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Inside the Centre: The Life of J. Robert Oppenheimer

Page 79

by Ray Monk


  The evidence for the Soviet bomb consisted of tiny samples of fission products, isotopes of cerium and yttrium (Ce-141 and Y-91), which had been detected on 3 September 1949 in rainwater collected and analysed by the US navy and in the air by an air-force reconnaissance plane flying over Japan. On 19 September, a group of experts that included Oppenheimer concluded that, with very little doubt, the radioactive traces came from a bomb exploded by the Soviet Union on 29 August. The following day, President Truman was informed (his first reaction was to refuse to believe it, so convinced was he of the inferiority of Soviet science and technology), and three days later, 23 September, Truman publicly announced: ‘We have evidence that within recent weeks an atomic explosion occurred in the USSR.’

  That evening Oppenheimer received a phone call from a very worried Edward Teller. ‘What shall we do? What shall I do?’ Teller asked Oppenheimer. Teller was at that point dividing his time between Chicago, where he worked on theoretical physics, and Los Alamos, where he worked on what had been his pet project for many years: the Super, the hydrogen bomb. ‘Just go back to Los Alamos and keep working,’ Oppenheimer told him. Then, after a long pause, during which Teller was clearly waiting for some additional response, Oppenheimer added: ‘Keep your shirt on.’

  To Teller it seemed obvious that the best – indeed, the only rational – response to the fact that the Soviet Union now had the atomic bomb was an accelerated programme to develop the Super. For surely, he reasoned, if the Soviets had worked out how to build a fission bomb, they would also have realised that a much more powerful fusion bomb was at least a theoretical possibility, and therefore it was essential to the protection of the United States that it get a hydrogen bomb before the Soviets. Similar thoughts had occurred to Lewis Strauss in Washington and to Alvarez and Lawrence in Berkeley, and it was not long before the four of them united in a campaign to persuade the President to authorise such an accelerated programme. At the very time that Oppenheimer was telling Life magazine that the news about the Russian bomb would not mean that the endeavours of physicists ‘will now be diverted as they were by the recent war’, three of the most respected physicists in the country were plotting with the man whose fierce hatred Oppenheimer had just aroused, to ensure that the endeavours of physicists were indeed so diverted.

  The plotters moved quickly. On 5 October, Lawrence phoned Strauss, as a result of which Strauss wrote a memo to his fellow AEC members calling for a crash programme to develop the hydrogen bomb, using words that carried an ironic echo of Oppenheimer’s. ‘We should now,’ he wrote, ‘make an intensive effort to get ahead with the Super. By intensive effort, I am thinking of a commitment in talent and money comparable, if necessary, to that which produced the first atomic bomb. That is the way to stay ahead.’ Lilienthal responded to this memo by asking Oppenheimer to arrange a special meeting of the GAC in order to advise the AEC on what to do about the Soviet bomb. Oppenheimer duly arranged the meeting, but, because of the busy schedules of the various eminent scientists on the committee, the earliest date on which he could get everybody together was 29 October.

  In the intervening three weeks, intensive lobbying was undertaken on behalf of the idea that a crash programme for the Super was the correct response to the Soviet bomb. On 6 October, Alvarez and Lawrence flew out to Washington from Berkeley, making an overnight stop at Los Alamos to confer with Teller and others about the current state of research into the feasibility of the Super. Teller’s view (not widely shared among physicists at this time) was that ‘it was highly probable that we could produce a fusion weapon’. ‘In the present situation,’ Lawrence delighted Teller by responding, ‘there is no question but that you must go ahead.’ Lawrence and Alvarez then proceeded to Washington, where they used all of Lawrence’s considerable influence to meet as many high-ranking officials as they could. These included members of the Joint Committee on Atomic Energy, advisors to the Defense Department, and anybody else who might have the ear of the President. They also met each of the AEC commissioners, attempting to undermine what they considered the baleful influence of Oppenheimer. One result of their efforts was the appearance of General Hoyt Vandenberg, the Chief of Staff of the fairly recently established US Air Force,fn64 before the Joint Committee on 14 October, when he stated: ‘Having the Super weapon would place the United States in the superior position that it had enjoyed up to the end of September by having exclusive possession of the weapon.’ Satisfied with their work, Alvarez and Lawrence then returned to Berkeley.

  At about the same time, Teller set off on his own lobbying trip, stopping first at Chicago, where he hoped to enlist Fermi to be the head of the new crash programme. Fermi, however, flatly refused even to consider it. Teller went next to Cornell, where he found Bethe more sympathetic. Bethe promised Teller that he would be willing to return to Los Alamos to work on the Super. While Teller was at Cornell, Bethe got a call from Oppenheimer, asking him to come to Princeton. When Bethe said that Teller happened to be there, Oppenheimer extended the invitation to him. On 21 October, then, Bethe and Teller went to Oppenheimer’s office at the institute, where Oppenheimer showed them a letter he had just received from Conant, expressing vehement hostility to the Super, which, Conant said, would be built ‘over my dead body’.fn65 Oppenheimer did not express his own opinion, but Bethe says: ‘Probably Oppenheimer wanted to influence us against the development of the hydrogen bomb and didn’t want to do it in his own words, so he used Conant’s letter instead.’

  A letter that Oppenheimer wrote to Conant that day suggests that Bethe might not have been right about that. The view that Oppenheimer expresses to Conant is that the AEC had no alternative but to embark on a crash programme to develop the hydrogen bomb, and therefore the GAC had no alternative but to recommend such a programme, not because the bomb was a good idea, scientifically or militarily, but because the political climate made any other course of action impossible. It has to be remembered that at this point Teller did not (despite what he told Lawrence) have a workable design of a hydrogen bomb, or any clear idea of how such a workable design might be arrived at. Nobody doubted that fusion was, in principle, possible, or that, if a way could be devised of fusing the nuclei of hydrogen (or, more likely, one of its isotopes, deuterium or tritium), enormous amounts of energy could be released. Neither did anyone doubt that if a fusion bomb could be built, its power would be colossal, measured in megatons, not kilotons, of TNT. The problem that had yet to be solved, however, was how the massively high temperatures required to initiate the fusion process could be created in a device that could, conceivably, be delivered successfully by an aeroplane or even a boat.

  ‘On the technical side,’ Oppenheimer told Conant, the Super was ‘a weapon of unknown design, cost, deliverability, and military value’. But, he added, ‘a very great change has taken place in the climate of opinion’, brought about partly by the fact that ‘two experienced promoters have been at work, i.e., Ernest Lawrence and Edward Teller’. As a result, the Joint Congressional Committee, ‘having tried to find something to chew on ever since September 23rd, has at last found its answer: We must have a Super and we must have it fast.’ Thus, Oppenheimer concluded: ‘It would be folly to oppose the exploration of this weapon’, even though ‘I am not sure the miserable thing will work, nor that it can be gotten to a target except by ox cart.’ Moreover:

  It seems likely to me even further to worsen the unbalance of our present war plans. What does worry me is that this thing appears to have caught the imagination, both of the congressional and military people, as the answer to the problems posed by the Russian advance . . . that we become committed to it as the way to save the country and the peace seems to me full of dangers.

  As the date for the fateful meeting approached, Lawrence asked Robert Serber to go to Washington to present his proposal to build heavy-water reactors as part of the programme to investigate fusion. Serber had been at Berkeley since 1946, and had taken over Oppenheimer’s graduate courses. On the subject of
the Super, his sympathies were with Oppenheimer, having earlier studied Teller’s design for a fusion bomb and identified its flaws. ‘I told Ernest that the Super wouldn’t work,’ Serber later wrote, ‘that Edward didn’t know how to build a thermonuclear bomb.’ He nevertheless agreed to go and present Lawrence’s proposals for the reactors, which, he thought, might be useful even if a fusion bomb could not be made to work. Serber arrived in Princeton the day before the meeting and stayed overnight with the Oppenheimers. Oppenheimer told Serber that Conant was very much against developing the Super, and showed him Conant’s letter, which Serber remembers as saying ‘that the United States should not build such a weapon. It said that if the Russians did so and used it against us, we could very well retaliate with our stockpile of atomic weapons.’ ‘I was astonished,’ Serber writes. ‘The East was evidently a completely different world from California. I had no idea that people like Conant and Oppenheimer would harbour any such ideas. At Berkeley they would have been unthinkable.’

  Actually, as Oppenheimer had indicated in his letter to Conant, the idea that the United States should not go ahead with an accelerated programme to build the Super was only very slightly more thinkable in the east than in Berkeley, and yet the GAC, after its meeting on 28–9 October 1949 (‘perhaps the most important one in its history,’ as Pais writes), ended up endorsing just that idea and recommending it to the AEC. It has often (most insistently by Teller) been supposed that, in advising the AEC against a crash programme to develop the Super, the GAC was bowing to the will of Oppenheimer. In fact, it would be truer to say that Oppenheimer was bending to the will of Conant, for the view that came out of the meeting was a good deal closer to Conant’s pre-meeting view than it was to Oppenheimer’s.

  Prior to the meeting, Glenn Seaborg had written to excuse himself from it on the grounds that he would be in Sweden that weekend, giving a series of lectures on the transuranic elements, having been invited by the Royal Academy of Sciences. ‘The clear implication,’ he said later, ‘was that they were looking me over for the Nobel Prize, so I wasn’t about to miss the trip.’ On the meeting to discuss the Super, Seaborg recalled: ‘I expressed my opinion in a letter to Oppie. I said that the idea of another horribly destructive weapon was disheartening, but that we had no choice but to develop the Super because the Soviet Union certainly would.’ In fact what Seaborg wrote was a good deal more verbose and less clear than his later paraphrasing would suggest:

  Although I deplore the prospect of our country putting a tremendous effort into this, I must confess that I have been unable to come to the conclusion that we should not . . . My present feeling would perhaps be best summarised by saying that I would have to hear some good arguments before I could take on sufficient courage to recommend not going towards such a program.

  James Conant could not attend the meeting until the second day. The remaining members of the committee – Oliver Buckley, Lee DuBridge, Enrico Fermi, John Manley, Isidor Rabi, Cyril Smith and Oppenheimer himself – were all there on the first morning, which was to be devoted to a series of talks from experts on various aspects of the matter in hand.

  The first to give evidence was George Kennan, the political scientist and historian. Having served under both George Marshall and his successor as Secretary of State, Dean Acheson, Kennan was, by this time, one of the most influential advisors on foreign policy, particularly with regard to Soviet affairs. On this occasion, he may have had a decisive effect on the development of the meeting by introducing a thought that had not, it seems, previously occurred to anyone else present. This was that the Soviet Union, given that its economy and industry were still in ruins after the devastation of the war, might not want to embark on an expensive arms race and might be willing to negotiate an agreement that ensured that neither side developed the hydrogen bomb. That thought certainly seems to have shaped much of what followed.

  After Kennan came Bethe, who reported on the present state of research on the Super, emphasising the technical problems that had yet to be solved. Then Serber did what he had been asked to do by Lawrence, which was basically a sales pitch, urging the committee to commission the Berkeley Rad Lab to build reactors that would increase the production of plutonium and tritium. After he had delivered this pitch, Serber did not fly back to Berkeley, but stayed overnight, returning with Oppenheimer the next morning to the AEC’s offices. ‘I met Luis [Alvarez] in the lobby of the AEC building,’ Serber remembers, ‘and we watched as the GAC members assembled, and later were impressed by the constellations of stars on the shoulders of the Joint Chiefs and other high-ranking officers going by to testify.’

  Among those Joint Chiefs were General Omar Bradley of the army and General Lauris Norstad of the air force, neither of whom seems to have given much thought to the military purpose of having a hydrogen bomb. Both said there was no choice but to build the Super, but when asked what advantages it might have over a stockpile of atomic bombs, Norstad was silent and Bradley replied: ‘mostly psychological’.

  At the lunch break Oppenheimer went with Alvarez and Serber to a nearby restaurant, where Serber was surprised and Alvarez was appalled to be told that the mood of the meeting was swinging away from a recommendation for a crash programme. As Alvarez later remembered his lunchtime conversation with Oppenheimer:

  He said that he did not think the United States should build the hydrogen bomb, and the main reason he gave for this, if my memory serves me correctly, and I think it does, was that if we built a hydrogen bomb, the Russians would build a hydrogen bomb, whereas if we did not build a hydrogen bomb, then the Russians would not build a hydrogen bomb.

  After lunch, an angry and disappointed Alvarez set off back to Berkeley, convinced, as he later put it, that ‘the program we were planning to start was not one that the top man in the scientific development of the AEC wanted to have done’. In his diary at the time, he noted that he had had an ‘interesting talk with Oppie’, in which he saw, however, some ‘pretty foggy thinking’.

  That afternoon the GAC members, together with four of the five AEC commissioners, talked through all the issues involved. Before he arrived at the meeting, Rabi had believed both that (as Lilienthal summarised Rabi’s views in his diary) the ‘decision to go ahead will be made; only question is who will be willing to join in it’ and that the crash programme was indeed the answer to the Russian atomic bomb. Fermi had been of the opinion that (again, in Lilienthal’s words) ‘one must explore it and do it and that doesn’t foreclose the question: should it be made use of?’, while Oppenheimer had believed, as he said in his letter to Conant, that it would be folly to resist the crash programme. Apart from these two, all the other GAC members present at this meeting had arrived believing, for a mixture of technical, strategic and moral reasons, that it would be wrong to develop the hydrogen bomb, even if some of them believed (as Oppenheimer did) that the decision to build the bomb was, for political reasons, unavoidable. By the end of the afternoon session, however, this political pessimism had been overcome and the GAC members had reached a unanimous decision not to recommend a crash programme, with Rabi and Fermi – perhaps having Kennan’s testimony in mind – believing it was important to stress that this should be conditional on getting an international agreement not to pursue research on the Super. At the end of the meeing Oppenheimer suggested that they spend the evening writing reports and reconvene the next morning.

  Three reports were written that evening. Manley and Oppenheimer wrote the main report, which was signed by all eight attending committee members. Part One of this report recommended an increase in the production of reactors, isotope-separation plants and atomic bombs, particularly ‘an intensification of efforts to make atomic weapons available for tactical purposes’. This last recommendation shows how far Oppenheimer’s thinking had changed since the end of the war, being, as it is, the exact opposite of his earlier Bohr-inspired view. At the centre of that earlier view was the thought that atomic bombs were not simply a new, more deadly weapon; they
were a radically different kind of weapon, so powerful that the (rational) fear of using them might put an end to war itself. Now Oppenheimer was advocating atomic bombs as tactical devices, treating them precisely as just another weapon.

  This change in attitude seems to have been prompted by two things: 1. the heavy burden of having led a project that resulted in the deaths of tens of thousands of Japanese civilians,fn66 and 2. his disillusionment following the breakdown of talks to negotiate international control of atomic weapons. He no longer believed in the notion of a bomb too big to use (if he did, the Super was, surely, just that), and he had no wish to be instrumental in the creation of a bomb that could kill civilians on a scale many times greater than the bomb that had been unleashed on Hiroshima. An atomic bomb designed to be used as a tactical weapon, against soldiers rather than civilians, was, for him, a lesser evil than a hydrogen bomb that was many times too big to be used in such a way and could only be used for the mass slaughter of civilians.

  Part Two of the main report spells this reasoning out. It takes a fairly optimistic view of the chances of overcoming the technical problems in the way of developing the Super: ‘We believe that an imaginative and concerted attack on the problem has a better than even chance of producing the weapon within five years.’ But it then addresses the question of why anyone would want to develop such a weapon. Given that ‘it has generally been estimated that the weapon would have an explosive effect some hundreds of times that of present fission bombs’, one had to face the question of what might be involved in actually using this weapon:

 

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