The Last Man Who Knew Everything

by David N. Schwartz

  FIGURE 11.1. A quiet moment in Stockholm, December 1938, during the Nobel Prize ceremonies. Pearl Buck is on the left, and Fermi is smiling at a young girl, identity unknown. Courtesy of the Pearl Buck Estate.

  A huge banquet in the town hall followed the ceremony, with the guests of honor and their spouses seated with the king at the center of the long main table. A formal ball finished the night off, and Laura was thrilled to dance with King Gustav V, although she noted later that this was the second European monarch with whom she had danced. Accompanying Enrico to the 1933 Solvay conference, she had danced with the king of Belgium. All in all, it was a heady few days, capped with a private dinner the next evening at the palace for recipients and their spouses.

  In what remains a tradition to this day, the recipients each made a speech reflecting on their work. Fermi chose, understandably, to focus on the efforts for which the Nobel committee had recognized him, the development of the slow-neutron method of bombardment and the results of that endeavor. It was a relatively short speech, not very technical, but it did specifically mention the discovery of two transuranic by-products: element 93, “ausonium,” and element 94, “hesperium.” He also noted that the German team of Otto Hahn and Lise Meitner had subsequently discovered elements through number 96. If he harbored doubts about the reality of these transuranic discoveries, he kept them to himself. This would come back to haunt him a month later.

  The Italian press was furious with Fermi’s decision to shake hands with the king rather than give the fascist salute. Fascist newspapers, increasingly aware of the growing relationship between Mussolini and Hitler, had downplayed the announcement of the award in November, keen to have an Italian honored by the Nobel Foundation but wary of aggravating Hitler. Now they pounced on Fermi, charging that his failure to deliver the fascist salute reflected subversive tendencies on the part of this vaunted member of the Accademia d’Italia. That he shook hands with the king only compounded the sin. Mussolini and his regime disparaged the shaking of hands as feminine. The public furor in Rome eventually died down, but the watchful eyes of the fascist regime were more alert than ever.

  The celebrations and parties behind them, the family proceeded south and west, first to Copenhagen to pay respects to Bohr, then across the English Channel and onto a ship at Southampton destined for New York Harbor. There they set sail for the New World on December 24, 1938. Across the Atlantic, a new life beckoned.

  PART THREE

  THE MANHATTAN PROJECT

  CHAPTER TWELVE

  THE NEW WORLD

  THE TRANSATLANTIC JOURNEY ON THE CUNARD LINER FRANCONIA was uneventful, and as the ship pulled into New York harbor on January 2, 1939, Fermi grandly announced that they had now established the American branch of the Fermi family.

  Neither he nor Laura had much to do with their fellow passengers, among whom were the great French composer Nadia Boulanger, the German stage director Erwin Piscator, and some seventy members of the famed D’Oyly Carte Opera Company of London, traveling to New York for a six-week run of Gilbert and Sullivan performances. Fermi was not particularly interested in music unless it formed the backdrop to a party and dancing.

  Perhaps of greater importance, it was not the happiest moment for the Fermi family. Fermi had uprooted himself from colleagues he had worked with for over a decade, men and women who were close friends as well as professional associates. Laura was even less happy, having left behind the city she called home all her life for a big and sometimes brutal city that Enrico had decided would be their new home. Passing through New York briefly on the way to the 1930 Ann Arbor summer school, she was impressed with the vitality and size of the city but also found it strange, crude, and unattractive. Now she also had two small children in tow and was under no illusion that her husband would make time to share the burdens of parenthood in a new and unfamiliar city. She would have to find Nella a school—she ended up at Horace Mann, a progressive, highly prestigious private school in the Riverdale section of the Bronx—and teach the younger Giulio English herself. She did, however, travel with a maid who could help her with the transition.

  Pegram met them on shore, along with Fermi’s former-student-turned-American-businessman Gabriello Giannini, and the two of them escorted the Fermis uptown to a small hotel on the Columbia campus, the King’s Crown on West 116th Street, where they were installed until they could find long-term lodgings. Its cramped and dark corridors gave the family an added impetus to find more permanent living quarters.

  A month had elapsed from the time they left Rome until they arrived in New York City. During this time, he was uncharacteristically out of touch with the vibrant, almost hyper-communicative scientific community in Europe and was unable to correspond with the many scientists on whom he relied for information about cutting-edge developments. This was, in retrospect, fortunate. During the month of December, dramatic events unfolded in Germany, proving that Fermi had colossally misunderstood the results of his neutron experiments, the very experiments for which he had just received the Nobel Prize. He would never quite get over the embarrassment of having been so wrong. When the news of those experiments eventually crossed the Atlantic, Fermi and others found themselves on a runaway train careening down the tracks in a direction no one could foresee.

  While Fermi was en route to the States, scientists in Germany, conducting experiments almost identical to those conducted by Fermi and his Panisperna boys in 1934, reported that they had split the nucleus of the uranium atom.

  OTTO HAHN WAS A CAUTIOUS AND CAREFUL MAN WHO, OVER A decades-long career, had built a reputation as one of the finest chemists in the world. Born in 1879, he had been engaged in intensive study of the chemistry of radioactive substances from the early 1900s, and as such is considered the father of radiochemistry, the chemical study of radioactive materials. He was particularly expert in chemical separation of radioactive elements from one another.

  In 1907 he met Lise Meitner, a young woman physicist who had been working with Max Planck. Born in Vienna in 1878 and raised as a Protestant, but with a Jewish grandfather, Meitner was the second woman to gain a doctorate in physics at Berlin, and Hahn was immediately drawn to her intellect and drive. With her physicist’s understanding of the radioactive processes inside the nucleus, Meitner collaborated with Hahn in the chemistry labs of the Kaiser Wilhelm Institute in Dahlem, Berlin, for the next thirty years.

  Hahn the chemist and Meitner the physicist were, in many ways, the ideal collaborators, able to complement each other’s skills as the team sought to understand radioactivity. It was, however, primarily a chemistry project, focusing almost entirely on the chemical separation and identification of the by-products of radioactive decay. Because of their work at the heavy end of the periodic table, among the class of elements called “actinides,” they were immediately taken with Fermi’s announcement in 1934 of the results of the initial neutron bombardment experiments on uranium, an actinide itself, in particular Fermi’s observation that one of the four by-products of uranium bombardment seemed to be a transuranic element, element number 93.

  The two colleagues began intensive work on neutron bombardment of uranium and over the next four years focused almost exclusively on identifying one after another of what they thought to be transuranic elements and their isotopes. By 1938, they believed they had identified elements 93 through 98 in the periodic table, but definitive confirmation continued to elude them.

  For these experiments, they brought on board a third chemist, Friedrich “Fritz” Strassmann, some twenty years younger than Hahn and Meitner, who had a reputation as a strong analytical chemist. An active anti-Nazi, in 1933 he resigned from the Society of German Chemists over its ejection of Jewish members, although he was what the Nazis would have considered a “pure” German. As Hahn and Meitner’s assistant, he was the crucial third member of the team.

  The German team had competition. Rutherford, an enthusiastic fan of Fermi’s experiments in 1934, was pursuing similar experiments at
his Cavendish Laboratories at Cambridge University, working with colleagues like James Chadwick, who discovered the neutron in 1932. Irene Joliot-Curie, Marie Curie’s daughter, whose work creating artificial radioactivity by bombarding nuclei with alpha particles in 1933 inspired Fermi in his neutron bombardment experiments, was working with her colleague Pavel Savitch to identify by-products of uranium bombardment. A bright graduate student of Ernest O. Lawrence at Berkeley, Philip Abelson, was a third competitor. In the end, though, it was Hahn and Strassmann, with significant help from Meitner and her young nephew, Otto Frisch, who made the critical discovery.

  Hitler’s annexation of Austria in March 1938 had a direct impact on the Berlin team. Meitner, one-quarter Jewish, was a citizen of Austria and thus untouchable by the Germans as Nazi anti-Semitic laws hit hard within the German academic community. Suddenly, with the stroke of a pen, she was a German citizen, without the protection of a sovereign foreign government. In July she escaped to Holland with the help of two Dutch physicists. Hahn gave her his mother’s wedding ring with which to bribe border guards if necessary. A promised position at the University of Groningen fell through, and she wound up in Stockholm, working with Manne Siegbahn, the head of the physics department at the Royal Swedish Academy of Sciences, whose members were about to elect Fermi as the next recipient of the Nobel Prize.

  Research back in Dahlem continued without Meitner, although Hahn corresponded frequently with his former partner. Hahn and Strassmann continued to analyze by-products of neutron bombardment of pure uranium and were struck by results produced in similar experiments done by the Joliot-Curies in Paris—results that neither the French nor the Berlin team could understand. They replicated these experiments themselves and eventually, having eliminated every conceivable alternative explanation, Hahn and Strassmann came to a shocking conclusion: there were no transuranic elements at all in the by-products of neutron bombardment of uranium. The by-products were, instead, much lighter elements, barium and krypton. The only way such by-products could have been produced was in the splitting of the uranium nucleus into two much smaller pieces.

  One of the main reasons Hahn had such trouble understanding what he had done was the lack of a theoretical framework to explain fission. It might be easy for us to imagine how fission occurs in a general way, but for a physicist or a chemist, the details are important, and Hahn’s knowledge of the nucleus and how it behaves was insufficient to provide a sound explanation. What seems obvious in retrospect was hardly obvious at the time. Before concluding that the by-products were barium and krypton, in early November Hahn traveled to Copenhagen to consult with Bohr, whom he believed would certainly have an answer to the conundrum of the perplexing results. Meitner and her nephew, a bright young physicist named Otto Frisch, were also there and the four of them discussed the puzzle at length, but came to no conclusions. Now, desperate for some sort of justification for his conclusion that the uranium nucleus had been split, he sent a private letter to Meitner, who was back in Sweden. Frisch happened to be visiting his aunt when the letter arrived.

  Together they spent an afternoon discussing Hahn’s astonishing news. Meitner’s insight—Frisch always credited his aunt—was that the nucleus of the uranium atom was held together in a manner analogous to the way surface tension holds together a drop of water. Under the right circumstances, forces can overcome the surface tension of a water drop (which is an electrostatic phenomenon) and cause the drop to push apart, or to “burst,” as Meitner put it, under electrostatic repulsion. The impact of the neutron on the uranium nucleus produced a similar effect, overcoming the force holding the nucleus together and pushing the nucleus apart into two distinct pieces, in the process releasing enormous energy. Meitner calculated that the energy released each time a uranium nucleus split would be on the order of several hundred million electron volts (MeV), tiny in absolute terms, but almost incomprehensibly large relative to the energy released in chemical reactions.

  She communicated her theory back to her former colleagues in Dahlem, who published their results on January 6, 1939. Frisch conducted a confirming experiment on January 13, 1939, detected the ionization pulse Meitner had predicted, and published his results four days later. Meitner and Frisch followed up a month after with an article explaining the theory behind fission, but by then everyone in the physics world knew of their work. For the second time in less than five years, a small scientific team, closeted away in a quiet corner of a highly oppressive totalitarian society, came up with pathbreaking, historic research.

  Frisch informed Bohr of the breakthrough in early January 1939. Bohr’s reaction: “Oh what idiots we have all been! Oh but this is wonderful!” Frisch extracted a promise from Bohr, who was about ready to sail to America to visit Einstein at Princeton and attend a physics conference in Washington, to postpone announcement of the news until Frisch could do his experiment. So when Bohr arrived in New York harbor aboard the steamship Drottningholm, word of uranium fission had not yet reached American shores, even though Frisch had completed his experiment. If Fermi had been in Rome at the time, Hahn would almost certainly have informed Fermi of his conclusion out of professional courtesy, knowing that it completely repudiated the transuranic hypothesis. As it was, he only became certain after Fermi was well on his way to the United States.

  LAURA SPENT TIME LOOKING FOR APARTMENTS IN THE COLUMBIA neighborhood, eventually identifying one on Riverside Drive just around the corner from the university campus. Enrico settled into new offices in Pupin Hall, the home of the Columbia physics department. Pegram, who had been instrumental in bringing Fermi to Columbia, found him space on the seventh floor but left it at that. Fermi was reduced to scrounging around for laboratory equipment.

  Back at the King’s Crown, Fermi ran into another of the hotel’s residents, a brilliant Hungarian scientist named Leo Szilard. Although he did not have a formal faculty position at Columbia, Szilard hung around the physics department, developing relationships with some of the young stars that Pegram had drawn to the department, men like I. I. Rabi and Willis Lamb. Szilard was a true eccentric, a brilliant polymath who flitted from one idea to another with the rapidity of a brightly colored butterfly in a bed of flowers. He had no visible means of support and an extravagant lifestyle, leading those who watched the fascinating, entertaining, and sometimes irritating Hungarian to conclude that he was either independently wealthy or that he had the support of wealthy friends. The latter explanation was no doubt closer to the truth. Szilard understood chemistry and physics and later in his career contributed to biology, as well. He was also an inveterate inventor. He worked with Einstein to develop and patent an ingenious refrigerator. Like many of his inventions, it amounted to nothing.

  One invention that was to become useful, however, was what Szilard called a “chain reaction.” In 1933, reportedly while standing at a central London street corner waiting for the light to change, he thought of a physical process in which radioactive emission of neutrons might strike the nuclei of neighboring atoms, causing them to emit more neutrons, which would strike other nuclei and so on and so forth in a geometrically increasing cascade, releasing enormous energy in the process. He did not yet know how to create such a chain reaction, but he patented the idea in England, where he was living at the time. Concerned even at this early date with secrecy and the risk of Nazi Germany gaining access to such dangerous technology, he assigned the patent rights over to the British Admiralty, who, not knowing what to do with it, promptly shelved and forgot it.

  Szilard was one of those unusual Hungarian refugees who arrived in the United States prior to the war and whom Szilard himself had christened “the Martians,” because they seemingly came from another planet, with an intelligence that surpassed most Earthlings. They had all known each other as youths in Budapest: Szilard, Edward Teller, John von Neumann, Eugene Wigner, Theodore von Karman, Paul Halmos, George Polya, and Paul Erdos. Fermi loved Szilard’s label. He once quipped: “Of course, they [extraterrestrials] are al
ready here among us: they just call themselves Hungarians.”

  Fermi and Szilard were polar opposites—the former, thorough, calm, methodical, frugal in his personal habits, and focused entirely on physics with few interests outside the field; the latter, highly excitable, easily distracted, jumping from inspiration to inspiration, crossing disciplinary boundaries with ease, a product of high European culture, an epicure if ever there was one—and the two geniuses would never have had much to do with each other had fission never been discovered, but news of Hahn’s discovery was about to reach the American shores, creating an historic and quite extraordinary, if momentary, case of strange bedfellows.

  CHAPTER THIRTEEN

  SPLITTING THE ATOM

  EXACTLY TWO WEEKS AFTER HIS ARRIVAL IN NEW YORK, ON January 16, 1939, Fermi and his wife traveled back to the Manhattan piers, this time to meet Niels Bohr, who was arriving on the Swedish-American Line’s SS Drottningholm. Also there to meet the great man was John Wheeler, a twenty-seven-year-old Princeton physicist whose job it was to take Bohr and his son Erik and fellow passenger, Belgian physicist Leon Rosenfeld, to the Princeton campus.