Hiroshima_ The World's Bomb - Andrew J. Rotter [163]
Kurchatov now asked Igor Tamm, a theoretical physicist at Moscow University’s Physics Institute (FIAN), to check Zeldovich’s math and oversee the project. Tamm, in turn, tapped several of FIAN’s young physicists to help with the work. One of them was Andrei Sakharov, the 27-year-old son of a physics teacher. The joke was that Tamm picked Sakharov because he pitied his young colleague’s housing situation, and knew that elevating Sakharov to the thermonuclear team would bring quick improvement. Tamm knew better: Sakharov was already well known and deeply respected by Soviet physicists. ‘He distinguished himself’, wrote a colleague, ‘through the clarity and correctness of his thought, and the conciseness of expression of his ideals.’ Sakharov joined the quest to develop an H-bomb. Partly, he felt, there was no choice: if he demurred he might be marginalized, arrested, or worse. He also admitted that he was drawn to the beauty of the physics involved. For Sakharov, as for Fermi and even Oppenheimer, the intellectual excitement of fashioning bombs, coupled with an attraction to the work that was aesthetic and even sensual, was irresistible. And this principled man, like many other men, was strongly affected by his direct experience of total war and Cold War. ‘I understood, of course, the terrifying, inhuman nature of the weapons we were building,’ wrote Sakharov. ‘But the recent war had also been an exercise in barbarity; and although I hadn’t fought in that conflict, I regarded myself as a soldier in this new scientific war.’ He would later say that the rough balance of terror achieved by the Soviet triumph in both fission and fusion weapons forged a deterrent to all-out war, though he confessed that he may not have imagined such a thing when he accepted Tamm’s invitation.49
Sakharov devised in his head a new design proposal for a hydrogen bomb. In his memoirs, he calls this the ‘First Idea’, but it became known to his project colleagues as a sloika, roughly ‘Layer Cake’. It was so named because it layered fission and fusion, heavy and light elements, and encased them in a high-explosive frosting. The explosive would cause the cake to implode, setting off an explosion of the fission trigger at its center and in this way initiating, in theory, fusion in the light element layers. In early 1949 Sakharov and his promising design were bundled off to Sarov and Yuli Khariton, over Tamm’s fruitless objections: ‘Things seem to have taken a serious turn,’ observed Tamm. Meanwhile, if Stalin, through his representative Beria, was initially disinclined to pursue another expensive and powerful weapon, Truman’s announcement on 31 January 1950 that the AEC was to ‘continue work’ on a hydrogen bomb turned the leadership around. Almost immediately Beria demanded from Kurchatov a progress report on H-bomb research, and within the month Stalin had ordered that such a bomb be built. ‘In other words,’ writes Gerard DeGroot, ‘the Americans decided to build the Super because they thought Soviets were doing so. And the Soviets did so because they were certain the Americans were building one.’ Indeed, these mutual perceptions were basically correct.50
Sensing himself vindicated by Truman’s decision, Teller pressed forward with his work on the Super. He continued to be frustrated, however, by the reluctance of some prominent scientists to embrace the project, and especially by technical problems with his weapon designs. Teller’s penchant for losing his temper made him a poor administrator, and he was frequently unwilling to take advice from others. His suggested designs for the Super had flaws, and the project seemed in jeopardy at the end of 1950. The mathematician Stanislaw Ulam bailed Teller out early in 1951. Ulam