FOUR - The United States I: Imagining and Building the Bomb

The high-level British scientific committee inspired by the Frisch— Peierls memorandum was meeting with regularity by the middle of spring 1940. Its chair, G. P. Thomson, thought it needed a name, so in June 1940 he christened it the MAUD (or Maud) Committee, imagining he was appropriating a fragment of code from a telegram sent to England by Lise Meitner—though in fact Meitner had only wished to contact Niels and Margrethe Bohr’s former governess, Maud Ray, who lived in Kent. The MAUD Committee coordinated and encouraged rudimentary bomb research. It employed a good number of so-called ‘alien’ scientists, or ‘exotics’ as some called them: Frisch and Peierls, Francis Simon, who did advanced work on isotope separation, Hans von Halban and Lew Kowarski, who had collaborated with Frederic Joliot in Paris, and methodical Klaus Fuchs. They were not allowed to work on radar or own bicycles without permission. They were permitted to do nuclear research. Under MAUD auspices, there occurred a number of remarkable advances in nuclear physics and chemistry that would be consolidated the following year.1

1. The MAUD Committee and the Americans

MAUD’s work was closely monitored by Frederick Lindemann, the Oxford physicist, recruiter to Britain of Central European scientists, and confidant of Winston Churchill. The committee and its scientists also cooperated fully with the Americans. John Cockcroft, the Cambridge physicist and an important figure in MAUD, corresponded frequently with American colleagues and visited the United States and Canada in the fall of 1940. British scientists also entertained high-level American visitors. James Conant, eminent chemist, president of Harvard, and head of the National Defense Research Committee (NDRC), established to follow and encourage the work of the American nuclear physics community, crossed the Atlantic in February 1941. He met Halban at Cambridge; the Austrian-born scientist discoursed on heavy water and chain reactions. (‘Look,’ said an uncomfortable Conant, ‘you’re not supposed to talk to me about this thing.’) But back in London Lindemann raised the issue too, confiding in Conant over lunch that it might be possible to make a powerful explosive by slamming together two pieces of U-235. Conant was followed to England by the nuclear physicist Kenneth Bainbridge. Invited to attend a MAUD meeting, Bainbridge was, like Conant, surprised to learn that British scientists had ‘a very good idea of the critical mass and [bomb] assembly’, and hoped to ‘exchange personnel’ and thus information with the Americans. Back home in early June, Bainbridge told the University of Chicago physicist Arthur Holly Compton and a group assembled at Harvard of British achievements and ambitions, including the hope that a nuclear explosive might be ready for use in two years.2

Similarly, the NDRC ordnance specialist Charles Lauritsen sat in on a MAUD meeting in early July, at which he heard Thomson give a preliminary survey of what was called, simply, ‘MAUD Report’. (The final version came at the end of that month.) The conclusions of the report echoed the optimism and determination previously expressed to Conant and Bainbridge. Building a uranium-based bomb was a project ‘of the very highest importance’, so the work must move forward ‘as rapidly as possible’. There should be more investigation of fission in U-235, an effort to design a fuse for the bomb, and construction of a ‘pilot plant’ for the separation of the uranium isotope, with the possibility held out that the full-scale plant would be built in Canada. Conant and Vannevar Bush, the inventor and lately scientific administrator who was then director of the government Office of Scientific Research and Development (OSRD), got a copy of the complete draft report in mid-July. It stirred them to nudge the NDRC to negotiate contracts for uranium work.3

The MAUD Report came also to Lyman Briggs, the director of the National Bureau of Standards who had in 1939 been designated by the president chair of the new Uranium Committee. Briggs’s admirers described him as conservative and methodical; those less inclined to charity found him maddening in his deliberateness and his seeming suspicion of nuclear physics, in which he was not trained. (He had studied soil for the Department of Agriculture.) Briggs mistrusted foreigners and had a mania for secrecy, and he tried to exclude Szilard and Fermi from his committee’s sessions. By 1940 he was 66 years old, inattentive at meetings, and worried about the effect on his reputation should his uranium project receive lavish funding yet fail to produce results. So he resisted lavish funding. Prodded by Bush, Roosevelt had in June 1940 placed the Uranium Committee under the control of Bush’s newly established NDRC. But the Uranium Committee retained bureaucratic authority over the nuclear program, and Briggs could still mount obstructions if he wished to. When he got his copy of the MAUD Report in July 1941, Briggs promptly put it in his safe without showing it to the other committee members. MAUD’s conclusions, Briggs thought, were too sensitive to remain in the light of day.4

Marcus Oliphant, the Australian-born Rutherford student who worked on radar and nuclear physics at the University of Birmingham and was a member of the MAUD Committee, was one of those who wondered why the Americans had seemed to respond so tepidly to the MAUD Report’s extraordinary conclusions. In late August, just as Adolf Hitler was escalating the air war against Britain, he flew to the United States seeking answers. In Washington he met Briggs, who reassured him that the report was tucked away safe from the prying eyes of other Uranium Committee members. Oliphant registered his dismay. Granted an audience with the committee as a whole, Oliphant pointedly and frequently used the word ‘bomb’ to describe what MAUD had recommended, and he insisted that the Americans, the only ones able to spare the $25 million he thought the bomb would cost, had a responsibility to build it. Not satisfied with the response, Oliphant flew to California in early September and in Berkeley met the practical-minded physicist Ernest Lawrence. Here, at last, he found someone who shared his sense of urgency about a possible nuclear weapon. Lawrence showed Oliphant around his Berkeley facility and talked of using great machines to separate uranium and create plutonium. Oliphant told him of the MAUD conclusions; Lawrence paced worriedly among the eucalyptus trees as he heard Oliphant out. (Robert Oppenheimer joined the men afterward in Lawrence’s office, and there heard, for the first time, about interest in building an atomic bomb.) Lawrence promised to help, and immediately called Bush and Conant and urged them to see Oliphant. Both subsequently did so, though both were coy about how much they already knew about chain reactions and fast neutrons, and Conant was as uncomfortably evasive as he had been in England earlier that year— Oliphant’s news was ‘gossip among nuclear physicists’, he said. Oliphant also saw Enrico Fermi, who seemed to him as skeptical and cautious as Bush and Conant had been. As Richard Rhodes writes: ‘Oliphant returned to Birmingham wondering if he had made any impression at all.’5

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