FRED HOYLE had left Cambridge in 1955 for the United States to continue astrophysical research related to his work on the composition of stars. Thus, at the end of myfirst year at Trinity, I suddenly found myself without a supervisor. According to the university rules, a research student at Cambridge had to have a supervisor. As my research was going reasonably well, obtaining a supervisor would be a mere formality because I would continue working on my own.
The university proposed that I be supervised by Abdus Salam, who was a young fellow of St. John’s College and a newly appointed lecturer in the university. Fortunately, Salam agreed to take me on. At the time, he was not particularly interested in relativity and gravity. He was busy researching quantum field theory and particle physics and building up a particle physics group at Cambridge in collaboration with his former supervisor, Paul Matthews. Consequently, my supervision under Abdus Salam turned out to be as haphazard as it had been with Fred Hoyle. A session most often consisted of my meeting Abdus at the Arts School on Benet Street and striding at breakneck speed through King’s Parade and Trinity Street on the way to St. John’s College, black gowns flapping, with me breathlessly explaining my pursuits in relativity and gravitation to a silent Salam. We would part at the gates of St. John’s College, and Salam would dart in to tutor undergraduates in his rooms.
He was known in Cambridge as Abdus Salam, but his real, unanglicized name was Ab-us-salam. Like his other students and physicists at the university, I called him Abdus. He had been born in the part of India that after partition became Pakistan, and his father was an Ahmadi Muslim, a sect that was subjected to much persecution in the Islamic world because its believers claimed that their late-nineteenth-century founder was the long-awaited Messiah, or Mahdi. Salam had married his first cousin and they could often be seen walking through Cambridge, she following him several yards behind, dressed in a black chador. I later learned that part of Salam’s motivation for being a physicist was that as a deeply religious person, he believed that any success he achieved in theoretical physics would contribute to revealing the secrets of Allah.
This is not to suggest that Salam was interested in physics primarily as a means towards a higher goal. On one occasion when we walked rapidly through Cambridge together, he commented that it would be interesting to know how physics would look fifty years hence. This was a strong indication to me that he, like Pauli, was passionately interested in seeing how the fundamental theory of matter would develop and how he could contribute to a deeper understanding of particle physics.
It was understood from the beginning that my supervision by Salam would be on a purely formal basis, for with the exception of his collaboration with two student-colleagues, John Polkinghorne and later Walter Gilbert, Salam did not collaborate with students. Such a pro-forma supervision arrangement was not untypical at Cambridge, where students were often left at arm’s length by their supervisors. It was a sink-or-swim situation, for without much guidance, you had to learn to be independent in your thinking and try to succeed on your own. I was quite happy with this arrangement.
I met Salam in the mid-1950s, before he became famous. He was a handsome man in his thirties then, with piercing dark brown eyes and a well-trimmed moustache. He usually dressed formally, in a three-piece suit and St. John’s College tie. Salam had been a highly successful undergraduate at Cambridge, and had achieved the status of wrangler in the notorious tripos exams, which I had successfully avoided. The famous Cambridge tripos was in three parts, and it normally took four years to study for these exams. They originated in 1641, and consisted of candidates sitting on three-legged stools—hence the term “tripos” —with the examiner firing questions at them. They in turn “wrangled” or debated with the examiner as they answered the questions. In 1794, Cambridge University officially instituted the tripos exams as written exams. Those with the highest scores were called wranglers, and the one with the highest score was called the senior wrangler. Salam also did very well in the special physics tripos exam, and he carried out experiments using the old apparatus left over from the Rutherford era of the Cavendish Laboratory, which had been used to investigate the structure of the atom. Prior to his becoming a lecturer at Cambridge, Salam had spent a year at the Institute for Advanced Study in Princeton, where, in collaboration with his former supervisor, Paul Matthews, he had solved a difficult problem in quantum field theory called the overlapping divergence problem.
It was inspiring to see how passionate Salam was about physics. During my time at Cambridge, he gave a series of lectures on the strong force in particle physics and what is called dispersion relations. These relations refer in general physics to the index of refraction of a medium, such as water, being a function of the frequency of waves in the medium. I spent a lot of time in those days in the upper gallery at the Arts School library, poring over microfilms, turning a little wheel to read them. These microfilms were a preliminary copy of The Theory of Quantized Fields by the Russian physicists Nikolay Bogoliubov and Dmitry Shirkov, which was Salam’s holy book on the subject. At one classroom session when Salam was lecturing and writing on the blackboard, he kept ignoring certain numerical factors, which made his calculations hard to follow—and I knew what those factors should have been, from reading the Bogoliubov-Shirkov book. I stood up halfway through Salam’s lecture and complained to him about the lack of rigour in his calculations, turned on my heel and walked out. Salam never showed any anger at me for this arrogant behaviour. In fact, it seemed to me that I had won more respect from him as a physicist.
During one of my early sessions with Salam, I told him how I had corresponded with Einstein prior to my arriving at Cambridge. His eyes lit up. “You corresponded with Einstein?” he said. “We have to do something about this.”
“What do you mean?” I asked.
Salam’s eyes narrowed. “You have to get these letters copied and send them out to the major universities and physicists like Dyson, Oppenheimer and Wheeler in America,” he said.
I was astonished at this proposal, alarmed at the idea of advertising myself in this way. Salam noted my discomfort and said, “Moffat, you have to learn to sell yourself. The physics world is a competitive place.”
Little did I know that this statement portended events in Salam’s own life, when he would be fiercely competitive and lobby research groups and even the Nobel committee, promoting his ideas. I and other graduate students at Cambridge idolized Paul Dirac, who seemed able to keep himself completely aloof from academic politics. He published his brilliant ideas and achieved fame without getting his hands dirty in the fiercely competitive world of physics. I realized that this was probably a naive and overly idealistic attitude to adopt, especially in view of mylowly position at Cambridge, but I could not make myself follow Salam’s advice.
About a week later, as I was descending the stairs at the Arts School, Salam was ascending them breathlessly. He stopped me and asked, “Well, Moffat, have you sent out those Einstein letters to the people I suggested?”
For a moment I said nothing, and then hesitantly said, “No, I haven’t done anything about it.”
“Why not?” Salam asked.
“Because I feel uncomfortable about it.”
“How do you expect to make a name for yourself in physics with this kind of attitude?”
I gazed at Salam and remained silent. After a few moments of frowning at me, he climbed up the stairs impatiently.
Salam was in a unique situation at Cambridge, being the only notable theoretical physicist from the Indian subcontinent. He was, in fact, the first Pakistani-appointed professor in the British university system after Pakistan was formed in 1947—and he undoubtedly at times felt discriminated against by the English academic establishment. Another wrangler at Cambridge, John Meggs, was working on a rather original approach to quantum field theory. He was a tall, gangly, bespectacled Englishman. The rumour among us research students was that he and Salam had had a serious difference of opinion about Meggs’s research, and Meggs had in anger uttered a racist epithet to Salam, which had greatly upset him.
Meggs eventually joined the army and set aside his final Ph. D. defence for a year. One day I happened to be present at the Arts School when Paul Matthews and Salam were standing outside a room waiting to examine John Meggs for his Ph. D. Richard Eden, a former student of Dirac’s, appeared and there ensued a heated discussion between the three of them, which I witnessed. Eden was warning Salam and Matthews that there would be serious repercussions if they did not award Meggs his Ph. D.; Meggs was an outstanding student at Cambridge, he said, and it would cause a scandal if they failed him. The undercurrent that I detected in Eden’s comments was that Salam should not allow Meggs’s possible racism to influence his judgment of the Ph. D. candidate’s intellectual achievements. Salam and Matthews did award Meggs his Ph. D., and Meggs subsequently left Cambridge for a position in industry.
In 1957, Salam was appointed professor of applied mathematics at Imperial College London. Again, I was left without a supervisor, and this was at the awkward time when I was almost finished with my thesis. The university suggested that a junior fellow at Cambridge, David Candlin, serve as my supervisor for the remainder of the year, the same David Candlin who had been one of the victims of Pauli’s grilling during his visit to Cambridge, and who was just two years ahead of me, having only recently earned his doctorate. Just as with my previous two supervisors, Candlin and I had no serious discussions about my research. He was engaged in research in quantum field theory, a topic that I also became involved in, working on quantum field theory along with my Ph. D. work on modifications of gravitation theory and the motion of particles in Einstein’s theory. The interlude with Candlin was brief, and not very satisfactory, because we had so little contact with one another. Without the respect and fame of a Hoyle or Salam backing him up, Candlin seemed nervous about my unusual status at Cambridge—a Ph. D. student without a prior degree.
Although I still had not earned my degree, I had to make plans for my future after Cambridge. The letters that Dirac must have written on my behalf began to bear fruit. One day a portly gentleman in a black suit and bowler hat, carrying an umbrella, arrived at Bridget’s and my small flat in Cambridge and said that he was with the security service at Aldermaston Laboratory. He interviewed me intensively about my past, no doubt to ferret out whether I had plans of becoming a spy and stealing secret atomic bomb information from Aldermaston. Needless to say, I had no such plans, and after scribbling in a notebook, he seemed satisfied and left. To me, the job at Aldermaston was definitely second choice. I earnestly hoped to receive a fellowship from the government in order to continue physics research after earning my Ph. D.
Not long after this, I took the train into London for an interview at the Department of Scientific and Industrial Research (DSIR), which awarded those research fellowships. I was discouraged to find at least ten other young hopefuls waiting on benches in a long, narrow corridor, all having applied for the two available fellowships. I felt very tense. The door opened and we were ushered into a large room where professors were seated at individual tables with little plaques announcing their titles and affiliations. I was seated in front of a tall, grey-haired, bespectacled gentleman wearing a light brown suit and a college tie from some university in England that I did not recognize. He began interviewing me about my academic background and raised his eyebrows when he heard that I didn’t have an undergraduate degree. I laid out reprints of my papers published in the Cambridge Philosophical Society’s journal on the table between us. He skimmed through them and seemed impressed. I explained that I expected to finish my Ph. D. shortly.
I left the building and walked down Oxford Street towards Piccadilly Circus feeling despondent, not expecting to win this fellowship with such competition from the other applicants, who, I imagined, possessed more conventional academic backgrounds. I took the train back to Cambridge and the flat Bridget and I were renting across the street from a neglected little cemetery. We had just one room with a pullout bed, and a combination kitchen and bathroom, with the bathtub placed against a wall next to the little gas stove. There, I continued typing my thesis on an old Royal typewriter, using carbon paper to make a copy. I laboriously printed in the equations with a pen between gaps I had left in the text. In those days long before word processors, writing a thesis was an agonizingly difficult task. In between bouts of typing, I would sit and stare out the window at the grey headstones across the street, attempting to feel positive about my future.
I was in close touch with my parents during this time. My father had recovered from tuberculosis and worked as a draftsman at an aircraft company outside Cambridge. On his way home in the late afternoons, he would often stop by to visit. He drove an ancient black sedan that constantly needed expensive repairs. My parents rented out a room in their house on Oxford Road, and my mother prepared meals for the lodger, who was usually a student from abroad.
Near the end of 1957, I submitted my Ph. D. thesis to the university and appeared before my examiners, the relativists William Bonnor, who was by this time a professor at the University of London, and William McCrea. Remarkably, these were two of the professors who had interviewed me when I had arrived in England three years before. After the intense verbal exam was over, I learned from McCrea, who met with me privately in one of the rooms at St. John’s College, that they weren’t happy with the way I had written the thesis, and wanted me to do more work on it. This dampened my spirits considerably, as more tedious work lay ahead. But not long afterwards I received a letter from the Department of Scientific and Industrial Research informing me that I had won the fellowship I had wanted so badly! This gave me renewed motivation to get back to work and make the required changes on the thesis. And when the job offer came from Aldermaston, I was relieved to be able to turn it down.
I later learned that Roy Kerr, who was finishing his Ph. D. at about the same time, also had Bonnor and McCrea as examiners, and he suffered the same fate as I did. I knew that Roy was not fussy about English grammar or the presentation of his work, and indeed, McCrea demanded that he not only rewrite parts of his thesis, but even put in literary quotations at the beginning of each chapter.
Abdus Salam was now a full professor at Imperial College London, where he had been asked to form a new group concentrating on particle physics and quantum field theory. Even though I had not yet finished my Ph. D., he invited me to join him there with my newly won government fellowship and become his first postdoctoral fellow. I went to London alone at first, without Bridget, who continued in her job in Cambridge, and I moved into a flat near Kew Gardens. The ensuing few months were not a happy time on my own, as I laboured away every day, rewriting parts of my thesis. I worked alone, without advice from either Bonnor or McCrea, and Salam was too busy forming his new group to be of any help. My parents seemed disappointed when they heard the news about my thesis. At the Cambridge bus station on the day I left for London, my father reprimanded me for not being more successful. Within a couple of months Bridget left her job in Cambridge and moved to be with me at the flat in Kew.
In the thesis that I originally submitted, I had developed a modification of Einstein’s gravity theory, general relativity, based on a different geometry than Einstein’s, a complex symmetric Riemann-ian geometry. McCrea and Bonnor had not thought this was enough to constitute a Ph. D. thesis, so in my revised version I included all my work on the motion of particles in Einstein’s gravity theory. This meant that I had to include the problems I had discovered in the paper by Einstein and Infeld published in the Canadian Journal of Mathematics in 1949, and my attempts to resolve these problems in a positive way.
When I was finally finished rewriting the thesis, I arranged with McCrea to have my second Ph. D. exam at Cambridge. I took the train back to Cambridge, stayed with my parents for a few days and then met my examiners on the prescribed day in rooms at St. John’s College. The exam lasted three hours, with Bonnor and McCrea asking one question after another. This time, they were very concerned about the issue of mycriticism of the Einstein-Infeld paper. In fact, they were rather disconcerted about how to handle it. I had provided detailed calculations in the thesis, showing how the problems had arisen in the paper and also how to solve them. My examiners couldn’t find anything wrong with my calculations, but they felt nervous about the political implications. Einstein was dead, but Infeld was in Warsaw—I had met him at the Einstein Fest in Bern before I had encountered the mistake in the famous paper—and he had never responded to my subsequent letters. Moreover, my modification of Einstein gravity was for that time quite a radical piece of work, which rang alarm bells for physicists as conservative as Bon-nor and McCrea.
After three exhausting hours, McCrea turned to Bonnor and said, “All right, this is enough.” They sent me out of the room and I sat outside waiting nervously, fearing that my postdoctoral fellowship, my father’s anticipated approval and my entire future were about to go down the drain. Finally, they called me back into the room, shook my hand in turn and announced that I had passed the examination.
The first Ph. D. exam, the rewriting of the thesis and the gruelling final exam had been the most stressful series of events I had experienced in my short academic life. I promptly lost my voice and was unable to speak for several days. I also developed a nervous-stomach disorder during those months, which has stayed with me ever since, a frequent and painful reminder of my initiation into physics.
On the bright side of things, however, I now had a Ph. D. from Trinity College, Cambridge. Being the first student in the history of Trinity College to be awarded a Ph. D. in theoretical physics without an undergraduate degree marked quite an achievement. I now officially joined Imperial College London, and, fortified with my doctorate and feeling more secure about my future, I buried myself in my research.
Bridget and I moved from the Kew flat into one looking out onto Kensington Gardens, not far from the Albert Memorial and concert hall, and only a short walk from Imperial College in South Kensington. We were living on my meagre government fellowship and her salary as a secretary in a bank in South Kensington, and we felt lucky to have secured this small but pleasant one-room flat. Early in the morning, we would be awakened by the Royal Guards in their magisterial uniforms with glittering helmets and white feather plumes. Mounted on their magnificent horses, they clattered down the street on the way to Buckingham Palace.