I was born in Camberwell, South London, on the 26th of March, 1938. I am told I only made it into the world on the date in question by seven minutes, thereby exhibiting at this early stage the tendency to procrastination which I fear has characterized much of my subsequent career. Not a great deal is known about my ancestry beyond a few generations, though one tidbit of information which has been passed down is that an ancestor on my father’s side served for a time as a cook on Nelson’s flagship, the Victory (it is unknown whether he was actually present at the battle of Trafalgar). As far as we can trace them, my father’s forebears were village cobblers in a small village in Hampshire, though his father broke with this tradition to become a greengrocer; my father would tell me how he used to ride with him to buy vegetables at the Covent Garden market in London. My mother’s parents were both of Irish stock; her father had emigrated to England and worked as a clerk in the naval dockyard in Chatham. My maternal grandmother, who survived into her eighties (and my twenties), was a remarkable person; sent out to domestic service at the age of twelve, she eventually married my grandfather and raised a large family, then in her late sixties emigrated to Australia to join her daughter and son-in-law, and finally returned to the UK for her last years. She was a very warm person, and I still have very fond memories both of my meetings with her (unfortunately few in her last years, because of the geography) and of the many letters she wrote me; since she had had no formal education, she simply wrote down on paper exactly what she would have said to you in person, and to read a letter from her was like having her stand in the room with you. It is interesting that that kind of spontaneity in the written word, which seemed to have been lost forever under the influence of universal secondary education, is now returning in the guise of e-mail.
My father and mother were each the first in their families to receive a university education; they met and became engaged while students at the Institute of Education at the University of London, but were unable to get married for some years because my father had to care for his own mother and siblings. He worked as a secondary-school (high-school) teacher of physics, chemistry and mathematics. My mother also taught secondary-school mathematics for a time, but had to give this up when I was born. I was eventually followed by two sisters, Clare and Judith, and two brothers, Terence and Paul (both now deceased). My parents were both Catholics (in my mother’s case ancestrally, in my father’s I believe because his own father had converted), so that we children were brought up in that faith, making us members of a small and somewhat embattled minority in the England of those days. Although I ceased to be a practicing Catholic in my early twenties, I still wonder from time to time how far the experience, in childhood and adolescence, of maintaining and defending, sometimes in public and in the face of some ridicule, beliefs and attitudes not shared by the vast majority of my compatriots may have influenced my subsequent attitude to physics and indeed to life in general (which, at least as regards the former, is I suspect sometimes regarded by my colleagues as reflecting a degree of iconoclasm verging on counter-suggestibility).
Soon after I was born, my parents bought a house in Upper Norwood, just outside the southern boundary of London proper (but well within the London conurbation). However, when I was eighteen months old, war broke out and we were “evacuated” to Englefield Green, a small village in Surrey on the edge of the great park of Windsor Palace, where we stayed for the duration of the war. The village was fortunate to escape the bombs that fell on towns all around (including Slough, perhaps in response to John Betjeman’s couplet!) and my war-related memories are relatively few: barrage balloons tethered above the Thames, lying in bed at night listening to the German “doodle-bugs” droning overhead (and praying they would not cut out immediately above our house), and the day I was “officially” informed that there was a war on (and decided that at no cost should my sister Clare, a year younger than me, find out about it). When in later life I read the memoirs of people who lived through those same years in the ravaged cities of continental Europe or Asia, or even through the Blitz in London, I realize how extraordinarily lucky we were.
Although Englefield Green is only a few miles outside the western borders of the Greater London conurbation, it is (or was!) in some sense in the countryside, and many of my memories of those years are of long walks through the fields and parks surrounding the village. However, one of my main activities, and the one which gained me most notoriety among our neighbors, was digging deep holes, I think on occasion deeper than my height at the time, in our front garden (not the easiest activity in a soil which was basically London clay). Exactly what motivated me to do this, and what deep insights it reveals into my psyche, is something I have never figured out, but it was perhaps loosely connected with my then choice of future career: after a brief flirtation with the idea of becoming a railway signalman, I decided firmly that I wanted to be an explorer (you have to remember that in those days there were still odd patches of the planet which had never been trodden by human feet, nor mapped by GPS). In the end I suppose that, like many academics, I achieved this ambition though in a more abstract way.
After the end of the war, we returned to the Upper Norwood house and lived there until 1950; my father taught at a school in north-east London (unfortunately a long commute) and my mother by that time had her hands full looking after what were eventually five of us children. I attended the local Catholic elementary (grade) school, and later, following a successful performance in the “eleven-plus” examination which I took rather earlier than most, transferred to the College of the Sacred Heart in Wimbledon (a “grammar”, i.e. state-financed academic-stream, school). This required a slightly complicated commute (bus, train, then another bus), which had the advantage that I could get a fair amount of reading done on the journey to and fro. (A few years ago, while on a brief return visit to the UK, I had for a reason I forget, to repeat exactly this journey and got completely lost – such have been the changes in the transportation system of southwest London in 50 years). Although I took part in the required physical sports at school, in particular in long-distance running, my main recreation in those years was chess, an interest I kept throughout my teens and into my Oxford years (I had a brief moment of glory when some years later, I was picked for the English team to compete against Scotland, Wales, and Ireland in the (under-16) Glorney Cup). Another practice I developed in those years was to take long hikes or cycle rides alone into the countryside surrounding southwest London; in later years I kept up this habit in much more untamed terrain, sometimes steering by compass, in thick mist, over many miles of trackless Welsh or Scottish mountainside. (Since I often did this alone and did not always leave details of my itinerary, and there are plenty of accidents in those areas even in good weather, I am perhaps lucky still to be here!)
In 1949 my father, who had become increasingly unhappy with the long commute to his job in north-east London, obtained a job teaching physics and chemistry at Beaumont College, a school run by the Jesuits near Windsor. This was a “public” school in the British sense of the word (i.e., “private” in the US sense) and we could certainly not have afforded the fees for even one of us three boys to attend it; however, my father negotiated as part of his conditions of service that all three of us could go to Beaumont free of charge, so we did. At the same time we moved to a large, rambling and somewhat broken-down house in Staines, on the far western edge of the London conurbation, which remained our family home until I was well into my thirties; this house was a delight to my father, who in another life would have been a handyman, but probably less so to my mother who had to endure the consequences of all the things he had not yet got around to fixing. One of the prime attractions, at least for us children, was the large garden and in particular the huge chestnut tree, in which we built many camps and “forts”.
Even within the somewhat esoteric world of British public schools, Beaumont was a rather unusual place. One feature which is, to my knowledge, unique to Jesuit schools, is that while the teaching staff includes both laymen, such as my father, and priests, those who are priests typically have not been school teachers for all or even most of their careers: they may have been for example parish priests, missionaries or even university teachers, and be doing the teaching job only for a few years before going back to one of those occupations. Also, in the case of “boarding” schools such as Beaumont, it is common for priests who are retired to live on the premises, whether or not they have been teachers there. As I will relate, this circumstance had totally unforeseen consequences for my career.
Not long after my transfer to Beaumont, at the age of thirteen, I had to make what under normal circumstances would have amounted to an irrevocable decision about my career in life. I imagine that to anyone reading this 50 years later, in the context of a European (even British) or North American school system, this will seem quite incredible; but in those days the degree of “channeling” even in progressive schools in Britain (and Beaumont was far from progressive!) was extreme: you had to choose at an early age (normally 15, but in my case 13) between specialization in classics, modern languages, mathematics and science. That choice then essentially determined which kinds of degree you could take at university (assuming you went), and that in turn put severe constraints on the kind of job you could reasonably apply for. At Beaumont, the unspoken tradition was that if you showed any signs of academic ability, as I apparently did, and had no strong predilection to the contrary, you were automatically channeled into the stream which was deemed most academically prestigious, namely the classics stream (Latin and Greek languages and literature). Remarkably, my father, despite his own training and employment, never exerted the least pressure on me to take the science option (which was generally regarded, for reasons which are unclear to me, but were probably a reflection of a common attitude in Britain at that time, as the least prestigious of all). So I indeed ended up, at the age of thirteen, committed to spending most of my school years on the classics, with only a small fraction available for other subjects such as English, history, or mathematics. My memories of this classics education are mixed: on the one hand, I still recall the soul-destroying discipline of the “gender rhymes”, jingles which we were required to memorize to remind us of the correct gender of Latin nouns, and fragments of which still 50 years later seem to take up kilobytes of storage space in my brain which I am sure could be put to better use (“. and common are to either sex, artifex and opifex …”). On the other hand, some of my teachers were enthusiastic and inspiring, and introduced me at an early stage to the poetry of Catullus and Horace and the historical analysis of Thucydides.
Although I by and large enjoyed the academic side of life at Beaumont and prospered at it, in most other respects I was a decided misfit: Almost all my fellow-pupils were fee-paying, which almost automatically meant that they enjoyed, at home, a lifestyle of which we had no experience; except in my last two years I was one of a small minority of “day-boys” (that is, I commuted daily from home rather than residing at the school throughout the term); and, perhaps most importantly, because of my academic precocity I was placed in classes with boys who were mostly a couple of years older than me. As a result, the five years I spent there, while not unhappy, do not stand out in retrospect as a particularly joyful period of my life.
However, at least two things happened during those years which were to have, in different ways, very happy long-term consequences. The first was that, for a reason I cannot now recall (I think it may have been to help my recovery from an illness which had kept me in bed for a month) my father decided to send me on a mountaineering course in Snowdonia. Unlike the rolling hills of Surrey and Berkshire which I had explored on my solitary hikes, the mountains around Llanberis were the real thing, craggy, mostly pathless and, in bad weather, decidedly not to be trifled with; I fell in love with them at first sight, and mountaineering in all its forms, from easy strolls to technically relatively demanding rock-climbing, has been a major passion of my life ever since.
The second serendipitous event actually occurred after I had competed for, and obtained, a scholarship to Balliol College, Oxford, in December 1954. I had to wait a few months before taking up the scholarship, and in those days there were no nationally organized programs to employ people in my position in voluntary service overseas, etc., so I somewhat reluctantly stayed at school. Also living at the school was a retired priest, Fr. Charles O’Hara, who had at one period of his career been a university teacher of mathematics and had in fact written a textbook on projective geometry. One day he ran into me in the corridor and said to me: “You seem to have a lot of time on your hands. Well, I have a lot of time on my hands. Why don’t you come along to my room for a couple of hours a week, and I’ll show you some interesting things in modern mathematics?” Now, at that point I had only the minimal mathematics required for the “O-level” examination (though I don’t recall clearly, I think it did not even include differential calculus, and certainly not the integral variety), and I had absolutely no reason to think that I would ever in my career need anything more sophisticated. However, I indeed had time to kill, Fr. O’Hara seemed enthusiastic, and perhaps to humor him as much as anything, I agreed to his proposal. So for the rest of those two terms he gave me, for a couple of hours a week, a sort of Cook’s tour of ideas in modern mathematics, involving concepts such as groups, rings, and fields which my O-level education had never even grazed and which I found quite fascinating. Even more importantly in retrospect, he actively encouraged me to do a few simple exercises involving those concepts, and to my initial surprise I found I could in fact do them without great difficulty. After the end of the school year I had other things on my mind and promptly forgot all the details of what he had taught me; but this was to be the first of a series of fortunate accidents that helped to shape my eventual career.
In early October of 1955 I went up to Oxford to take up my scholarship at Balliol, with the intention of reading (majoring in) the degree technically known as Literae Humaniores, and informally as Greats (on which more below). For me, coming as I did from a school background which even by the standards of those days was somewhat restrictive and conservative, entering university was like stepping through a door and finding myself in a completely new world. I still have idyllic memories of my first two weeks in Oxford, with the autumn colors in the parks at their peak and the scent in the air of infinite possibilities, both intellectual and social. Although of course that initial sense of excitement didn’t last forever, by and large my nine years at Oxford, as undergraduate and graduate, were very happy indeed; not only did I thoroughly enjoy and prosper at my academic work, but I made a variety of friends from all over the world, especially from south and east Asia, with many of whom I have kept in lifelong contact. On the sports side, I had done some sculling at school, and initially rowed bow in the Balliol third eight. However, it was not long before the coach noticed that I was two stone lighter than the then coxswain (“cox”) and interchanged us, and thereafter my destiny was fixed; I eventually rose to be cox of the first eight, and while I did not exactly steer them to victory (in fact, in the year of my coxswainship we did, formally, just about as badly as it is possible to do!), I nevertheless feel we put up a good fight. (Incidentally, I should have no such career possibility today: one consequence of the gender-integration of the Oxford colleges which took place in the 70’s is that the coxes of college eights are now, for obvious reasons, almost invariably female).
The Oxford Greats degree is one of those many British institutions which need to be understood in historical rather than logical terms. It takes four years (12 trimesters), and for the first five trimesters one studies Greek and Latin languages and literature, thus making it the obvious choice of degree for anyone who, like me, has specialized in the classics at school. For the last seven trimesters one studies in parallel “ancient”, that is Greek and Roman, literature and philosophy; the philosophy side of the degree has only a relatively small “ancient” component (Plato and Aristotle), and is (or was in my day) mostly centered in the analytic and mostly Anglo-Saxon tradition (Descartes, Locke, Berkeley, Hume, Russell, Wittgenstein … and in more contemporary terms Ayer, Ryle, Austin …). I thoroughly enjoyed all the components of the course; I found particularly rewarding the individual (or sometimes two-person) tutorials characteristic of the “Oxbridge” system, in which I could discuss with my tutors, at least prima facie on equal terms, the most recent journal articles on the origins of coinage in the ancient Mediterranean or the concept of machine consciousness. (One disappointment I encountered on eventually switching to physics is that in that subject, as I suspect in most of the “hard” sciences, such cutting-edge discussions are not realistically possible at the undergraduate level).
I am often asked whether and how my Greats training has been useful to me in my subsequent career in physics. To that question I have a joking answer, namely that unlike (apparently) some of my physics colleagues I at least know the difference between the Greek letters j and y! However, there is a serious answer: I certainly do feel the philosophy component of the degree, at least, has helped to shape the way at which I look at the world and in particular at the problems of physics. This is not something which is easy to quantify or make concrete; I have never undergone a course of psycho-analysis, but I imagine that anyone who does so can never again look at the world in quite the same light, and I think that the same is true for the kind of rigorous course of analytic philosophy which I went through at Oxford. Another analogy might be with the feeling I experienced later when I learned to speak Japanese with a reasonable degree of fluency; it is as if one has learned to use a muscle that one did not know one had. At any rate I have never for a moment regretted the years I spent on this degree.
Towards the end of my third year in Oxford it gradually began to dawn on me that I could not go on being a student for ever and must start looking for gainful employment. Not being endowed with a great deal of initiative, I first looked around to see what careers previous Greats students at Balliol had chosen. With few exceptions, it seemed that they had either gone into the British civil service or become teachers, at university or high-school level, of one of the subjects they had studied (classics, ancient history or philosophy). As regarded the first option, it did not take me long to figure out that even were I to pass the examination for the civil service (something which was by no means a foregone conclusion, since it tested qualities rather different from the ones which had advantaged me in a purely academic context), a career there was likely to be both uncongenial to me and of dubious benefit to the British public. So I started contemplating a career in academia; and since the subject which I had enjoyed most, and performed best in, was philosophy, this seemed the natural choice.
But the more I thought about the prospect of doing a doctorate in philosophy and eventually obtaining a university lectureship in that subject, the more I realized that in my bones I just did not want to do it. Why not? It never occurred to me – as it no doubt would have to someone with more imagination – that maybe I was not actually cut out for an academic career at all. Rather I asked myself what exactly it was about philosophy as such which deterred me from doing it professionally for life. And I eventually came up with the answer that it was because what counted as good or bad work in philosophy – at least as it was practiced in Oxford at that time – seemed to depend so strongly on the precise nuances of one’s wording (something, incidentally, which I suspect may have subtly disadvantaged non-native English speakers in that discipline); there seemed to be no objective criterion of what was correct or not, or even what was good work or bad, and I felt in my bones that it was just such a criterion that I needed if I was going to pursue an academic career. I did indeed briefly consider the possibility of going into pure mathematics, but rejected it on the grounds that in mathematics, almost by the definition of the subject, to be wrong means you are stupid: I wanted the possibility of being wrong without being stupid – of being wrong, if you like, for interesting and nontrivial reasons. Physics seemed to fill that bill, and while I had zero formal training in that subject, the confidence which I had acquired from Fr. O’Hara in advanced mathematics led me to believe that that aspect of the subject, at least, would not give me major difficulty. So, in the early summer of 1958 I took my courage in both hands and applied to do a second Oxford undergraduate degree, in physics, following the anticipated completion in spring 1959 of my Greats degree.
In those days in Britain to do a second undergraduate degree in anything, let alone in a subject in which one had no secondary-school experience, was practically unheard of, and I immediately faced several practical obstacles. In the first place, I had to persuade some college to accept me; secondly, I had to find some way of financing two more years of undergraduate education, and finally, since 1959 was known to be the last year of conscription in Britain, I had to persuade my draft board that my application to do a second degree was not just a ruse to avoid military service for ever (a consequence it in fact had). At this point I had another piece of luck: in October of 1957 engineers in the Soviet Union had propelled into space the first Sputnik, thus stealing a march on the West in what not just governments, but every layman could see was an extraordinarily important area of technology. Immediately the cry went up from politicians and the press: how have the Soviets managed to get ahead of us in this crucially important enterprise? And the answer was not long coming: It was because we have encouraged all our best brains to study useless subjects (such as classics) rather than useful ones (such as science and engineering and particularly physics). Immediately all sorts of scholarships became available for students in the arts who wished to transfer to science; and while I did not in the end need to apply for any of these, I think that the general shift in cultural attitudes which they reflected was an enormous psychological boost to me in making the switch, and in particular may have been the crucial element in helping my prospective tutors to convince the draft board that they could dispense with my services on the parade ground.
The two people who played the most indispensable role in helping me make the transition are David Brink and Michael Baker. In those days most Oxford colleges did not have a tutor in theoretical physics as such, but Balliol had recently appointed David in this role, and since I initially applied to Balliol it was he who had to take a decision on whether I was or was not a reasonable prospect for a degree in physics, despite my lack of background. He asked me to read various sections of that beautiful book, “What is mathematics?” by Courant and Robbins in the summer vacation between my third and fourth years, and when I returned in October tested me on them; on the basis of my performance he recommended that Balliol should accept me for a second degree. However, by that time I had applied somewhat speculatively to Merton, where Michael Baker was a tutor in physics, for a Domus scholarship. These scholarships were normally given to students undertaking a postgraduate degree, but in my case the Fellows generously made an exception. Thus, I ended up doing my degree in physics at Merton; Michael was my principal tutor, but since he was an experimentalist and Merton did not at the time have a tutor in theoretical physics as such, I went to David for most of the more theoretically oriented parts of the course. In order to get a classified degree I had to complete the course in two years rather than the standard three, and this resulted in a certain degree of mental indigestion: I recall simultaneously struggling with old-fashioned problems involving rods and pulleys from Humphrey and Topping’s “Intermediate Mechanics” and with the properties of Hilbert space as set out in Mandl’s text on quantum mechanics.
The final examination at Oxford was in those days (maybe it still is) an ordeal unimaginable by those who have not experienced it: there was no continuous assessment at all, and one’s whole academic fate depended on a succession of closed-book three-hour written papers (in the case of Greats fourteen of them), one after the other, two per day, with only the weekend as a short respite. Not surprisingly, the population of the psychiatric wards of the local hospitals used to peak markedly before and during those periods. Actually, in my Greats degree I had thrived on the stress and come out with a straight first class, so I was probably over-confident going into the physics final exam. In the event this nearly turned into a complete disaster: the first paper was, I think, on thermodynamics, an area where problems notoriously require just the right trick to solve them, and after an hour and a half of the three hours I had got nowhere with the first problem I had tackled. I remember sitting at my desk in the exam room, my head figuratively if not literally in my hands, and contemplating the prospect of having dashed the hopes of all those who had supported and shown faith in me; it was one of the blackest moments of my life. In the end I pulled myself together and was able to answer one or two questions on that paper, as well as coping reasonably with the remaining papers; but when I was told that I was on the borderline between two (unspecified) classes and would therefore have to undergo a viva (oral exam) to decide between them, I was convinced that the two classes in question were a second and a third. Imagine my incredulity and, eventually, my delight when a few days after the viva, a letter arrived informing me that I had a first (and would therefore qualify more or less automatically for public funding for an advanced degree should I so chose). If nothing else, I think that experience has convinced me that no examination system, and certainly not the one I went through, can be an infallible measure even of purely academic ability.
I was now in a position to proceed to postgraduate research in physics. I had specialized on the theoretical side as an undergraduate, and my memories of the (rather small) amount of lab work I had had to do were not particularly rosy, so it seemed natural to apply for research on the theoretical side. But where, in which area and to whom? The first question answered itself easily, since I felt (perhaps wrongly) that no university other than Oxford itself was likely to appreciate my peculiar academic background. As to the second, the main areas of theoretical work at Oxford in those days were particle theory and condensed-matter (or, as it was known in those days, “solid-state”) physics. The time was early 1961, and the advice I got from the theorists I consulted was that the current state of particle theory was not very exciting (an opinion which had to be revised a few months later, when the concept of unitary symmetry burst on the scene); so I opted for the condensed-matter area. Finally, one person who was willing to overlook my unorthodox credentials was Dirk ter Haar, then a reader in theoretical physics and a fellow of Magdalen College; so I signed up for research under his supervision. As with all his students in that period, the tentatively assigned topic of my thesis was “Some Problems in the Theory of Many-Body Systems,” which left me a considerable degree of latitude.
Even by the standards of British universities in those days, Dirk’s supervisory style was somewhat unusual. He took a great interest in the personal welfare of his students and their families, and was meticulous in making sure they received adequate support; indeed, in the middle of my second year of research he encouraged me to apply for a Prize Fellowship (junior fellowship) at Magdalen. To my great surprise I was successful, I am sure in considerable measure thanks to his advocacy, and thereafter was able to enjoy a lifestyle rather more opulent than had been possible on the standard graduate studentship which had supported me earlier. On the other hand, Dirk’s method of supervising graduate research was to throw his students in at the deep end: by a few months into our relationship I had got the message that it was up to me not only to solve my thesis problem, once posed, but to find a viable problem in the first place. (I try to encourage my own graduate students to do the same, although I do not take Dirk’s extreme position of refusing, in effect, to make any suggestions at all). In the end my thesis work consisted of studies of two somewhat disconnected problems in the general area of liquid helium, one on higher-order phonon interaction processes in superfluid 4He and the other on the properties of dilute solutions of 4He in normal liquid 3He (a system which unfortunately turned out to be much less experimentally accessible than the other side of the phase diagram, dilute solutions of 3He in 4He). Although both halves resulted in publications, neither made much impact, and the only feature which in retrospect distinguishes my D. Phil. thesis in any way is that a small part of it (the acknowledgements) is, as permitted by the Oxford examination statutes and as a result of what our forebears would no doubt have described as a “conceit”, written in Latin.
One part of my graduate student experience which I have always felt was particularly valuable to me was the undergraduate teaching I did during this period. I had started this, I think as soon as I began graduate research, with a view to supplementing my rather subsistence-level studentship, but kept it up even after the Magdalen fellowship eliminated the need for this; as I recall, it was six hours per week of one-on-one or one-on-two individual tutorials in the undergraduate “theoretical option”, and I found I enjoyed it immensely and learned at least as much from it as from my formal research activities. Nowadays I always insist, as a matter of principle rather than financial economy, that my own graduate students spend at least one semester per year as teaching assistants.
In the spring of 1964, as I approached the three-year deadline for submission of my D. Phil. thesis, I began to think about postdoctoral work. In applying I had two criteria: the group in question should be a world-class center of excellence in many-body theory, and the environment should be as different as possible from Oxford (where I had by now spent nine years, more than a third of my life). So posed, the problem had an essentially unique solution, namely the group of David Pines at the University of Illinois at Urbana-Champaign, and it was there that I applied; I don’t think I even bothered applying anywhere else in those pre-information revolution days, the preparation of multiple applications was quite a daunting and time-consuming task. Despite this, I was quite surprised and gratified to be accepted. (David tells me that the letter Dirk wrote for me said in effect that I had a good training on the arts side but didn’t know any physics – a statement which in view of my highly compacted education in that subject was certainly true, but to which David’s reaction was “well, that’s something we can teach him!”). So I spent the period August 1964 – August 1965 at UIUC, and David and his colleagues (John Bardeen, Gordon Baym, Leo Kadanoff and others) did indeed teach me a great deal. And it was indeed very different from Oxford …
From the academic point of view that year at UIUC was a turning-point in my career; as recounted in my Nobel lecture, I not only became interested in the (at the time hypothetical) superfluid phase of liquid 3He, but produced my first research (on Fermi-liquid effects in the superfluid phase) to make any real impact internationally. However, I did not find the physical environment congenial (it was only a few years since Dutch elm disease had wiped out more of the town’s mature trees, something which is an essential ingredient of the quality of life in small Midwestern towns), and I remember swearing an oath to myself, as I left at the end of the year, that I would never come back and live permanently in Champaign-Urbana – an oath which I was to break rather spectacularly twenty years later.
My Magdalen fellowship still had a couple of years to run, and the natural thing would have been to return to Oxford and spend them there. However, I had become increasingly interested in north-east Asia, and anxious to spend some time there before committing myself to the standard British academic career; and the Fellows of the college eventually consented, with considerable generosity, to allow me to spend a year of my fellowship in the group of Professor Takeo Matsubara at Kyoto University in Japan. This year at Kyoto was a marvelous experience for me. It was my first real experience of living and working in a foreign culture, and I tried to exploit it to the fullest: I lived in a standard Japanese student room, put a considerable amount of effort into learning the language and tried as far as possible to avoid using English or mingling very much with other foreigners. At this time this was not at all the typical behavior of Western visitors, and many years later I was told that it had caused considerable interest and speculation among some of my Japanese colleagues, who finally hit on what had to be the only logical explanation – that I must be a trainee CIA agent! Fortunately this opinion did not prevent me making many good friends during that year, and I have very warm memories of all the parties, mountain hikes and home visits we shared. Although the academic work I did during this year was overall not particularly remarkable, it included the paper on two-band superconductors which was to play a crucial role in my research on superfluid 3He a few years later.
After one more postdoctoral year which I spent in “roving” mode, spending time at Oxford, Harvard and Illinois, in the autumn of 1967 I took up a lectureship at the University of Sussex, where I was to spend the next fifteen years of my career. Sussex was one of the “new” universities founded in the fifties, and at that point was only a few years old, but had managed to attract among other things a lively group of theoretical physicists under the leadership of Roger Blin-Stoyle and a constellation of able low-temperature experimentalists headed by Douglas Brewer. However, what attracted me most was the liberal and collegial atmosphere both in the University as a whole and in the Physics Department, which actively encouraged people to explore their intellectual interests across traditional academic boundaries; quite a few of my colleagues, though trained in the traditional areas of physics, ended up spending much of their time on science policy, physics education and elsewhere. However, although I enjoyed this relaxed environment, I spent my first five years at Sussex mostly teaching the standard undergraduate physics courses and, in the time available for research, working on various problems in theoretical low-temperature physics, including some such as the possible “supersolid” phase of helium which appear to still be of interest nearly forty years later. Being without family attachments, I was able to spend a lot of time abroad during the vacations, and in particular had an extended stay at the Max-Planck-Institute in München and a couple of trips to winter schools in Karpacz, Poland (at the time something of a minor adventure, since the Iron Curtain was still firmly in place).
In the summer of 1972 there occurred the series of events which were to shape my research career for the next decade; I have recounted these in my Nobel lecture and will not repeat them here. At just about the same time an important event occurred on the personal front: I became engaged to Haruko Kinase, at that time an undergraduate student at Sussex, and we married in June 1972. (Since Haruko’s nationality was and is Japanese, and her undergraduate major was international relations, the family joke is that at least she passed the practical!). We had a sort of extended honeymoon in Japan, living in central Tokyo with Haruko’s parents while I worked in the group of Professor Yasushi Wada at the Hongo campus of Tokyo University. One spin-off from this stay was that I got to know Shin Takagi, who was in his final year as a graduate student in the Wada group, and was sufficiently impressed with him that I invited him to Sussex as a postdoc; he spent a couple of years there, and we collaborated extensively on superfluid 3He as well as having many conversations ranging over the whole of physics. Incidentally, if my early years in the extreme outer reaches of the London conurbation are not counted, the only large cities anywhere in the world where I have ever lived for more than a few months are Kyoto and Tokyo; I can think of a lot worse.
As this note has to be of finite length, I will speed up at this point and just review the important events in my life since 1974. Soon after our return from Japan, in early 1975, Haruko and I acquired a small house that we still own in the warren of streets above London Road station in central Brighton, and it was there (or more accurately on the twelfth floor of the nearby Royal Sussex County Hospital) that our daughter Asako was born in September 1978, and there that she spent the first five years of her life. After returning from Japan I spent several more very enjoyable years at Sussex, with various excursions including two one-semester trips in 1976 and 1977 to the University of Science and Technology in Kumasi, Ghana, with which Sussex had a teaching exchange arrangement. This was another interesting cultural shock; one unexpected aspect was that because of the generally relaxed atmosphere in Ghana, I had for the first time in many years a surfeit of free time, and I used it among other things to write a paper on nonlocal hidden-variables theories which I eventually published a full quarter-century later.
In the spring of 1982 I received, out of the blue, an offer from the University of Illinois at Urbana-Champaign of the MacArthur Chair with which the university had recently been endowed, and after the three of us had been across for a visit (where I observed, inter alia, that the trees had recovered from the blight of the early 60’s!) we decided to make the move. As I had already committed myself to an eight-month stay at Cornell in early 1983, we finally arrived in Urbana in the early fall of that year, and have been there ever since, so that Asako has in effect grown up as an American (she and I both eventually received U.S. citizenship, which we hold dual with that of the U.K., in the summer of 2002). Haruko eventually obtained a Ph.D. in cultural anthropology from the University of Illinois, and is currently doing research on the hospice system; Asako has graduated, also from UIUC, with a joint major in geography and chemistry. My own research interests have shifted away from superfluid 3He since around 1980 (although I still maintain an interest in some problems involving violent departures from equilibrium); I have worked inter alia on the low-temperature properties of glasses, high-temperature superconductivity, the BEC atomic gases and above all on the theory of experiments to test whether the formation of quantum mechanics will continue to describe the physical world as we push it up from the atomic level towards that of everyday life (a program for which my shorthand is “building Schrödinger‘s Cat in the laboratory”). It is satisfying that this program, which when proposed twenty-five years ago met with considerable skepticism, seems in the last three or four years to have come to fruition, in the sense that several experimental groups have realized, in Josephson devices, quantum superpositions which can be legitimately regarded as of the “Schrödinger’s Cat” type.
When I look back on the chain of events which led to the research which the Nobel Committee has recognized, I realize how incredibly fortunate I have been – not just because of the intervention in my career of seemingly irrelevant events such as the propulsion of Sputnik into orbit in the fall of 1957, but because so many people were prepared to put their faith in me, and in particular my ability to make a successful career in physics, at a time when the evidence in favor of that proposition was nonexistent or perhaps even negative. I shall remain forever grateful.
This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.