American Prometheus (12 page)

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.

The new physics was, to be sure, highly controversial. When Max Born sent Albert Einstein a copy of Heisenberg’s 1925 paper on matrix mechanics, an intensely mathematical description of the quantum phenomenon, he explained somewhat defensively to the great man that it “looks very mystical, but is certainly correct and profound.” But after reading the paper that autumn, Einstein wrote Paul Ehrenfest that “Heisenberg has laid a big quantum egg. In Göttingen they believe in it. (I don’t.)” Ironically, the author of the theory of relativity would forever believe the
Knabenphysik
incomplete if not profoundly flawed. Einstein’s doubts were only heightened when in 1927 Heisenberg published his paper on the central role of
uncertainty
in the quantum world. What he meant was that it is impossible to determine at any given moment both an entity’s precise position
and
its precise momentum: “We cannot know, as a matter of principle, the present in all its details.” Born agreed, and argued that the outcome of any quantum experiment depended on chance. In 1927, Einstein wrote Born: “An inner voice tells me that this is not the true Jacob. The theory accomplishes a lot, but it does not bring us closer to the secrets of the Old One. In any case, I am convinced that He does not play dice.”

Obviously, quantum physics was a young man’s science. The young physicists in turn regarded Einstein’s stubborn refusal to embrace the new physics as a sign that his time had passed. A few years down the road, Oppenheimer would visit Einstein in Princeton—and he came away distinctly unimpressed, writing his brother with cocky irreverence that “Einstein is completely cuckoo.” But in the late 1920s, the boys from Göttingen (and Bohr’s Copenhagen) still had hopes of recruiting Einstein to their quantum vision.

The first of Oppenheimer’s papers written at Göttingen demonstrated that quantum theory made it possible to measure the frequencies and intensities of the molecular band spectrum. He had become obsessed with what he called the “miracle” of quantum mechanics precisely because the new theory explained so much about observable phenomena in a “harmonious, consistent and intelligible way.” By February 1927, Born was so impressed with Oppenheimer’s work on the application of quantum theory to transitions in the continuous spectrum that he found himself writing S. W. Stratton, the president of the Massachusetts Institute of Technology: “We have here a number of Americans. . . . One man is quite excellent, Mr. Oppenheimer.” For sheer brilliance, Robert’s peers ranked him with Dirac and Jordan: “There are three young geniuses in theory here,” reported one young American student, “each less intelligible to me than the others.”

Robert got into the habit of working all night and then sleeping through a good part of the day. Göttingen’s damp weather and poorly heated buildings wreaked havoc on his delicate constitution. He walked around with a chronic cough which friends attributed to either his frequent colds or his chain-smoking. But in other respects, life in Göttingen was pleasantly bucolic. As Hans Bethe later observed of this golden age in theoretical physics, “. . . life at the centers of the development of quantum theory, Copenhagen and Göttingen, was idyllic and leisurely, in spite of the enormous amount of work accomplished.”

Oppenheimer invariably sought out those young men with growing reputations. Others could not help but feel they had been snubbed. “He [Oppenheimer] and Born became very close friends,” Edward Condon said rather peevishly years later, “and saw a great deal of each other, so much so, that Born did not see much of the other theoretical physics students who had come there to work with him.”

Heisenberg passed through Göttingen that year and Robert made a point of meeting the brightest of Germany’s young physicists. Just three years older than Oppenheimer, Heisenberg was articulate, charming and tenacious in argument with his peers. Both men possessed original intellects and knew it. The son of a professor of Greek, Heisenberg had studied with Wolfgang Pauli at the University of Munich, and later he had done postdoctoral work with both Bohr and Born. Like Oppenheimer, Heisenberg had a way of using his intuition to cut to the root of a problem. He was an oddly charismatic young man, whose sparkling intellect commanded attention. By all accounts, Oppenheimer admired Heisenberg and respected his work. He could not have known then that in the years ahead they would become shadowy rivals. Oppenheimer would one day find himself contemplating Heisenberg’s loyalty to wartime Germany and wondering whether the man was capable of building an atomic bomb for Adolf Hitler. But in 1927, he was building on Heisenberg’s discoveries in quantum mechanics.

That spring, prompted by a remark from Heisenberg, Robert became interested in using the new quantum theory to explain, as he put it, “why molecules were molecules.” In very short order, he found a simple solution to the problem. When he showed Professor Born his notes, the older man was startled and very pleased. They then agreed to collaborate on a paper, and Robert promised that while he was in Paris for Easter, he would write up his notes into a first draft. But Born was “horrified” when he received from Paris a very spare, four- or five-page paper. “I thought that this was about right,” Oppenheimer recalled. “It was very light of touch and it seemed to me all that was necessary.” Born eventually lengthened the paper to thirty pages, padding it, Robert thought, with unnecessary or obvious theorems. “I didn’t like it, but it was obviously not possible for me to protest to a senior author.” For Oppenheimer, the central new idea was everything; the context and the academic window dressing were clutter that disturbed his acute aesthetic sense.