyson wrote to his parents, he received confirmation of his own celebrity when a young physicist from Columbia gave a talk during which he repeatedly referred to the ‘beautiful theory of Feynman–Dyson’. The next day, Dyson recalls, ‘Oppenheimer gave a presidential address in the biggest hall’:
and such was the glamour of his name after being on the cover of Time that the hall was packed with two thousand people half an hour before he was due to start. He spoke on the title ‘Fields and Quanta’ and gave a very good historical summary of the vicissitudes of our attempts to understand the behaviour of atoms and radiation. At the end he spoke with great enthusiasm of my work and said that it was pointing the way for the immediate future even if it did not seem deep enough to carry us farther than that. I was thinking happily to myself: Last year it was Julian Schwinger, this year it is me. Who will it be next year?
It was not only Oppenheimer whose interests were moving away from Schwinger and towards Feynman and Dyson; the whole physics community was moving in the same direction. Dyson’s paper would not appear in print until shortly after the conference, and Feynman’s classic papers setting out his version of QED would not appear until September 1949, but word of mouth is a quick, efficient and powerful means of communication and, even before these papers came out, there was much talk among physicists of ‘Feynman diagrams’ or, for a while at least, ‘Dyson graphs’.
This January 1949 meeting has, in fact, gone down in history as the moment when not just the world at large, but Feynman himself realised the power of his diagrammatic methods of performing the extraordinarily intricate calculations required in quantum electrodynamics. It was this meeting, Feynman later said, ‘when I really knew I had something. That was the moment that I really knew that I had to publish – that I had gotten ahead of the world.’ The particular incident that prompted this realisation was one that involved Oppenheimer, and, more specifically, it involved Oppenheimer’s relish for publicly crushing the views and arguments of others.
Murray Slotnick, a young physicist at Cornell who had worked with Hans Bethe, reported at the meeting on a certain extremely complicated calculation in meson theory that he had done relating to the interaction between a neutron and the electrostatic field of an electron. He had done this calculation for both ‘pseudoscalar’ and ‘pseudovector’ interactions, getting a finite result for the first and an infinite result for the second. In the discussion period after Slotnick’s presentation, Oppenheimer flummoxed Slotnick by asking ‘What about Case’s Theorem?’ When asked to explain what he meant, Oppenheimer
said that Kenneth Case, an ex-student of Schwinger’s who was now at the Institute for Advanced Study, had just proven that the two kinds of interactions had to be the same – a proof that Case would be presenting to the conference the following day. Since Slotnick’s calculations violated Case’s Theorem, Oppenheimer insisted, they had to be wrong. As Case’s Theorem had not been published, nor was there even a pre-print of it available, Slotnick, naturally, did not know how to respond, and so allowed Oppenheimer’s point to stand and accepted that his own work had been summarily refuted.
Feynman was not there during this exchange, but when he arrived at the conference later that day he was asked for his opinion on Slotnick’s calculation and ‘Case’s Theorem’. Feynman had never studied meson theory, but his methods of calculation using ‘Feynman diagrams’ had been developed precisely to perform calculations relating to interactions between particles and electrostatic fields, so he was pretty sure that he could do this calculation. Sure enough, after a few hours that evening, he had results for both the pseudoscalar and pseudovector cases, results that confirmed his hunch that Slotnick was right. The next day, Feynman sought out Slotnick and showed him his work of the previous evening. Slotnick was absolutely dumbstruck. He had spent two years on this problem, and Feynman had solved it in an evening. Not only that, but Feynman’s calculation was more fine-grained than Slotnick’s, since he had built in a variable for the momentum transferred by the electron, a complication that Slotnick had ignored. It was Slotnick’s flabbergasted reaction that convinced Feynman that he really had something wonderful. ‘That was the moment I got my Nobel Prize,’ Feynman said, ‘when Slotnick told me that he had been working two years . . . That was an exciting moment.’