by Ray Monk
That day, after Case had given his talk, Feynman got up and asked: ‘But what about Slotnick’s calculation? Your theorem must be wrong because a simple calculation shows that it’s correct. I checked Slotnick’s calculation and I agree with it.’ ‘I had fun with that,’ Feynman later remarked. After the conference he worked out what was wrong with Case’s reasoning, a laborious task, since it involved working with Schwinger’s formalism. What made it worthwhile was the demonstration that, as Dyson had been saying for a long time, Feynman’s methods were easier and quicker to use than Schwinger’s and, therefore, likely to give more reliable results. After the meeting Feynman worked hard to write up his version of the new theory and on 8 April 1949 the Physical Review received ‘The Theory of Positrons’, the first published account by Feynman of his method of calculating the energies of electrons and positrons – that is, his first statement of the new QED. Three days after delivering this paper, Feynman was in Oldstone-on-the-Hudson, Peekskill, about forty miles north of New York City, for the third and final conference in the series that had begun at Shelter Island two years earlier.
Like the one at Pocono, this conference was organised by Oppenheimer, who, a month before it bgean, had sent to the invitees a rather brisk, businesslike letter, informing them that the Oldstone Inn had been reserved for the nights of 10–14 April. ‘We will start work on Monday morning and should have four full days together.’ Twenty-four scientists attended the conference. Among those who had not been at the other two were Yukawa, now a visiting fellow at the institute, and Freeman Dyson, whose invitation was recognition of his new-found status as a member of the elite group of leading physicists.
‘We had lovely weather for the conference,’ Dyson wrote to his parents soon after it had finished, ‘and could sit outside whenever we were not conferring. However, since the conference was run by Oppenheimer, that was not often.’
One of the things which simply amazes me about Oppenheimer is his mental and physical indefatigability; this must have a lot to do with his performance during the war. There was no fixed program for the conference, and so we just talked as much or as little as we liked; nevertheless Oppenheimer had us in there every day from ten a.m. till seven p.m. with only short breaks, and on the first day also after supper from eight till ten, this night session being only dropped on the second day after a general rebellion. And all through these sessions Oppenheimer was wide awake, listening to everything that was said and obviously absorbing it.
Everyone agreed that this Oldstone conference was, as Pais puts it, ‘Feynman’s show’. Having worked out his methods systematically, Feynman was now able to demonstrate them persuasively, and at Oldstone, Pais writes, Feynman’s version of QED ‘began its rapid and never-waning rise in popularity’. At the end of the meeting Oppenheimer wrote to the National Academy of Sciences, the sponsors of all three conferences in the series, expressing, on behalf of the people who had taken part, ‘a real sense of satisfaction for the fruitfulness and value of the conference’. He added:
The two years since the first conference have marked some changes in the state of fundamental physics, in large part a consequence of our meetings. The problems of electrodynamics which appeared so insoluble at our first meeting, and which began to yield during the following year, have now reached a certain solution; and it is possible, though in these matters prediction is hazardous, that the subject will remain closed for some time.
Remarkably, he was not exaggerating. During the two years of these conferences, QED went from being a set of unsolved problems to what Feynman insisted was a part of physics that ‘is known, rather than a part that is unknown’. ‘At the present time,’ Feynman declared in 1983, more than thirty years after the theory was developed, ‘I can proudly say that there is no significant difference between experiment and theory!’
We physicists are always checking to see if there is something the matter with the theory. That’s the game, because if there is something the matter, it’s interesting! But so far, we have found nothing wrong with the theory of quantum electrodynamics. It is, therefore, I would say, the jewel of our physics – our proudest possession.
In 1965, Feynman, Schwinger and Tomonaga were awarded the Nobel Prize in Physics for their respective contributions to constructing this ‘jewel’. Dyson has been called the greatest physicist not to have won the prize, his main rival for that title being Oppenheimer himself.
17
Massive Retaliation
DURING THE TWO years that American physicists excitedly solved the problems of quantum electrodynamics – or excitedly watched them being solved – the world outside became a much darker place. The Berlin Blockade of 1948–9 and the Communist Party victories in Czechoslovakia (1948) and Hungary (1949) had persuaded public opinion in the West that the Soviet Union was indeed, as Churchill had predicted, attempting to expand its sphere of influence and that democracy therefore had to be defended from the communist threat. The post-war world that many scientists had dreamed of in 1945 – a world of international cooperation, based on the mutual recognition of the folly of a nuclear arms race – never looked like materialising. Instead what transpired was exactly what the scientists had warned against: growing tensions between the world’s superpowers brought about and fostered by the mutual suspicion, paranoia and fear that inevitably accompanied the forlorn attempt to keep scientific facts secret from scientists.
In December 1948, Oppenheimer gave a lecture at Rochester entitled ‘The Open Mind’, in which, while accepting the failure of past attempts to cooperate with the Soviet Union and agreeing that the blame for that failure lay chiefly with the Soviets, he emphasised, against the prevailing cultural current, the advantages of openness and magnanimity in international relations. ‘We need to remember that we are a powerful nation,’ he urged. The United States did not have to conduct its affairs in an atmosphere of fearful suspicion. The policies developed and pursued in such an atmosphere ‘appear to commit us to a future of secrecy and to an imminent threat of war’. As a model of an alternative attitude, Oppenheimer cited the example of Ulysses Grant, who, at the end of the Civil War, spoke to the defeated Confederate General Lee and allowed Lee’s troops to keep their horses, since ‘they would need them for the spring plowing’. Even in recognition of the evils committed by the Soviets in the past, Oppenheimer urged, Americans should keep an open mind about the future and act from a position of magnanimous strength rather than fearful weakness.
When he gave this lecture Oppenheimer possibly imagined himself to be, as he believed the United States to be, in a position of unassailable strength. It was just a month earlier that he had been on the cover of Time magazine, which began its long article on him with an impressive list of his achievements and titles:
More & more physicists are coming to know the Institute as the home of an authentic contemporary hero of their trade: Dr J. (for nothing) Robert Oppenheimer, who is president of the American Physical Society, chairman of the technical advisers to the Atomic Energy Commission, and one of the world’s top theoretical physicists. Laymen know him as the man who bossed the production of the atom bomb. Last week, at 44, Oppenheimer was beginning his second year as director of the Institute for Advanced Study.
In the years that followed, however, it would be shown that none of those titles and achievements could save him from the very fear and suspicion against which he had campaigned. For five years, starting in the summer of 1949, his standing – among his fellow scientists, among politicians and among military men – would be systematically attacked in a concerted and successful attempt to ruin him. What made the attack all the more pitiable to watch was the fact that his enemies were able to use against him his own personal and moral weaknesses, which were often cruelly exposed during these years.
The first serious blow to Oppenheimer’s reputation, and the moment when those personal and moral frailties were first held up for all to see, was his appearance before HUAC on 7 June 1949. As Oppenheimer had co
rrectly remarked in his letter to Frank the previous October, the revelations about Alger Hiss that had come out of the HUAC hearings were a ‘menacing portent’ of things to come. Having investigated communist ‘subversion’ among actors in Hollywood and politicians in Washington, in April 1949 the committee, under its new chairman, John Wood, turned its attentions to scientists, and, in particular, to the group of young radicals at Berkeley that had so concerned the FBI and military security during the war.
The four young scientists whose group photograph had been bought by an agent tailing Rossi Lomanitz – David Bohm, who was now teaching physics at Princeton University; Max Friedman, who, having changed his name to Ken Manfred, was at the University of Puerto Rico; Joseph Weinberg, who was now a colleague of Frank’s at Minnesota, and Lomanitz himself, who was teaching at Fisk University, Nashville, Tennessee – were all subpoenaed to testify before HUAC. All of them except Weinberg pleaded the Fifth Amendment. Weinberg, who of course did not know the FBI had a transcript of his conversation with Steve Nelson back in March 1943, continued to deny any involvement with espionage.
In contrast, Oppenheimer knew all about his FBI file and what it contained, and was very alarmed to discover that one of the six members of HUAC, Harold Velde, was a former FBI man. When his turn to testify duly arrived, Oppenheimer took with him the AEC’s lawyer, Joseph Volpe. As it turned out, the meeting seemed to go quite well. The committee members went out of their way to assure Oppenheimer that his loyalty, having been vouched for by General Groves, was not in doubt. In response to their polite and gentle, even deferential, questioning, Oppenheimer repeated what had by now become the standard version of the ‘Chevalier Affair’ (the chief feature of which was that Chevalier had approached just one scientist, namely Oppenheimer himself) and was no doubt relieved not to be asked why he had originally claimed that Chevalier had approached three scientists. He also gave bland and protective answers to questions about Lomanitz and Weinberg. When asked about Frank, he said: ‘Mr Chairman, I will answer the questions you put to me. I ask you not to press these questions about my brother. If they are important to you, you can ask him. I will answer, if asked, but I beg you not to ask me these questions.’ Remarkably, the response to this was to withdraw the question.
With regard to the unfortunate Bernard Peters, however, Oppenheimer revealed himself to be willing not only to confirm the damaging things he had said to Peer de Silva in January 1944, but also to elaborate on them. He confirmed that he had described Peters as ‘a dangerous man and quite Red’, and added that Peters had been a member of the German Communist Party, but had ‘violently denounced’ the American Communist Party, because it was ‘too constitutional and conciliatory an organization, not sufficiently dedicated to the overthrow of the Government by force and violence’. Perhaps most extraordinary, though, were Oppenheimer’s remarks when asked to explain his comment to de Silva that Peters’s past had been filled with incident that pointed towards ‘direct action’. As grounds for believing Peters to be prone to such action, Oppenheimer cited:
Incidents in Germany where he [Peters] fought street battles against the National Socialists on account of Communists; being placed in a concentration camp; escaping by guile. It seemed to me those were past incidents not pointing to temperance.
The implied suggestion seemed to be that being placed in a concentration camp and then escaping from it were evidence of some sort of character flaw in Peters. When asked how he knew Peters had been in the German Communist Party, Oppenheimer replied: ‘It was well known. Among other things, he told me.’
These remarks about Peters not only go beyond what Oppenheimer had said to de Silva, but also go way beyond what was required of him on this occasion. When one tries to explain why he was prepared to say so many damaging things about a man who had been his student and friend, the only thing that comes to mind is that he thought that, if he gave the appearance of candour, his bland evasions about his other students, about Chevalier and about Frank would be more likely to be accepted. He must also have believed (though this would have required extraordinary naïvety in the circumstances) that, because this was a closed, executive session with no reporters present, what he said would never be made public. At the hearing there were some signs that, if Oppenheimer’s aim had been to charm the committee into trusting him, then he had been successful. The committee members did not probe him about these other people, and yet seemed delighted by his testimony. At the end of the session, all six members of the panel came down to shake his hand, and one of them, the future President Richard Nixon, made a short speech:
Before we adjourn, I would like to say – and I am sure this is the sense of all who are here – I have noted for some time the work done by Dr Oppenheimer and I think we all have been tremendously impressed with him and are mighty happy we have him in the position he has in our program.
Bernard Peters, who was at this time an assistant professor at the University of Rochester, was called before the committee the very next day, but was not faced with Oppenheimer’s allegations. Instead, in a session that lasted a mere twenty minutes and was presumably an attempt to get him to perjure himself, he was given the opportunity (which he took) to deny that he had been a member of the Communist Party, either in Germany or in the US. On his way back to Rochester, Peters visited Oppenheimer at Princeton and asked him what he had told HUAC. Oppenheimer replied: ‘God guided their questions so that I did not say anything derogatory.’
A week later, however, both Oppenheimer and Peters received a very nasty shock. On 15 June 1949, a Rochester newspaper, the Times-Union, had on its front page the headline ‘Dr Oppenheimer once termed Peters “quite Red”’, beneath which was a full account of what Oppenheimer had said about Peters, both to de Silva and to HUAC. Clearly someone (the chief suspect is surely Velde, the FBI man on the committee) had leaked this information to the newspaper.
On the day this newspaper article was published, Peters was in Idaho Springs, Colorado, attending a conference on cosmic rays. Also there were Hans Bethe, Ed Condon and Frank Oppenheimer. Victor Weisskopf had intended to be there, but on the way had stopped to visit David Hawkins, who lived in Boulder, Colorado, and was enjoying himself so much that he decided to skip the conference and stay in Boulder. Weisskopf, however, read the article, and – like Bethe, Condon, Frank and Peters himself – was appalled by it. All five of them wrote to Oppenheimer expressing their anger and disappointment.
In his letter, Weisskopf mentioned that he did not actually like Peters very much, ‘because of his intransigence and his lack of humour and human understanding’, but, he told Oppenheimer: ‘If Peters loses his job because of the statement about his political leanings made by you . . . we are all losing something that is irreparable. Namely confidence in you.’ Here, Weisskopf had put his finger on the central point, and, one suspects, the main purpose of leaking the testimony: not to ruin Peters, but to undermine the respect Oppenheimer enjoyed among his fellow scientists.
Condon’s letter also made an excellent point. He had, he said, ‘lost a good deal of sleep trying to figure out how you could have talked this way about a man whom you have known so long, and of whom you know so well how good a physicist and good a citizen he is:
One is tempted to feel that you are so foolish as to think that you can buy immunity for yourself by turning informer. I hope this is not true. You know very well that once these people decide to go into your own dossier and make it public that it will make these ‘revelations’ that you have made so far look pretty tame.
Bethe’s letter, meanwhile, was concerned with what could be done practically to limit the damage to Peters’s career. He urged Oppenheimer to write to the president of Rochester University correcting the impression that Peters was a dangerous subversive.
Peters himself, accompanied by Frank (the pair were working on a joint project analysing cosmic rays), went to see Oppenheimer personally. It was, he reported to Weisskopf, ‘rather dismal’. Oppenheimer confirm
ed that he had indeed said the things attributed to him, but that it had been a ‘terrible mistake’ on his part. At first, Oppenheimer had refused to write a public retraction of his testimony, but Weisskopf’s letter changed his mind about that, and he wrote a partial retraction, which he sent to a different Rochester newspaper and which Peters, sending Weisskopf a copy of it, called ‘a not very successful piece of double-talk’. Oppenheimer, Peters added, ‘was obviously scared to tears of the hearings but that is hardly an explanation’. His letter concludes: ‘I found it a rather sad experience to see a man whom I regarded very highly in such a state of moral despair.’ Similar feelings were expressed by the other young physicists who had so revered Oppenheimer at Berkeley. ‘I think mostly,’ Lomanitz said, speaking for them all, ‘we came to feel sad personally about the man’s weaknesses, and also very sorry that he was not able to give any kind of leadership needed during very bad times.’
As it happened, the incident did not ruin Peters’s career. Displaying a moral steadfastness that was all too rare during these troubled times, Alan Valentine, the president of the University of Rochester, not only refused to fire Peters, but promoted him to full professor. The University of Minnesota showed no such resoluteness, however, and fired Weinberg after he had been charged with perjury, even though (because the evidence obtained from the wire tap in Nelson’s house was not produced) he was acquitted. A similar fate befell Bohm and Lomanitz, both of whom lost their academic jobs.