by Ray Monk
What is true, however, and what Condon’s career illustrates, is that if, as a Berkeley graduate, one wanted to pursue research on quantum mechanics under the supervision of leading experts in that field, it was essential to leave Berkeley and, preferably, go to Europe. Condon has given vivid accounts of some of the people who taught him at Berkeley in the early 1920s, and, while he clearly admired many of them, he would have been the first to admit that most of them were not top-flight research scientists. In fact, the professor who had the greatest influence on him, William Howell Williams, conducted no original research, published not a single paper and remained almost entirely unknown to the wider scientific community. After a brief career as a soldier, Williams had become a high-school teacher of physics – an ‘extraordinarily good’ one, according to Condon – and then a lecturer in physics at Berkeley. In time, he was promoted to full professor, but, because he never completed his PhD, his promotion was slow, and, in his subsequent bitterness and insecurity Williams turned to drink. ‘In other words,’ Condon concludes, ‘[Williams] never fitted into the normal academic pattern, but he was a very sympathetic and understanding person . . . and he also was an extremely able interpreter of modern theoretical physics.’
The chairman of the Berkeley physics department in the days when Condon was a student there was E.P. Lewis, an experimental physicist who, Condon recalls, ‘had a certain amount of spectroscopic work going on with very crude and home-made apparatus. He belonged really to that school of love and string and sealing wax, the junkiest kind of home-made apparatus.’ Lewis was not a physicist of the first rank, but he did publish more than seventy papers during his lifetime. When he died in 1926, he was replaced by a man called Elmer Hall, who, like Williams, does not seem to have published anything during his entire career. Hall was, however, still chair of the department when Oppenheimer joined in 1929, and remained in that post until his death in 1932.
One of the people at Berkeley most dedicated to improving and expanding its physics department was a professor of chemistry. Gilbert N. Lewis, one of America’s most distinguished physical chemists, had been at Berkeley since 1912, and was to stay there until his death in 1946. Though he was in the chemistry department, Lewis often worked with physicists, including, most notably, Richard Tolman at Caltech. Together with Merle Randall, his colleague at Berkeley, Lewis co-wrote the book on thermodynamics that became the standard teaching text for graduate-level courses on the subject (it was one of the books Oppenheimer claimed to have read at the end of his first year at Harvard), and was well known and well regarded by both chemists and physicists.
Helped and encouraged by Gilbert Lewis, the transformation of the physics department at Berkeley into one of the world’s leading centres of physical research did not begin in 1929 with the appointment of Oppenheimer, but rather in 1918, with the appointment of Raymond T. Birge. Birge, like E.P. Lewis, was a spectroscopist, and, like Gilbert N. Lewis, was interested in the area of scientific research where physics and chemistry meet. During the early part of his career at Berkeley he published a number of papers that made significant contributions to the ‘old quantum theory’ (the theory that centred on the Rutherford–Bohr–Sommerfeld model of the atom), including one that was cited by Sommerfeld himself in his ‘bible’, Atombau und Spektrallinien. For an American scientist in the early 1920s even to be noticed by the leading European scientists was unusual; to be cited by an acknowledged authority like Sommerfeld was a rare honour indeed. In recognition of his role in thus putting Berkeley physics on the map, Birge was made a full professor in 1926. Though he would not take over as chairman of the department until after E.P. Lewis’s death in 1932, Birge was, when Oppenheimer joined in 1929 (and had been for some time before that), recognised as its leading figure.
Condon seems not to have liked Birge, labelling him one of the ‘pedants’ who held back the promotion of William Howell Williams, thereby driving him to drink. Nevertheless, it was Birge who was responsible for most of the major steps that enabled Berkeley’s physics department to compete with the best in the world. Though Birge shared Gilbert Lewis’s enthusiasm for bridging the gap between chemistry and physics, ironically the close cooperation between the two departments at Berkeley was, to begin with, hampered by a clash between these two major figures. The clash was caused by Birge’s insistence on teaching the Rutherford–Bohr–Sommerfeld model of the atom, which contradicted Lewis’s own ‘cubical’ theory. In a short time, of course, the Rutherford–Bohr–Sommerfeld model prevailed, and many chemists at Berkeley, including at least two who went on to win the Nobel Prize – William Giauque and Harold Urey – acquired their understanding of that model from Birge’s lectures.
Because Birge, unlike his predecessors at Berkeley, published work that was read and cited by the leading European physicists, those physicists became more inclined to visit Berkeley. It was after a visit from Max Born that Condon was inspired to go to Göttingen; other great physicists to visit the department during the 1920s were Heisenberg, Sommerfeld and Ehrenfest. Birge also attracted to Berkeley home-grown American physicists who were active research scientists and conversant with modern theoretical work, most notably Leonard Loeb, who joined the department in 1923 and was promoted to full professor in 1929, the year Oppenheimer joined. Though Condon singled out William Howell Williams for special praise as a teacher, it was principally from Birge and Loeb that he acquired his knowledge and understanding of modern theoretical physics.
Birge and Loeb made it their joint business to expand the physics department and made sure every promising young American scientist knew that if they came to Berkeley they would be well paid, enjoy a perfect atmosphere for research and have excellent opportunities for rapid promotion. Before the appointment of Oppenheimer, their greatest success in this recruitment drive was with the young experimental physicist Ernest Lawrence, originally from South Dakota. Since 1927, Lawrence had been an assistant professor of physics at Yale, where he had completed his PhD under the English physicist William Swann. Swann left Yale the same year, after which Lawrence grew dissatisfied. He did not get on well with the chairman of the physics department, John Zeleny, who refused to allow him to supervise graduate students, reserving them for more senior members of faculty. Lawrence was also impatient for promotion to associate professor, which Zeleny again refused. Hearing that Birge and Loeb were keen to build up the Berkeley department, Lawrence wrote to them and received an offer of an associate professorship, which he immediately accepted. Zeleny’s parting words to Lawrence’s family were: ‘Ernest is making a mistake.’
Lawrence arrived at Berkeley in the summer of 1928, and discovered to his delight that, far from having to fight to concentrate on graduate teaching and research, such concentration was exactly what Birge, Loeb and Hall wanted from him. Encouraged by this, Lawrence threw himself without restraint into his work. He slept on campus at the faculty club, gave classes on electromagnetic theory and devoted himself to physics all day and every day, including weekends. At the centre of his work was a preoccupation with solving a problem that had been articulated by none other than Ernest Rutherford. Rutherford, noting that all progress so far made in understanding atomic structure had come about through the bombardment of atoms by various particles such as alpha particles, drew attention to the dangers of relying on nature, in the form of naturally radioactive substances like radium, to provide these bombarding particles. In a lecture to the Royal Society in 1927, Rutherford urged his colleagues throughout the world to put their minds to devising a means of producing high-energy particles artificially. This would not only free researchers from their dependence on relatively rare radioactive substances, but might also mean that particles could be produced that had even more energy, and therefore more potential for atomic disintegration, than those released by naturally occurring radioactivity.
It was Lawrence’s chief ambition to rise to that challenge. By the time Oppenheimer arrived at Berkeley, a year after him, Lawrence had not yet
built his first cyclotron (as his particle accelerator came to be called), but he had already achieved the conceptual breakthrough that subsequently allowed him to design and build it. The breakthrough came one afternoon in the university library. Lawrence was casually flicking through a German electrical-engineering journal when he saw a diagram of a device for producing high voltages using positively charged particles. Essentially, the device increased the energy of the particles by alternately pulling them towards a negative charge and then pushing them away by switching to a positive charge. Immediately, Lawrence realised that this basic principle, if applied to a device with circular trajectories, might allow one to keep increasing the energy of the ions almost without limit. The next day, he was seen hurrying across campus looking extremely elated and called out to a colleague’s wife: ‘I’m going to be famous.’
During Oppenheimer’s first year at Berkeley, Lawrence began to build his cyclotron, which in January 1931 successfully accelerated hydrogen ions up to energies of 80,000 volts.fn26 The following year, a considerably bigger machine achieved one million volts. Inspired by this success, the university set up the Radiation Laboratory, specifically for the purpose of conducting research using the cyclotron, and in 1936 it became an official department of the University of California, with Lawrence as its director. Three years later, Lawrence became the first person employed at an American state university to receive the Nobel Prize, by which time, no doubt, even John Zeleny would have admitted that neither Berkeley’s decision to hire Lawrence nor Lawrence’s decision to leave Yale had been a mistake.
From the moment he arrived at Berkeley and moved into the faculty club, Oppenheimer took to Lawrence warmly. He admired what he described as Lawrence’s ‘unbelievable vitality and love of life’, which allowed him to ‘work all day, run off for tennis, and work half the night’. For the first few years of Oppenheimer’s work at Berkeley, he and Lawrence spent a good deal of time together. They were not only united by their shared devotion to physics; there was also between them the attraction of opposites. Lawrence had an open, confident and untroubled manner. He made friends easily and had none of Oppenheimer’s enigmatic elusiveness. Harold F. Cherniss, who was a doctoral student in classics at Berkeley when he met Oppenheimer in 1929, remarked: ‘The more intimately I was acquainted with him, the less I knew about him.’ Oppenheimer, Cherniss thought, ‘wanted friends very much’, but ‘he didn’t know how to make friends’.
Oppenheimer may not have been very good at developing close friendships, but he knew how to charm people, and partly through Lawrence and partly through the magnetism exerted by his own exotic appeal, he quickly became integrated into the social life at Berkeley. ‘His mere physical appearance,’ Cherniss remembers, ‘his voice and his manners made people fall in love with him – male, female. Almost everybody.’ A story often told later of his first few days at Berkeley concerns a picnic that the Berkeley physicists and their wives had arranged in order for him to get to know everybody. Seizing the opportunity to impress, Oppenheimer said he would take care of the food, promising to cook for them an Indonesian dish called nasi goreng, which he had been taught by George Uhlenbeck’s wife, Else. After they had driven across the Bay and Oppenheimer produced the dish, however, it was met with universal repugnance (‘It tasted like sweepings from a Bombay gutter,’ one person there remembered) and was ever after referred to as ‘nasty gory’. Not only was it foul, but there was not enough of it, Oppenheimer assuming that everyone else would be content, as he was, with just a mouthful. After waiting unsuccessfully for Oppenheimer to realise that they were all still hungry, the members of the group were relieved when Lawrence announced: ‘We passed a hot-dog stand about two miles back.’ To Oppenheimer’s evident bewilderment, everyone immediately got in the car and went looking for the hot-dog stand.
‘I have been pretty busy,’ Oppenheimer wrote to Frank on 7 September 1929, shortly before the start of term, ‘preparing lectures and giving miscellaneous counsel and working and getting to know people.’ In his next letter he offered Frank himself some counsel when he returned to the question of how to treat women, or ‘the refractory problem of the jeunes filles Newyorkaises’, as Oppenheimer put it. Frank had evidently mentioned being ill at ease with women, in response to which Oppenheimer’s counsel was to associate only with those women who took responsibility for putting him at ease. ‘The obligation,’ he told Frank, ‘is always on the girl for making a go of conversation: if she does not accept the obligation, nothing that you can do will make the negotiations pleasant.’
Perhaps this advice offers some clue as to why Oppenheimer’s relations with women during this time seem to have been restricted to those who were already married. To meet a woman who was the wife of a colleague did not impose on him the obligation to initiate contact, with all the potential for embarrassment and risk of rejection that is involved in, say, asking a woman out for a date. Helen Allison, with whom Oppenheimer had flirted during his time as an NRC fellow at Caltech in 1928, remembers at Berkeley ‘young wives falling for Robert, charmed by his conversation, gifts of flowers, etc.’ Oppenheimer, she thought, ‘had an eye for women’, but his attentions ‘should not be taken too seriously’.
‘I can’t think that it would be terrible of me to say –’ Oppenheimer wrote to Frank, ‘and it is occasionally true – that I need physics more than friends.’ At Berkeley, Oppenheimer was eventually able to combine his need for friends with his need for, and love of, physics, and to combine both with his desire to build an American school of theoretical physics by finding his friends from among his students. This, however, was a long process. In the first year or two, most of the students who took his courses found them incomprehensible and him intimidating.
The lectures Oppenheimer mentions preparing in his letter to Frank were part of a graduate course on quantum mechanics that he gave in the first semester of the 1929–30 academic year. His teaching at Berkeley was entirely confined to graduates. It was, he said later, ‘very rarely and only in quite different contexts that I ever worked with undergraduates. I think they didn’t think I’d be any good for them and it didn’t occur to me to ask to teach freshman physics or anything like that.’ As well as the course on quantum mechanics, he gave a graduate seminar concentrating on some aspect of theoretical physics, the title of which rotated between ‘Introduction to Theoretical Physics’ and ‘Methods of Theoretical Physics’. Oppenheimer did not approach this teaching in the spirit of someone preparing students for an exam (in fact, as some of his students complained, he never set them any tests and so had no formal means of assessing how much they had understood). Rather, as he says in the quotation given at the beginning of this chapter, he approached it from the point of view of ‘a propagator of the theory which I loved’. As far as he was concerned, he was there not to teach – and certainly not to assess – students, but to bring quantum mechanics to Berkeley.
‘I think from all I hear I was a very difficult lecturer,’ he admitted. ‘I started as a lecturer who made things very difficult.’ Oppenheimer’s notes for his lectures on quantum mechanics survive and show that he did indeed make great demands upon his students. The way he remembered it was that ‘I found myself . . . the only one who understood what this was all about, and the gift which my high-school teacher of English had noted for explaining technical things came into action.’ Presumably by ‘this’ he meant quantum mechanics, though in fact he was not the only one at Berkeley with any understanding of quantum mechanics: Birge, Loeb, Williams and Lawrence were all familiar with the Schrödinger wave-function version of the theory. All of them, however, were unfamiliar with, and baffled by, Heisenberg’s matrix mechanics and Dirac’s transformation theory, and these are what, just two weeks into the course, Oppenheimer asked his students to understand. Naturally many of them struggled, and when they asked for further elucidation, they were referred to books, most of which were written in German.
‘Almost immediately,’ Birge later said, ‘studen
ts came to complain that he was going too fast.’ Birge asked to see Oppenheimer’s notes and, after reading them, urged his students to persevere. Oppenheimer, meanwhile, complained to Birge: ‘I’m going so slowly that I’m not getting anywhere.’ ‘This,’ Birge recalled, ‘was my first intimation of the speed at which Oppenheimer’s mind worked.’ Oppenheimer delivered his lectures in a low, quiet voice, while smoking incessantly; as soon as he finished a cigarette, he stubbed it out and lit a new one, almost in a single action. ‘Since we couldn’t understand what he was saying,’ one of his students remembered, ‘we watched the cigarette. We were always expecting him to write on the board with it and smoke the chalk, but I don’t think he ever did.’
For the first two years of his joint post Oppenheimer would lecture at Berkeley from August until Christmas and then journey 350 miles south to Pasadena, teaching at Caltech from January until June, before spending as much of the summer as he could in New Mexico. After two years of this, Berkeley (the administrators of which were never entirely happy with having to share Oppenheimer with another university) changed the dates of their semesters, so that the first semester extended into January, making this arrangement impossible. Oppenheimer was determined to maintain the connection with Caltech, so he negotiated with Berkeley an agreement to teach at Caltech for the last six weeks of the academic year, just before the summer break. In this way, the fifty–fifty split that he had originally envisaged was transformed into an arrangement whereby he was basically employed by Berkeley, but released by them to spend a few weeks each year at Pasadena.
‘In Pasadena,’ Oppenheimer later said, ‘I taught all right, but it was never an important part of the Caltech curriculum except conceivably that first year in the spring of ’30 when I was there a long time and where I probably gave a pretty good “course of sprouts” in quantum theory.’ The title of this ‘course of sprouts’ was ‘Topics in Theoretical Physics’. Again, it was restricted to graduates, and, perhaps because Oppenheimer had higher expectations of Caltech students than he had of Berkeley students, it was pitched at an even higher level, consisting of dense and concentrated discussions of subjects dealt with in recent research papers.