by Ray Monk
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:
Crossing
It was evening when we came to the river
with a low moon over the desert
that we had lost in the mountains, forgotten,
what with the cold and the sweating
and the ranges barring the sky.
And when we found it again,
in the dry hills down by the river,
half withered, we had
the hot winds against us.
There were two palms by the landing:
the yuccas were flowering; there was
a light on the far shore, and tamarisks.
We waited a long time, in silence.
Then we heard the oars creaking
and, afterwards, I remember,
the boatman called to us.
We did not look back at the mountains.
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.
In a letter he wrote to Frank at about the time he was wooing Ava Pauling, Oppenheimer offered his teenage brother some advice on how to treat women – advice that, he wrote, ‘may possibly be of use to you, as the fruit and outcome of my erotic labours’. The woman’s profession, he told Frank, was ‘to make you waste your time with her’, while ‘it is your profession to keep clear’. ‘The whole thing,’ he added, ‘is only important for people who have time to waste. For you and me, it isn’t.’
And for the last rule: Don’t worry about girls, and don’t make love to girls, unless you have to: DON’T DO IT AS A DUTY. Try to find out, by watching yourself, what you really want; if you approve of it, try to get it; if you disapprove of it, try to get over it.
Another woman in whom Oppenheimer showed especial interest during his time at Caltech was as unavailable to him as Ava Pauling had been. This was Helen Campbell, who was a friend and Vassar classmate of Inez Pollak, and, when Oppenheimer first met her, was engaged to a physicist at Berkeley called Samuel K. Allison. She and Allison married in May 1928. This, however, did not deter Oppenheimer from spending as much time alone with her as he could. He took her out to dinner, read Baudelaire to her and talked with her about psychoanalysis and New Mexico. It did not lead to romance, but neither did it lead to Samuel Allison breaking off contact with Oppenheimer.
While Oppenheimer was having his amorous advances rebuffed, he himself was fending off professional advances from universities. He later recalled that he had ‘many invitations to university positions, one or two in Europe, and perhaps ten in the United States’. In his letter to Frank he says: ‘I am trying to decide whether to take a professorship at the University of California next year or go abroad.’ He had visited Berkeley and was attracted to it partly because it was not an important centre of theoretical research, thus offering him, as it were, a blank sheet upon which to write his own script. Or, as he put it:
I thought I’d like to go to Berkeley because it was a desert. There was no theoretical physics and I thought it would be nice to try to start something. I also thought it would be dangerous because I’d be too far out of touch, so I kept the connection with Caltech.
What he wanted was a joint appointment, working half the time at Berkeley and the other half at Caltech.
Meanwhile, he was being assiduously courted by Harvard. On 10 April 1928, Professor Theodore Lyman, director of the department of physics at Harvard, wrote to Oppenheimer offering him a lectureship. Oppenheimer replied on 21 April, saying that he would ‘like to be able to accept’ the offer, but he ‘planned to spend next year in Europe’. About two weeks later, Oppenheimer wrote again to Lyman, finally refusing the offer at Harvard and telling him that he had accepted instead precisely the arrangement he had wanted: first he would spend the following year abroad, then he would take up a joint appointment, dividing himself between Berkeley and Caltech.
Oppenheimer’s plan to spend a year abroad conducting postdoctoral research under the guidance of the great European physicists was perhaps a result of what he described in his letter to Edwin Kemble as ‘the Ramsauer fiasco’, feeling that he still needed to improve his technical competence if he was to make important contributions to theoretical physics. Explaining the decision to the head of the Berkeley physics department, Elmer Hall, Oppenheimer said it was based on his intention to ‘try to learn a little physics there’. Abraham Pais thought, more specifically, that Oppenheimer’s experiences at Caltech ‘revealed to him his deficiencies in mathematics’, which made him want to return to Europe. Because he wanted to pursue postdoctoral work in Europe rather than the US, Oppenheimer’s application to renew his NRC fellowship came under the auspices of the Rockefeller Foundation’s International Education Board, which on 26 April 1928 considered and approved Oppenheimer’s application to work on ‘problems of quantum mechanics’ first with Ralph Fowler in Cambridge and then with either Ehrenfest in Leiden or Bohr in Copenhagen.
Having thus secured both his fellowship for the year 1928–9 and his two teaching positions, starting the year after that, Oppenheimer left Caltech in July 1928, intending to spend the first part of the summer at Ann Arbor and the second part in New Mexico with his family. The attraction of Ann Arbor was not only the chance it offered of reuniting with Goudsmit and Uhlenbeck, but also the opportunity of attending the famous summer school in theoretical physics, which had become (and would remain until the Second World War) an annual event, attracting distinguished theoretical physicists from all over the world.
From Ann Arbor, Oppenheimer on 2 August wrote to the International Education Board to tell them that he would have to postpone his fellowship because he had tuberculosis and ‘several doctors have told me that it would not be very wise to go abroad until I am better’. For a few years Oppenheimer had suffered from a nasty, persistent cough, caused no doubt by his heavy smoking, but it is unlikely that he had tuberculosis. Frank, asked many years later, thought there never had been a secure and confirmed diagnosis of tuberculosis, leading some to wonder – just as Herbert Smith had wondered about Oppenheimer’s ‘dysentery’ before starting at Harvard – whether Oppenheimer, ill with worry about whether he could meet the expectations he and others had of himself, had invented a medical cause for his feeling unwell, one that would allow him to delay the challenge that he faced.
After the summer school finished, Oppenheimer headed for New Mexico, as planned. In his letter to Frank the previous spring, Oppenheimer had asked him what his plans were for the summer. ‘If you are out here [that is, in the South-west],’ he suggested, ‘we might knock around for a fortnight on the desert.’ During Oppenheimer’s time at Caltech, his family’s situation had changed somewhat. Having already sold the Bay Shore house, in 1928 they sold the Riverside Drive apartment too and moved into a smaller apartment on Park Avenue, between 47th and 48th Street in Midtown, Manhattan – then, as now, one of the most expensive areas in the world. Frank, who would turn sixteen on 14 August 1928, was, like his older brother, tall, slim and good-looking, but without his brother’s intensity and instability.
While Oppenheimer had been attending the summer school at Ann Arbor, Frank had been at a summer camp in Colorado. They arranged to meet at Katherine Page’s house in Los Pinos. Oppenheimer arrived a few days before Frank and was taken by Katherine to a cabin a mile or so from her ranch at Cowles. It was built of half-trunks and adobe mortar and commanded a magnificent view of the Sangre de Cristo mountains and the Pecos River. ‘Like it?’ Katherine asked, and when Oppenheimer nodded, she told him that it was available for rent. ‘Hot dog!’ said Oppenheimer. ‘That’s what you should call it,’ Katherine told him. ‘Hot Dog. Perro Caliente.’
When Frank arrived, he and Oppenheimer moved into Perro Caliente, which they persuaded their father that winter to lease. When the lease ran out in 1947, Oppenheimer bought it outright. For the rest of his life Perro Caliente was to be his refuge. For two weeks, Oppenheimer and his brother stayed at the cabin and cemented a mutual admiration for, and bond with, each other. Almost every day they rode in the mountains, acquiring a reputation among the locals for expert horsemanship. While they rode, they talked about physics, poetry, literature, philosophy and religion. Francis Fergusson visited them and would later tell how, after a hot and tiring day on the range, he headed for the icebox in the cabin, to find only half a bottle of vodka, a jar of pickled artichokes, some caviar and a can of chicken livers.
Despite this inadequate nutrition, Oppenheimer’s health improved enormously during his time in
New Mexico, and on 25 August he wrote from there to the NRC’s Fellowship Board, thanking them for their letter of 16 August (in which, in response to Oppenheimer’s statement that he had tuberculosis, they had told him that his fellowship had been withdrawn) and telling them: ‘It now seems certain that I shall be able to take the fellowship of the International Education Board . . . I therefore very much hope that the withdrawal of the fellowship will not prove permanent.’
Understandably perplexed, the IEB asked Oppenheimer to undergo a complete medical examination. The Oppenheimer brothers had arranged, after their two-week sojourn in New Mexico, to meet their parents at the Broadmoor Hotel in Colorado Springs. Thus it was in Colorado Springs that Oppenheimer underwent the medical examination insisted upon by the IEB. It took place on 18 September 1928 and was conducted by a Dr Gerald B. Webb, who found no trace of tuberculosis and reported that, apart from having some ten months previously a ‘slight sinus infection and slight tonsillitis since’, Oppenheimer was in ‘first class’ medical condition. After receiving this report, the NRC approved the IEB stipend, although, unusually, it was not for twelve months but for nine, starting on 1 November.
In the meantime, after taking a few driving lessons, the Oppenheimer brothers bought a car, a Chrysler Roadster, and set off for Pasadena. Before they were even out of Colorado, they had an accident. With Frank at the wheel, the car skidded on some loose gravel and rolled over into a ditch. The windscreen was shattered, the cloth top ruined and Oppenheimer’s right arm broken. Remarkably, they got the car running again the next day, but Frank drove it onto a slab of rock from which they were unable to move. They spent that night on the desert floor, as Frank remembered it, ‘sipping from a bottle of spirits . . . and sucking on some lemons’. Oppenheimer arrived in Pasadena dishevelled, unshaven, one arm in a sling and with little time to pack and prepare to leave for Europe. However, during what had been an eventful and memorable summer, his little brother had been transformed into his closest friend.