Brotherhood of the Bomb

by Gregg Herken

  The 60-inch was still under construction in January 1939 when word came of the discovery of nuclear fission in Germany. This time Lawrence and his colleagues learned of the development from the newspapers rather than academic journals. Once again for the boys, surprise and elation rapidly gave way to the frustrating realization that another major find had narrowly escaped them.

  On Telegraph Avenue, Luis Alvarez leaped from a barber’s chair and ran to the lab upon seeing the headline in the San Francisco Chronicle. A graduate student of his, Philip Abelson, had been puzzled for weeks by x-rays emanating from uranium following neutron bombardment. (“I have something terribly important to tell you,” Alvarez told Abelson. When the student proceeded to sit down, Luie suggested that Abelson lie down instead.) It was immediately clear to both men that fission was the solution to the mystery.92

  Within hours of receiving the news, Oppenheimer had given a seminar on atom-splitting at LeConte, and McMillan had fashioned a simple but elegant experiment to demonstrate the phenomenon.93 Chemist Glenn Seaborg, a Berkeley graduate whom Lawrence had recruited to help with the radioisotope work, walked the streets of the city that evening, incredulous that he and his colleagues had failed to see what was right before their eyes.

  But the disappointment that Lawrence felt was soon overcome by the dawning realization of fission’s possibilities. “This uranium business is certainly exciting,” he wrote Fermi that winter.94 Ernest had been thinking about building a new and more powerful accelerator since the previous year.95 This latest discovery gave that project new impetus.

  There was, moreover, a certain cold logic behind Lawrence’s warm enthusiasm this time. The Germans at Berlin’s Kaiser Wilhelm Institute had split the uranium atom using neutrons from a natural radiation source, a small lump of radium. Ernest reasoned that the cyclotron—a much more powerful source of directed radiation, able to penetrate to the atom’s very core—would yield proportionately more interesting results. As he had observed in his riposte to Rutherford, atom-smashing was just a matter of marksmanship.

  The goal this time would be 100 million electron volts, the threshold of energy believed to hold atomic nuclei together. For the boys, Lawrence’s new machine held out not only the promise of exciting discoveries in science but something more personal: a chance at redemption.

  That spring, during a nationally broadcast radio lecture, Lawrence spoke for the first time publicly of his plans for a gargantuan super-cyclotron. Fully two months before the 60-inch began operating at the brand-new Crocker Laboratory—its pencil-thin blue beam of light reminding the assembled journalists of a science-fiction death ray—Ernest had already moved well beyond the medical cyclotron in his mind.

  Lawrence calculated that the next machine would require a 2,000-ton magnet. Artist’s drawings commissioned for a lecture tour showed a beam 140 feet long, compared to the 60-inch’s 4-foot beam. There was, as yet, no structure on the Berkeley campus big enough to house the mammoth machine, nor any charitable foundation willing to bear its projected million-dollar cost.

  But Ernest’s hope was that his new machine might yield answers to some of the fundamental questions that the experiment in Germany had raised. Among them, whether other elements could be made to fission, and whether the number and energy of neutrons released by splitting uranium atoms would be sufficient to sustain a chain reaction. On the resolution of that last question, physicists realized, lay the answer to whether atomic energy could be used to propel ships and power industry—or to build a bomb.96

  True to type, Lawrence chose to focus on the brighter prospect. “We are trying to find out whether neutrons are generally given off in the splitting of uranium; and, if so, prospects for useful nuclear energy become very real!” he enthused in a February 1940 letter to scientists at the Cavendish. Although it went unmentioned, between the lines was Ernest’s hope that the vindication of his long-deferred dream at Solvay might be at hand. “It may be that the day of useful nuclear energy is not so far distant after all,” he mused.97

  By contrast, Oppenheimer remained wary and pessimistic. Writing to friends at the University of Michigan, he professed to find uranium and fission more worrisome than exciting, and the potential consequences ominous indeed: “So I think it really not too improbable that a ten [centimeter] cube of uranium deuteride … might very well blow itself to hell.”98

  2

  A PRACTICAL PHILOSOPHER’S STONE

  LAWRENCE’S OPTIMISM EXTENDED to politics. “I still think war is going to be avoided. All this discussion certainly must mean that Hitler is backing down,” he wrote to his parents on August 29, 1939, three days before the Germans invaded Poland, sparking the Second World War.1

  A few weeks earlier, other physicists—European born and hence preternaturally more inclined toward pessimism—had sent a warning letter to President Franklin Roosevelt that proved far closer to the mark.

  Leo Szilard was a Hungarian theorist who had fled Germany in 1933, only days before the border was closed to Jews, and found a sinecure at Columbia University. Eugene Wigner, a friend of Szilard’s from Budapest, joined Princeton’s physics faculty in 1930. Another fellow countryman and theoretician, Edward Teller, had come to the United States in 1935. A professor at George Washington University, Teller in summer 1939 was teaching at Columbia during the day and discussing fission with Szilard at night.2 Albert Einstein, the German-born physics theorist, was the oldest and by far the best known of their number.

  While their leader was Szilard—the letter was his idea—the driving force was Teller, literally.3 Since Szilard lacked an operator’s license, he relied upon Teller and the latter’s temperamental 1935 Plymouth to get him to Einstein.

  At thirty-one, Teller already had a dark and somewhat moody visage, famously prominent eyebrows, and a noticeable limp, the result of a streetcar accident years earlier in Munich, where he had lost part of his right foot. He possessed an agile, self-deprecating wit, but his easy and high-pitched laugh hid a large and surprisingly fragile ego. (Overprotected by his mother, he “reached adolescence still a serious child with no sense of humor,” Teller later wrote. He found the taunts of his schoolmates “intolerable.”) Once, in 1934, while Teller was a student at Niels Bohr’s famous physics salon in Copenhagen, he had been casually reprimanded by the master for a careless comment. The rebuke was not intended as an insult, and the moment quickly passed. But Bohr’s students were surprised to see Teller left pale and shaken by the incident.4

  Teller’s colleagues then, and later, would remark upon his restless, seemingly driven energy. (Teller himself described his personality type as neither “melancholic” nor “sanguine” but “choleric,” or quick to anger. Fermi thought Teller the only monomaniac he knew who had several manias.) This peculiar intensity was evident not only in Teller’s work but even in his piano playing: friends observed that he played all of Mozart’s pieces fortissimo.

  Late one evening in March 1939, Teller and a violin accompanist had been in the middle of a Mozart sonata at Edward’s home when they were interrupted by an urgent telephone call from Szilard. “I have found the neutrons,” Szilard announced melodramatically, in Hungarian—their secret code—before hanging up. Since Teller knew that his colleague’s most recent experiments concerned chain reactions in uranium, he had reason to suspect, with Szilard, that the world was headed for grief.5

  At the end of July, Szilard asked Teller to drive him to Einstein. Despite Edward’s car breaking down and another stop along the way to ask directions of a child, the pair finally made it to the famous physicist’s summer house on the north fork of Long Island. While Einstein served tea, Szilard persuaded the author of the relativity theory to sign the letter he had drafted, which warned FDR that since “the element uranium may be turned into a new and important source of energy in the immediate future,” … “it is conceivable … extremely powerful bombs of a new type may thus be constructed.”6

  The letter was forwarded to a contact of Szilard’
s at the White House. The Hungarians sat and waited impatiently for an answer while, in Europe, Hitler’s armies began their advance.7

  * * *

  Although the outbreak of war briefly brought work at the Rad Lab to a halt, Lawrence insisted that the march of science continue. On September 2, 1939, the day after the war began, the conflict came suddenly closer to home. Ernest received word that John, returning from a European vacation onboard the Athenia, was listed as missing after that liner was torpedoed and sunk by a German submarine. For several anxious days, Molly and Ernest sat by the radio awaiting news, until a telegram confirmed that John was among the survivors.

  Life at the Rad Lab quickly returned to routine. On only one occasion in those early days had Lawrence been heard to express an opinion on the war. (“That man must be stopped,” McMillan heard him mutter while the two listened to one of Hitler’s speeches on the radio.) Oppenheimer told friends that Lawrence’s aversion to politics stemmed from the fact that Ernest’s father had lost his job teaching German during the First World War. Like the rest of the boys, McMillan believed that Ernest did not start taking the war seriously until his brother had almost been killed.8

  Lawrence’s focus since the preceding spring had been upon raising money for what he called the “great cyclotron.” During the summer, Ernest had approached the Rockefeller Foundation with a request that $750,000 be devoted to building the machine. That fall, Lawrence appealed to Vannevar Bush—the newly installed president of Washington’s Carnegie Institution—and also promoted the giant cyclotron at the annual meeting of the National Academy of Sciences in Providence, Rhode Island.9

  A flinty New Englander who traced his seafaring ancestry to Province-town whalers, Bush was dean of the American scientific establishment and a crucial ally for Lawrence. (Trained as an electrical engineer, Bush had a pragmatic approach to life, which was revealed in his choice of hobbies. He took up archery during the war because it required neither expensive equipment nor rationed gasoline.)10 Ernest was already certain of his standing with Sproul, who had instructed the university’s comptroller to “do your best to keep [Lawrence] happy.”11

  On November 9, Lawrence wrote again to Bush, noting that his hopes of getting money from a previous benefactor, dying of cancer, had begun to look dim.12 Later that afternoon, in the midst of a game at the Berkeley Tennis Club, Lawrence learned that Sweden’s Nobel committee had voted him the 1939 prize in physics. The Nobel prize came in recognition of his invention of the cyclotron and the machine’s role in producing radioisotopes. Lawrence was the first professor at a state-funded American university to receive one.

  It took Cooksey and the boys a week to organize the celebration at DiBiasi’s, a cheap Italian restaurant in nearby Albany that was a favorite hangout for Berkeley’s cyclotroneers. The centerpiece of the party was a giant cake in the shape of a cyclotron. Since no one was yet certain what the great cyclotron would look like, the 60-inch provided the model. Inscribed on it was a boast that exceeded even Lawrence’s lofty ambitions: “Eight Billion volts or Bust!”13

  For Lawrence, the significance of the Nobel prize was evident soon enough. Confident at last that the machine would be built, he was convinced that it could also begin to grow. Just two weeks earlier, he had spoken of a 120-inch cyclotron with a 2,000-ton magnet. Responding to a congratulatory telegram from Niels Bohr in mid-November, Ernest described a machine with a magnet weighing 3,000 tons.14 The new cyclotron was still “growing progressively and has now attained the size of four thousand tons—correction four thousand five hundred—the four thousand was yesterday,” a visiting alumnus of the lab wrote in mid-December.15

  By Christmas, the giant cyclotron had swelled to 5,000 tons, with pole faces 184 inches across—the largest diameter of commercially available steel plate. (Until that barrier, Lawrence had reportedly flirted with the idea of submitting plans for a 210-inch machine to Rockefeller. His cyclotron would then outdo the 200-inch-diameter Palomar telescope, also Rockefeller funded.) The cost of the great cyclotron had likewise soared, to $1.5 million.16

  At that far shore, the supercyclotron finally came to rest. As the maximum obtainable, it had become the minimum acceptable to Lawrence.17

  Yet for all his grandiose designs, and his success in achieving them, Lawrence still had no clear idea of what his mammoth machine might actually achieve. In a memorandum to Rockefeller trustees that December, he raised the possibility that 100 million volts was the threshold at which nuclear chain reactions could be initiated: “Should this prove to be true we will have a discovery of great immediate practical importance. On the one hand, we will have a practical philosopher’s stone transmuting elements on a large scale; and, as a corollary thereto, we will have tapped, on a practical scale, a vast store of nuclear energy.”18 Thus was Lawrence’s vision at Solvay boldly resurrected.

  But another, competing view of the future lay buried among the telegrams and well-wishes of the previous month. It came from Johns Hopkins physicist R. W. Wood, whose letter showed that Wood saw further and understood even better than its own inventor the destiny of the new machine: “As you are laying the foundations for the cataclysmic explosion of uranium (if anyone accomplishes the chain reaction),” he wrote Lawrence, “I’m sure old Nobel would approve.”19

  * * *

  On the morning of March 29, 1940, the cream of the country’s scientific establishment crowded into a cramped corner office on the second floor of Berkeley’s Durant Hall to decide the fate of Lawrence’s great cyclotron. The gathering showed not only the concentration of power in the world of American science but also how small and closely knit that world really was.

  Two of the six men present were brothers. Arthur Holly Compton was a Nobel prize–winning physicist at the University of Chicago who had gotten to know Lawrence in 1923, when the latter was a graduate student. Arthur’s younger brother, Karl, also a physicist, was president of MIT. Vannevar Bush and James Conant, a chemist who was president of Harvard, would soon be made as close as brothers by the war.20 Lawrence attended long enough to sketch his plans for the big machine on the blackboard and to answer questions before discreetly withdrawing. The outcome was never really in doubt.21

  Cooksey—it was his office—stopped by long enough to take a photograph of the group laughing at a joke. A figure at the edge of the picture, partly cut out of the scene, was Alfred Loomis, the man who had summoned the great and powerful for the occasion yet remained virtually unknown outside the room.22

  Loomis was a former Wall Street financier and eccentric whose real avocation was physics, which he indulged at a well-equipped private laboratory on his Tuxedo Park estate some thirty-five miles north of New York City. The Loomis Institute for Scientific Research was located in a Tudor-style stone mansion, complete with turrets and battlements, to which the world’s eminent physicists were invited annually to carry out research at their host’s expense.23 Loomis was so taken with Lawrence’s project that he promised not only to help raise foundation money but to supplement the budget with his own funds if necessary.

  Karl Compton left immediately after the Berkeley meeting to carry the group’s endorsement to Rockefeller trustees in New York. Lawrence and Cooksey drove those remaining down the coast to Carmel, where they spent the weekend at Del Monte Lodge, a posh resort overlooking Monterey Bay, at Loomis’s expense. Between passing rain squalls, Lawrence and Loomis led picnic excursions to view the sea lions at nearby Point Lobos.24

  But this seaside idyll was soon spoiled by talk of the war. Arthur Compton was surprised to find Lawrence moody and distracted by events in Europe. Conant and Bush, both recently returned from a tour of England’s laboratories, spoke of rumors among British scientists that the Germans were working to harness the energy of fission for a revolutionary new kind of weapon.25

  * * *

  Although Oppenheimer had seen the Nazis in action while a student at Heidelberg, the war in Europe initially seemed an abstraction. It only became real when a fa
vorite aunt escaped from Germany in 1937 and moved to nearby Oakland with her son and his family.26

  Like many on the political left, Oppenheimer remained resolutely opposed to U.S. intervention in the struggle—particularly after the signing of the Hitler-Stalin nonaggression pact in August 1939. “I know Charlie [Lauritsen] will say a melancholy I told you so over the Nazisoviet pact, but I am not paying any bets yet on any aspect of the hocuspocus except maybe that the Germans are pretty well into Poland. Quel stink,” Oppie wrote to a Caltech colleague that fall.27

  Oppenheimer’s political awakening had occurred only a few years earlier, the result of his association with two individuals.28

  Jean Tatlock was an attractive green-eyed brunette whom Oppenheimer had met in spring 1936 at a benefit for the Spanish Loyalists organized by his landlady, Mary Ellen Washburn. Tatlock was working on a graduate degree in psychology at Stanford University; her father was a professor of English literature at Berkeley, an expert on Chaucer.

  Oppenheimer’s students believed that Jean Tatlock had a humanizing influence upon their mentor. (“I need physics more than friends,” Robert once wrote to Frank during his bachelor days.)29 Jean introduced Oppie to the romantic poetry of John Donne.30

  Theirs was a tempestuous, on-again, off-again relationship. Twice Oppie had come close to proposing marriage, but Jean had drawn away. Finally, after graduation, she had gone back east to medical school, and their passion had cooled with distance. Given to frequent and prolonged bouts of depression, Tatlock wanted to become a psychiatrist.31

  Intense about politics as well as poetry, Jean had belonged to several organizations on campus and felt a particular affinity for the Loyalist cause. At one point she joined the local branch of the Communist Party. That first fall, when they had begun dating regularly, Tatlock introduced Oppie to Rudy Lambert, a party functionary in nearby Alameda County, and also to Dr. Thomas Addis, a physician at Stanford Medical School who was a recruiter for the party.32