Inside the Centre: The Life of J. Robert Oppenheimer (28 page)

At the Como conference quantum mechanics had received its definitive and final statement; at the fifth Solvay Congress, in the form it had been given at Como, it triumphed over its most influential sceptics. One imagines that Oppenheimer would have longed to be in Europe at this moment when the movement to which he had pinned his colours came of age and emerged victorious. However, competing – and winning – against his desire to be at the forefront of modern physics was his love of America. In the summer of 1927, with quantum mechanics poised to make its greatest triumph, his deepest desire was to be back home; he had by then been away for almost two years and was extremely homesick.

Oppenheimer wanted to spend time revisiting familiar places and being with his family, especially his brother. To his dismay, his parents had sold the Bay Shore house the previous winter, but his boat, the
Trimethy
, was still moored there and so he and Frank were still able to go sailing along the Long Island coast. After a while the two of them took the boat up to Nantucket Island, Massachussetts, where they joined their parents for a holiday. There, Frank remembers: ‘My brother and I spent most of the days painting with oils on canvas the dunes and grassy hills.’

Oppenheimer no doubt enjoyed creating a permanent reminder of the countryside he loved, and had missed during his two years in Europe. At Leiden, in his anxiety to return home, he had evidently overdone his praise of his homeland. ‘He’s too much,’ a fellow student remarked. ‘According to Oppenheimer, even the flowers smell better in America.’ It wasn’t just the landscape he loved, either. Along with other American physicists studying in Europe, Oppenheimer had been upset by how little
respect there was for American science among Europeans. As Isidor Rabi put it: ‘We were not highly regarded, I must say, nor was there any thought that America would amount to anything as far as physics was concerned. There were a few people, certainly, but one looked down their noses on Americans . . . We felt very bad about this.’ A sense of what American physicists had to put up with can be gained from Paul Dirac’s response when he was asked in 1927 by Edward Condon if he would like to visit America: ‘There are no physicists in America.’.

The NRC fellowship scheme was one way of stimulating American physics; another was attracting European physicists to work in American universities. Max Born, during his visit to the USA in 1925–6, had received several job offers. He declined, but many others accepted, including Oppenheimer’s Dutch friends George Uhlenbeck and Samuel Goudsmit, who both accepted positions at the University of Michigan, starting in the autumn of 1927. Charlotte Riefenstahl, meanwhile, was offered and accepted a job at Vassar College.

So it was that in the late summer of 1927, Uhlenbeck, Goudsmit and Riefenstahl, along with Uhlenbeck’s new wife, Else, travelled together to New York aboard the SS
Baltic
. There at the dockside to welcome them to America was Oppenheimer, together with his father’s car, complete with uniformed chauffeur. ‘We all got the real Oppenheimer treatment,’ Goudsmit later said, ‘but it was for Charlotte’s benefit really. He met us in this great chauffeur-driven limousine, and took us downtown to a hotel he had selected in Greenwich Village.’ The hotel was the Brevoort, one of New York City’s oldest and most famous hotels, known for its French cuisine and fine wines, and chosen by Oppenheimer for his guests because of its European atmosphere. In the evening, Oppenheimer treated the party to dinner at a Brooklyn hotel from which they could see the lighted Manhattan skyline. Having persuaded the Uhlenbecks to delay their journey to Ann Arbor, the next day he took them, together with Charlotte, to meet his parents at their apartment on Riverside Drive. Else Uhlenbeck later recalled the beautifully furnished living room, the Van Gogh and other paintings, Mrs Oppenheimer’s graciousness and Frank, just turned fifteen, standing at the door looking shy and awkward.

After the Uhlenbecks and Goudsmit left for Ann Arbor, Charlotte stayed in New York for a few weeks, where, as Oppenheimer’s guest, she ate at the very finest restaurants in the city. As she was well aware, she was being courted, but the courtship was short-lived. This was not only because she had to leave for Vassar, and he for Harvard, but also because she came to think that Oppenheimer was not emotionally ready for a romantic attachment. She found the atmosphere at Riverside Drive stifling, and Oppenheimer evasive and detached whenever she asked him
anything personal, for example about his past. She was particularly put off when she asked him about his mother’s gloved hand and was met with a stony silence. If, when she arrived in New York, she was tempted to consider Oppenheimer a possible future husband, by the time she left such temptations had been overcome.

^fn23
John C. Slater, then a young physics professor at Harvard. Later he became chairman of the physics department at MIT.

IN THE SUMMER
of 1927, when Oppenheimer started his period as a postdoctoral fellow, he must have arrived at Harvard with a scientific paper already written, or at least nearly finished. For his first published article as ‘J.R. Oppenheimer. National Research Fellow’ is dated ‘August 1927’ and is reported as having been sent from the Jefferson Physical Laboratory at Harvard. The article, published in the
Physical Review
, is entitled ‘Three Notes on the Quantum Theory of Aperiodic Effects’, and is today one of his better-known and most-cited publications, containing as it does one of the earliest discussions by a physicist of the strange phenomenon of ‘tunnelling’, whereby a particle, such as an electron or an alpha particle, can ‘tunnel’ its way through a barrier, even though it lacks the energy that classical physics would require it to have to perform such a feat.

Oppenheimer was at Harvard for a mere five months (he left for Caltech at the end of 1927), but he published two more articles during his time there: one on the polarisation of impact radiation in the
Proceedings of the National Academy of Sciences
and another on the capture of electrons by alpha particles in the
Physical Review
. In a letter to Paul Dirac, written on 28 November, Oppenheimer – after sending his ‘very best felicitations’ on the news that Dirac had been made a Fellow of St John’s College – gave Dirac a fairly detailed summary of all three papers, perhaps revealing that, despite describing them as ‘a lot of little things, but nothing at all important’, he was actually quite proud of his productivity.

Oppenheimer also mentioned to Dirac that he had sent a paper on what is known as the ‘Ramsauer effect’ to Ehrenfest. The Ramsauer effect is a phenomenon discovered by the German physicist Carl Ramsauer that defies explanation by Newtonian physics, but is explicable using quantum mechanics. What Ramsauer discovered was that when electrons move
through certain gases, the probability of a collision between an individual electron and an individual atom of the gas does not, as Newtonian physics would predict, decrease with the energy of the electron; rather, at a certain low energy, the probability of collision reaches a minimum below which it will not sink. The explanation for this relies upon taking into account the wave-like properties of the electron in a quantum-mechanical way.

Oppenheimer thought he had an alternative explanation of the Ramsauer effect, one that could be generalised for all atoms and molecules. Unfortunately, Ehrenfest noticed several errors in Oppenheimer’s calculations, forcing Oppenheimer to delay publication of the paper. While he reworked his figures, he published a short note in the
Proceedings of the National Academy of Sciences
, announcing his conclusions and promising: ‘Details of the theory will be published elsewhere.’ In fact, the paper was abandoned and contributed only to Oppenheimer’s reputation as a physicist who, while undeniably brilliant, was prone to making mathematical mistakes.

Not that such errors affected his ability to intimidate. Philip Morse, who would later enjoy an illustrious career as a physicist and an administrator, was in 1927 a PhD student at Princeton, and has recalled in his autobiography how, when he came to Harvard to attend a seminar that autumn, he met ‘a thin high-strung postdoctoral fellow by the name of Oppenheimer, who gave me a bad case of inferiority by talking mysteriously about Dirac electrons and quaternions. I didn’t know what he was talking about and his talk didn’t enlighten me.’ ‘Oppie always affected me that way,’ Morse adds. ‘I never could figure out whether his sibylline declarations were just a form of one-upmanship or whether he really did see a lot more in a theory than I did. Some of both, I finally decided.’

Oppenheimer seems to have made few new friends during this second period at Harvard, but he did re-establish contact with two old friends: John Edsall, who was then at Harvard Medical School, and William Boyd, who was studying for a PhD in biochemistry at Boston University Medical School. With Boyd in particular, Oppenheimer shared an unusual intimacy. He told Boyd about his psychological problems at Cambridge and also showed him a poem he had written, which Boyd encouraged him to send to Harvard’s avant-garde literary magazine,
Hound & Horn
, which had just been founded by a group of English undergraduates inspired by T.S. Eliot’s
The Criterion
. The poem, in full, is as follows:

One of Oppenheimer’s earliest biographers, Denise Royal, has interpreted the poem as an expression of Oppenheimer’s ‘own dry, sterile intellectuality’, but it seems more obviously a nostalgic evocation of his beloved New Mexico. Far from being sterile, the desert in the poem – with its yuccas, palms and tamarisks – is fertile, warm and welcoming, its ‘forgotten’ new moon appearing to call Oppenheimer from the ‘cold’ mountains that he is leaving behind without so much as a backward glance. These mountains might, it seems to me, represent the peaks of academia – Cambridge, Göttingen and Harvard – that he is anxious to leave in favour of a return to the New Mexico desert.

In any case, as soon as the Christmas holiday season was over, Oppenheimer left Harvard and headed for the South-west, to spend the rest of his NRC fellowship at the California Institute of Technology (Caltech) in Pasadena. Ten miles north-east of Los Angeles in the South Californian desert, Pasadena was then a fairly small town (with about 50,000 inhabitants), notable mainly for two things: first, hosting the Rose Bowl, an annual college football game that has been played in Pasadena on the first day of each new year since 1902; and second, the California Institute of Technology itself, which though only six years old in 1927, was already recognised as one of the leading centres of scientific research in the US. At the head of Caltech (his official title was ‘Chairman of the Executive Council’) was the Nobel Prize-winning physicist Robert A. Millikan, who, while often derided as a pompous anti-Semite, was an extraordinarily successful fund-raiser and administrator.

From its beginnings in 1921, Caltech had a special relationship with the National Research Council. Its founder, the astronomer George Ellery
Hale, had been the chairman of the NRC, and, through the influence of first Hale and then Millikan (who got to know Hale when he served as vice chairman of the NRC), a substantial proportion of NRC fellows conducted their research at Caltech. Through his connections with the NRC, Millikan would have received reports about Oppenheimer from Göttingen and Harvard, and was clearly already considering him as a potential permanent member of staff.

At this time appropriately trained physicists – that is, those who had studied under the leading quantum physicists in Europe – were scarce and the competition to hire them was intense. This is reflected in the first surviving letter that Oppenheimer wrote from Pasadena, which was to Kemble in Harvard, advising him about potential appointments. William Houston, who was then assistant professor of physics at Caltech, was, Oppenheimer told Kemble, ‘very much the man you want’, though ‘You may have a little trouble getting him, as they are very fond of him here.’ (Oppenheimer, it is a little easy to forget, was still only twenty-three.)

Oppenheimer also mentioned to Kemble the work of one of Caltech’s most promising young chemists, Linus Pauling. For a short while, Pauling and Oppenheimer got on very well. Pauling’s interests coincided with Oppenheimer’s and, in time, he was to produce the definitive textbook on a subject very close to Oppenheimer’s heart, the theory of chemical bonding (as Oppenheimer had put it: what makes a molecule a molecule). Pauling’s graduate work had been on the use of X-ray diffraction to determine the structure of crystals, and he had, before he met Oppenheimer, published several papers on the crystal structure of minerals. In an act of extraordinary kindness that shows how much regard he must have had for Pauling, Oppenheimer gave him his entire collection of minerals – the collection he had built up since the age of five, when his grandfather presented him with the box of rocks that had first inspired his interest in science. Pauling, Oppenheimer later recalled, ‘was then still stuck on crystals – inorganic crystals – so that he not only used them but he was very pleased [with] these enormous calcites’.

Oppenheimer and Pauling formed a plan of working together on what is now known as quantum chemistry. In particular, they intended to produce jointly authored work on the nature of the chemical bond. However, before this work had got very far, Pauling cut off his relations with Oppenheimer. The reason was that Oppenheimer was taking far too much interest in Pauling’s pretty wife, Ava. Conforming to what one would later recognise as Oppenheimer’s ‘type’, Ava Helen Pauling was not only very attractive, she was also socially aware and politically active. She is credited with inspiring and encouraging her husband’s later concern
with the issues of nuclear proliferation and world peace.
^fn24
Oppenheimer made a bizarre approach to Ava one day; while her husband was at work, he went to their house and invited her to join him – without her husband – on a ‘tryst to Mexico’. She refused and told her husband about it, whereupon he decided to have nothing more to do with Oppenheimer. After Linus Pauling’s death, there was discovered among his papers a Caltech envelope marked ‘Poems by J. Robert Oppenheimer 1928’. It contained eleven poems: six on nature, three on love, and two on ageing and death. It is possible that Oppenheimer presented this collection to Pauling, but more likely, I think, that he gave it to Ava, as part of his clumsy attempt to seduce her.