In a kind of belated victory for the nonsigners, the California courts declared the university’s loyalty oath unconstitutional in April 1951, ordering those who had been fired reinstated. Following Neylan’s resignation as chairman of the Board of Regents that fall, the oath requirement was officially rescinded.43 But the damage had already been done.
Across the Bay, in Livermore, Alvarez soldiered on amid the fearsome thunder of the Mark I. His partner in the control room was relieved to learn that he was being reassigned to another new project at the Rad Lab: preparing the diagnostic measurements for George.44
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At Los Alamos, the war news from Korea had become an almost daily reminder that progress on the Super remained stalled. “The third world war has started and I do not know whether I care to survive it,” Teller wrote to his confidante that winter. Physicist Marshall Holloway, whom Bradbury had made head of the Weapons Division at Los Alamos, had no plans for large-scale thermonuclear tests beyond George. The success or failure of the Cylinder would determine whether future tests along the same line would be worthwhile. But Teller, who was once again back at Los Alamos, on leave from Chicago, wanted Bradbury and Holloway to commit in advance to an ambitious series of tests aimed at producing a superbomb.
As 1951 began, Ulam had been toying with a new idea for what he called “a bomb in a box”—confining an exploding atomic bomb for a fraction of a second in a vessel of dense material, so as to compress the thermonuclear fuel at the other end.45 Key to Ulam’s idea was the notion of focusing the energy from the fission trigger, the “primary,” upon the fusion fuel, the “secondary,” to implode it, thereby dramatically increasing the efficiency of the thermonuclear reaction. In principle, the concept was not unlike the use of high-explosive lenses to implode Fat Man’s plutonium core.
Ulam showed a sketch of his so-called staged bomb to Theoretical Division leader Carson Mark and Bradbury one morning in late January. Mark, preoccupied with last-minute preparations for nuclear tests in Nevada, regarded it as just another candidate for the lab’s thermonuclear “zoo.” Bradbury was only slightly more encouraging.46 But Ulam’s idea received a more welcoming reception from Teller the following day.47
While working on the design of the Cylinder, Teller had been wrestling for months with the question of how radiation flowed from the atomic bomb to the adjoining capsule of tritium and deuterium. Ulam’s sketch inspired Teller to think of another, better way to compress the fusion fuel without heating it—by using radiation from the exploding fission trigger, traveling at the speed of light.48
Heretofore, radiation from the H-bomb’s fission trigger had been the principal problem with the Super; it was what had made Teller’s design appear unworkable. Now it was the solution. Maria Mayer’s work on opacity had finally borne fruit.
Teller had used the words cylindrical implosion to describe what happened in George. A new term—radiation implosion—was coined to describe the phenomenon at work in the Teller-Ulam invention.49
Teller modified and refined the concept over the next several weeks. In early March, he informed Hans Bethe, von Neumann, and Oppenheimer of the modified bomb-in-the-box idea during a meeting at Princeton. All immediately recognized the possibilities. “There are some new thoughts which may be important for you to know,” Oppie wrote Conant in June.50
But Ulam was not nearly as sanguine as Teller that the revolutionary potential of the staged bomb could be exploited anytime soon. The day following the Princeton meeting, Ulam told division leaders at Los Alamos that it might be several years before the lab could incorporate radiation implosion into its weapons. “Edward is full of enthusiasm about these possibilities; this is perhaps an indication they will not work,” Ulam puckishly wrote von Neumann.
Teller, on the other hand, had already begun lobbying for a full-scale test of the concept as soon as possible. Just a few weeks before, citing the lack of progress on the Super, Bradbury had pushed the earliest date for the next series of Pacific tests back another six months.51
Teller’s resentment of Ulam’s role in discrediting the original Super also had not abated.52 On March 9, 1951, Edward published the paper that contained the critical ideas behind the new superbomb: LA-1225, “On Heterocatalytic Detonations I: Hydrodynamic Lenses and Radiation Mirrors.” Although Ulam’s name was on the cover sheet, Teller later would dismiss his coinventor’s contribution as insignificant.53
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By the time preparations for George were under way, Teller was convinced that what he called the “big forces” opposing the superbomb would endeavor to cancel the program if the test of the Cylinder was anything less than a complete success. Lawrence shared his concern.
On May 8, 1951, Ernest rendezvoused with Teller on Eniwetok following the twenty-hour flight from California. Ferried by Piper Cub to the VIP barracks on nearby Parry Island, the two men went swimming in the warm surf that ringed the island. Colleagues whom Edward told of the idea for the staged bomb were surprised to find themselves with goose bumps in the tropic heat.
The next morning, after a delay to allow the weather to clear, Lawrence and Teller joined the admirals, generals, and other VIPs in front of the corrugated tin barracks, where deck chairs had been set up. As at Trinity, Edward had brought suntan lotion as protection from the bomb’s ultraviolet rays. He and Lawrence slipped dark goggles over their eyes when a green flare signaled the five-minute warning.
At 9:30 the Cylinder exploded on Eleleron Island, 16 miles away. In eerie silence, a brilliant white light shone through the gray overcast, spreading quickly across the horizon. From within the familiar mushroom-shaped cloud, the blue-violet light of ionizing radiation shone.
Despite George’s impressive display, the leaden skies made it
