Exuberantly Lawrence ran off to tell the world. An astronomer who was still awake at the faculty club was drafted to check his mathematics. He shocked one of his graduate students the next day by bombarding him with the mathematics of spiral accelerations but mustering no interest whatever in his thesis experiment. “Oh, that,” Lawrence told the questioning student. “Well, you know as much on that now as I do. Just go ahead on your own.”540 A faculty wife crossing the campus the next evening heard a startling “I’m going to be famous!” as the young experimentalist burst past her on the walk.541
Lawrence then traveled East to a meeting of the American Physical Society and discovered that not many of his colleagues agreed. To less inspired mechanicians the scattering problem looked insurmountable. Merle Tuve was skeptical. Jesse Beams, a Yale colleague and a close friend, thought it was a great idea if it worked. Despite Lawrence’s reputation as a go-getter—perhaps because no one encouraged him, perhaps because the idea was solid and sure in his head but the machine on the laboratory bench might not be—he kept putting off building his spiral particle accelerator. He was not the first man of ambition to find himself stalling on the summit ridge of a famous future.
Oppenheimer arrived in a battered gray Chrysler in the late summer of 1929 from another holiday at the Sangre de Cristos ranch with Frank—the ranch was named Perro Caliente now, “hot dog,” Oppenheimer’s cheer when he had learned the property could be leased.542 He put up at the faculty club and the two opposite numbers, he and Lawrence, became close friends. Oppenheimer saw “unbelievable vitality and love of life” in Lawrence. “Work all day, run off for tennis, and work half the night. His interest was so primarily active [and] instrumental and mine just the opposite.”543 They rode horses together, Lawrence in jodhpurs and using an English saddle in the American West—to distance himself, Oppenheimer thought, from the farm. When Lawrence could get away they went off on long recreational drives in the Reo to Yosemite and Death Valley.
A distinguished experimentalist from the University of Hamburg, Otto Stern, a Breslau Ph.D., forty-one that year and on his way to a Nobel Prize (though Lawrence would beat him), gave Lawrence the necessary boost. Sometime after the Christmas holidays the two men dined out in San Francisco, a pleasant ferry ride across the unbridged bay. Lawrence rehearsed again his practiced story of particles spinning to boundless energies in a confining magnetic field, but instead of coughing politely and changing the subject, as so many other colleagues had done, Stern produced a Germanic duplicate of Lawrence’s original enthusiasm and barked at him to leave the restaurant immediately and go to work. Lawrence waited in decency until morning, cornered one of his graduate students and committed him to the project as soon as he had finished studying for his Ph.D. exam.
The machine that resulted looked, in top and side views, like this:
The two cylinders of the Wideröe accelerator have become two brass electrodes shaped like the cut halves of a cylindrical flask. These are contained completely within a vacuum tank and the vacuum tank is mounted between the round, flat poles of a large electromagnet.
In the space between the two electrodes (which came to be called dees because of their shape), at the center point, a hot filament and an outlet for hydrogen gas work together to produce protons which stream off into the magnetic field. The two dees, alternately charged, push and pull the protons as they come around. When they have been accelerated through about a hundred spirals the particles exit in a beam which can then be directed onto a target. With a 4.5-inch chamber and with less than 1,000 volts on the dees, on January 2, 1931, Lawrence and his student M. Stanley Livingston produced 80,000-volt protons.
The scattering problem solved itself at low accelerations when Livingston thought to remove the fine grid of wires installed in the gap between the dees that kept the accelerating electric field out of the drift space inside. The electric fields between the dee edges suddenly began functioning as lenses, focusing the spiraling particles by deflecting them back toward the middle plane. “The intensity then became a hundred times what it was before,” Livingston says.544 That effect was too weak to confine the higher-speed particles. Livingston turned his attention to magnetic confinement. He suspected the particle beam lost focus at higher speeds because the pole faces of the magnet were not completely true, a lack of uniformity which in turn caused irregularities in the magnetic field. Impulsively he cut sheets of iron foil into small shims “having a shape much like an exclamation point,” as Lawrence and he would write in the Physical Review, and inserted the shims by trial and error between the pole faces and the vacuum chamber.545 Thus tuning the magnetic field “increased the amplification factor . . . from about 75 to about 300”—Lawrence added these triumphant italics. With both electric and magnetic focusing, in February 1932 an eleven-inch machine produced million-volt protons. It had a nickname by then that Lawrence would make official in 1936: cyclotron. Even in the formal scientific report to the Physical Review on April 1, 1932, he was unable to contain his enthusiasm for the new machine’s possibilities:
Assuming then a voltage amplification of 500, the production of 25,000,000 volt-protons [!] would require 50,000 volts at a wave-length of 14 meters applied across the accelerators; thus, 25,000 volts on each accelerator with respect to ground. It does appear entirely feasible to do this.546
The magnet for that one would weigh eighty tons, heavier than any machine used in physics up to that time. Lawrence, now a full professor, was already raising funds.
* * *
In his graduate-student days in Europe Robert Oppenheimer told a friend that he dreamed of founding a great school of theoretical physics in the United States—at Berkeley, as it happened, the second desert after New Mexico that he chose to colonize.547 Ernest Lawrence seems to have dreamed of founding a great laboratory. Both men coveted success and, each in his own way, the rewards of success, but they were differently driven.
Oppenheimer’s youthful preciosity matured in Europe and the early Berkeley years into refinement that was usually admirable if still sometimes exquisite. Oppenheimer crafted that persona for himself at least in part from a distaste for vulgarity that probably originated in rebellion against his entrepreneurial father and that was not without elements of anti-Semitic self-hatred. Along the way he convinced himself that ambition and worldly success were vulgar, a conviction bolstered nicely by trust fund earnings to the extent of ten thousand dollars a year. Thereby he confounded his own strivings. The American experimental physicist I. I. Rabi would later question why “men of Oppenheimer’s gifts do not discover everything worth discovering.”548 His answer addresses one possible source of limitation:
It seems to me that in some respects Oppenheimer was overeducated in those fields which lie outside the scientific tradition, such as his interest in religion, in the Hindu religion in particular, which resulted in a feeling for the mystery of the universe that surrounded him almost like a fog. He saw physics clearly, looking toward what had already been done, but at the border he tended to feel that there was much more of the mysterious and novel than there actually was. . . . Some may call it a lack of faith, but in my opinion it was more a turning away from the hard, crude methods of theoretical physics into a mystical realm of broad intuition.
But Oppenheimer’s revulsion from what he considered vulgar, from just those “hard, crude methods” to which Rabi refers, must have been another and more directly punishing confusion. His elegant physics, so far as an outsider can tell—his scientific papers are nearly impenetrable to the nonmathematician and deliberately so—is a physics of bank shots. It works the sides and the corners and uses the full court but prefers not to drive relentlessly for the goal. Wolfgang Pauli and the hard, distant Cambridge theoretician Paul A. M. Dirac, Eugene Wigner’s brother-in-law, both mathematicians of formidable originality, were his models. Oppenheimer first described the so-called tunnel effect whereby an uncertainly located particle sails through the electrical barrier around the nucleus
on a light breeze of probability, existing—in particle terms—then ceasing to exist, then instantly existing again on the other side.549 But George Gamow, the antic Russian, lecturing in Cambridge, devised the tunnel-effect equations that the experimenters used. Hans Bethe in the late 1930s first defined the mechanisms of carbon-cycle thermonuclear burning that fire the stars, work which won for him the Nobel Prize; Oppenheimer looked into the subtleties of the invisible cosmic margins, modeled the imploding collapse of dying suns and described theoretical stellar objects that would not be discovered for thirty and forty years—neutron stars, black holes—because the instruments required to detect them, radio telescopes and X-ray satellites, had not been invented yet.550 (Alvarez believes if Oppenheimer had lived long enough to see these developments he would have won a Nobel Prize for his work.) That was originality not so much ahead of its time as outside the frame.
Some of this psychological and creative convolution winds through a capsule essay on the virtues of discipline that Oppenheimer composed within a letter to his brother Frank in March 1932, when he was not quite twenty-eight years old. It is worth copying out at length; it hints of the long, self-punishing penance he expected to serve to cleanse any stain of crudity from his soul:
You put a hard question on the virtue of discipline. What you say is true: I do value it—and I think that you do too—more than for its earthly fruit, proficiency. I think that one can give only a metaphysical ground for this evaluation; but the variety of metaphysics which gave an answer to your question has been very great, the metaphysics themselves very disparate: the bhagavad gita, Ecclesiastes, the Stoa, the beginning of the Laws, Hugo of St Victor, St Thomas, John of the Cross, Spinoza. This very great disparity suggests that the fact that discipline is good for the soul is more fundamental than any of the grounds given for its goodness. I believe that through discipline, though not through discipline alone, we can achieve serenity, and a certain small but precious measure of freedom from the accidents of incarnation, and charity, and that detachment which preserves the world which it renounces. I believe that through discipline we can learn to preserve what is essential to our happiness in more and more adverse circumstances, and to abandon with simplicity what would else have seemed to us indispensable; that we come a little to see the world without the gross distortion of personal desire, and in seeing it so, accept more easily our earthly privation and its earthly horror—But because I believe that the reward of discipline is greater than its immediate objective, I would not have you think that discipline without objective is possible: in its nature discipline involves the subjection of the soul to some perhaps minor end; and that end must be real, if the discipline is not to be factitious. Therefore I think that all things which evoke discipline: study, and our duties to men and to the commonwealth, war, and personal hardship, and even the need for subsistence, ought to be greeted by us with profound gratitude, for only through them can we attain to the least detachment; and only so can we know peace.551
Lawrence, orders of magnitude less articulate than Oppenheimer, was also fiercely driven; the question is what drove him. A paragraph from a letter to his brother John, written at about the same time as Oppenheimer’s essay, is revealing: “Interested to hear you have had a period of depression. I have them often—sometimes nothing seems to be OK—but I have gotten used to them now. I expect the blues and I endure them. Of course the best palliative is work, but sometimes it is hard to work under the circumstances.”552 That work is only a “palliative,” not a cure, hints at how blue the blues could be. Lawrence was a hidden sufferer, in some measure manicdepressive; he kept moving not to fall in.
To all these emotional troublings—Oppenheimer’s and Lawrence’s, as Bohr’s and others’ before and since—science offered an anchor: in discovery is the preservation of the world. The psychologist who studied scientists at Berkeley with Rorschach and TAT found that “uncommon sensitivity to experiences—usually sensory experiences” is the beginning of creative discovery in science. “Heightened sensitivity is accompanied in thinking by overalertness to relatively unimportant or tangential aspects of problems. It makes [scientists] look for and postulate significance in things which customarily would not be singled out. It encourages highly individualized and even autistic ways of thinking.”553 Consider Rutherford playing his thoroughly unlikely hunch about alpha backscattering, Heisenberg remembering an obscure remark of Einstein’s and concluding that nature only performed in consonance with his mathematics, Lawrence flipping compulsively through obscure foreign journals:
Were this thinking not in the framework of scientific work, it would be considered paranoid. In scientific work, creative thinking demands seeing things not seen previously, or in ways not previously imagined; and this necessitates jumping off from “normal” positions, and taking risks by departing from reality. The difference between the thinking of the paranoid patient and the scientist comes from the latter’s ability and willingness to test out his fantasies or grandiose conceptualizations through the systems of checks and balances science has established—and to give up those schemes that are shown not to be valid on the basis of these scientific checks. It is specifically because science provides such a framework of rules and regulations to control and set bounds to paranoid thinking that a scientist can feel comfortable about taking the paranoid leaps. Without this structuring, the threat of such unrealistic, illogical, and even bizarre thinking to overall thought and personality organization in general would be too great to permit the scientist the freedom of such fantasying.554
At the leading edges of science, at the threshold of the truly new, the threat has often nearly overwhelmed. Thus Rutherford’s shock at rebounding alpha particles, “quite the most incredible event that has ever happened to me in my life.” Thus Heisenberg’s “deep alarm” when he came upon his quantum mechanics, his hallucination of looking through “the surface of atomic phenomena” into “a strangely beautiful interior” that left him giddy. Thus also, in November 1915, Einstein’s extreme reaction when he realized that the general theory of relativity he was painfully developing in the isolation of his study explained anomalies in the orbit of Mercury that had been a mystery to astronomers for more than fifty years. The theoretical physicist Abraham Pais, his biographer, concludes: “This discovery was, I believe, by far the strongest emotional experience in Einstein’s scientific life, perhaps in all his life. Nature had spoken to him. He had to be right. ‘For a few days, I was beside myself with joyous excitement.’ Later, he told [a friend] that his discovery had given him palpitations of the heart. What he told [another friend] is even more profoundly significant: when he saw that his calculations agreed with the unexplained astronomical observations, he had the feeling that something actually snapped in him.”555
The compensation for such emotional risk can be enormous. For the scientist, at exactly the moment of discovery—that most unstable existential moment—the external world, nature itself, deeply confirms his innermost fantastic convictions. Anchored abruptly in the world, Leviathan gasping on his hook, he is saved from extreme mental disorder by the most profound affirmation of the real.
Bohr especially understood this mechanism and had the courage to turn it around and use it as an instrument of assay. Otto Frisch remembers a discussion someone attempted to deflect by telling Bohr it made him giddy, to which Bohr responded: “But if anybody says he can think about quantum problems without getting giddy, that only shows that he has not understood the first thing about them.”556 Much later, Oppenheimer once told an audience, Bohr was listening to Pauli talking about a new theory on which he had recently been attacked. “And Bohr asked, at the end, ‘Is this really crazy enough? The quantum mechanics was really crazy.’ And Pauli said, ‘I hope so, but maybe not quite.’ ”557 Bohr’s understanding of how crazy discovery must be clarifies why Oppenheimer sometimes found himself unable to push alone into the raw original. To do so requires a sturdiness at the core of identity—even a brutality—that
men as different as Niels Bohr and Ernest Lawrence had earned or been granted that he was unlucky enough to lack. It seems he was cut out for other work: for now, building that school of theoretical physics he had dreamed of.
* * *
On June 3, 1920, Ernest Rutherford delivered the Bakerian Lecture before the Royal Society of London.558 It was the second time he had been invited to fill the distinguished lectureship. He used the occasion to sum up present understanding of the “nuclear constitution” and to discuss his successful transmutation of the nitrogen atom reported the previous year, the usual backward glance of such formal public events. But unusually and presciently, he also chose to speculate about the possibility of a third major constituent of atoms besides electrons and protons. He spoke of “the possible existence of an atom of mass 1 which has zero nucleus charge.” Such an atomic structure, he thought, seemed by no means impossible. It would not be a new elementary particle, he supposed, but a combination of existing particles, an electron and a proton intimately united, forming a single neutral particle.559
“Such an atom,” Rutherford went on with his usual perspicacity, “would have very novel properties. Its external [electrical] field would be practically zero, except very close to the nucleus, and in consequence it should be able to move freely through matter. Its presence would probably be difficult to detect by the spectroscope, and it may be impossible to contain it in a sealed vessel.” Those might be its peculiarities. This would be its exceptional use: “On the other hand, it should enter readily the structure of atoms, and may either unite with the nucleus or be disintegrated by its intense field.” A neutral particle, if such existed—a neutron—might be the most effective of all tools to probe the atomic nucleus.
Making of the Atomic Bomb Page 21