The First War of Physics (68 page)

Standing at the pond of Auschwitz concentration camp in the early 1970s, Polish-born mathematician and biologist Jacob Bronowski made a plea to the cameras filming a BBC television documentary series. He repeated words once spoken by Oliver Cromwell: ‘I beseech you, in the bowels of Christ, think it possible you may be mistaken.’ In
The Ascent of Man
, he wrote:

It is said that science will dehumanise people and turn them into numbers. That is false, tragically false. Look for yourself. This is the concentration camp and crematorium at Auschwitz. This is where people were turned into numbers. Into this pond were flushed the ashes of some four million people. And that was not done by gas. It was done by arrogance. It was done by dogma. It was done by ignorance. When people believe that they have absolute knowledge, with no test in reality, this is how they behave. This is what men do when they aspire to the knowledge of the gods.

When Bronowski, not long returned from Hiroshima, overheard someone say in Szilard’s presence that it was the tragedy of scientists that their discoveries had been used for destruction, Szilard replied that it was not the tragedy of scientists: ‘it is the tragedy of mankind.’ This may be true, but the triumph of the scientists was no less tragic for all that. In helping to defeat the evils of arrogance, ignorance and dogma they had unleashed a primordial force upon the world, the threat of which would endure long after the perpetrators of evil were gone. Through their efforts they had helped to put the world in an even greater jeopardy.

The world was not about to thank them for what they had done.

Witch-hunt

Of course, the great dictators of the twentieth century had no monopoly on arrogance, ignorance and dogma. These human failings can birth, grow and thrive also in free, democratic societies, as Oppenheimer would discover to his cost. Julius and Ethel Rosenberg would pay the ultimate penalty.

The House of Representatives Un-American Activities Committee (HUAC) had been established originally as a special committee in 1934 and was then constituted four years later as a special investigating committee. It was charged with the investigation of Nazi propaganda, GermanAmerican involvement in Nazi activities, and the Ku Klux Klan. Having failed to gather sufficient information on Klan activities, the HUAC turned
its attention to the American Communist Party. It became a standing committee in 1945. Its investigation of the American movie industry began two years later and led ultimately to the blacklisting of some 300 artists, including Richard Attenborough, Leonard Bernstein, Charlie Chaplin, Dashiell Hammett, Lillian Hellman, Paul Robeson and Orson Welles.

In 1949 HUAC turned its attention to Rad Lab physicist Joe Weinberg. The evidence assembled by the FBI was compelling but there had been no warrant for the bug in Steve Nelson’s home that had caught Weinberg betraying atomic secrets. This evidence was therefore inadmissible in court. In an attempt to trigger a confession, in April 1949 both Weinberg and Nelson were called to a HUAC hearing where they met face to face. Weinberg denied ever having met Nelson before.

Knowing full well that Weinberg had committed perjury, the HUAC lawyers issued subpoenas to Lomanitz, Friedman and Bohm in an attempt to force the truth. Lomanitz had been pursued relentlessly around the country by the FBI, hounded out of a succession of jobs when the FBI exposed his Communist past to his employers. Bohm, in contrast, had moved to an academic position at Princeton University and was building the beginnings of a promising career in theoretical physics.

Einstein advised Bohm to refuse to testify, suggesting that he ‘may have to sit for a while’, meaning that the penalty for his silence might be a short prison term. Lomanitz and Bohm met in Princeton to discuss the impending hearings. Encountering Oppenheimer in the street, they explained what was happening. ‘Oh my God,’ Oppenheimer exclaimed, ‘All is lost. There is an FBI man on the Un-American Activities Committee.’ Oppenheimer too had been served with a subpoena, and was aware that one member of the HUAC was a former FBI agent who had investigated the Rad Lab during the war.

Bohm chose to testify. When asked on 25 May 1949 if he had ever been a member of the Young Communist League he refused to answer, pleading freedom of assembly and association under the First Amendment. When asked if he knew Steve Nelson he again refused to answer, pleading the right of refusal to self-incriminate under the Fifth Amendment. When asked if
he had ever been affiliated with any political party or association, he told the hearing: ‘I would say definitely that I voted the Democratic ticket.’

Bohm refused to divulge names at this hearing and at a subsequent hearing on 10 June. Princeton University expressed support and declared him a ‘thorough American’.

Oppenheimer testified on 7 June and skilfully negotiated his way around the questions. When asked about the ‘Chevalier incident’, he gave the version of events that he had reported to the FBI in September 1946. He was not asked to elaborate the ‘cock and bull’ story he had given to Pash and Johnson in Berkeley three years earlier.

Oppenheimer’s brother Frank had been denounced in 1947. The headlines of the
Times Herald
had screamed: ‘US atom scientist’s brother exposed as Communist who worked on A-bomb.’ When questioned by HUAC about his brother’s membership of the Communist Party, Oppenheimer replied: ‘I will answer, if asked, but I beg you not to ask me these questions.’ Oppenheimer, lauded as the ‘father of the atom bomb’, was not yet the target. The counsel for HUAC withdrew the question.

At the end of Oppenheimer’s testimony one HUAC member, Congressman Richard M. Nixon, voiced his appreciation: ‘I think we all have been tremendously impressed with him and are mighty happy we have him in the position he had in our program.’

But events over the next twelve months would build anti-Communist sentiment to unprecedented heights. Earlier, in August 1948, Whitaker Chambers, a former GRU agent and editorial staff member of
Time
magazine, had revealed in testimony to HUAC the names of highly-placed Communists in the Truman administration – Alger Hiss in the State Department and Harry Dexter White at the Treasury.
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Hiss was subsequently convicted on two counts of perjury in January 1950 and sentenced to two concurrent five-year sentences. As the ‘red scare’ now gathered momentum, Truman’s Democrat administration was targeted particularly by Republicans for its lax security and apparent unconcern. Even after the conviction of Hiss, Truman himself dismissed the allegation that there were Soviet spies in the White House as a ‘red herring’.

Republican Senator Joseph McCarthy saw an opportunity to make political hay. In a Lincoln Day speech in Wheeling, West Virginia, in February 1950, he declared: ‘I have here in my hand a list of 205 that were known to the Secretary of State as being members of the Communist Party and who nevertheless are still working and shaping the policy of the State Department.’
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McCarthy touched a nerve left raw by a series of post-war international events that had spooked the American public. He was quickly overwhelmed by media attention.

‘Senator McCarthy’s crusade, which was to last for the next several years, was always anathema to me’, wrote FBI special agent Lamphere some years later. ‘McCarthy’s approach and tactics hurt the anti-Communist cause and turned many liberals against legitimate efforts to curtail Communist activities in the United States … McCarthy’s star chamber proceedings, his lies and overstatements hurt our counterintelligence efforts.’

But the unfolding events lent credibility to McCarthy’s claims of Communist spies in high places. Fuchs, convicted at the Old Bailey on 1 March 1950, had been given the maximum sentence of fourteen years’ imprisonment. He had initially resisted naming his espionage contacts and, in any case, knew them only by their cover names. However, Fuchs agreed to co-operate when, during a visit to Wormwood Scrubs in May, Lamphere dropped vague but dark hints about the future safety in America of his sister Kristel. When it became clear that Gold was the FBI’s prime target, Fuchs admitted on 22 May that Gold had ‘very likely’ been his contact, Raymond. Gold was arrested that same day. A search of his Philadelphia apartment had uncovered the map of Santa Fe that Fuchs had given him. He had previously denied ever having been to New Mexico. He slumped in his chair and declared: ‘I am the man to whom Fuchs gave the information.’

Gold was the weak link in the espionage network. From Gold the trail led to Greenglass, already a suspect based on the Venona decryptions. He was arrested in June. From Greenglass the trail led to Julius and Ethel Rosenberg, arrested a month later. In the meantime, North Korean forces had on 25 June attacked the Republic of Korea along the Ongjin Peninsula, intent on reunifying Korea under a Communist flag. On 5 July, the US Army’s 24th Infantry Division was fighting and losing its first battle at Osan in South Korea. The Cold War had escalated to a limited ‘hot’ conflict. A real, large-scale war loomed, ominously.

HUAC gained no new evidence from the testimonies of Bohm and Lomanitz, yet it had concluded in September 1949 that Weinberg, Lomanitz and Bohm had been members of a Communist cell that had passed atomic secrets to the Soviets. Bohm was arrested on 4 December 1950 and charged with contempt of court. He was subsequently bailed. This time the Princeton University administrators were not so supportive. Concerned for the continuation of financial support from the university’s wealthy benefactors, Princeton president Harold Dodds suspended Bohm from his post for the duration of the trial.

Bohm was brought to trial on 31 May 1951. He was acquitted. Lomanitz was also acquitted, as was Weinberg a few years later. Princeton did not renew Bohm’s contract when it expired in June 1951. Einstein tried to bring him to the Institute for Advanced Study, declaring that if anyone could create a radical new quantum theory then it would be Bohm. But Oppenheimer vetoed the move. Bohm left America for exile in Brazil in October 1951. He carried with him a copy of his new book
Quantum Theory.
The thought processes sparked by the writing of this book would lead eventually to some remarkable discoveries, and would help set a path towards some of the most profound experiments in modern quantum physics.

Technically sweet

When Truman had announced on 31 January 1950 the intention to build a hydrogen bomb, the scientists at Los Alamos hadn’t the faintest idea how to do it. Despite Teller’s constant nagging and his report declaring a prima facie proof of the weapon’s feasibility, the general consensus among scientists was rather different. George Gamow would demonstrate the practical problems of the classical Super design by trying – and failing – to ignite a piece of petrified wood by setting fire to a small cotton wool ball sat alongside. The cotton wool, representing the fission bomb, would flare up and burn out quickly, leaving unaffected the wood, representing the deuterium/tritium fuel for the thermonuclear bomb. ‘That is where we are just now in the development of the hydrogen bomb’, he would say.

Teller had by now returned to Los Alamos from Chicago but continued to be unpredictable, erratic and irascible. He flitted from one obsession to the next, unable to fix on any one idea and run with it. His frustrations continued to build along with his paranoia, as Oppenheimer and the GAC and Bradbury at Los Alamos continued to put obstacles in his path.

The breakthrough came from Ulam, staring intently out of a window one afternoon in late January 1951. The problems they had been experiencing were related to the difficulty of triggering the fusion reactions simultaneously or near-simultaneously with fission. At issue was the fact that much of the energy from the fission device would be carried away rapidly by radiation, much as Gamow’s cotton wool ball burnt itself out without igniting the wood. Ulam now realised that by staging the sequence – more clearly separating the ‘primary’ fission device from the ‘secondary’ thermonuclear device – it would be possible to make use of the massive flux of neutrons from the primary to compress and heat the fuel in the secondary sufficient to trigger thermonuclear fusion reactions.

The idea quickly evolved. Teller realised that compression could be achieved by the X-ray radiation from the primary fission device which, as high-speed photons, would bombard the deuterium/tritium fuel a lot sooner than the heavier, much more sluggish neutrons. In itself, radiation compression was not new – Fuchs and von Neumann had filed a patent
application for this idea in 1946 – but Teller had hitherto dismissed it as irrelevant. Now, with radiation compression combined in a two-stage design, he realised that he had made a mistake, one that was ‘simple, great and stupid’.
⁴

When Oppenheimer reviewed the two-stage Teller–Ulam design at a GAC meeting in June 1951, he declared it ‘technically sweet’ and supported further work to build the H-bomb. This time there was no debate about the morality of the weapon. It seems that, once again, fear of the potential for ‘enemy’ scientists to make similar breakthroughs led the physicists to set aside any moral misgivings. Bethe, resolutely opposed to the development of the H-bomb, recognised that the new design changed everything. Soviet physicists were quite clearly capable of coming up with a similar design and, with the Korean war threatening to escalate way beyond a regional conflict, he felt that the Americans should strive to be the first to build such a weapon. History was repeating itself. Once again, a major discovery in nuclear physics was made beneath the storm clouds of a threatening war. Bethe returned with some reluctance to Los Alamos that summer.

Teller, who had pushed relentlessly for development of the Super since the summer school at Berkeley in 1942, had finally won the argument by showing, with Ulam, how it could be done. He should have been satisfied, but he was not. He offered to stay on at Los Alamos and assume managerial responsibility for the H-bomb programme, but was told that he could continue only as an assistant director or consultant. To have put the peripatetic Teller in charge would have been a calamity. When Bradbury appointed physicist Marshall Holloway to head the H-bomb programme, Teller resigned from Los Alamos. He continued to carp from the sidelines as he lobbied for the establishment of a second nuclear weapons laboratory.