by American Prometheus: The Triumph;Tragedy of J. Robert Oppenheimer
They began their deliberations by studying a previous man-made explosion: the detonation in 1917 of a fully loaded ammunition ship in Halifax, Nova Scotia. In this tragic accident, an estimated 5,000 tons of TNT had decimated 2½ square miles of downtown Halifax and killed 4,000 people. They quickly estimated that any fission weapon might easily explode with a force two to three times that of the Halifax explosion.
Oppenheimer then directed his colleagues’ attention to the development of the basic design of a fission device that could be small enough to be militarily deliverable. They quickly determined that a chain reaction could probably be achieved with a uranium core placed inside a metal sphere only eight inches in diameter. Other design specifications required extremely precise calculations. “We were forever inventing new tricks,” Bethe recalled, “finding ways to calculate, and rejecting most of the tricks on the basis of the calculations. Now I could see at firsthand the tremendous intellectual power of Oppenheimer who was the unquestioned leader of our group. . . . The intellectual experience was unforgettable.”
While Oppenheimer soon concluded that there were no major theoretical gaps to fill in designing a fast-neutron reaction device, the seminar’s calculations on the actual amount of fissionable material needed were necessarily vague. They simply lacked hard experimental data. But what they did know suggested that the amount of fissionable material necessary for a weapon might easily be twice the estimated amount indicated to the president just four months earlier. The discrepancy implied that the fissionable materials could not be refined in small amounts in a mere laboratory but would have to be manufactured in a large industrial plant. The bomb would be very expensive.
At times, Robert despaired of being able to solve so many imponderables. He so feared that they were already in a losing race against the Germans that he impatiently dismissed any research efforts that seemed too time-consuming. When one scientist proposed a laborious scheme for measuring fast-neutron scattering, Oppenheimer argued that “we would do better to have a rapid and qualitative survey of scattering. . . . Landenburg’s method [is] so tedious and uncertain that we may well have lost the war before he has found an answer.”
In July, their deliberations were temporarily sidetracked when Edward Teller informed the group of calculations he had completed on the feasibility of a hydrogen or “super” bomb. Teller had come to Berkeley that summer convinced that a fission bomb was a sure thing. But bored with discussions of a mere fission weapon, he had entertained himself with calculations on another problem, suggested to him by Enrico Fermi over lunch a year earlier. Fermi had observed that a fission weapon might be used to ignite a quantity of deuterium—a heavy form of hydrogen—thus producing a far more powerful fusion explosion, a super bomb. Teller stunned Oppenheimer’s group in July with calculations suggesting that a mere twenty-six pounds of liquid heavy hydrogen, ignited by a fission weapon, could produce an explosion equivalent to one million tons of TNT. Magnitudes of this scale raised the possibility, Teller suggested, that even a fission bomb might inadvertently ignite the earth’s atmosphere, seventy-eight percent of which was made of nitrogen. “I didn’t believe it from the first minute,” Bethe said later. But Oppenheimer thought it advisable to hop a train East and personally report to Compton on both the super bomb and Teller’s apocalyptic calculations. He tracked Compton down at his summer cottage on a lake in northern Michigan.
“I’ll never forget that morning,” Compton later wrote in a tone of high drama. “I drove Oppenheimer from the railroad station down to the beach looking out over the peaceful lake. There I listened to his story. . . . Was there really any chance that an atomic bomb would trigger the explosion of the nitrogen in the atmosphere or the hydrogen in the ocean? . . . Better to accept the slavery of the Nazis than to run a chance of drawing the final curtain on mankind.”
In the event, Bethe soon ran further calculations that convinced both Teller and Oppenheimer of the near-zero possibility of igniting the atmosphere. Oppenheimer spent the rest of the summer writing up the group’s summary report. In late August 1942, Conant sat reading it and scribbled notes to himself headed “Status of the Bomb.” According to Oppenheimer and his colleagues, an atomic device would explode with “150 times energy of previous calculation”—but it would need a critical mass of fissionable material six times the previous estimate. An atomic bomb was entirely feasible, but it would require the marshaling of massive technical, scientific and industrial resources.
One evening before the summer seminar ended, Oppenheimer invited the Tellers to dinner at his home on Eagle Hill. Teller vividly recalled Oppenheimer saying with absolute conviction that “only an atomic bomb could dislodge Hitler from Europe.”
By September 1942, Oppenheimer’s name was being floated within the bureaucracy as the obvious candidate to direct a secret weapons lab that would be dedicated to the development of an atomic bomb. Bush and Conant certainly thought Oppenheimer was the right man for the job; everything he had done over the summer had borne out their confidence. But there was a problem: The Army was still refusing to issue him a security clearance.
Oppenheimer himself was aware that one of his problems was his many communist friends. “I’m cutting off every communist connection,” he said in a phone conversation with Compton, “for if I don’t, the government will find it difficult to use me. I don’t want to let anything interfere with my usefulness to the nation.” Nevertheless, in August 1942, Compton was informed that the War Department had “turned thumbs down on O.” His security file contained numerous reports of his allegedly “questionable” and “Communistic” associations. Oppie himself had filled out a security questionnaire in early 1942, listing the many organizations he had joined, including some considered by the FBI to be communist front groups.
Despite all this, Conant and Bush began pushing the War Department to approve clearances for Oppenheimer and other scientists with left-wing backgrounds. In September, they took him with them to Bohemian Grove. In this beautiful setting, amid giant redwood trees, Oppenheimer attended his first meeting of the highly secret S-1 Committee. In early October, Bush told Secretary of War Stimson’s executive assistant, Harvey Bundy, that even though Oppenheimer was “decidedly left-wing politically,” he had “contributed substantially” to the project and ought to be cleared for further work.
By then, Bush and Conant had taken steps to bring the military into the project. Bush took his case to Gen. Brehon B. Somervell, the senior officer in charge of Army logistics. Somervell, already familiar with the S-1 project, informed Bush that he already had a man picked to supervise S-1 and lend it new urgency. On September 17, 1942, Somervell met with a forty-six-year-old career Army officer, Col. Leslie R. Groves, in the corridor outside a congressional hearing room. Groves had been the Army Corps of Engineers’ key man on the construction of the newly completed Pentagon. Now he wanted an overseas combat assignment. But Somervell told him to forget it: He was staying in Washington.
“I don’t want to stay in Washington,” Groves said evenly.
“If you do the job right,” Somervell replied, “it will win the war.”
“Oh, that thing,” said Groves, who was familiar with S-1. He was not impressed. He was already dispensing far more money on Army construction projects than S-1’s expected $100 million budget. But Somervell had made up his mind and Groves had to accept his fate, which included a promotion to the rank of general.
Leslie Groves was used to getting others to do his bidding, a talent he shared with Oppenheimer. Otherwise, the two men were opposites. Nearly six feet tall and weighing over 250 pounds, Groves had muscled his way through life. Gruff and plainspoken, he had no time for the subtleties of diplomacy. “Oh yes,” Oppenheimer once remarked, “Groves is a bastard, but he’s a straightforward one!” By temperament and training, he was an authoritarian. Politically, he was a conservative who barely concealed his contempt for the New Deal.
The son of a Presbyterian army chaplain, Groves had stu
died engineering at the University of Washington in Seattle and later at the Massachusetts Institute of Technology. He graduated fourth in his class at West Point. Men serving under him grudgingly admired his ability to get things done. “General Groves is the biggest S.O.B. I have ever worked for,” wrote Col. Kenneth D. Nichols, his aide throughout the war. “He is most demanding. He is most critical. He is always a driver, never a praiser. He is abrasive and sarcastic. He disregards all normal organizational channels. He is extremely intelligent. He has the guts to make timely, difficult decisions. He is the most egotistical man I know. . . . I hated his guts and so did everybody else, but we had our form of understanding.”
On September 18, 1942, Groves formally took charge of the bomb project—officially designated the Manhattan Engineer District, but most often referred to as the Manhattan Project. That very day, he arranged to buy 1,200 tons of high-grade uranium ore. The next day, he ordered the acquisition of a site in Oak Ridge, Tennessee, where the uranium could be processed. Later that month, he began a tour across the country of all the laboratories engaged in experimental work on uranium isotope separation. On October 8, 1942, he met Oppenheimer at a Berkeley luncheon hosted by the president of the university. Soon afterwards, Robert Serber saw Groves walk into Oppenheimer’s office, accompanied by Colonel Nichols. Groves took off his Army jacket and handed it to Nichols, saying, “Take this and find a dry cleaner and get it cleaned.” Serber was astounded by this treatment of a colonel as a mere errand boy: “That was Groves’ way.”
Oppenheimer understood that Groves guarded the entrance to the Manhattan Project, and he therefore turned on all his charm and brilliance. It was an irresistible performance, yet Groves was most struck by Oppie’s “overweening ambition,” a quality he thought would make him a reliable and perhaps even pliable partner. He was also intrigued by Robert’s suggestion that the new lab should be located in some isolated rural site rather than in a large city—a notion that fit nicely with Groves’ concerns for security. But more than anything else, he just liked the man. “He’s a genius,” Groves later told a reporter. “A real genius. While Lawrence is very bright, he’s not a genius, just a good hard worker. Why, Oppenheimer knows about everything. He can talk to you about anything you bring up. Well, not exactly. I guess there are a few things he doesn’t know about. He doesn’t know anything about sports.”
Oppenheimer was the first scientist Groves had met on his tour who grasped that building an atomic bomb required finding practical solutions to a variety of cross-disciplinary problems. Oppenheimer pointed out that the various groups working on fast-neutron fission at Princeton, Chicago and Berkeley were sometimes just duplicating each other’s work. These scientists needed to collaborate in a central location. This, too, appealed to the engineer in Groves, who found himself nodding in agreement when Oppenheimer pitched the notion of a central laboratory devoted to this purpose, where, as he later testified, “we could begin to come to grips with chemical, metallurgical, engineering, and ordnance problems that had so far received no consideration.”
A week after their first meeting, Groves had Oppenheimer flown to Chicago, where he could join him on the Twentieth Century Limited, a luxury passenger train bound for New York. They continued their discussions aboard the train. By then, Groves already had Oppenheimer in mind as a candidate for the directorship of the proposed central laboratory. He perceived three drawbacks to Oppenheimer’s selection. First, the physicist lacked a Nobel Prize, and Groves thought that fact might make it difficult for him to direct the activities of so many of his colleagues who had won that prestigious award. Second, he had no administrative experience. And third, “[his political] background included much that was not to our liking by any means.”
“It was not obvious that Oppenheimer would be director,” Hans Bethe noted. “He had, after all, no experience in directing a large group of people.” No one to whom Groves broached the idea showed any enthusiasm for Oppenheimer’s appointment. “I had no support, only opposition,” Groves later wrote, “from those who were the scientific leaders of that era.” For one thing, Oppenheimer was a theorist, and building an atomic bomb at this point required the talents of an experimentalist and engineer. As much as he admired Oppie, Ernest Lawrence, among others, was astonished that Groves had selected him. Another great friend and admirer, I. I. Rabi, simply thought him a most unlikely choice: “He was a very impractical fellow. He walked about with scuffed shoes and a funny hat, and more important, he didn’t know anything about equipment.” One Berkeley scientist remarked, “He couldn’t run a hamburger stand.”
When Groves proposed Oppenheimer’s name to the Military Policy Committee, there was, again, considerable opposition. “After much discussion I asked each member to give me the name of a man who would be a better choice. In a few weeks it became clear that we were not going to find a better man.” By the end of October, the job was Oppenheimer’s. Rabi, who didn’t like Groves, grudgingly observed, after the war, that the appointment “was a real stroke of genius on the part of General Groves, who was not generally considered to be a genius. . . . I was astonished.”
IMMEDIATELY AFTER his appointment, Oppenheimer began to explain his new mission to a few key figures in the scientific community. On October 19, 1942, he wrote Bethe: “It is about time that I wrote to you and explained some of my wires and actions. I came east this time to get our future straight. It is turning out to be a very big order and I am not at liberty to tell all that is going on. We are going to have a laboratory for the military applications, probably in a remote spot and ready for use, I hope, within the next few months. The essential problems have to do with taking reasonable precautions about secrecy and nevertheless making the situation effective, flexible, and attractive enough so that we can get the job done.”
By the autumn of 1942, it was more or less an open secret around Berkeley that Oppenheimer and his students were exploring the feasibility of a powerful new weapon associated with the atom. He had sometimes talked about his work, even to casual acquaintances. John McTernan, an attorney for the National Labor Relations Board, and a friend of Jean Tatlock’s, ran into Oppenheimer one evening at a party and vividly recalled the encounter: “He talked very fast, trying to explain his work on this explosive device. I didn’t understand a word he was saying. . . . And then, the next time I saw him he made it clear that he was no longer free to talk about it.” Almost anyone who had friends in the physics department might have heard speculation about such work. David Bohm thought that “many people all around knew what was going on at Berkeley. . . . It didn’t take much to piece it together.”
A young graduate student in the psychology department, Betty Goldstein, arrived on campus fresh from Smith in the autumn of 1942 and befriended several of Oppenheimer’s graduate students. The future Betty Friedan began dating David Bohm, who was writing his doctoral dissertation in physics under Oppie’s supervision. Bohm—who decades later became a world-famous physicist and philosopher of science—fell in love with Betty, and introduced her to his friends, Rossi Lomanitz, Joe Weinberg and Max Friedman. They all socialized on weekends and sometimes saw each other in what Friedan characterized as “various radical study groups.”
“They were all working on some mysterious project they couldn’t talk about,” Friedan recalled, “because it had something to do with the war.” By the end of 1942, when Oppenheimer began recruiting some of his students, it was pretty clear to everyone that a very big weapon was going to be built. “Many of us thought,” said Lomanitz, “ ‘My God, what kind of a situation it’s going to be to bring a weapon like that [into the world]; it might end up by blowing up the world.’ Some of us brought this up to Oppenheimer; and basically his answer was, ‘Look, what if the Nazis get it first?’ ”
STEVE NELSON—whose job it was to serve as the Communist Party’s liaison to the Berkeley university community—had also heard the rumors about a new weapon. Some of these rumors were actually published when local newspape
rs quoted a congressman boasting about the weapons research being conducted at Berkeley. Rossi Lomanitz heard Nelson say in a public speech: “I’ve heard some of these congressmen talk about how there’s some big weapon being developed here. I’ll tell you, people’s wars aren’t being won by big weapons.” And then Nelson went on to argue that this war would be won when a second front was opened up in Europe. The Soviets were fighting four-fifths of the Nazi armies and desperately needed relief. “It’s going to take the American people making that sacrifice—that’s how this war is going to be won.”
Lomanitz had met Nelson at various public meetings of the Communist Party and, he said, “respected him a great deal.” He regarded Nelson as a hero of the Spanish Republic, a veteran labor organizer and a courageous critic of racial segregation. By his own account, Lomanitz, while strongly sympathetic to the Party in many ways, never formally became a member. “I attended some Communist Party meetings,” he said, “because at that time meetings were much more open. There wasn’t any great distinction. . . . Who was officially a member or what it took to be officially a member, I can’t tell you to this day. It just wasn’t all that conspiratorial.”
In his memoirs, Nelson described his relationship to Oppenheimer’s students like Lomanitz, Weinberg and others: “I was responsible for working with people from the university, getting them to conduct classes and discussions. A number of Oppenheimer’s graduate students in the field of physics were quite active. Our contacts were more on their terms than ours. They lived in a more rarefied intellectual and cultural atmosphere, although they were friendly and not at all pretentious.”
BY THE EARLY SPRING of 1943, the FBI had installed a microphone in Nelson’s home. In the early morning hours of March 30, 1943, Bureau agents overheard a man they could identify only as “Joe” talking about his work at the Radiation Lab. “Joe” had arrived at Nelson’s home at 1:30 a.m. and was obviously anxious to speak with him. The two men talked in whispers. Nelson began by saying that he was looking for a “comrade who was absolutely trustworthy.” “Joe” insisted that he was that man. “Joe” then explained that “certain portions of the project were to be moved to some remote section of the country, hundreds of miles away,” where highly secret experimental explosions could be carried out.
