Before the Fallout Page 12
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Einstein severed his links with Germany early and forever. He was about to sail back to Europe from California when Hitler came to power, and roundly denounced the land of his birth for turning its back on "civil liberty, tolerance, and equality of all citizens before the law." A few days later, in Antwerp, he announced his resignation from the Prussian Academy of Sciences, thereby infuriating the Prussian minister for education, Bernhard Rust, who had hoped to mark the national boycott of Jewish businesses called for 1 April 1933 by expelling him.
As enraged Nazis ransacked Einstein's house and the authorities confiscated his bank account, Germany's most famous scientist crossed the Channel to England with his wife, Elsa, protected by a British naval commander and MP who had had the singular experience of having once been invited to kill Rasputin. Einstein was safe but confessed to Max Born, "My heart aches when I think of the young ones." He also told him that he had never thought highly of "the Germans" but the degree of their brutality and cowardice had surprised even him. In the autumn of 1933, finding England too formal and preferring a life with "no butlers. No evening dress," Einstein accepted a post at the Institute for Advanced Study at Princeton. Paul Langevin, watching events from Paris, thought his emigration highly significant, remarking only half in jest that "it's as important an event as would be the transfer of the Vatican from Rome to the New World. The Pope of Physics has moved and the United States will now become the centre of the natural sciences."
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Einstein rounded on German intellectuals for behaving "no better than the rabble." Certainly, some prevaricated while books by "undesirables" were tossed on fires and professors sympathetic to the new order donned brown shirts to lecture on such absurdities as "Aryan mathematics." A number hoped that the expulsion of so many scholars would further their own careers. However, many were troubled, and a few, including Max Planck, had the courage to try to help their Jewish colleagues. Planck was given an audience with Hitler on 16 May 1933, but, according to Planck, the fiihrer "whipped himself into such a frenzy" that Planck could only listen in appalled silence, then leave. Heisenberg also considered protesting, despite his fragile personal position. He visited a tired-looking Planck, whose "finely chiseled face," he thought, "had developed deep creases" and whose smile "seemed tortured." The initiator of quantum theory, shaken by his encounter with completely irrational forces, convinced Heisenberg that protests would be "utterly futile."
Heisenberg took Planck's advice, trying to convince himself that the extremism could not last, even that something good might rise out of the mayhem. However, his optimism seemed naive to the point of absurdity to his Jewish friends. He told Born, "Since . . . only the very least are affected by the law—you and Franck certainly not . . . the political revolution could take place without any damage to Gottingen physics. . . . Certainly in the course of time the splendid things will separate from the hateful." Heisenberg would later justify his position as one of "inner exile," during which he sought to protect "the old values" so that something would survive "after the catastrophe." Looking back after the war, he even suggested that his Jewish friends had faced easier choices than himself. Forced to leave, "at least they had been spared the agonising choice of whether or not they ought to stay on." "Inner exile" would come to involve many compromises, both conscious and unconscious, for Heisenberg.
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Lise Meitner wondered anxiously what would happen to her. She was an Austrian national, not a German. Also, the Kaiser Wilhehn Institute was not directly under government control, and its staff were not government servants. Nevertheless, she felt threatened and, on 3 May 1933, wrote to her long-term friend and collaborator Otto Hahn, then in the United States, begging him to come home. Hahn, who had received equally disturbing letters from other Jewish friends, hurried back to Berlin to see for himself. He was so shocked that he suggested a group of prominent Aryan academics should protest against the treatment of their Jewish colleagues. Yet, just as he had counseled Heisenberg, Max Planck, on the basis of his own protest, warned that it would be pointless: "If today you assemble 50 such people, then tomorrow 150 others will rise up who want the positions of the former." Planck believed the best way to protect German science was for the present to keep quiet. In an amoral, practical sense he was right. Once the Jewish academics were gone, German science was allowed to proceed largely unmolested.
Hahn too followed Planck's advice. Like Heisenberg, he steadfastly refused to join the Nazi Party. He also resigned his lectureship at the University of Berlin to avoid having to participate in Nazi Party meetings. In 193c, on the first anniversary of the death of Fritz Haber—he had died of a heart attack during a visit to Switzerland the year before—Hahn and Max Planck, prompted to action again, organized a memorial service, despite official threats, at which they both spoke. University professors, as government employees, were too nervous to attend, fearing they would be dismissed, but sent their wives in one of the very few concerted gestures of solidarity by the scientific community with those who had been ousted. Planck ended his oration with the words "Haber was true to us, we shall be true to him."
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Solvay Conference attendees, 1933
The Solvay Conference of October 1933 in Brussels was a refuge and a distraction from the disturbing happenings in the wider world. Forty experimentalists and theoreticians attended, including Rutherford, Chadwick, Lawrence, Madame Curie, the Joliot-Curies, Langevin, Meitner, and Bohr, to debate the "Structure and Properties of the Atomic Nucleus." They argued about whether Chadwick's neutron was a composite of particles or—as experiments would shortly confirm—a particle in its own right. They also discussed the recent finding of another new subatomic particle—the positively charged electron, or "positron"—by Carl Anderson, a physicist at Cal-tech, Pasadena, researching into cosmic radiation. Anderson had made his discovery using a clever device invented many years earlier by the Scotsman Charles Wilson—the cloud chamber—designed to make the invisible path of particles visible. This was achieved by shooting particles through a saturated water vapor created in the chamber, causing them to leave a trail of droplets, like the tail of a meteor. Their track, thus revealed, could be photographed through a window in the side.*
Just like the neutron, the positron had previously been glimpsed but misinterpreted by others. Chadwick had come close to it but, fixated on the neutron, had missed the significance of some observations. The Joliot-Curies had photographed electrons in a magnetic field "going backwards the wrong way," but had not recognized them as positrons until they read of Anderson's work. Piqued by their failure to identify the positron, the Joliot-Curies had launched a series of experiments to discover more about it. Placing a cloud chamber in a strong magnetic field, they bombarded elements with alpha particles. The bombardment caused elements in the middle of the periodic table to release protons, but light elements like aluminum sometimes ejected a neutron and a positron instead. This finding caused them to wonder whether a proton might be a compound of a neutron and a positron. However, their suggestion met fierce opposition at the Solvay Conference, particularly from Lise Meitner. Undeterred by the hostile gaze of Marie Curie, who resented her daughter's work being criticized, she stated, "My colleagues and I have done similar experiments. We have been unable to uncover a single neutron."
Deflated and anxious, the Joliot-Curies hurried back to Paris to recheck their results but could find no mistakes. The light elements had definitely emitted neutrons. Encouraged, they resumed their experiments and so stumbled upon one of the most significant discoveries so far.
After bombarding ordinary aluminum with alpha particles, Frederic Joliot-Curie used a Geiger counter to measure the results. To his surprise, when he moved the radioactive source emitting the alpha particles away from the aluminum, the counters, instead of immediately falling silent, continued noisily clicking. He could not believe it and repeated the maneuver. The results were the same. He fetched Irene, wh
o was equally puzzled. That evening, having to attend a dinner engagement, they asked a colleague to check that the counters were not faulty. Hastening back to their laboratory the next morning, they found his note: The counters were operating perfectly.
Painstakingly, the Joliot-Curies worked out what had happened. Until then, all reactions that scientists had produced had occurred immediately and ceased as soon as the bombarding source was removed. However, on being bombarded with alpha particles, the aluminum had transmuted into an intermediate radioactive isotope of phosphorus, which, as it decayed back to its stable state, silicon, continued to emit radioactivity (positrons) for some time after the bombarding source of alpha particles had been removed. They had induced a new phenomenon: "artificial radioactivity." An exultant Joliot told his assistant, "With the neutron we were too late. With the positron we were too late. Now we are in time." Until then, physicists had known that by bombarding it with a particle of sufficient energy, a nucleus could be disintegrated and a new, stable one formed. No one had realized that in certain circumstances, an unstable element in the process of nuclear decay could be created. In other words, man could force the elements to release their energy in the form of radioactive decay. The Joliot-Curies rushed to publish the news of "A New Type of Radioactivity."
Irene and Frederic Joliot-Curie
The discovery caused consternation and disappointment at Berkeley. As one of Lawrence's team observed, "We could have made the discovery any time." If, rather than concentrating on continued improvement of the performance parameters of their accelerators, they had only thought to run a Geiger counter over one of their targets, they too would have heard the telltale click announcing the creation of a new radioactive element. This had not happened for practical reasons: The laboratory's Geiger counter and the cyclotron worked on the same switch, so that the team had never had the chance to explore whether the counters kept registering after the cyclotron was switched off. It was an irritating thought. As another man admitted, "We felt like kicking each other's butts." They altered the wiring, left the Geiger on after taking the cyclotron down, and sure enough heard the counter's rhythmic tick—"a sound that none who was there would ever forget," recalled Stanley Livingston.
The discovery brought Marie Curie great satisfaction. Joliot wrote of "the expression of intense joy which overtook her when Irene and I showed her the first [artificially produced] radioactive element in a little glass tube. I can see her still taking this little tube . . . in her radium-damaged fingers. To verify what we were telling her, she brought the Geiger counter up close to it and she could hear the numerous clicks. . . . This was without a doubt the last great satisfaction of her life." Marie told a friend, "We're back in the fine days of the old laboratory."
"La Patronne" was still a powerful presence at the Curie laboratory. When the young chemist Bertrand Goldschmidt arrived for an interview in June 1933, s n e told him in a strong Polish accent, "For a year or two you will be my slave in chemistry and do everything for me." He was in awe of this "rather small old lady with big hairs on her chin" and dressed entirely in black who looked much older than her sixty-five years. He was also fascinated by the stories still circulating of a once-active love life. There were, he recalled, "many rumours," including that Eve Curie, born in 1904 and with her blue eyes and dark hair so different from her older, fairer sister, Irene, was not Pierre Curie's daughter "but Andre Debierne's," but that Debierne had later been "succeeded in Madame Curie's heart by Langevin."
However, any such passions were long spent. Marie's life was ending. She died, aged sixty-six, at dawn on 4 July 1934 in a sanatorium in the mountains. The cause of death was extreme pernicious anemia "of rapid, feverish development. The bone marrow did not react, probably because it had been injured by a long accumulation of radiations." She had insisted on reading her own temperature, holding the thermometer "in her shaking hand," and recognizing from the sudden fall in her fever that her end was near.
Her coffin was buried above Pierre Curie's. There was no priest and no prayers, as befitted a devout skeptic, but her brother and sister cast a few grains of Polish soil on her coffin.
The following year, the Joliot-Curies were awarded the Nobel Prize for Chemistry for their finding of artificial radioactivity. In his acceptance speech, Frederic Joliot-Curie remarked that "scientists who can construct and demolish elements at will may also be capable of causing nuclear transformations of an explosive character." Few paid much public attention to these prophetic words. In 1933, at a meeting of the British Association for the Advancement of Science, Ernest Rutherford had insisted that anyone who believed that atomic energy could be released on a large scale was "talking moonshine." Niels Bohr believed that even if a release of explosive power from the nucleus was possible in theory, in practical terms it was unattainable: "Not only are such energies at present far beyond the reach of experiments, but it does not need to be stressed that such effect would scarcely bring us any nearer to the solution of the much discussed problem of releasing nuclear energy for practical purposes. Indeed the more our knowledge of nuclear reactions advances the remoter this goal seems to become." To Einstein, the chances of achieving a massive release of energy were like "a blind man in a dark night hunting ducks by firing a shotgun straight up in the air in a country where there are very few ducks."
For the present, nuclear science remained an open subject studied for the joy of knowledge.
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Rutherford took the Nazi threat to science extremely seriously. He agreed to head up the Academic Assistance Council, created in May 1933 in London to find academic jobs in Britain for the Jewish scientific refugees. It was a formidable task. More than fifteen hundred had been thrown out of work, including at least a quarter of Germany's physicists. Rutherford chaired a huge gathering in the Albert Hall, at which one of the chief speakers was Einstein, unmistakable according to one of those present, with his shaggy mane of hair, "great furrowed forehead," and "enormous bulging chocolate-brown eyes."
Rutherford helped many personally, including Max Born and his Quaker wife, doing everything from finding the Borns somewhere to live in Cambridge and driving them to visit their quarantined dog to providing Born with temporary work at Cambridge until the offer of the physics chair at Edinburgh University came through. So successful were Rutherford's efforts at practical as well as moral support that Born later wrote: "A disaster turned out to be a blessing. For there is nothing more wholesome and refreshing for a man than to be uprooted and replanted in completely different surroundings." Although he supported his right to receive help, Rutherford did not wish to meet Fritz Haber, who in the year prior to his death was living in England. Born recorded how Rutherford "declined violently" an invitation to his house because Haber was to be present; "he did not wish to have any contact with the man who had invented chemical warfare with the help of poison-gas."
Niels Bohr, half-Jewish himself, was also very active on behalf of Germany's displaced scientists, firing off unsolicited invitations to people to come to Copenhagen. The international conference he held there every summer became, in the words of one refugee, "a sort of labour exchange." James Franck found sanctuary in Copenhagen before going to America. So did Edward Teller before going first to England and then on to the United States. Teller was unstinting in his praise of the Academic Assistance Council and of the British, saying, "They accepted many more scientists than Britain could possibly use and all of us were welcomed as permanent residents. . . . the English are truly among the most hospitable and ethical people in the world."
Bohr also helped Lise Meitner's young nephew, Otto Frisch, who had been dismissed from Hamburg University. In October 1933 Frisch had arrived in England to work under Patrick Blackett, the left-leaning head of the physics department in Birkbeck College, London. Learning of the Joliot-Curies' discoveries, Frisch built himself some apparatus from a few bits and pieces from Woolworth's and began investigating artificial radioactivity for himself. When Bohr
came to London to visit Blackett later that year, he offered the ingenious but unknown young man the chance to come to Copenhagen. Frisch wrote to his mother that it was as if "God Almighty himself has taken me by my waistcoat button and spoken kindly to me."
In the United States Hungarian Eugene Wigner, who had emigrated there before Hitler came to power, joined forces with another emigre colleague and wrote in German to a small group of physicists at American educational establishments. They asked them to set aside a small percentage of their income for the next two years to help former colleagues find academic posts in America. Oppenheimer, who had relatives in Germany and, in his words, felt "a continuing, smoldering fury about the treatment of Jews in Germany," was one of the recipients. However, the originators of the scheme were wary of launching a general appeal not only because academic jobs in the United States were in short supply but also because some universities were known to be reluctant to employ Jews.
In Russia, despite Stalin's desire to push his country to the forefront of science, the Soviet authorities made few attempts to attract the talented, jobless people so anxiously seeking new positions. Growing paranoia about infiltration by foreign agents meant that only those with known communist sympathies were admitted. Until 1937 they were allowed to work in Russia's physics institutes, but many then fell victim to Stalin's purges. Suspected of being spies, they were imprisoned, tortured and exiled.
Just as in Germany, Russia's scientists were becoming progressively caught in an ideological web. Abram Joffe felt he was "living on top of a volcano." After the defection of a leading theoretical physicist, George Gamow, at the 1933 Solvay Conference, Joffe was no longer permitted to travel outside Russia. Soviet scientists working abroad also felt vulnerable. Lev Landau, studying in Berlin, implored colleagues never to discuss politics with him in case it got him into trouble. Peter Kapitza, however, felt perfectly at ease. He was about to take charge of the splendid new Mond Laboratory for magnetic field and low-temperature research in Cambridge. The building was a model of art-deco chic, with a crocodile etched on the facade in affectionate tribute to Rutherford.