Maker of Patterns

by Freeman Dyson

  Peierls was shown round the new and lavishly built nuclear laboratory, which will be opened formally with a party on Saturday. Feynman remarked that it was a pity to think that after all the work that the builders had put into building it, so little would probably be done by the people who lived in it; and Bethe said that only because of the steel shortage is any nuclear physics worth mentioning done in the United States. This may well be true; the most outstanding experiments in the world are at present being done at Bristol by Powell with no apparatus more elaborate than a microscope and a photographic plate.

  Cecil Powell, and his team of sharp-eyed ladies scanning photographic plates with powerful microscopes, discovered particles stopping in the plates with other particles starting where the first ones stopped. This proved that there are two kinds of mesons, later given the names pions and muons, the pions interacting strongly and the muons weakly with ordinary matter. This discovery was a big step forward in the new science of particle physics.

  NOVEMBER 27, 1947

  [Philip] Morrison is a young professor of theoretical physics for whom I have a considerable admiration; he is the most politically active of all the Los Alamos people here; his chief scientific achievement was the construction of the fast neutron chain reactor, a nerve-racking device which consists essentially of a lump of plutonium kept permanently in a state in which it just doesn’t blow up.

  The fast neutron device was built at Los Alamos and given the name Jezebel. It was important for measuring the state of affairs in a not-quite-exploding bomb.

  The trip to Rochester last week was a great success. I went there and back in Dick Feynman’s car with Philip Morrison, and we talked about everything from cosmic rays downward; the seminar was given by Morrison, and we then repaired to the house of [Robert] Marshak, who is the chief physicist at Rochester and is just back from Europe. Marshak is also politically active and had long talks in Europe with [Frédéric] Joliot, [Nevill] Mott, and various other people. The general impression he got was that the Europeans said, “It’s up to you to make your government behave; we’ll support you when we can, but there is very little we can do from this end.” I get the impression that the political responsibility that has been thrust onto scientists here has been very good for them; they are almost all well-informed and liberal-minded and badly worried at the way things are going. It hits them much harder than it hits scientists in England, partly because the country itself has so much greater power in the world, but mainly because of the chaotic condition of the administration here. In England, if an important decision is to be taken, there will probably be at least some department officially responsible for it, and the scientists can get their views considered without undue difficulty; while here the situation has been so fluid that the scientists must force themselves into the picture by all means at their disposal, which means in practice sitting in Washington and badgering influential people.

  Bethe has asked me to give a short talk at a meeting of the American Physical Society in New York in January on the work I have done in the last two months; this is very gratifying, even if (as I think) the work will not interest people much. It will be an excellent opportunity for meeting people. I am now just about to start on a second major problem, which should be rather more interesting, if it turns out successfully.

  On Saturday we had our great inaugural party for the synchrotron building. It was a great success; I played my first game of poker and found I was rather good at it; I won thirty-five cents. The synchrotron itself does not arrive for some time yet, so the building is still empty. The party consisted chiefly of dancing and eating; Bethe and Trudy Eyges danced together for about an hour, very beautifully, while Rose Bethe and Leonard Eyges exchanged disapproving glances.

  DECEMBER 7, 1947

  Yesterday I had a talk with Bethe about my future. Bethe told me that unless I raise objections, he will press for me to be given a second year; he said this was “in the interests of science as well as in your own interests.” He said I should spend the second year at Princeton with Oppenheimer, and that Oppenheimer would be very glad to look after me. When I first went to see Peierls at Birmingham, he told me that Oppenheimer was the deepest thinker at present in the field of physics, but at that time he was director of the physics department of the University of California and still involved in a lot of secret work at Los Alamos, so that my position would be rather dubious if I went to work with him. However, this summer Oppenheimer announced that he was fed up with all this secrecy and wanted to do some real physics, threw up the California job, and moved to Princeton. So one could hardly ask for anything better than to go to him.

  Oppenheimer moved from Berkeley to Princeton in 1947. He invited a group of young physicists to the Institute for Advanced Study in Princeton with the intention of working with them. He hoped to resume his career as an active research physicist after the interruption caused by the war. This hope was never fulfilled. He remained heavily involved in government business and public affairs. He could never again give his full attention to research. As director of the institute, he helped the young physicists as a listener and a critic but never as a collaborator. He did not eat and talk with us at lunch every day as Bethe did at Cornell. He never sat down at his desk doing detailed calculations. I showed him my work to discuss it after it was finished, not while it was in progress. At the institute I learned more from my young colleagues than I did from Oppenheimer.

  All this shows how fundamentally right was the idea that made me change from mathematics to physics, in spite of many discouragements. I have done nothing in the last two months that you could call clever or difficult; nothing one-tenth as hard as my fellowship thesis; but because the problems I am now dealing with are public problems and all the theoretical physicists have been racking their brains over them for ten years with negligible results, even the most modest contributions are at once publicised and applauded. If ever I should have the luck to do something clever in this field, I should have to be careful not to have my head turned.

  Political argument here is dominated by the problem of atomic energy. It is betraying no secret to say that there have been newspaper reports that the atomic bomb can be increased in power by a factor of one thousand with very little increase in cost, and I know enough physics (not much is necessary) to be able to see how this is done. Knowledge of such facts as these tends to strengthen the hands of the out-and-out idealists, who say “nothing but world government can save us.” The main split at present is between these people (headed by Einstein) and the compromisers (headed by Morrison and supported by Bethe) who believe that the existence of superbombs is very regrettable but does not essentially change the nature of the political problem. The compromisers, of whom I am certainly one, believe that there is very little that anyone can do at present to alter the course of history, but nothing is lost by continuing to negotiate with the Russians as honestly as we can and making compromises on as many of their demands as possible.

  DECEMBER 16, 1947

  The great excitement this week has been a visit from the notorious Henry Wallace. He came at the invitation of various student societies to address a mass meeting, which was held in the big concert hall in the lunch hour, and enormous crowds went to hear him. The verdict on Wallace is that he has absolutely no chance at present of a political comeback, but he is performing a most valuable service in reminding the millions of Americans who only read their newspapers that it is possible to disagree with the foreign policy of the government without necessarily being a Russian agent.

  Henry Wallace had been vice president in the third term of Franklin Roosevelt’s presidency, to be replaced by Harry Truman in the unfinished fourth term. He ran as leader of the Progressive Party in the presidential election of 1948, standing for a policy of peace and reconciliation with the Soviet Union.

  JANUARY 2, 1948

  Several of my friends are second-generation Americans, whose parents came over from Germany or Poland or Lithuania or so
me such place, and I am always curious to ask them questions about their parents’ histories in Europe and their reasons for emigrating and their emotional backgrounds. Always I have been amazed to find that the young people know practically nothing, and apparently care little, about such matters. It is very strange when one thinks how much we have absorbed about the history and society to which our family belonged. Not that I dislike the Americans on the whole; it is probably in the long run a good thing that they live so much in the present and the future and so little in the past. The fact that they are more alone in the world than average English people probably accounts for their great spontaneous friendliness. I had heard this friendliness attributed to the size of the country and to people’s loneliness in space, but I think the loneliness in time is more important.

  JANUARY 9, 1948

  It seems to me that one may reasonably compare the present situation of England with the position after the Napoleonic Wars. Then we were suffering from an increasing population and a static agriculture, and it took about thirty years before the industrial revolution finally pulled us out of the soup. Now we are just beginning the second industrial revolution, and it is reasonable to expect that in twenty or thirty years we shall find the results of it solving our problems again. Meanwhile we shall muddle along somehow. It is interesting that the new ideas about photosynthesis were derived from tracer chemistry, which is a by-product of nuclear physics. Many people have said that the industrial revolution produced by nuclear physics would ultimately be effected more by tracer chemistry than by nuclear power.

  See Chapter 5 for my meeting with Melvin Calvin, who was doing historic experiments with tracer chemistry in California.

  JANUARY 24, 1948

  A new period in physics started with the Columbia University experiments last summer which for the first time contradicted the existing quantum theory outside the nucleus. The first step was taken by Bethe when he showed how the theory could be extended to explain the Columbia results. My calculations of last term were part of the detailed carrying out of this extension. Then there was another big step in November when Julian Schwinger at Cambridge, Mass., produced a formally unified theory including Bethe’s work and covering the whole of nonnuclear physics. This Schwinger theory is now generally recognised as correct, at least to a much higher degree of approximation than the old theory. It is rather like the step from special to general relativity; the new theory, although in principle very much superior to the old, only gives exceedingly small differences when applied to practical problems. However, already two experiments have been suggested apart from the original Columbia experiment which will give a chance of verifying the existence of these minute effects, and the results are already in favour of the Schwinger theory. All these experiments would be impossible to do with the necessary accuracy, without the apparatus invented during the war for use in radar.

  Julian Schwinger, a young professor at Harvard, had been the most brilliant student of Oppenheimer’s at Berkeley before the war. Oppenheimer invited him to come as a professor to the institute, but he preferred to stay at Harvard.

  Having a new theory at our disposal, the great question is: will it succeed in making sense of nuclear forces, where the old theory so lamentably failed? During the last vacation Bethe developed a programme for applying the new ideas to nuclear forces, and the job he has given me to do is to try to carry out the programme for certain types of nuclear particle. It is very exciting to be working on such a basic problem, and there is no doubt that as more and more experimental evidence comes in, we shall ultimately find the solution. Big machines are fast coming into operation in various universities, and before long we shall gradually be given more and more experimental facts.

  FEBRUARY 11, 1948

  On Saturday night we had a party, a cinema followed by supper at a restaurant, attended by three physicists and their wives. We munched popcorn in the cinema in true American style, and very good it was. The film also was quite outstanding, being called The Treasure of the Sierra Madre. It was a story of three men who went out to the wilds of Mexico to dig for gold, armed with guns to protect themselves against bandits. The point of the story is the gradual realisation of the men, as the gold accumulated, of the power that each of them held to shoot the others and make off with the loot. Gradually they get more and more suspicious and nervous, until finally one of them goes mad and starts shooting. There is a fairly obvious application to present-day international relations. Apart from this, it was a most artistic production, using real Spanish-speaking Mexicans instead of fake ones.

  I see quite a lot of Phil Morrison nowadays, as he comes to the fortnightly play reading at the Eygeses’. After the play we usually start talking, and this usually means a brilliant exposition of some recondite subject by Morrison while the rest of us listen. He has a type of mind rare among native American physicists, interested in all branches of science and especially biology, and looking on physics more as a hobby than a job. He is always astonishing me by his use in conversation of phrases that only an Englishman could understand, and which he says he picks up from reading English novels. The last play we read was Faust, in a new and racy translation by an American professor; I liked it very much. When Bethe returned from his travels on Monday, he found inscribed on the blackboard in his room Grau, teuerer Freund, ist alle Theorie, / Und grün des Lebens goldner Baum.

  “Gray, dear friend, is all theory, and green the golden tree of life.” I do not know whether it was Morrison who wrote these famous lines from Faust on Bethe’s blackboard. Bethe would certainly have known that they were spoken to Faust by Mephistopheles.

  FEBRUARY 24, 1948

  We had recently a package of physics journals from Japan, which have caused a sensation because they have done such a lot of first-rate work in isolation from the rest of the world. At the same time as these journals came the news that Hideki Yukawa, the leading man over there, will be at Princeton next year. This will be a great opportunity for me, because very few people have ever met him in the flesh; it was he who made the prediction of the original meson in 1935. Just as I was writing this last sentence, a remarkable coincidence happened; Bethe arrived with the great tidings, obtained over the telephone from Oppenheimer, that the people at California have for the first time made a meson. This has been the purpose for which all these big machines are being built, and its achievement at last is really epoch-making. Now we shall begin to be able to know something. Everyone is tremendously elated by this. Nothing has yet been officially confirmed.

  What makes the story amusing is that the people at California have been making hundreds of mesons a day for several weeks and looking furiously through their microscopes to try to find them in the photographic film; but they didn’t see any because they were not developing the film properly. Fortunately [Eugenio] Lattes, one of Powell’s team, happened to be on a visit to Berkeley, and he told them that the films should be soaked for half an hour instead of for four minutes, and when they did this, lo and behold, there the mesons were.

  The story was amusing to physicists because the machine in Berkeley was built by Ernest Lawrence, the original inventor of the cyclotron, who also invented the “big science” style of research in particle physics. Lawrence was supreme as a machine-builder and organizer but not so good as a scientist. His competitors were amused that he won the race to produce mesons but needed the help of Lattes from Bristol to see what he had done.

  Yesterday Sir Geoffrey Taylor was here, the man who first suggested Cornell to me as a suitable place to work. He came to give a talk to the seminar about the work his people have been doing at Cambridge. It was specially interesting to me because the research students who did most of the work were the Australian contingent and good friends of mine. Taylor seemed to have a high opinion of them. Like all Taylor’s work, this was done in his little wind tunnel at the Cavendish, which he built himself and claims to be the smallest in the world; and the results are about ten times as accurate as a
nybody else’s. In this connection, Taylor told me that one of the reasons he likes Cornell is that we have here the smallest cyclotron in the world.

  After dinner Bethe invited me in to discuss the state of the world over a glass of whiskey, Taylor and various other notables being there. Concerning the European situation, Taylor said he saw no reason why a solution to the problem should not be found in a deliberate policy of very large-scale emigration, and that there was certainly no other solution. To which Bethe replied, “Well, we know what emigration means. You can make people emigrate if you hold a pistol at their back or starve them to death, but nothing short of that is much use.”

  The “European situation” here means the fear that the rising population of Europe would be unable to feed itself. This fear was particularly strong in 1948 in England and in Germany. The expected disaster never happened, partly because birth rates remained lower than expected and partly because the Green Revolution made food production higher than expected.

  FEBRUARY 29, 1948

  Walter Macafee, the negro in our room, I see a lot of as he lives by himself like me and we are often left by ourselves in the evening to go to supper. [In those days the word negro was used as African-American is used today.] He is a most good-natured fellow, and his only fault is that he will not often talk about serious questions. He grew up in Texas, moved up to Ohio State College to get his university training, and resolved never to go back to the South if he could help it. He had not the resources to take a doctor’s degree when he graduated and was compelled to work for a number of years in a very badly paid teaching job in Ohio; there he got married and gave up hope of rising any higher. Then came the war and with it a job in a government research laboratory working on radar, with pay and conditions customary for whites. To him, this was such wealth that he was easily able to save enough during the war to get through his doctor’s degree here, which he has now nearly finished. When he has his degree, he has his government job to go back to, and there is no reason why he should not live happily ever after. He is much older than the rest of us and has the handicap of his lost years. His story is an object lesson in the wastefulness of the discrimination policy.