Hiroshima_ The World's Bomb - Andrew J. Rotter [54]
In the aftermath of Szilard and Rabi’s confrontation with Fermi, both Szilard (with Walter Zinn) and Fermi, working in Columbia labs, produced fissions; Szilard called Teller in Washington to report, in Hungarian, that he had ‘found the neutrons’. It was vital, Szilard thought now, to conceal this information from the Nazis, so he urged a ban on publishing accounts of progress toward creating chain reactions. This was too much to ask, at this point, of the scientific republic, members of which insisted, variously, that the Germans had pioneered fission anyway, that publication of data would spur essential research in American labs, that no one had yet actually produced a chain reaction, and that even a chain reaction would not necessarily lead to the creation of an atomic bomb. In France, Frederic Joilot and two collaborators replicated the Szilard and Fermi fissions and refused to withhold publication of their results. The world was not yet officially at war, nor had Werner Heisenberg yet declared to American-based interlocutors that he would stay in Germany. Szilard shifted tactics. He called Albert Einstein in Princeton.36
It was July 1939, and Einstein had gone north to Peconic, Long Island, to sail and think. On Sunday 16 July Szilard and Wigner—the former never learned to drive—drove to the Long Island house. The conversation came quickly to chain reactions, using uranium, of which Einstein had neither heard nor conceived. He was persuaded that there was grave danger should the Nazis find a way to weaponize atomic energy, so he dictated, in German, a letter to a Belgian Cabinet member he knew, with the understanding that it first be cleared by the US State Department. Several days later, Szilard met Dr Alexander Sachs, a Russian-born economist with the Lehman Corporation who was on good terms with President Franklin D. Roosevelt. Sachs knew the physics literature and recognized the urgency of the issue as Szilard presented it to him, along with Einstein’s letter. Sachs wanted Einstein to redraft the letter and address it to the President. He himself would deliver it. Szilard drafted the letter, met Einstein again to discuss it, then rewrote it twice more, with the second redraft receiving Einstein’s signature. The final version, given to Sachs to give to Roosevelt, told of the near certainty of achieving a nuclear chain reaction ‘in the immediate future’. ‘This phenomenon’, Einstein/Szilard went on, ‘would also lead to the construction of bombs, and it is conceivable—though much less certain—that extremely powerful bombs of a new type may thus be constructed.’ (The language is curious here: chain reactions ‘would’, not could, ‘lead to’ an atomic bomb, yet such a thing was by no means ‘certain’.) The letter closed by noting the German embargo on sales of uranium and the presence of Carl Friedrich von Weizsacker, son of the high-ranking German Foreign Office man, at the KWI, ‘where some of the American work on uranium is now being repeated’. The letter was dated 2 August 1939; Szilard gave it to Sachs on the 15th.37
Delay set in. Sachs admitted to Szilard that he was ‘still sitting’ on the letter. In the realm of nuclear research, Szilard complained, ‘things were not moving at all’. Sachs finally moved on 11 October, over a month after the outbreak of war in Europe. Given to prolixity and indirection, Sachs nevertheless managed to hold Roosevelt’s attention for nearly an hour, reading to the President from a recent book describing some of the history of nuclear exploration, from his own lengthy memorandum, detailing (as Peter Wyden has described it) ‘the roles of Hahn and Meitner and Szilard and Fermi and Wigner and Teller’, and finally from a portion of the Einstein/Szilard letter dated more than two months earlier. Roosevelt began to flag, so Sachs cadged an invitation for the following morning. He spent the night rethinking his approach, and, though he still could not avoid rambling, he managed at breakfast to make his point: