Szilard was convinced that a bomb was possible and, given Hitler’s goal of conquering the world, even probable. In early July he persuaded Albert Einstein to put his name to a letter alerting the president of the United States to the threat. That was the genesis of what would become one of the seminal documents of the atomic age, Albert Einstein’s message to Franklin Roosevelt, dated August 2, 1939. Drafted mostly by Szilard with Einstein’s input, the two-page, eight-paragraph document buries the urgency of the situation under dry and conditional prose, its momentousness communicated largely by Einstein’s signature at the bottom. “Some recent work by E. Fermi and L. Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future,” it read. “Certain aspects of the situation which has arisen seem to call for watchfulness and, if necessary, quick action on the part of the Administration.”
The letter mentioned the possibility of “extremely powerful bombs of a new type.” It closed with the ominous observation that German scientists might have already started working on such a project.
The missive was duly placed in the hands of Alexander Sachs, a Russian-born economist with a scientific background and, more to the point, access to the White House inner circle as an advisor to FDR. Sachs finally gained entrance to the Oval Office on October 11, a few weeks after the Nazi invasion of Poland had instigated the European war. After a brief exchange of jocular anecdotes and the pouring of two glasses of Napoleon brandy, Sachs read FDR a digest of Einstein’s letter that he had prepared himself, in the hopes of reducing its abstruse science and circumlocutions into language the president would grasp quickly.
He chose his words well. “Alex,” Roosevelt said, “what you are after is to see that the Nazis don’t blow us up.”
“Precisely,” Sachs replied.
Roosevelt summoned his military aide, General Edwin M. “Pa” Watson. Handing over Sachs’s documents, he said forcibly, “This requires action.”
• • •
Even the fretful Szilard could not have been unhappy with the pace of action that followed. Before Sachs left the White House that day, Watson was already jotting down names for a committee to investigate the military applications of fission. No scientific bureaucracy existed in the government to assume the task, so Watson created one on the fly. It would be led by Lyman J. Briggs, a career government scientist then directing the National Bureau of Standards, which by default served as the government’s physics laboratory. Lieutenant Colonel Keith Adamson and Commander Gilbert C. Hoover, two members of Watson’s staff, were its other members. On October 21 Briggs presided over the so-called Uranium Committee’s first meeting, with Szilard, Teller, and Eugene Wigner, another émigré Hungarian physicist, on hand as technical advisors. It was a lightning-fast schedule for government work.
But fault lines between the officers and the scientists opened up immediately, as the talk turned to how much money the scientists considered necessary for their research. When Teller said that Fermi would need tens of thousands of dollars to build a preliminary reactor to test conditions for a chain reaction, Adamson responded scornfully. At the army’s Aberdeen Proving Grounds, he sneered, “we have a goat tethered to a stick with a ten-foot rope, and we have promised a big prize to anyone who can kill the goat with a death ray. Nobody has claimed the prize yet.” He informed the scientists crisply that men and morale, not fancy weaponry, were what won wars, and continued in that vein until he was interrupted by Wigner, a slight, red-haired man whose diffident personality concealed a razor-sharp mind. “It’s very interesting for me to hear this,” he said politely. If it is correct, he suggested, perhaps the army’s budget for armaments ought to be cut stringently. Taken aback, Adamson snapped, “All right, you’ll get your money.” The committee voted to send Fermi an initial grant of $6,000.
After that, however, the Uranium Committee’s work ground to a halt. Szilard and Wigner, who had left the initial meeting confident that the urgency of research was understood at the highest levels of government, now came face-to-face with the natural sluggishness of the bureaucratic process. The experience was like “swimming in syrup,” Wigner would recall. Szilard was mystified. “I had assumed that once we had demonstrated that in the fission of uranium neutrons are emitted, there would be no difficulty in getting people interested, but I was wrong.”
Szilard and Wigner were not the only physicists feeling frustrated. So too was Ernest Lawrence.
• • •
The war had thrust itself upon Lawrence’s consciousness in an especially personal way. His brother, John, who had sailed for Britain a month before the Nazi invasion of Poland, was scheduled to return home at the beginning of September from a nation at war, on an ocean crossing that now seemed immeasurably perilous. Carl and Gunda wired Ernest anxiously from South Dakota for word of John’s plans; Ernest wired back the soothing news that John was to sail from Liverpool on the liner Athenia—a British ship, but an unarmed passenger vessel immune from attack according to the Hague conventions governing the conduct of war.
No sooner had Ernest’s wire been dispatched than horrifying news arrived: the Athenia had been sunk by a German U-boat torpedo, in the war’s first attack on British shipping. During the next two nights, the family received only sporadic, contradictory reports about the disaster: some said all hands had been lost; others, that hundreds of passengers had been saved. Ernest spent the hours pacing by the radio, silent and withdrawn among friends and colleagues from the lab. Unnerved by the sensation of utter powerlessness, he only summoned his reserves of sunny optimism to field phone calls from his parents. At last, a miraculous cable arrived from John, pronouncing himself “safe and sound” aboard a British destroyer. His story turned out to be one of outstanding heroism: having remained aboard the foundering Athenia to minister to injured passengers and crew, he was the very last passenger to board a lifeboat.
The experience instantly altered Ernest’s attitude toward politics in the lab. It was no longer possible to view conditions even in distant Europe as irrelevant to the work going on in Berkeley. Physicists visiting the Rad Lab now found themselves being drawn by Ernest into discussions of the military applications of the latest research rather than the progress of the sixty-inch and the achievements of the cyclotron team. Arthur Compton, arriving in Berkeley to report for the National Advisory Cancer Council on the nuclear medicine program funded by its $30,000 grant, was sidetracked into what Lawrence described for Alfred Loomis as a discussion “regarding the war situation.” He added that Compton, “like all of us, is very anxious that we scientists do everything we can in the direction of preparedness, and we discussed ways and means.” Among the topics they had discussed was how to use the new cyclotron in the war effort, he told Loomis. “We certainly will not be unmindful of the possibilities of discoveries of military value in the energy range above one hundred million volts.”
As Lawrence became more interested in the military applications of nuclear research, he grew more dismayed at the lack of progress under the dead hand of the Uranium Committee. Briggs had taken Szilard’s concerns about publicity to heart but applied them in a peculiarly counterproductive way. He instituted a regime of “compartmentalization” in which physicists working on one aspect of fission were denied access to research on different aspects, even if they might be relevant to their own. The bottleneck frustrated scientists up and down the line: Merle Tuve, who had the training, equipment, and willingness to advance the field, complained that he was “hard pressed to get any data on uranium fission,” including such fundamental information as nuclear cross sections. Even Harold Urey, who was a member of the Briggs committee, had no luck obtaining access to other scientists’ work to help him develop an isotope separation process for uranium.
To be fair to Briggs, his office was not the only place developing an obsession with secrecy. In June 1940 Ed McMillan and Philip Abelson of the Rad Lab
published an account in the Physical Review of their discovery of element 93, a radioactive daughter of uranium. (The element subsequently would be named neptunium.) After the article’s appearance, Lawrence received a scolding from none other than James Chadwick, via an envoy dispatched from the British Embassy in Washington, for allowing the publication of research that could aid the Nazi regime. The Physical Review soon acceded to a system by which it would accept articles on nuclear reactions but keep them in a vault, to be published after the conclusion of the war.
But there was a difference between suppressing the publication of research findings and restricting the personal give-and-take among scientists that was indispensable for scientific progress. European scientists were sharing more among themselves than were the Americans, albeit through personal contacts, not in the pages of widely published journals. As a result, they were making startling discoveries that only underscored the constraints faced by their American colleagues.
One such pioneer was Otto Frisch, a nephew of Lise Meitner, the gifted Austrian physicist whose work with Otto Hahn had led to the discovery of fission, for which she then proposed a theoretical foundation from her political exile in Sweden. (History judges her to have been unfairly excluded from the Nobel Prize for the discovery, which went to Hahn alone in 1944.) Frisch, who had assisted his aunt with her experiments, had been evicted from the University of Hamburg under the Nazi racial laws, which barred Jews from high academic positions beginning in 1936. Mark Oliphant came to his rescue by inviting him to move to the University of Birmingham. “Just come over,” Oliphant told him. “We’ll find you something to do.”
As a German national, Frisch was barred from Oliphant’s main research project, a secret effort to develop radar. Instead, he probed the explosive characteristics of U-235 and soon realized that a bomb could be made from roughly a pound of the separated isotope. “That set me thinking,” he recalled later. “I felt one pound is, after all, not such a lot.”
Frisch and his fellow refugee Rudolf Peierls, who also was becalmed at Birmingham, calculated how much equipment would be needed to acquire a pound of 235 by thermal diffusion, which employs temperature differentials to separate the 235 and 238 isotopes by weight. (The heavier isotope gravitates toward cooler temperatures, the lighter U-235 toward heat.) Their figure of £1 million was forwarded to Henry Thomas Tizard, the Oxford University chemistry don spearheading his country’s scientific effort in the war. Tizard’s formation of a committee to study the theory under the leadership of G. P. Thomson, son of the legendary J. J. Thomson, marked the start of organized atom bomb research in Britain.
Filled out with Oliphant, Chadwick, and Cockcroft as members, the group met for the first time in April 1940 as the MAUD Committee. (Although the initials appear to be an acronym, the name actually came from a cable to Cockcroft from Meitner asking him to send a message from Niels Bohr to “Maud Ray Kent”; Cockcroft had interpreted the words as an anagram for “radium taken,” which suggested that the Nazis were acquiring radioactive substances for fission experiments. In fact, they referred to Maud Ray, a former governess to Bohr’s children, who lived in the county of Kent.)
The MAUD Committee was Britain’s counterpart to Briggs’s panel, but any resemblance was entirely superficial. The MAUD members were all accomplished nuclear scientists. They were “electrified” by the conclusions of Frisch and Peierls that the critical mass of U-235 might be only a pound and that a chain reaction could build up rapidly to explosive force, Oliphant reported later. It would take the MAUD Committee fifteen months to determine decisively that a bomb was practical and to outline the necessary steps. By the time it had done so, the American effort had been laboring for nearly two years without reaching a conclusion.
The Briggs committee’s stranglehold on American fission research showed signs of loosening, if slightly, only in June 1940, two months after the MAUD Committee was formed. That was when Vannevar Bush emerged from a meeting at the White House with the treasured initials “OK-FDR” scrawled on a single sheet of paper. The document’s four short paragraphs outlined Bush’s proposal to establish a National Defense Research Committee to coordinate all technical research with military applications under his chairmanship. The meeting with President Roosevelt had taken ten minutes. After that, Bush would recall, “All wheels began to turn.”
Bush wrote later that many in Washington regarded the establishment of the NDRC as “an end run, a grab by which a small company of scientists and engineers, acting outside established channels, got hold of the authority and money for the program of developing new weapons.” To this he had a simple answer: “That, in fact, is exactly what it was . . . The only way in which a broad program could be launched rapidly and on an adequate scale.”
Bush’s appointment as the nation’s science czar would soon give Ernest Lawrence entrée to the highest councils of government. But Bush’s first act on nuclear weapons development was not especially encouraging: he slashed Lyman Briggs’s request for additional funding for Fermi’s atomic-pile research to $40,000 from $140,000; his reasoning was that no evidence existed yet that the pile was practical or that it could lead to a weapon. For Fermi, this was a disappointment, and for Szilard, an all-too-familiar setback. The Briggs committee had finally seemed willing to press ahead, but now it was the NDRC holding back.
Lawrence would soon jolt it in the right direction. Bush had asked Ernest to take on a roving brief for the committee, injecting himself into any area encountering problems as “a sort of fire department.” This underscored Bush’s esteem for the breadth of Lawrence’s scientific knowledge and his emollient managerial technique. To Lawrence, however, the assignment seemed both inchoate and potentially overwhelming. Tactfully, he turned it down. That turned out to be fortunate, because it left him free to take on a new project that soon landed on the NDRC’s plate.
The project was an outgrowth of the secret research Oliphant had been conducting at Birmingham. It involved an invention known as the cavity magnetron, a source of high-powered microwaves. The British had sent Cockcroft to the United States to solicit engineering help to turn the magnetron into a serviceable radar apparatus. Alfred Loomis was brought into the talks; after hosting the British delegation for a week at Tower House, he pressed Bush to make radar a priority of the NDRC. This led to the formation of a microwave committee with Loomis as chairman and Lawrence as a member, and in turn to the NDRC’s subsequent decision to establish a crash program at MIT. Lawrence agreed to recruit the new lab’s staff.
His first call was to Lee DuBridge, a Caltech-trained physicist who had first met Lawrence in 1934 at one of the “vaudeville” demonstrations of radio-sodium. DuBridge went on to build a cyclotron at the University of Rochester, which brought the two physicists closer. Reaching DuBridge by phone in early October, Lawrence informed him curtly that he was needed to lead an important defense initiative. “I can’t tell you about it, but I assure you it’s very important,” he said. Bush could not fail to be impressed by DuBridge’s instantaneous assent and what it indicated about Lawrence’s standing in the scientific community. “If Lawrence was interested in the program,” DuBridge explained later, “that was what I wanted to be in.” He boarded a train for New York that same evening.
Lawrence’s role did not end there. He and DuBridge worked together to fill out the personnel roster of the project, which was code-named the “Rad Lab” in the perhaps naïve assumption that the name might confuse the enemy into thinking it was merely a spinoff of Lawrence’s lab in Berkeley. They started with physicists they knew personally: “We just got our good cyclotron friends together,” DuBridge would recall. Lawrence did not spare his own staff: among the first scientists he summoned to MIT were Edwin McMillan, who was then deeply involved in the search for element 93, and Luis Alvarez. Both accepted the call out of a combination of fidelity to Lawrence and duty to country—the latter communicated to them also by Lawrence, who emphasized that their work would be crucial to the war ef
fort.
“It was essentially an order, although he didn’t phrase it that way,” McMillan recalled. “He told Alvarez and me . . . that this great project was starting and that we must get into it, that Hitler has to be stopped.” McMillan thought wistfully of his orphaned research into the transuranics—those elements heavier than uranium, such as element 93—but reckoned that “it would have been very bad grace for us to have said, ‘Well, we’ve got other things to do.’ ” Ernest tried to soften the blow by assuring McMillan that he would be needed for only a few months, but McMillan doubted him. “I had the strong feeling that I was going to be away a long time. And I was right.” Many of the scientists Lawrence and Loomis assembled at the MIT Rad Lab would eventually move on to the team that was to build the bomb.
Having proved his worth by organizing the MIT Rad Lab from scratch, Lawrence thought himself well positioned to press his concerns with the NDRC brass about the slothful pace of the Briggs committee. He was about to learn the hard way about the perils of pressing too hard.
He started his campaign auspiciously enough with an overture to James Conant, who visited Berkeley in May to deliver the keynote address at Charter Day, the university’s annual founding celebration. The time had come to “light a fire under the Briggs committee,” Lawrence urged Conant. “What if German scientists succeed in making a nuclear bomb before we even investigate possibilities?” He blamed Briggs for placing the NDRC in doubt about the potential of uranium research in war. At a further meeting with Loomis and Arthur Compton at MIT on March 17, Lawrence startled them with the news that he was prepared to manufacture U-235 on his own by converting the 37-inch cyclotron—rendered obsolete by the completion of the 60-inch and the planning for the 184-inch—into a mass spectrograph to separate uranium isotopes electromagnetically.
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