Inside the Centre: The Life of J. Robert Oppenheimer (100 page)

Now, in June 1949, Strauss, who had never accepted that he was wrong about the possible military application of isotopes, had another chance to reverse the policy. This time the occasion was not a closed session of a small committee in an out-of-the-way office, but a full Congressional hearing, with cameras and reporters present, held in the huge Caucus Room of the Senate. The hearing was before the Joint Committee on Atomic Energy, which had been set up in 1946 to ‘oversee’ the AEC and had the power, if necessary, to veto AEC decisions. In 1949, the chairman of the Joint Committee was Brien McMahon, who had become an enthusiastic advocate of the policy of building huge stockpiles of atomic bombs. Also on the committee was the right-wing Republican senator Bourke Hickenlooper, who had a fierce distrust of the AEC and of Oppenheimer in particular. The general purpose of the hearings now under way was to investigate Hickenlooper’s allegations that the AEC was guilty of ‘incredible mismanagement’. Strauss, whose political views were in general close to Hickenlooper’s, had succeeded in enlisting the senator as an ally in his campaign to stop the export of radioactive isotopes, the practice of which was now examined as an example of the alleged mismanagement of the AEC. On 9 June, Strauss had testified before the Joint Committee that isotopes might, indeed, have some military value and that therefore he was against their export. Hickenlooper agreed. When the US provided other nations with isotopes, he said, it was embarking on a programme ‘inimical to our national defense’.

This was the context in which Oppenheimer gave his very public, and subsequently heavily reported, demolition of Strauss’s position. Oppenheimer himself, of course, was not without vanity, especially about his legendary ability to make fools of others. Jeremy Bernstein remembers that at physics seminars at the institute, Oppenheimer ‘sat in the front row, and if he made what he thought was a witty comment he would look around to make sure that we had all taken it in’. He liked an audience, and this hearing provided him with a large and attentive one.

The specific issue at hand was whether the US should, as they had been requested, provide Norway with an isotope of iron, Fe-59, to use in the monitoring of the manufacture of molten steel. Strauss had discovered that one of the members of the Norwegian research team was a communist,
which, in his eyes and Hickenlooper’s, made all the more pressing the question of whether Fe-59 could have any conceivable military use. When called upon as a witness, Oppenheimer made it clear that his purpose was not only to refute Strauss’s view, but to subject it to lacerating ridicule. ‘No one,’ he said, ‘can force me to say that you cannot use these isotopes for atomic energy.’

As Philip Stern, who was there at the time, has noted: ‘Even to an observer who had no background on the issues and personalities involved, it was clear that Oppenheimer was making a fool of someone.’

The AEC lawyer Joe Volpe was sitting next to Oppenheimer and, looking over to where Strauss was sitting, saw Strauss’s eyes narrowing, his jaws working and colour rising in his face. From that point on, he said, he kept ‘one eye on Oppenheimer and the committee and one eye on Strauss’. Rubbing salt into the wound, Oppenheimer continued: ‘My own rating of the importance of isotopes in this broad sense is that they are far less important than electronic devices, but far more important than, let us say, vitamins, somewhere in between.’ The official record of the meeting records at this point: ‘[laughter]’. When Oppenheimer stepped down, he said to Volpe: ‘Well, Joe, how did I do?’ ‘
Too
well, Robert,’ Volpe replied. ‘Much too well.’ Years later, David Lilienthal, recalling the sight of Strauss at the end of Oppenheimer’s testimony, remarked: ‘There was a look of hatred there that you don’t see very often in a man’s face.’

A few months later the cover of
Life
magazine carried a photograph of Oppenheimer that Abraham Pais has described as ‘the best picture of him I know’. Looking extraordinarily self-confident and strikingly handsome, he is staring straight at the camera, intense but relaxed, with his head resting on his right hand, while in his left hand burns a cigarette. Inside the magazine there is another arresting image of him, standing in front of a blackboard, upon which are written impressively unintelligible symbols. The caption to the photograph explains: ‘Equations at top of the board describe processes of meson production in cosmic ray explosions. Those below pertain to certain interactions in quantum field theory.’

The
Life
profile covers much the same ground as the previous year’s
Time
magazine piece, but in both content and tone it is interestingly and significantly different. The emphasis in
Time
had been on Oppenheimer
as a leader – of physicists, of the institute and of humanity. It delved fairly deeply into his politics, both the radical views of his past and his later campaigns for international control of atomic energy, and hardly at all into his achievements in science, not one of which, in fact, was mentioned. In these respects the
Life
piece could not have been more different. It does not mention his radical past at all, and talks about his post-war involvement in politics as if it had been something imposed upon him against his will (‘although he tried to immerse himself again in academic duties at California and Cal Tech, the demands made on him by various branches of the government were so numerous that he found himself spending much of his time in the air between the West Coast and Washington’).

In the
Life
article, the emphasis was instead firmly on Oppenheimer as a scientist, and not just one who had done good work in the past, but a practising physicist at the top of his game, whose work was at the cutting edge of his field: particle physics. Indeed, one would almost get the impression from this article that Oppenheimer had retired from politics to concentrate on physics. The article quotes Oppenheimer as saying that those physicists who, during the war, were ‘off doing the devil’s work making armaments and whatnot – things that have nothing to do with physics’ were now ‘back at their real work – the sober, modest, consecrated task of penetrating the unknown’.

The article then goes on to describe in some detail both Oppenheimer’s own contributions to physics, concentrating in particular on the Oppenheimer–Phillips effect and his role in the development of positron and meson theory, and the present state of physics. Rather oddly, the author, Lincoln Barnett, does not mention the QED revolution that had just taken place, or Oppenheimer’s midwifery role in that revolution. The article does, however, give a good idea of what issues were dominating physics in the summer of 1949, by which time the QED revolution was complete, and physicists had turned their attention away from quantum electrodynamics and towards the attempt to understand elementary particles.

This was a field in which everything was unclear and, seemingly, getting a little bit more unclear with every discovery, and the article conveys well the confused state of particle physics during this time, emphasising in particular the alarming growth in the number of elementary particles that were being discovered. Where previously there had been three – the electron, the proton and the neutron – there were now fifteen.
^fn62
These included some that most people had by this time got used to, such as the photon, the neutrino and the positron, and also some recently discovered
exotica such as the pi-meson (in positive, negative and neutral forms), the mu-meson (likewise) and the tau-meson (the heavy meson, soon to be renamed the K-meson or kaon). Nearly half a page of this article is devoted to a table, grouping these fifteen particles into five categories: nucleons, electrons, mesons, massless particles and ‘probable particles’.

‘Almost every month has surprises for us in the findings about these particles,’ Oppenheimer is quoted as saying. Indeed, ‘what we are forced to call elementary particles retain neither permanence nor identity’. For example, protons and neutrons might really be composites: ‘each of these may have some kind of bare substructure in the center and around it, bound closely to it, a cloud of mesons’. His hope was that ‘what is at the moment just a picture of chaos will ultimately reveal again that deep harmony and order which one has always found in the physical world when one has pushed hard, and which is very beautiful indeed’.

The impression is given that this revelation of deep harmony would come, if it came at all, from people working at the institute, ‘the world’s foremost center of elementary particle research’. In particular, the article suggests, it might come from Oppenheimer himself, who, having before the war ‘devoted most of his investigative efforts to the study of mesons, their role in the atomic world and their possible relation to nuclear force’, was now working ‘in close partnership with Yukawa whom he recently brought to the Institute’, in a renewed attempt to solve those questions – questions that constituted ‘the deepest and most urgent challenge to physics at the present time’.

In fact, almost all of this is a fantasy. It is as if Oppenheimer had bewitched the
Life
writer into accepting as fact what was merely wishful thinking on Oppenheimer’s part. Oppenheimer may have
wanted
to work with Yukawa on meson theory – indeed, that was surely the reason he invited Yukawa to the institute – but the two of them never collaborated on a single piece of work, and by the time this
Life
article was published, October 1949, Yukawa had left the institute for a professorship at Columbia. Nor was it true that the Institute for Advanced Study was ‘the world’s foremost center of elementary particle research’. There were in 1949 just a handful of particle physicists at the institute, only one of whom was doing important original work in the subject, namely Abraham Pais, who, curiously, is not mentioned in this article. Oppenheimer does not mention, for example, that less than two years earlier Pais had made an important and, as it turned out, lasting contribution to the taxonomy of the rapidly proliferating elementary particles, when he introduced the term ‘lepton’ to characterise particles like electrons and positrons (and, it would soon be realised, mu-mesons) that are not subject to the strong nuclear force. However, while there is no sign of Pais in this article, the influence of Yukawa is apparent in almost everything Oppenheimer is
quoted as saying, much of which strongly echoes things noted by Yukawa in a survey article that he published in July 1949 called ‘Models and Methods in the Meson Theory’.

Finally, and most significantly, it is not true that Oppenheimer was at this time making important contributions to particle physics. Indeed, this article was published at precisely the time when he effectively ceased to be an active research scientist altogether. In January 1949 he had published a short paragraph in
Reviews of Modern Physics
as part of a discussion on the disintegration and nuclear absorption of mesons, but this was to be his last-ever publication in physics.
^fn63
He continued to be an avid follower of cutting-edge research, and could be relied upon to summarise the important work in more or less any given area of the subject, but he himself did not make a single original contribution to particle physics – or indeed to any branch of the subject – from January 1949 till the day he died. Nor did he provide the kind of leadership in particle physics that he had provided in QED with his running of the Shelter Island, Pocono and Oldstone conferences. After Oldstone, it was decided to end that particular series and to put in its place a series that concentrated solely on particle physics. These were organised not by Oppenheimer, but by Robert Marshak at the University of Rochester. It was at places like Rochester, Columbia, Chicago and Berkeley that most of the leading work in particle physics would be done in the 1950s; places, that is, with large experimental-physics departments and, crucially, large particle accelerators. The institute had neither – as the
Life
article was at pains to stress, it had no laboratory of any sort.

One way of reading this article is to see it as a response by Oppenheimer to the attacks upon him and other left-wing physicists by the FBI and HUAC, as his way of saying that he was happy to withdraw from the fight, to give up politics and return to pure research. But as he did not, in fact, return to pure research or give up politics (he did not, for example, resign his chairmanship of the GAC), perhaps the best way to read the article is as an insight into what Oppenheimer, in the autumn of 1949,
wished
his life was like: dominated by fundamental research (‘Of his manifold activities, however, the one that gives him the fullest measure of satisfaction, the one he considers his
real
calling is exploration’) at the very centre of progress in theoretical physics, and in the company of other people absorbed in the struggle to understand the nature of physical matter.

Actually, what dominated his life at this point, and would (as he well knew) dominate it for the foreseeable future, was the fact that a month
earlier irrefutable evidence had been obtained that the Soviet Union had exploded its own atomic bomb. This fact is mentioned in the
Life
article, but in a way that seeks to downplay its importance. From the perspective of the physicists who took part in the ‘devil’s work making armaments’, the article says blithely, ‘the news that Russia has at last produced an atomic bomb comes as no great surprise, nor does it appear in the aftermath of this revelation that their endeavours will now be diverted as they were by the recent war’. This, like so much of the article, was wishful thinking. As chairman of the General Advisory Committee, it fell to Oppenheimer to advise the AEC, and therefore the US government, on how to respond to the news that the Soviet Union had its own atomic bombs. This was such a heavy burden that it does not take much imagination to see why Oppenheimer would wish to pretend that it did not exist.