Nuclear Family

Rudolf Peierls

  • Disturbing the Universe by Freeman Dyson
    Harper and Row, 283 pp, £6.95, November 1979, ISBN 0 06 011108 9

The most striking thing about this book is how well it is written. Each word is right for its place, the images are apt, and the quotations expressive. In explaining that his style is not that of the social scientists, the author says: ‘The methodology of this book is literary rather than analytical. This is the result of my upbringing and background.’ The outcome is a work which it is a pleasure to read, even in places where one cannot agree. For believers in the ‘Two Cultures’, this writing by a scientist would be hard to classify.

Freeman Dyson is a scientist of great distinction. He is best-known for his share in laying the foundations of quantum electrodynamics, the discipline which describes the interplay of charged particles, such as electrons, with each other and with radiation. In the pre-war years, when other parts of our understanding of atoms had reached an impressive fruition, the extension to electrodynamics appeared to be beset by insurmountable difficulties. In the late Forties there was a breakthrough. This development was set in motion partly by new and sensitive experiments, notably that by Willis Lamb at Columbia University, which posed specific questions for the theory to answer. Responding to this challenge, Julian Schwinger and Richard Feynman invented novel ways of tackling the problem. Some of the steps had already been taken earlier by Sin-Itiro Tomonaga in Japan.

Dyson was the first to understand the approaches both of Schwinger and of Feynman, and to demonstrate that, while different in form, they were identical in content. This made it possible to accept the mathematical rigour of Schwinger’s work, while using the intuitive and much more manageable techniques of Feynman. Today these methods are the standard tools of every theoretical physicist, and they are mostly used in the form set out and explained by Dyson.

He tells in the book about this success, achieved when he was at the very beginning of his career, barely a year after he had started learning modern physics. He talks about it without false modesty, but without exaggeration. Since then his research has borne fruit in many other ways, in the areas of nuclear and solid-state physics, astrophysics and cosmology. He has made his contributions to the struggle with the deeper problems of subatomic physics which are not as yet solved. But among his colleagues his name is associated predominantly with his great work of 1948–49. The book does not tell us much about the rest of his work in pure physics. It is in part autobiographical, but it is selective, and the emphasis is on his thoughts and ideas; the story stresses those experiences which were relevant to the development of these ideas.

His parents come out as remarkable people: Sir George Dyson, composer, conductor, and director of the Royal College of Music, had been a music teacher at Winchester, and Freeman breathed the Winchester atmosphere even before he became a scholar there himself. Childhood memories are scanty, but he tells us about a book by Edith Nesbitt, whose fantastic world becomes a symbol for some later ideas. We hear about his early interest in mathematics and relativity, teaching himself the art of differential equations in order to understand Einstein. At the same time, in the atmosphere of impending war, there starts a concern with moral problems. He was inclined to be a pacifist, but decided it was his duty to participate in the fight against Hitler, and Chapter Three finds him in Operational Research for the Air Force. He comes out of this experience an angry young man, shocked by the waste of lives in what he sees as senseless bombing of cities, and equally by official obtuseness in failing to accept measures that could have reduced the casualty rate among air crews.

This chapter is followed by one about Frank Thompson, whom he knew at Winchester, and who was executed in Bulgaria for fighting with the anti-Nazi resistance. The portrait of Thompson belongs here because it is part of the war, but perhaps also as a contrast with Dyson’s own wartime record, with which he is evidently not very satisfied. He is enough of a realist to know he could not have altered the bombing policy, and probably not even the tactics of bombers, but, he seems to say, he could have put up more of a fight. He paints a vivid picture of Frank Thompson’s faith (in the cause of Communism), his enthusiasm and courage. We are not told how and when Dyson managed to spend time at Cambridge and to make his mark in pure mathematics, but in the next chapter he has gone to Cornell University for an apprenticeship in theoretical physics. There is a legend around, probably apocryphal, that about that time a fellow student at Cambridge, who was working in theoretical physics, remarked that modern theoretical physics was getting too complicated, and he had decided to switch to pure mathematics. According to the legend, Dyson replied: ‘It is true that theoretical physics is getting too complicated, therefore I have decided to switch to theoretical physics.’

He went to work with Hans Bethe at Cornell, and the group there also included Feynman. The personalities of Bethe and Feynman and the spirit of the group stand out very vividly. The friendship with Feynman is consolidated in a joint drive west to Albuquerque. Later on that trip Dyson joined a summer school at Ann Arbor, and had the chance of learning directly from Schwinger about his new methods. In the bus back east comes the insight that allows him to unify the Schwinger and Feynman approaches.

This new understanding was not accepted at once. Dyson was now joining the Institute for Advanced Study at Princeton, and Robert Oppenheimer, its director, at first refused to believe in the new theories, or in Dyson’s exposition. Oppenheimer usually had a very quick and deep perception, but when he did not accept an argument he could be very cutting in his comment and make it hard for the opponent to present his case. Eventually he was won over and became infected by Dyson’s enthusiasm. The portrait of Oppenheimer is one of the strongest parts of the book. Dyson is critical of many of Oppenheimer’s qualities, but he writes with affection and respect, and he describes how to him real greatness became evident in the way Oppenheimer approached death. One cannot write about Oppenheimer without referring to his ‘trial’ and to the part played in it by Edward Teller. Dyson does not condone Teller’s actions, but shows some understanding and sympathy, and remains a friend of his. The portrait of Teller does not come off, however, compared with those of many other people in the book, who are made to seem solidly alive.

Dyson became involved with some practical design projects, first on the design of a nuclear reactor (his first experience of working with Teller) and later, with much more enthusiasm, on Project Orion, the plan for a space-ship propelled by a series of small nuclear explosions. This kind of team work on applied-science projects was a new and important experience for him. His main research had been of a very abstract kind, and it was lone work, although requiring a close understanding of what other people were doing. It related to an empirical subject, and aimed both at understanding experimental results and at suggesting new ones, but the relation with what went on in the laboratory was always tenuous and indirect. So the more practical collaborative work was for him a little like the work of Goethe’s Faust in the Dutch villagers’ fight with the tides, to which he refers in the course of the book.

All this time Dyson was thinking deeply and seriously about the ethical problems of war and peace, and in particular about nuclear weapons. He is somewhat suspicious of the people who worked on the atom bomb in Los Alamos during the war. He interprets Oppenheimer’s famous phrase about the physicists – they ‘have known sin’ – as referring to the fact that they actually enjoyed their work on the weapon. I do not believe this is a fair interpretation of Oppenheimer or a fair charge against the Los Alamos scientists. Any group of people working intensely on a difficult task against time will find it hard to suppress feelings of comradeship and of pride in their progress, as long, of course, as they do not believe the objective to be fundamentally evil. These feelings are not inconsistent with an awareness of the seriousness of the enterprise, and responsibility for the consequences. Those of us who allowed this awareness to fade would merit Dyson’s censure.

Dyson became involved in discussions about disarmament, partly while spending periods with the Arms Control and Disarmament Agency. His first major public expression of views was in an article in Foreign Affairs in 1960, in which he opposed the Test Ban Treaty then under discussion. He later changed his mind and became a supporter of the Treaty. Everybody, except for unusually narrow-minded people, changes his views occasionally: but not everybody discusses his change of heart, and comments on the previous, discarded views, as candidly as Freeman Dyson, who sees, and says, clearly that his article was influenced in part by his enthusiasm for Project Orion, which was made illegal by the Treaty, and in part by his friendship for colleagues who were working hard on (‘clean’) weapons.

He is aghast at the present balance of terror, and at the idea of deterrence based on Mutually Assured Annihilation. In this he is not alone, though he presents his objections more powerfully than many. This leads him to advocate a policy based on defence: but this would only be feasible if a highly efficient anti-ballistic missile system were technically possible – and this still isn’t clear. A great number of scientists (including myself) are extremely sceptical on this point, and believe that any alternative to the present frightening situation must be looked for elsewhere.

While recounting his experiences in test-ban and other negotiations, he gives his views, which are always responsibly thought out and vividly expressed, on such matters as nuclear terrorism, the dangers of biological warfare and the controversy about ‘genetic engineering’. The last eight chapters contain speculations about the future. They include a vision of self-reproducing automata, which may alter the appearance of deserts, and ultimately perhaps of the solar system. He points out that the nature of such developments is critically dependent on time-scale, on whether a generation of these automata is comparable to a human generation, or as short as, say, one year. The latter possibility seems to me to belong to extreme Science Fiction. There is also no mention of how one is to provide for dealing with faults, breakdowns and design errors. Another extreme speculation is about a scheme for colonising extraterrestrial lands, perhaps some of the asteroids. It is probably this pet scheme of his that gave rise to the title of the book, which derives from T.S. Eliot.

This miscellany of thoughts about the future also contains many items which are much more down to earth, both literally and otherwise. He stresses convincingly the contrast between the clumsiness and inflexibility of projects run by large bureaucratic organisations (including the present nuclear-power technology) and schemes pursued by teams of devoted and imaginative individuals, of which there are many examples to be found in the early development of new technologies.

There is a plea for diversity, and for preserving national, ethnical and linguistic differences; and a report on a visit to his son in the wild areas of North-West Canada, and the lessons to be learned from his kind of life. This again reflects the longing for a way of life based on individual activity rather than on the impersonal institutions of ‘civilised’ society. There are remarks about the relation between science and religion. And that is not the complete list.

It is a remarkable book but it does not achieve one of its stated objectives. On page 5, after reminding the reader that policy decisions about the use of science have to be taken by non-scientists, he says: ‘If you, unscientific people, are to succeed in this task, you must understand the nature of the beast you are trying to control. This book is intended to help you understand.’ The book is clearly not attempting to explain the content or method of science, although all scientific points mentioned are explained with great clarity and simplicity. Will it help the layman to understand scientists? One certainly learns much about Freeman Dyson, but he is hardly a run-of-the-mill specimen of the genus, even if one only looks at the top range of distinction. In fact, it is his uniqueness which gives the book much of its attraction. If the reader insists on wanting to learn about scientists in general he may be disappointed. If he enjoys getting to know one particular individual among the leading scientists and his thoughts, he will find the book rewarding.