American Prometheus (17 page)

In 1932, Ralph Fowler, one of Oppie’s former teachers from Cambridge, England, visited Berkeley and had a chance to observe his old student. In the evenings, Oppie persuaded Fowler to play his particularly complicated version of tiddlywinks for hours on end. Some months later, at a time when Harvard was trying to recruit Oppenheimer away from Berkeley, Fowler wrote that “his work is apt to be full of mistakes due to lack of care, but it is work of the highest originality and he had an extremely stimulating influence in a theoretical school as I had ample opportunity of learning last fall.” Robert Serber agreed: “His physics was good, but his arithmetic awful.”

Robert did not have the patience to stick with any one problem very long. As a result, it was frequently he who opened the door through which others then walked to make major discoveries. In 1930 he wrote what would become a well-known paper on the infinite nature of spectral lines using direct theory. A splitting of the line in a spectrum of hydrogen suggested a small difference in the energy levels of two possible states of the hydrogen atom. Dirac had argued that these two states of hydrogen should have precisely the same energy. In his paper, Oppenheimer disagreed, but his results were inconclusive. Years later, however, an experimental physicist, Willis E. Lamb, Jr., one of Oppenheimer’s doctoral students, resolved the issue. The so-called “Lamb shift” correctly attributed the difference between the two energy levels to the process of self-interaction—whereby charged particles interact with electromagnetic fields. Lamb won a Nobel Prize in 1955, in part for his precise measurement of the Lamb shift, a key step in the development of quantum electrodynamics.

During these years, Oppenheimer wrote important, even seminal, papers on cosmic rays, gamma rays, electrodynamics and electron-positron showers. In the field of nuclear physics, he and Melba Phillips calculated the yield of protons in deuteron reactions. Phillips, an Indiana farm girl, born in 1907, was Oppenheimer’s first doctoral student. Their calculations on proton yields became widely known as the “Oppenheimer-Phillips process.” “He was an idea man,” recalled Phillips. “He never did any great physics, but look at all the lovely ideas that he worked out with his students.”

Physicists today agree that Oppenheimer’s most stunning and original work was done in the late 1930s on neutron stars—a phenomenon astronomers would not actually be able to observe until 1967. His interest in astrophysics was initially sparked by his friendship with Richard Tolman, who introduced him to astronomers working at Pasadena’s Mt. Wilson Observatory. In 1938, Oppenheimer wrote a paper with Robert Serber titled “The Stability of Stellar Neutron Cores,” which explored certain properties of highly compressed stars called “white dwarfs.” A few months later, he collaborated with another student, George Volkoff, on a paper titled “On Massive Neutron Cores.” Laboriously deriving their calculations from slide rules, Oppenheimer and Volkoff suggested there was an upper limit—now called the “Oppenheimer-Volkoff limit”—to the mass of these neutron stars. Beyond this limit they would become unstable.

Nine months later, on September 1, 1939, Oppenheimer and a different collaborator—yet another student, Hartland Snyder—published a paper titled “On Continued Gravitational Contraction.” Historically, of course, the date is best known for Hitler’s invasion of Poland and the start of World War II. But in its quiet way, this publication was also a momentous event. The physicist and science historian Jeremy Bernstein calls it “one of the great papers in twentieth-century physics.” At the time, it attracted little attention. Only decades later would physicists understand that in 1939 Oppenheimer and Snyder had opened the door to twenty-first-century physics.

They began their paper by asking what would happen to a massive star that has begun to burn itself out, having exhausted its fuel. Their calculations suggested that instead of collapsing into a white dwarf star, a star with a core beyond a certain mass—now believed to be two to three solar masses—would continue to contract indefinitely under the force of its own gravity. Relying on Einstein’s theory of general relativity, they argued that such a star would be crushed with such “singularity” that not even light waves would be able to escape the pull of its all-encompassing gravity. Seen from afar, such a star would literally disappear, closing itself off from the rest of the universe. “Only its gravitation field persists,” Oppenheimer and Snyder wrote. That is, though they themselves did not use the term, it would become a black hole. It was an intriguing but bizarre notion—and the paper was ignored, with its calculations long regarded as a mere mathematical curiosity.

Only since the early 1970s, when the technology of astronomical observation caught up with theory, have numerous such black holes been detected by astronomers. At that time, computers and technical advances in radio telescopes made black-hole theory the centerpiece of astrophysics. “Oppenheimer’s work with Snyder is, in retrospect, remarkably complete and an accurate mathematical description of the collapse of a black hole,” observed Kip Thorne, a Caltech theoretical physicist. “It was hard for people of that era to understand the paper because the things that were being smoked out of the mathematics were so different from any mental picture of how things should behave in the universe.”

Characteristically, however, Oppenheimer never took the time to develop anything so elegant as a theory of the phenomenon, leaving this achievement to others decades later. And the question remains: Why? Personality and temperament appear to be critical. Robert instantly saw the flaws in any idea almost as soon as he had conceived it. Whereas some physicists—Edward Teller immediately comes to mind—boldly and optimistically promoted all of their new ideas, regardless of their flaws, Oppenheimer’s rigorous critical faculties made him profoundly skeptical. “Oppie was always pessimistic about all the ideas,” recalled Serber. Turned on himself, his brilliance denied him the dogged conviction that is sometimes necessary for pursuing and developing original theoretical insights. Instead, his skepticism invariably propelled him on to the next problem.
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Having made the initial creative leap, in this case to black-hole theory, Oppenheimer quickly moved on to another new topic, meson theory.

Years later, Robert’s friends and peers in the world of physics, who generally agreed that he was brilliant, would ruminate on why he never won a Nobel Prize. “Robert’s own knowledge of physics was profound,” recalled Leo Nedelsky. “Perhaps only Pauli knew more physics and knew it more profoundly than Robert.” And yet, winning a Nobel, like much in life, is a matter of commitment, strategy, ability, timing, and, of course, chance. Robert had a commitment to doing cutting-edge physics, to attacking problems that interested him; and he certainly had the ability. But he did not have the right strategy—and his timing was off. Finally, the Nobel Prize is a distinction awarded to scientists who achieve something specific. By contrast, Oppenheimer’s genius lay in his ability to synthesize the entire field of study. “Oppenheimer was a very imaginative person,” recalled Edwin Uehling, a postdoctoral student who studied under him during the years 1934–36. “His knowledge of physics was extremely comprehensive. I am not sure that one should say that he didn’t do Nobel Prize–quality work; but it just didn’t happen to lead to that kind of result which the Nobel Prize committee regarded as exciting.”

“The work is fine,” Oppenheimer wrote to Frank in the autumn of 1932. “Not fine in the fruits but the doing. . . . We have been running a nuclear seminar, in addition to the usual ones, trying to make some order out of the great chaos. . . .” While Oppenheimer was a theorist who knew how incompetent he was in the laboratory, he nevertheless stayed close to experimentalists like Lawrence. Unlike many European theorists, he appreciated the potential benefit from close collaboration with those who were involved in testing the validity of the new physics. Even in high school, his teachers had noted his gift for explaining technical things in plain language. As a theorist who understood what the experimentalists were doing in the laboratory, he had that rare quality of being able to synthesize a great mass of information from disparate fields of research. An articulate synthesizer was exactly the kind of person needed for building a world-class school of physics. Some physicists have suggested that Oppenheimer possessed the knowledge and resources to publish a comprehensive “bible” of quantum physics. By 1935, he certainly had the material for such a book at hand. His basic lectures explaining quantum mechanics were so popular on campus that his secretary, Miss Rebecca Young, had his lecture notes mimeographed and sold them to students. The proceeds were used for the physics department’s petty cash fund. “Had Oppenheimer gone one step further and compiled his lectures and papers,” argues one colleague, “his work would have made one of the finest textbooks on quantum physics ever written.”

ROBERT HAD PRECIOUS LITTLE TIME for diversions. “I need physics more than friends,” he confessed to Frank in the autumn of 1929. He managed to go horseback-riding once a week in the hills overlooking San Francisco Bay. “And from time to time,” he wrote Frank, “I take out the Chrysler, and scare one of my friends out of all sanity by wheeling corners at seventy. The car will do seventy-five without a tremor. I am and shall be a vile driver.” One day he crashed his car while recklessly racing the coast train near Los Angeles; Robert escaped unscathed but for a moment he thought his passenger, a young woman named Natalie Raymond, was dead. Actually, Raymond had only been knocked unconscious. When Julius found out about the accident, he gave her a Cézanne drawing and a small Vlaminck painting.

Raymond was a beautiful woman in her late twenties when she met Oppenheimer at a Pasadena party. “Natalie was a dare-devil, an adventurer, as was Robert to some extent,” wrote a mutual friend. “This may have been the common ground of their natures. Robert grew up (or did he?), Natalie less so.” Robert called her Nat, and they saw quite a bit of each other in the early 1930s. Frank Oppenheimer described her as “quite a lady,” and Robert himself wrote Frank after seeing her at a New Year’s Eve party: “Nat has learned to dress. She wears long graceful things in gold and blue and black, and delicate long earrings, and likes orchids, and even has a hat. To the vicissitudes and anguishes of fortune which have brought this change to her I need say nothing.” After spending an evening with her at Radio City Music Hall listening to a “most marvelous” Bach concert, he wrote Frank, “The last days were impregnated with Nat; her always new & always moving miseries.” She even spent part of the summer of 1934 with Robert and others at Perro Caliente. But the relationship ended when she moved to New York to work as a free-lance book editor.

Nat wasn’t the only woman in Oppenheimer’s life. In the spring of 1928, he had met Helen Campbell at a Pasadena party. Though she was already engaged to a Berkeley physics instructor, Samuel K. Allison, Helen found herself strongly attracted to Oppenheimer. He took her out to dinner and they had a few walks together. When Oppenheimer returned to Berkeley in 1929, they resumed their friendship. By then Helen was a married woman, and she watched with some amusement as she observed “young wives falling for Robert, charmed by his conversation, gifts of flowers, etc.” She realized that he “had an eye for women and that his attentions to her should not be taken too seriously.” She thought he “liked to talk to slightly discontented women and seemed specially sensitive to lesbianism.” He possessed plenty of charisma.

“Everyone wants rather to be pleasing to women,” Robert wrote to his brother in 1929, “and that desire is not altogether, though it is very largely, a manifestation of vanity. But one cannot aim to be pleasing to women, any more than one can aim to have taste, or beauty of expression, or happiness; for these things are not specific aims which one may learn to attain; they are descriptions of the adequacy of one’s living. To try to be happy is to try to build a machine with no other specification than that it shall run noiselessly.”

When Frank wrote him to complain about his problems with “the jeunes filles Newyorkaises,” Robert replied, “I should say that you were wrong to let the creatures worry you . . . you should not associate with them unless it is for you a genuine pleasure; and that you should have truck only with those girls who not only pleased you, but who were pleased, and who put you at your ease. The obligation is always on the girl for making a go of conversation: if she does not accept the obligation, nothing you can do will make the negotiations pleasant.” Obviously, relations with the opposite sex were still a matter of uneasy negotiations for Robert, let alone his seventeen-year-old brother.

To most of his friends, Robert was a maddening bundle of contradictions. Harold F. Cherniss was getting his doctorate in Berkeley’s Classical Greek Department when he first met Oppenheimer in 1929. Cherniss had just married a childhood friend of Oppenheimer’s, Ruth Meyer, who also had known Robert at the Ethical Culture School. Cherniss was immediately taken by Oppenheimer: “His mere physical appearance, his voice, and his manners made people fall in love with him—male, female. Almost everybody.” But he admitted that “the longer I was acquainted with him, the more intimately I was acquainted with him, the less I knew about him.” A keen observer of people, Cherniss sensed a disconnect in Robert. Here was a man, he thought, who was “very sharp intellectually.” People thought him complicated simply because he was interested in so many things, and knew so much. But on an emotional level, “he wanted to be a simple person, simple in the good sense of the word.” Robert “wanted friends very much,” Cherniss said. And yet, despite his tremendous personal charm, “he didn’t quite know how to make friends.”

CHAPTER SEVEN

“The Nim Nim Boys”

Tell me, what has politics
to do with truth,
goodness and beauty.