Kai Bird & Martin J. Sherwin

by American Prometheus: The Triumph;Tragedy of J. Robert Oppenheimer

  It was Oppenheimer’s good fortune to arrive shortly before an extraordinary revolution in theoretical physics drew to its close: Max Planck’s discovery of quanta (photons); Einstein’s magnificent achievement—the special theory of relativity; Niels Bohr’s description of the hydrogen atom; Werner Heisenberg’s formulation of matrix mechanics; and Erwin Schrödinger’s theory of wave mechanics. This truly innovative period began to wind down with Born’s 1926 paper on probability and causality. It was completed in 1927 with Heisenberg’s uncertainty principle and Bohr’s formulation of the theory of complementarity. By the time Robert left Göttingen, the foundations for a post-Newtonian physics had been laid.

  As chairman of the physics department, Professor Max Born nurtured the work of Heisenberg, Eugene Wigner, Wolfgang Pauli and Enrico Fermi. It was Born who in 1924 coined the term “quantum mechanics,” and it was Born who suggested that the outcome of any interaction in the quantum world is determined by chance. In 1954 he would be awarded the Nobel Prize for physics. A pacifist and a Jew, Born was regarded by his students as an unusually warm and patient teacher. He was the ideal mentor for a young student with Robert’s delicate temperament.

  That academic year Oppenheimer would find himself in the company of an extraordinary collection of scientists. James Franck, with whom Robert was also studying, was an experimental physicist who had won the Nobel Prize just a year earlier. The German chemist Otto Hahn would in just a few years contribute to the discovery of nuclear fission. Another German physicist, Ernst Pascual Jordan, was collaborating with Born and Heisenberg to formulate the matrix mechanics version of quantum theory. The young English physicist Paul Dirac, whom Oppenheimer had met at Cambridge, was then working on early quantum field theory, and in 1933 he would share a Nobel Prize with Erwin Schrödinger. The Hungarian-born mathematician John Von Neumann would later work for Oppenheimer on the Manhattan Project. George Eugene Uhlenbeck was an Indonesian-born Dutchman who, together with Samuel Abraham Goudsmit, discovered the concept of electron spin in late 1925. Robert quickly drew the attention of these men. He had met Uhlenbeck the previous spring during his weeklong visit to the University of Leiden. “We got along very well immediately,” recalled Uhlenbeck. Robert was so deeply immersed in physics that it seemed to Uhlenbeck “as if we were old friends.”

  Robert found lodging in a private villa owned by a Göttingen physician who had lost his medical license for malpractice. Once very well-to-do, the Cario family now had a spacious granite villa with a walled garden of several acres near the center of Göttingen—and no money. With the family’s fortune eaten away by Germany’s postwar inflation, they were compelled to take on boarders. Fluent in German, Robert quickly grasped the debilitating political atmosphere of the Weimar Republic. He later speculated that the Carios “had the typical bitterness on which the Nazi movement rested.” That autumn, he wrote his brother that everyone seemed concerned with “trying to make Germany a practically successful & sane country. Neuroticism is very severely frowned upon. So are Jews, Prussians & French.”

  Outside the university’s gate, Robert could see that times were tough for most Germans. “Although this [university] society was extremely rich and warm and helpful to me, it was parked there in a very miserable German mood.” He found many Germans “bitter, sullen . . . angry and loaded with all those ingredients which were later to produce a major disaster. And this I felt very much.” He had one German friend, a member of the wealthy Ullstein publishing family, who owned a car. He and Robert used to take long drives in the countryside together. But Oppenheimer was struck by the fact that his friend “parked this car in a barn outside Göttingen because he thought it was dangerous to be seen driving it.”

  Life for the American expatriates—and especially for Robert—was quite a different matter. For one thing, he was never short of money. At twenty-two, he dressed casually in rumpled herringbone suits made of the finest English wool. His fellow students noted that, in contrast to their own cloth luggage, Oppenheimer packed his belongings in gleaming, expensive pigskin suitcases. And when they strolled down to the fifteenth-century Zum Schwarzen Bären—the Black Bear pub—to drink frisches Bier or went to sip coffee at the Cron & Kon Lanz coffee shop, it was often Robert who picked up the tab. He was transformed; he was now confident, excited and focused. Material possessions were unimportant to him, but the admiration of others was something he sought every day. To that end, he would use his wit, his erudition and his fine things to attract those people he wanted within his orbit of admirers. “He was,” said Uhlenbeck, “so to say, clearly a center of all the younger students . . . he was really a kind of oracle. He knew very much. He was very difficult to understand, but very quick.” Uhlenbeck thought it remarkable that so young a man already had “a whole group of admirers” trailing around after him.

  In contrast to Cambridge, at Göttingen Oppenheimer felt a pleasant camaraderie with his fellow students. “I was part of a little community of people who had some common interests and tastes and many common interests in physics.” At Harvard and Cambridge, Robert’s intellectual pursuits had been solitary forays into books; at Göttingen, for the first time, he realized that he could learn from others: “Something which for me—more than most people—is important began to take place, namely, I began to have some conversations. Gradually, I guess, they gave me some sense and, perhaps more gradually, some taste in physics, something that I probably would not have ever gotten to if I’d been locked up in a room.”

  Lodging with him in the Cario family villa was Karl T. Compton, age thirty-nine, a professor of physics at Princeton University. Compton, a future president of MIT, felt intimidated by Oppenheimer’s extraordinary versatility. He could hold his own with the young man when the topic was science, but found himself at a loss when Robert began talking about literature, philosophy or even politics. No doubt with Compton in mind, Robert wrote his brother that most of the other American expatriates in Göttingen were “professors at Princeton or California or some such place, married, respectable. They are mostly pretty good at physics, but completely uneducated & unspoiled. They envy the Germans their intellectual adroitness & organization, & want physics to come to America.”

  In short, Robert thrived in Göttingen. That autumn he wrote enthusiastically to Francis Fergusson, “You would like Göttingen, I think. Like Cambridge, it is almost exclusively scientific, & such philosophers as are here are pretty largely interested in epistemological paradoxes & tricks. The science is much better than at Cambridge, & on the whole, probably the best to be found. They are working very hard here, & combining a fantastically impregnable metaphysical disingenuousness with the go-getting habits of a wall paper manufacturer. The result is that the work done here has an almost demoniac(?) lack of plausibility to it, & is highly successful. . . . I find the work hard, thank God, & almost pleasant.”

  Most of the time, he felt himself on an even keel emotionally. But there were some momentary relapses. One day, Paul Dirac saw him faint and fall to the floor, just as he had done the previous year in Rutherford’s laboratory. “I still was not entirely well,” Oppenheimer recalled decades later, “and I had several attacks during the year, but they became much more isolated and interfered less and less with work.” Another physics student, Thorfin Hogness, and his wife, Phoebe, also roomed that year in the Cario mansion and found Oppenheimer’s behavior sometimes odd. Phoebe often saw him lying in bed, doing nothing. But then these periods of hibernation were invariably followed by episodes of incessant talking. Phoebe thought him “highly neurotic.” On occasion, some witnessed Robert trying to overcome an episode of stuttering.

  Gradually, with his self-assurance returning, Oppenheimer found that his reputation had preceded him. One of his last acts before leaving Cambridge had been to present two papers before the Cambridge Philosophical Society titled “On the Quantum Theory of Vibration-rotation Bands” and “On the Quantum Theory of the Problem of the Two Bodies.” The first paper dealt with mole
cular energy levels and the second investigated transitions to continuum states in hydrogenic atoms. Both papers represented small but important advances in quantum theory, and Oppenheimer was pleased to learn that the Cambridge Philosophical Society had published them by the time he arrived in Göttingen.

  Robert responded to the recognition his publications brought him by throwing himself enthusiastically into seminar discussions—with such abandon that he often annoyed his fellow students. “He was a man of great talent,” Professor Max Born later wrote, “and he was conscious of his superiority in a way which was embarrassing and led to trouble.” In Born’s seminar on quantum mechanics, Robert routinely interrupted whoever was speaking, not excluding Born, and, stepping to the blackboard with chalk in hand, would declare in his American-accented German, “This can be done much better in the following manner. . . .” Though other students complained about these interruptions, Robert was oblivious to his professor’s polite, halfhearted attempts to change his behavior. One day, however, Maria Göppert—a future Nobelist—presented Born with a petition written on thick parchment and signed by her and most of the other members of the seminar: Unless the “child prodigy” was reined in, his fellow students would boycott the class. Still unwilling to confront Oppenheimer, Born decided to leave the document on his desk in a place where Robert could not help but see it when he next came to discuss his thesis. “To make this more certain,” Born later wrote, “I arranged to be called out of the room for a few minutes. This plot worked. When I returned I found him rather pale and not so voluble as usual.” Thereafter his interruptions ceased altogether.

  Not that he was by any means completely tamed. Robert could startle even his professors with his bruising candor. Born was a brilliant theoretical physicist, but because he sometimes made small mistakes in his long calculations, he often asked a graduate student to recheck his math. On one occasion, Born recalled, he gave a set of calculations to Oppenheimer. After a few days, Robert returned and said, “I couldn’t find any mistake—did you really do this alone?” All of Born’s students knew of his propensity for calculation errors, but, as Born later wrote, “Oppenheimer was the only one frank and rude enough to say it without joking. I was not offended; it actually increased my esteem for his remarkable personality.”

  Born soon began collaborating with Oppenheimer, who wrote one of his Harvard physics professors, Edwin Kemble, a veritable summary of their work: “Almost all of the theorists seem to be working on q-mechanics. Professor Born is publishing a paper on the Adiabatic Theorem, & Heisenberg on ‘Schwankungen [fluctuations].’ Perhaps the most important idea is one of [Wolfgang] Pauli’s, who suggests that the usual Schroedinger ψ [psi] functions are only special cases, and only in special cases—the spectroscopic one—give the physical information we want. . . . I have been working for some time on the quantum theory of aperiodic phenomena. . . . Another problem on which Prof. Born and I are working is the law of deflection of, say, an α-particle by a nucleus. We have not made very much progress with this, but I think we shall soon have it. Certainly the theory will not be so simple, when it is done, as the old one based on corpuscular dynamics.” Professor Kemble was impressed; after less than three months in Göttingen, his former student seemed steeped in the excitement of unraveling the mysteries of quantum mechanics.

  By February 1927, Robert felt so confident of his mastery of the new quantum mechanics that he was writing his Harvard physics professor, Percy Bridgman, to explain its finer points:

  On the classical quantum theory, an electron in one of two regions of low potential which were separated by a region of high potential, could not cross to the other without receiving enough energy to clear “impediment.” On the new theory that is no longer true: the electron will spend part of its time in one region, & part in the other. . . . On one point the new mechanics suggests a change, however: the electrons, which are “free” in the sense defined above, are not “free” in the sense that they are carriers of equipartition thermal energy. In order to account for the Wiedemann-Franz law one might have to adopt the suggestion, due, I think, to Professor Bohr, that when an electron jumps from one atom to another the two atoms may exchange momentum. With best greetings,

  Yours,

  J. R. Oppenheimer

  Bridgman was no doubt impressed by his former student’s command of the new theory. But Robert’s lack of tact made others leery. He could be engaging and considerate one moment and in the next rudely cut someone off. At the dinner table, he was polite and formal to an extreme. But he seemed incapable of tolerating banalities. “The trouble is that Oppie is so quick on the trigger intellectually,” complained one of his fellow students, Edward U. Condon, “that he puts the other guy at a disadvantage. And, dammit, he is always right, or at least right enough.”

  Having just earned his Ph.D. from Berkeley in 1926, Condon was struggling to support a wife and an infant child on a small postdoctoral fellowship. It annoyed him that Oppenheimer spent money so casually on food and fine clothes while seeming blissfully unaware of his friend’s familial responsibilities. One day, Robert invited Ed and Emilie Condon out for a walk, but Emilie explained that she had to stay with the baby. The Condons were startled when Robert replied, “All right, we’ll leave you to your peasant tasks.” And yet, despite his occasional cutting remarks, Robert often displayed a sense of humor. Upon seeing Karl Compton’s two-year-old daughter pretending to read a small red book—which just happened to be on the topic of birth control—Robert looked over at the very pregnant Mrs. Compton and quipped, “A little late.”

  PAUL DIRAC ARRIVED IN Göttingen for the winter term of 1927, and he too rented a room in the Cario villa. Robert relished any contact with Dirac. “The most exciting time in my life,” Oppenheimer once said, “was when Dirac arrived and gave me the proofs of his paper on the quantum theory of radiation.” The young English physicist was perplexed, however, by his friend’s determined intellectual versatility. “They tell me you write poetry as well as working at physics,” Dirac said to Oppenheimer. “How can you do both? In physics we try to tell people in such a way that they understand something that nobody knew before. In the case of poetry, it’s the exact opposite.” Flattered, Robert just laughed. He knew that for Dirac life was physics and nothing else; by contrast, his own interests were extravagantly catholic.

  He still loved French literature, and while in Göttingen he found time to read Paul Claudel’s dramatic comedy Jeune Fille Violaine, F. Scott Fitzgerald’s short story collections, The Sensible Thing and Winter Dreams, Anton Chekhov’s play Ivanov and the works of Johann Hölderlin and Stefan Zweig. When he discovered that two friends were regularly reading Dante in the original Italian, Robert disappeared from Göttingen’s cafés for a month and returned with enough Italian to read Dante aloud. Dirac was unimpressed, grumbling, “Why do you waste time on such trash? And I think you’re giving too much time to music and that painting collection of yours.” But Robert lived comfortably in worlds beyond Dirac’s comprehension and so was merely amused by his friend’s urgings, during their long walks around Göttingen, to abandon the pursuit of the irrational.

  Göttingen was not all physics and poetry. Robert also found himself attracted to Charlotte Riefenstahl, a German physics student, and one of the prettiest women on campus. They had met on a student overnight trip to Hamburg. Riefenstahl was standing on the train platform when she glanced down at the assembled luggage and her eyes were drawn to the one suitcase not made from cheap cardboard or worn brown leather.

  “What a beautiful thing,” she said to Professor Franck, pointing to the shiny tan leather pigskin grip. “Whose is it?”

  “Who else but Oppenheimer’s,” said Franck with a shrug.

  On the train ride back to Göttingen, Riefenstahl asked someone to point out Oppenheimer, and when she sat down beside him he was reading a novel by André Gide, the contemporary French novelist whose works dwelt on the individual’s moral responsibility for the affairs of the
world. To his astonishment, he discovered that this pretty woman had read Gide and could intelligently discuss his work. Upon arriving in Göttingen, Charlotte casually mentioned how much she admired his pigskin bag. Robert acknowledged the compliment, but seemed perplexed that anyone would bother to admire his luggage.

  When Riefenstahl later recounted the conversation to a fellow student, he predicted that Robert would soon try to give her the bag. Among his many eccentricities, everyone knew that Robert felt compelled to give away any possession of his that was admired. Robert was smitten with Charlotte, and courted her as best as he could in his stiff, excessively polite manner.

  So too did one of Robert’s classmates, Friedrich Georg Houtermans, a young physicist who had made a name for himself with a paper on the energy production of stars. Like Oppenheimer, “Fritz”—or “Fizzl” to some of his friends—had come to Göttingen with a family trust fund. He was the son of a Dutch banker, and his mother was German and half-Jewish, a fact that Houtermans was unafraid to advertise. Contemptuous of authority and armed with a dangerous wit, Houtermans liked to tell his gentile friends, “When your ancestors were still living in the trees, mine were already forging checks!” As a teenager growing up in Vienna, he had been expelled from his gymnasium (high school) for publicly reading the Communist Manifesto on May Day. He and Oppenheimer were virtual contemporaries, and both would receive their doctorates in 1927. They shared a passion for literature—and Charlotte. As fate would have it, Oppenheimer and Houtermans would later both work on developing an atomic bomb—but Houtermans would do so in Germany.

  PHYSICISTS HAD BEEN IMPROVISING quantum theory for nearly a quarter of a century when suddenly, in the years 1925–27, a series of dramatic breakthroughs made it possible to construct a radical and cohesive theory of quantum mechanics. New discoveries were then made so rapidly that it was hard to keep up with the literature. “Great ideas were coming out so fast during that period,” Edward Condon recalled, “that one got an altogether wrong impression of the normal rate of progress in theoretical physics. One had intellectual indigestion most of the time that year, and it was most discouraging.” In the highly competitive race to publish the new findings, more papers on quantum theory were written from Göttingen than from Copenhagen, Cavendish or anywhere else in the world. Oppenheimer himself published seven papers out of Göttingen, a phenomenal output for a twenty-three-year-old graduate student. Wolfgang Pauli began to refer to quantum mechanics as Knabenphysik—“boys’ physics”—because the authors of so many of these papers were so young. In 1926, Heisenberg and Dirac were only twenty-four years old, Pauli was twenty-six and Jordan was twenty-three.