Around Mecca
In the beginning, until 1935, the disciples, or some of them, worked directly with the prophet, or, better, "the high priest."[114] But as the administrative burden and the complexity of the machine increased, Lawrence became more and more removed from the work and workers in the Laboratory. He could be very generous to his students—some parents praised him lavishly for his kindness to their offspring—but he could also be impatient and
unreasonably demanding when the machine stopped.[115] His impatience was enhanced by his frequent colds, picked up on his travels.[116] He was often away from the Laboratory lecturing, at meetings of the National Academy of Sciences or the American Physical Society, and fund-raising (which he did to greatest effect in person in New York, where all his main supporters among foundations had their headquarters). These trips occupied more time than they need have done, since Lawrence insisted on going by train; he had worked out that flying was dangerous, that the chance of a fatal accident in a round trip from San Francisco to New York was one in a thousand, and would have nothing to do with airplanes.[117] No doubt the long journeys by rail were necessary to him for quiet relaxation and unhurried future planning. After the settlement of 1936, Lawrence was in Berkeley long enough to encourage the staff and create his family. Otherwise he left the execution of his plans to Cooksey.[118]
Lawrence retained his boyishness and ebullience for successes of the Laboratory and for approaches to his backers. It was only natural that he would come to identify with the men of wealth on whom he had come to depend and who appeared to like his company. He enjoyed the entertainments of New York bankers and brokers; he liked the style of Alfred Loomis, whose patronizing of the Laboratory, which began late in 1939, included a weekend at the plush Del Monte Hotel in Carmel for the Sprouls, the A.H. Comptons, the Vannevar Bushes, and the E.O. Lawrences. In these tastes and associations, Lawrence was followed, as in much else, by Alvarez.[119] In the same line, Lawrence set some store on
family background; whenever the ancestry of his students permitted it, he would include in his letters of recommendation the irrelevance that they came "of good family."[120] He came to dislike nonconformity (to his ideas!) and liberal causes, to hold that "science is justified only to the extent that it brings substantial riches to mankind," and to declare research scientists—among whom he enrolled himself—to be "essentially conservative people."[121] In these sentiments he disagreed altogether with his colleagues Urey, A.H. Compton, and, closer to home, Oppenheimer, whose personal style influenced the apprentice theorists at Berkeley at least as much as Lawrence's helped define the cyclotroneer.[122]
The contrast between the two men is the stuff of stories.[123] Lawrence grew up in rigid and rigorous South Dakota, worked during high school, learned to build radios, went into physics, knew little else, had no regrets, never doubted his way. Oppenheimer came from a wealthy Jewish family, grew up surrounded by books and pictures, attended the indulgent Ethical Cultural School, collected beautiful rocks, had literary ambitions, drifted into physics, suffered severe depressions. He also suffered from cultural ambitions, which caused him to learn, or affect to know, diverse languages, good food and wine, the best in music, painting, and books; he would take girls to dinner and read them Baudelaire; he sketched in charcoal and painted in oils; at Berkeley he studied with professors of Sanskrit, read Plato in Greek, and, what was worse, talked about it.[124] They moved in opposite directions
politically under the strong polarizing forces of the late 1930s. Lawrence trusted that the world would muddle through without requiring his attention. He had faith in the great powers, which, he thought, had established at Munich that international disputes would be settled by peaceful negotiations; "I am not concerned about the political atmosphere," he reassured Cockcroft, concerning a meeting in Europe planned for September 1939, "which I personally think will be all right." Oppenheimer did not allow the world to get on without his help. While Lawrence drifted complacently to the right, he rushed to the left, to the support of the Spanish Loyalists, American labor, and other pinkish causes.[125]
It might therefore appear astonishing that from Oppenheimer's first semester at Berkeley in 1929, he and Lawrence were fast friends.[126] His Jewishness bothered him more than it did Lawrence; as one of his Harvard professors once wrote, by way of recommendation, "Oppenheimer is a Jew, but entirely without the usual qualifications of his race."[127] The basis of their friendship was their fundamental honesty, kindness, and openness, qualities each would soon enough come to compromise. They also shared a liking for, and for showing off, feats of physical prowess. Oppenheimer delighted in long journeys by horseback through remote reaches of New Mexico and surprised those foolhardy enough to accompany him by his stamina. Lawrence visited the Oppenheimer family retreat near what became the Los Alamos Laboratory once or twice, but preferred to take his exercise on the tennis court or in a small boat bought with the proceeds of the Comstock prize. "He plays a good game of tennis," said the Scientific American , "[and] has a cruising boat on San Francisco Bay that he won't take out unless there is rough water."[128]
At the professional level, Lawrence and Oppenheimer esteemed each other as physicists, recognized each other's ambitions, saw that they did not conflict, and possessed the tie natural to the men expected by their Department to raise Berkeley physics to national distinction. "For all his sketchiness, and the highly questionable character of what he reports," Oppenheimer wrote, "Lawrence is a marvelous physicist." "He has all along been a valued partner," Lawrence allowed in support of Oppenheimer's promotion to full professor. He might have added: "His physics [is] good, but his arithmetic awful."[129] Where Lawrence misinterpreted and mismeasured, Oppenheimer erred by factors of 100 or 1,000. When he was close. Here is a compliment from a German theorist who followed his calculations for pair production: "Oppenheimer's formula . . . is remarkably correct for him, apparently only the numerical factor is wrong."[130]
Oppenheimer himself did not trust the theories he elaborated. He wrote his brother in 1932: "The work is fine: not fine in the fruits but the doing. . . . We are busy studying nuclei and neutrons and disintegrations; trying to make some place between the inadequate theory and the revolutionary experiments." And again, in 1934: "As you undoubtedly know, theoretical physics . . . is in a hell of a way."[131] For a time Lawrence thought that Gamow would be more helpful than Oppenheimer; but he could offer only theoretical dollars, and nothing came of his effort to bring Gamow to Berkeley.[132] Thereafter Lawrence and his Laboratory had only the theoretical advice they obtained casually from Oppenheimer's group and from an occasional short-time visitor. It is likely that Lawrence shared the views of his old friend Ernest Pollard of Yale. "To tell the truth, I don't absolutely think any current
nuclear theory worth much, but theoreticians regrettably have the power to divert thought from a constructive interpretation of experiment which doesn't agree with the present pervading jargons."[133]
The most productive interaction between Lawrence's and Oppenheimer's groups concerned the hypothesis of deuteron disintegration, which Oppenheimer at first accepted fully and with a certain pleasure: "that makes, as far as I can see, a hopeless obstacle to Heisenberg's pseudo q.m. [quantum mechanics] of the nucleus." But the implausibility of the consequent character of the deuteron gave him pause, and he accepted the explanation of contamination long before Lawrence did. From the shambles, as we know, he and his former doctoral student, Melba Phillips, extracted the Oppenheimer-Phillips mechanism, which did help importantly in the interpretation of disintegration experiments at the Laboratory.[134] There are a few other cases of productive interaction beyond the mixed advice Oppenheimer gave at the weekly seminars: his postdoc Robert Serber's analysis of the proton-proton scattering experiments of Lawrence's student Milton White; McMillan's measurements of absorption of g rays, in rough confirmation of calculations by Oppenheimer and Furry; and Oppenheimer's explanation of Henderson's results on the energy dependence of the disintegration of lithium by protons.[135]
These interactions belong to the early years, when Oppenheimer felt a responsibility to help to elucidate disintegration. After 1936 the most useful of Oppenheimer's group for Lawrence's work was Sydney Dancoff, who pushed the theory of isomeric and radioactive transitions beyond what the European theorists had achieved and did not disdain to calculate the absorption of neutrons in the
cyclotron's water shielding. This unusual interest on the part of an Oppenheimer theorist in problems central to the Laboratory inspired a still rarer thought on Lawrence's part, one perhaps not expressed since the unsuccessful approach to Gamow: the thought of adding a theorist to the Laboratory's staff. Oppenheimer did not think that a very promising employment, and Dancoff went to join Serber in Urbana.[136]
A rough measure of the closeness of the two groups may be obtained from an analysis of the composition of the thesis committees on which Lawrence served during the 1930s. Between 1931 and 1941 inclusive, thirty-seven theses were completed under these committees, twenty-one of which had Lawrence as nominal director. His associates on the thirty-seven committees divide into two classes, those with six to eight appearances and those with three or fewer, except for Leonard Loeb, who figures four times. Those in the first class: experimentalists R.T. Birge (units), R.B. Brode (cosmic rays), F.A. Jenkins and H. White (spectroscopy), theorist Oppenheimer, and chemists G.N. Lewis and Willard Libby. Perhaps the strongest showing was Libby's, who tied with Oppenheimer with eight appearances, on half of which he was the principal reader. On this showing, Lawrence's students—that is, students in experimental nuclear physics who had Lawrence as their nominal thesis director—were no closer to Oppenheimer than they were to any other active member of the Physics Department or to chemists interested in nuclear processes.
The makeup of these committees does not indicate anything about casual consultation of Oppenheimer or his students by perplexed members of the Laboratory. For graduate students, we have some measure of the extent of this consultation: six of them who had Lawrence but not Oppenheimer on their committees thank both Lawrence and Oppenheimer for advice.[137] Also,
Oppenheimer's students occasionally did a calculation or elucidated a theoretical point for Lawrence's: for example, Willis Lamb's explanation of Laslett's failure to detect decay in Na22 and Eldred Nelson's collaboration with Alvarez and Carl Helmholz on the behavior of isomeric silver nuclei.[138]
Just as many (we do not say all!) of Lawrence's "boys" adopted his rough-and-ready approach to physics and had little time or interest in much outside the Laboratory, so Oppenheimer's aped his gestures, tried to acquire his tastes, went to concerts, and talked books, art, and politics.[139] A Lawrence man rushed through his preparation, knowing that, if he did well, he would have a choice of eligible positions; an Oppenheimer man proceeded with greater leisure, knowing that the art was long, and "jobs for theorists . . . not too common."[140] The divergent cultures of the theorists and experimenters, the problematic state of nuclear theory, the peculiar fascinations of the cyclotroneers, and the increasing importance of biomedicine in the Laboratory worked to prevent the development there of the sort of theory-driven experiments that mark the big-machine physics of the postwar era.
Perhaps more important for the direction of nuclear science at the Laboratory than its relations with Oppenheimer's group and even with the entire Physics Department was its interactions with the College of Chemistry. Besides Lewis and Libby, there was Seaborg, who became the Laboratory's most productive chemist in 1937. As an instructor in the College of Chemistry, which he became in 1939, after two years of easy service as Lewis's assistant, Seaborg brought excellent doctoral students to do nuclear chemistry around the cyclotron, with consequences that were literally earthshaking.[141] Another young chemist closely associated with the Laboratory, Samuel Ruben, worked with Kamen and the
radioisotope C11 on the mechanism of photosynthesis. Their discovery of a better tracer, C14 , was one of the high points of the Laboratory's prewar work.[142]
Spiralling further out, Lawrence's people had an opportunity, not frequently seized, of easy exchanges with their colleagues at Stanford. When Felix Bloch, a theoretical physicist with the highest European pedigree, took up an assistant professorship at Stanford in the fall of 1934, he and Oppenheimer began joint weekly seminars, three-quarters of which were held at Berkeley. This interchange resulted in collaborations between Bloch and Oppenheimer's students and between Bloch and Alvarez, and in the inspiration for an investigation by Laslett. The work of Alvarez and Bloch on the magnetic moment of the neutron was probably the most advanced piece of exact physics done at the Laboratory during the 1930s. Stanford also offered the advantage of a summer course by a visiting theorist; we do not know how many of Lawrence's people besides Nahmias took the opportunity or trouble to go to Stanford to hear Gamow, Victor Weisskopf, Rabi, John Van Vleck, or Fermi. Nor have we been able to trace much useful interaction where it might be expected, between the Berkeley cyclotroneers and the applied physicists in and around Stanford, William Hansen and the Varian brothers. These men also had an interest in accelerators, but for electrons, not ions. Their "rhumbatron" and "klystron," which did not interest Lawrence in the late 1930s, came to play a part at Berkeley during the war.[143]