Authors: Jennet Conant
For Oppenheimer, this turn of events was an unmitigated nightmare. In July 1944, implosion looked like anything but a sure thing. Yet the urgency of getting the implosion method to work would necessitate both expanding and reorganizing the laboratory to meet this massive new challenge. Rabi recalled sitting in a Los Alamos meeting room while the senior scientists debated the problem. “The question was asked: Should the laboratory be extended? The big problem was: Where was the enemy in the field of work?” They reviewed everything they knew of the Nazi bomb effort since the announcement of uranium fission in 1939, as well as the history of their own development, and tried to figure out if the Germans had better judgment or had made the same mistakes. “We finally arrived at the conclusion that they could be exactly up to us, or perhaps further,” said Rabi. “We felt very solemn. One didn’t know what the enemy had. One didn’t want to lose a single day, a single week. And certainly, a month would be a calamity.”
The shake-up of the laboratory would require the creation of new divisions and, far trickier from an administrative point of view, the appointment of new division heads. Here Neddermeyer’s personality, which up to now Oppenheimer had managed to treat with forbearance, presented a major problem. Neddermeyer was extremely difficult. He liked to proceed slowly and methodically, and was constantly in conflict with his boss, Captain Deke Parsons, a navy officer accustomed to running a large and efficient military ordnance operation. When Kistiakowsky arrived, Oppenheimer was relieved to be able to find someone so qualified to assign as Parsons’ deputy to run interference between the two scientists on the implosion project. But Kistiakowsky had quickly tired of refereeing Neddermeyer and Parsons, who were always “at each other’s throats” and shot off a memo asking to be released from the project. An additional complication was that Jim Tuck, a member of the British mission, had been experimenting with explosive lenses and had found a way to bend the explosion wave going through the explosive. As Kistiakowsky put it, “If you have two explosives with different detonation velocities, and you put them together in the right way, you can shape the wave, and instead of having it expand, make it converge.” Theoretically, it should be possible to line the core with explosive lenses and, by detonating them simultaneously, produce a tremendous symmetrical shock wave. It was the problem that Neddermeyer had been struggling for months to solve, but for which he had been unable to come up with an acceptable answer.
Oppenheimer’s predicament was whether to leave Neddermeyer in place or risk alienating an extremely valuable member of the team, who had spearheaded implosion from the very beginning, by handing the new expanded implosion program over to someone else. During the last few weeks of July and the beginning of August, he agonized over what to do. “I remember Oppie’s even calling me in and asking what I thought of Seth Neddermeyer,” said Priscilla Greene. “He was hesitant about putting him in charge. [Neddermeyer] was sort of cranky, and didn’t communicate well, and could be stubborn about his ideas.” What followed was “a great period of tension” during which Oppie became more high-handed and abrupt than usual, and reverted to some of the bad habits he had been known for before the war. He relied increasingly on a close circle of intimate colleagues, shut others out, and summarily ended arguments with sardonic or wounding remarks. “But when he tried that on the scientists at Los Alamos,” Greene noted, “Robert didn’t always get away with putting them down.”
Whether Oppenheimer was trying to goad Neddermeyer into action, or was simply at the end of his rope, the result was the same. Some of their fights were particularly bitter. Oppie’s mishandling of Neddermeyer made him another enemy and alienated a number of the physicists close colleagues. “From my point of view, he was an intellectual snob,” Neddermeyer said after the war. “He could cut you cold and humiliate you right down to the ground. On the other hand, I could irritate him.” But even Neddermeyer acknowledged his deliberate pace was partly to blame. “He became terribly, terribly impatient with me in the spring of 1944,” he said. “I think he felt very badly because I seemed not to push things for war research but acted as though it was just a normal research situation.”
In the end, Oppenheimer felt compelled to choose Kistiakowsky as head of the new X (Explosives) Division, the man he thought would best lead a crash effort on the daunting problem of producing an explosive lens for the implosion weapon. There was so much work to do on implosion that the whole project would essentially be transformed. Nearly every important scientist, except Teller, who was still single-mindedly focused on the Super, would be affected. Oppenheimer asked Alvarez to be Kistiakowsky’s chief aide, and Neddermeyer went back to working in a corner, off by himself. Bob Bacher was put in charge of the new G (Gadget) Division, which focused on weapons physics and the plutonium sphere. Parsons continued to head the Ordnance Division, concentrating on bomb construction and delivery. Parsons was also appointed associate director of the laboratory, along with Fermi, who would be moving to Los Alamos permanently that fall to lend a hand. Double-tracking the two projects meant that more manpower would be required to supplement the existing staff, and Oppenheimer arranged for hundreds more SEDs—personnel from the military’s Special Engineer Detachment—to come to the project to help with the implosion work and bomb construction.
Everyone at the laboratory took solace in the news that Enrico Fermi had finally been persuaded to come to Los Alamos full-time. Many of the physicists regarded Fermi as the soul of wisdom—he was sometimes referred to as “the pope” because of the weight of his pronouncements—and believed that his even temperament and common sense would help provide the support and balance that was badly needed at this stage. For his part, Oppenheimer hoped that Fermi could help mediate some of the running disputes between the different division heads. Fermi was unique even among the array of talents at Los Alamos in that he excelled at both experimental and theoretical physics, and could go toe-to-toe with anyone on the site.
Los Alamos was thick with experts and know-it-alls, with more arriving every day, so that Oppenheimer spent an inordinate amount of time settling disputes and preventing work from being disrupted. There was Teller’s ongoing dissatisfaction with the project and refusal to do what he regarded as mundane work on the implosion bomb. Fermi liked Teller, and the two got along well, and Oppenheimer could only hope the Italian Nobel laureate would be able to convince Teller to stay and undertake some useful theoretical investigations. By now, he was no longer under any illusion that Teller could be won over to his point of view, but he was shrewd enough to realize that it was better to keep the troublemaker inside the tent, where he could at least serve as a useful critic in group debate. If Oppenheimer was fed up with Teller, he usually managed to hide his antagonism, though the physicist Charles Critchfield recalled that occasionally after talking about the progress of the lab, Oppenheimer would mutter a little prayer: “May the Lord preserve us from the enemy without and the Hungarians within.”
Oppenheimer also had his hands full dealing with escalating tension between Parsons and Kistiakowsky, who clashed over everything from who knew more about explosive technology to scheduling access to the S-Site, the new testing facility located at the site of an old sawmill near Anchor Ranch. The problem between Parsons and Kistiakowsky could be boiled down to a difference in style, between that of the classic can-do military approach to developing detonation devices and that of theoretical and experimental physicists struggling to perfect a radical assembly design for implosion. Parsons had insisted on bringing in a veteran navy ordnance officer, who had proceeded to build an explosives casting plant that Kistiakowsky regarded as “a monstrosity.” Kistiakowsky, who could be just as imperious, demanded that a completely new plant be built according to his group’s specifications.
Parsons argued that I was wanting to do an undoable job. He believed there was something else that should be done, a kind of smoothing out of the difficulties with plutonium, minimizing them rather than really overcoming them. Perhaps I am biased but I felt the way Oppenheimer handled this difference, his grasp of the technical problems, was really most impressive.
He called a big meeting of all the group heads, and there he sprang on Parsons the fact that I had plans for completely redesigning the explosives establishment. Parsons was furious—he felt I had by-passed him and that was outrageous. I can understand perfectly how he felt but I was a civilian, so was Oppie, and I didn’t have to go through him.
After much debate, Oppenheimer decided the S-Site would be expanded to accommodate Kistiakowsky’s new explosives plant. Parsons never forgave Kistiakowsky, and the Russian noted that from then on they were never “on good terms.” But Oppenheimer may have seen the rivalry between the two group leaders as productive, and from a political point of view, it may have been more convenient to have Parsons believe Kistiakowsky had bypassed him, rather than think the laboratory director had subverted his authority.
As adept as Oppenheimer was at reconciling divergent viewpoints, it was a measure of his exasperation with the more fractious members of his staff that he told the Administrative Board on August 3 that “certain” parties could be working harder. Groves had ordered a fifty-four-hour workweek for all military personnel at Los Alamos and canceled all leaves, and while Oppenheimer resisted imposing the same draconian measures, he instituted a number of organizational changes. Those “certain” few who were perceived as dragging their feet were transferred to different divisions, and several scientists were appointed to help hear complaints and expedite the work. He also announced that the Tech Area siren would sound at more frequent intervals to induce people to get to work on time and return from their lunch break in a more orderly fashion. When Fermi arrived that August to head up the F Division, which included theoretical and nuclear physics, his relaxed and unpretentious style, which was in its own way every bit as dominant as Oppie’s, did much to help defuse the summer’s simmering tensions and restore peace on the mesa.
By the end of the summer, Oppenheimer wrote Groves that he thought he had managed to bring the project leaders in line and restore harmony. He enclosed a report from Parsons, “with the general intent and spirit of which I am in full sympathy,” but eloquently and resolutely defended the conduct of his physicists on several counts:
I believe that Captain Parsons somewhat misjudges the temper of the responsible members of the laboratory. It is true that there are a few people here whose interests are exclusively “scientific” in the sense that they will abandon any problem that appears to be soluble. I believe that these men are now in appropriate positions in the organization. For the most part the men actually responsible for the prosecution of the work have proven records of carrying developments through the scientific and into the engineering stage. For the most part these men regard their work here not as a scientific adventure, but as a responsible mission which will have failed if it is let drop at the laboratory phase. I therefore do not expect to have to take heroic measures to insure something which I know to be the common desire of the overwhelming majority of our personnel.
It was hardly surprising that tempers ran high in the implosion divisions. The scientists at Los Alamos were working with explosives; and pressed for time and good alternatives, they often took enormous chances. “There was no time to build barricades, so we just worked,” recalled Kistiakowsky. They made up new rules regarding safety as they went along, but manufacturing high-explosive castings was tough and dangerous work. At Los Alamos, they handled explosives by the ton, never forgetting that only one gram going off at the wrong time would “finish off the whole hand.” One of Kistiakowsky’s main concerns about the S-Site was that explosives had to be trucked all the way across the mesa, and right through the heart of the project. “With the whole theoretical division sitting in offices on one side of the road, Oppenheimer’s office (and mine) on the other, and with hundreds of wild WACs and GIs driving trucks and jeeps there,” he explained, “a truck loaded with five tons of high explosive (H.E.) going off there would have wiped out 90 percent of the brains in those temporary buildings.” During the peak period of production, they were trucking up to five tons of high explosives up the Hill monthly over some of the worst roads he had ever seen.
Phil Morrison, one of Oppenheimer’s Berkeley grads who had been working for Fermi in Chicago as a neutron engineer, was recruited to help with the difficult implosion work and assigned to the G Division. “We were working with critical assemblies, and it was clearly very dangerous work,” said Morrison. “It was better than the front line, but not by much. I was very aware of the risks, but very motivated by the war … the urgency of the war. We believed the Germans could be ahead. We believed Heisenberg could do this, and that they had plenty of good people on their side.”
Oppenheimer’s driving desire to make headway on the implosion bomb spurred everyone on, and differences were put aside in the name of progress. He never spared himself in work, and as a consequence inspired an equally dedicated effort from his staff. He faced tremendous pressure from above. Groves insisted that two bombs were essential for victory in the war. From a strategic point of view, Groves believed they could not risk dropping one with no backup in reserve. General George Marshall thought that figure might be closer to nine. Forced to scratch the Thin Man, Groves presented a revised timetable for weapons delivery to Marshall on August 7, 1944, two months after the Normandy invasion. He promised the delivery of a small uranium gun bomb—nicknamed “Little Boy,” Thin Man’s lighter, smaller brother—by August 1945, with the addition of one or two more by the end of the year. If the experimental work went smoothly, small implosion bombs would be ready by the second quarter of 1945. There was no longer any escaping the fact that they were building instruments of war that would soon be used against another country. While the scientists had all been focused on Germany, Groves made it clear that if Hitler surrendered before the bombs were ready, Japan would become the target. As if underlining his own resolve, Oppenheimer wrote Groves, “The laboratory is operating under a directive to produce weapons; this directive has been and will be rigorously adhered to.”