Inside the Centre: The Life of J. Robert Oppenheimer (67 page)

Notwithstanding Oppenheimer’s somewhat optimistic estimates of the daily production of uranium and plutonium to be expected in the coming years, the scientists and engineers at Los Alamos knew that it would be two years or so until enough fissionable material would be available to actually build a bomb. Their job, the urgency of which was felt by everyone concerned, was to have the theory, design and manufacture problems solved in time for the arrival of sufficient quantities of the fissionable materials. As one history of the Manhattan Project puts it, once the material was ready to use, ‘every month’s delay had to be counted as a loss to the war’. The fact that fissionable material was in such short supply at the start of the new laboratory’s work meant that, to a much larger extent than would otherwise have been the case, the enterprise was reliant upon
theory
. Thus the theoretical physicists that Oppenheimer had recruited – which included, of course, a good proportion of the best in the country – were absolutely central to the project,
even though
it was, in essence, an engineering project. As Feynman once put it: ‘All science
stopped during the war except the little bit that was done at Los Alamos. And that was not much science; it was mostly engineering.’

Unlike the experimentalists, who required the equipment to be up and running before they could begin their work, the theoreticians could start right away. So, during the months of May and June, while the builders continued to construct houses and laboratories, and the leaders of the project continued to construct ever more elaborate organisational charts and to revise upwards their estimates of how many people the project would need, the theoreticians – needing only their slide-rules, their minds and, occasionally, a blackboard – could get on with their calculations. As Teller had emphasised the previous summer in Berkeley, the basic science of the atomic bomb had already been done. There was no doubt, from a theoretical perspective, that the fission of uranium or plutonium could potentially produce an explosive of enormous power. There was no fundamental theoretical science left to do regarding the fission process. On the other hand, in the spring of 1943, the idea of a bomb based upon the science of fission was
only
theoretical. The Met Lab in Chicago had succeeded in producing a chain reaction, but nobody had even come close to building an atomic bomb. In order to make that a reality, the theoreticians needed to work with the experimentalists and the engineers, not only in the formulation of fundamentally new physics, but also in the performing of certain mathematical calculations that only they could do because only they understood.

‘Every day,’ Feynman remembers, ‘I would study and read, study and read. It was a very hectic time.’ Though still young and as yet relatively undistinguished, Feynman quickly established a lively rapport with Bethe. As Feynman remembers it, Bethe would come into their office, explaining his ideas, and Feynman would say: ‘No, no, you’re crazy. It’ll go like this.’

Despite the fact that it fundamentally contradicted the idea of compartmentalisation, Oppenheimer insisted on having a weekly colloquium, in which scientists could exchange information and criticise each other’s ideas. Having failed to recruit Rabi and to keep Condon, he became more and more accommodating to the anti-military sensibilities of many top scientists. For example, after the April conference, he decided that the perfect man to lead the Experimental Physics Division was Robert Bacher. Bacher accepted the position, but only after he made it clear to
Oppenheimer that his letter of acceptance should be regarded also as a letter of resignation if the laboratory ever became, as was officially still the intention, fully militarised. Partly because of the trenchant opposition to militarisation shown by Bacher and his fellow scientists, the intention to bring the laboratory under full military control was never realised. As Bacher rather diplomatically recalled:

It seems possible that in insisting on making his views on militarisation clear from the start, Bacher was responding to what had happened to Condon, who had left Los Alamos bewildered by Oppenheimer’s willingness to conform to the dictates of military authority, even when they conflicted with the requirements of science. As Condon suspected, Oppenheimer shared his views on compartmentalisation – as, surely, did all the scientists at Los Alamos – but what Condon did not know was that Oppenheimer was not in a position to openly support Condon’s objections to the security arrangements at Los Alamos. As he himself did not yet have security clearance, Oppenheimer could ill afford to alienate those responsible for providing security. Indeed, as a result of Joe Weinberg’s late-night conversation with Steve Nelson, things were far worse than Oppenheimer himself could possibly have known.

In the spring of 1943, at the time that Condon left the project and the organisation of the laboratory was being put into place, the chances of Oppenheimer being granted security clearance did not look good. Though Weinberg had not yet been identified as ‘Joe’, the authorities knew perfectly well who ‘the professor’ was, and Pash and de Silva were not alone in their view that a man who numbered among his friends and students at least three people who were either actively engaged in Soviet espionage or closely associated with those who were (Nelson, Lomanitz and the as-yet-unidentified ‘Joe’) was not the man to appoint as the head of the US’s most important and most secret military research project. And that was before they knew anything about Haakon Chevalier’s attempt to persuade Oppenheimer to aid Eltenton’s espionage efforts – the disclosure of which, Oppenheimer knew, would almost certainly bring an end to his directorship of the Los Alamos laboratory before it had really begun.

And so Oppenheimer kept that particular secret to himself for several
months, during which he was followed everywhere by Pash’s agents, who continued to hunt for irrefutable confirmation that he was not to be trusted. Meanwhile, the FBI stepped up its investigation of those civilians not employed by the Manhattan Project who yet seemed to be taking an unhealthy interest in it, particularly those people who had a history of involvement with the Communist Party. This, of course, included some of the radical young scientists connected with Berkeley’s Radiation Laboratory, the best known of whom, to both the FBI and to army intelligence, was Lomanitz, whose every movement was now closely watched by both agencies.

In June 1943, the constant surveillance of Lomanitz resulted in the identification of Weinberg as ‘Joe’. A G-2 agent following Lomanitz saw him pose with three friends for a picture taken by a commercial photographer at one of the entrances to the Berkeley campus. As soon as the four men were out of sight, the agent approached the photographer and bought the negative of the picture he had taken. The other three men in the photograph were identified as David Bohm, Max Friedman and Joseph Weinberg, and in a short while the agency was able to identify Weinberg as ‘Joe’. All four of the people in the photograph were physicists at Berkeley, all of them politically radical and all of them associated with Oppenheimer (Bohm, Lomanitz and Weinberg had been students of his, and Friedman was regarded socially as a member of the same group).

For the rest of the war each of these four friends was watched closely by the security services, who saw to it that none of them had any access whatsoever to sensitive information. When Oppenheimer asked for Bohm to be transferred to Los Alamos, his request was refused on the grounds that Bohm could not possibly be granted security clearance. Lomanitz, meanwhile, was offered a job liaising between the Rad Lab and Oak Ridge, but before he could take up the position he was drafted into the army. Friedman was hired first by the Rad Lab and then by the Met Lab in Chicago, but was quickly fired from both. Weinberg, like Lomanitz, was drafted into the army. As a direct result of the monitoring of Weinberg’s conversation with Nelson in March 1943, then, the Soviets would have received no further information about the US bomb project from Weinberg, Lomanitz, Bohm, Friedman or Nelson. That particular ‘spy ring’ was effectively shut down.

The idea that those four, together with Nelson, constituted a spy ring is not altogether fanciful; Weinberg, for one, had shown himself perfectly prepared to pass secret information to the Soviets via Nelson. And, given their connections with Oppenheimer, and the fact that Oppenheimer had recruited (or at least tried to recruit) at least three of them to positions that would give them access to secret information, it was perfectly natural to suspect Oppenheimer of being in some sense a member of that ‘spy ring’.

In June 1943, at about the same time that Weinberg was being identified as ‘Joe’, Oppenheimer himself provided further reason for suspicion when, followed, as ever, by army intelligence agents, he left Los Alamos for Berkeley. His ostensible reason for the trip was to recruit a personal assistant, his chosen candidate for the job being his friend, the Berkeley philosopher David Hawkins – a man with many connections to radical, left-wing politics, suspected by the FBI of being a communist. Such a choice added a little more credibility to Pash’s suspicions of him, but much more serious grounds for questioning his judgement, if not his loyalty, were provided by Oppenheimer’s decision to use this trip to California to pay a visit to his ex-lover Jean Tatlock, who was at this time living in San Francisco.

By the summer of 1943 Jean was far more interested in psychology than politics – she was working as a child psychiatrist at Mount Zion Hospital, and was herself receiving psychoanalysis from the Freudian doctor Siegfried Bernfeld – but, nevertheless, she was well known to the security services as a woman with a history of communist sympathies, activities and connections. Before Oppenheimer left for Los Alamos in March, Jean had asked him to visit her, but he had refused. When he was asked later why, on this occasion, he did see her, he replied:

Asked
why
she ‘had to’ see him, Oppenheimer replied: ‘Because she was still in love with me.’

What transpired when the two met is recorded in some detail by the report that Pash’s agents sent to the FBI. On 14 June 1943, those agents reported, Oppenheimer went from Berkeley to San Francisco, where he was met by Jean Tatlock, ‘who kissed him’. The two then drove in her car to a local bar, where they ate and had a few drinks, after which Jean drove them back to her apartment on Montgomery Street, San Francisco. The agents, sitting in a car outside the apartment, noted that at half past eleven the lights went off, and the following morning Oppenheimer and Jean left the building together. That evening the two met again in downtown San Francisco, where they ‘greeted each other affectionately’ and then went to have dinner together at a place called Kit Carson’s Grill. After dinner Jean drove him to the airport, where he caught a plane back to New Mexico.

At this time, of course, Oppenheimer did not know that Joe Weinberg had incriminated both himself and, potentially, everybody close to him.
But he did know that he himself was regarded with some suspicion by those whose job it was to provide the Manhattan Project with security from espionage, and he presumably also knew, or might well have surmised, that the success or failure of his application for security clearance was therefore still in the balance. Given this, and given that he was in daily contact with members of US army intelligence, it is surprising that he did not assume, or at the very least suspect, that his every movement was being watched. Or, even more surprising, that he chose to spend a night with Jean even though he was most likely being kept under surveillance. At his security hearing in 1954, he squirmed uncomfortably when asked about the occasion:

‘Not good practice’ hardly does justice to the scale of Oppenheimer’s lapse in judgement at this point. Taking everything we know about Oppenheimer and Jean Tatlock at this time, it seems extremely unlikely that what they talked about that night was the work being conducted at Los Alamos, but, to a mind full of suspicion (of both communists in general and of Oppenheimer in particular), it was natural to imagine that Oppenheimer might be using Tatlock as a go-between, in order to pass on to the Soviet Union details of the Manhattan Project.

Certainly such thoughts occurred to Pash, who, on 29 June 1943, two weeks after Oppenheimer’s trip to Berkeley and San Francisco, made a formal recommendation to the Pentagon to refuse security clearance to Oppenheimer on the grounds that he ‘may be connected with the Communist Party’, citing in evidence Oppenheimer’s visit to Jean and his decision to appoint Hawkins as his assistant. Pash recommended not only that Oppenheimer be replaced as scientific director of Los Alamos, but also that he be thoroughly investigated and interviewed.