Maker of Patterns

by Freeman Dyson

  Hermann Weyl was the only person at the institute with world-class stature both as a mathematician and as a physicist. He was largely responsible for making symmetry-groups the central concept of modern particle physics. He retired from the institute and returned to Switzerland one year after I joined the faculty. I was lucky to make friends with him during his final year in Princeton. He died one year later in Zürich.

  FEBRUARY 29, 1956

  I got invited again to Moscow, this time to a conference from May 14 to 20, and this time I intend to go. The arguments which persuaded me not to go last time are entirely absent, now that I know last year’s conference to have been a genuine and nonpolitical affair. I still shall take a risk not to be readmitted to the United States when I return, but this I am prepared to accept; in case of trouble my position will be strong enough to fight it through successfully—the whole American scientific public will fight for me. I shall probably leave for Russia on May 12. Already I started taking Russian classes at the university, and these I am enjoying very much. It is fun to be a student again and sit with boys and be scolded for making grammatical mistakes.

  The death of Stalin in 1953 started a period of rapid change in Soviet society. Symbolic of the changes was a novel, The Thaw, by Ilya Ehrenburg (1955). Ehrenburg was a friend of Nikita Khrushchev, who became leader of the USSR in the same year and made the thaw real. Four important consequences of the thaw were: (1) the release of millions of prisoners from the gulag camps, (2) a speech by Khrushchev officially denouncing the abuse of personal power by Stalin, (3) loosening of censorship of speech and writing, and (4) the opening of the USSR to foreign visitors and international meetings. Ehrenburg was a loyal Communist, considered by dissident Russians to be a party hack. His novel carried a powerful message, with dripping icicles and budding leaves of spring presaging the rebirth of human feelings after a long freeze. In 1956 when we visited Russia, the thaw was in full swing and hopes of further liberation were high. In retrospect, we can now see that the thaw was real and permanent, but the hopes for the future were exaggerated. The USSR never went back to Stalinist terror and never went forward to Western-style freedom.

  MARCH 17, 1956, PITTSBURGH

  There is much talk about Russia. Invitations have been sent out wholesale, not only to our high-energy conference in Moscow but also to a solid-state conference a week later in Sverdlovsk just the other side of the Urals. Everybody who is invited is happy because the others decided to accept. No one is refusing to go. We shall be a big and merry crowd. Amongst others, Peierls is definitely going and also Bethe from Cornell. I have sent in my application for the Russian visa and was happy to find on the application form I must identify myself as Freeman Georgievitch, as in the old Russian novels.

  The American Atomic Energy Commission has completely reversed itself since last year when they stopped Feynman from going to Moscow. I am at the moment under investigation because I am applying for AEC clearance to do secret work during the summer in California. I wrote a letter, not asking the AEC for permission to go to Moscow, but informing them that I shall go and that I shall understand it if in consequence they do not want to give the clearance. The reply came back by telephone that the clearance will not be affected one way or the other. The AEC has also given its blessing to Bethe who knows much more about hydrogen bomb secrets than Feynman ever did. It seems some common sense has finally penetrated into the AEC.

  Just before I left Princeton, there came a telephone call from the AEC asking, “Who are the Princeton people who are going to the Moscow conference?” I thought, “Well now, here starts the trouble.” Then the AEC official said, “Please tell them that if any of them are working on AEC supported contracts, we shall help pay their fares to Russia.” It looks as if this opening of communications will be more or less permanent, and there will be many more trips to Russia in years to come. This makes me happy that I did not lose much by being cautious and refusing to go last year.

  APRIL 4, 1956, ROCHESTER, NEW YORK

  Today I had the pleasure of putting to good use the Russian I have been studying for so many years. I had supper with Veksler the Russian accelerator expert. After a while I found myself saying “Nyet spasibo” to the American waitress, which caused some amusement. Veksler said they are all so much looking forward to having me in Moscow that I must be careful not to be questioned to the point of exhaustion by eager young theoreticians. It is lucky that we got this chance to make friends and overcome the language problems before the trip to Moscow. I shall feel no strangeness at all when I go there. Veksler said I was welcome to come to lecture in Moscow for a few months “whenever you find it convenient.” It is all somehow intoxicating.

  MAY 15, 1956, HOTEL MOSKVA, MOSCOW

  I am safely here and settled in. I feel as if I had already been here a long time. The Russians work terribly long hours. We have meetings every day from ten till two and from five till nine. For each session we drive half an hour in a bus there and back, so not much of the day is left. I am amazed to find what an exaggerated reputation I have in Russia. This is partly because I am the one who reads and reviews their papers. They treat me with enormous respect. And they have evidently read what I write, not only in the Physical Review but also in the Scientific American and even the obituary of Weyl in Nature. The meetings themselves, apart from being too long, are lively and interesting. The Russians are informal, more like Americans than Western Europeans, and they contradict and argue and make jokes freely in the meetings. Last night I managed to get out for an hour and walk around the streets. It is a little like Paris. Lots of cheerful people strolling around and enjoying the warm evening, chattering and laughing. Most of the houses in a state of genteel decay with plaster and paint flaking off. Many cafés open with tables and chairs on the sidewalk and people drinking wine or coffee. How I should love to be here for two weeks with nothing to do but sit around and explore the city. But we shall be organised almost every hour of our stay. After two weeks I shall be ready to come home.

  The Russia that I saw in 1956 and on several later visits was no Potemkin village. I knew the language well enough to see the fears and tensions below the surface of the society. Russians talked to me with astonishing freedom about the corruption and incompetence of their government. The thaw was real, and the ice that held Stalin’s Russia in place was softening. Russia was already moving, in a slow but massive slide, towards the peaceful collapse of the USSR that took us all by surprise thirty-five years later.

  In 1955 there was an international conference in Geneva, at which government officials from countries with nuclear projects met to decide how much of their secret information should be made public. Until that meeting, all of nuclear science and engineering was secret. It clearly made no sense to keep secret the basic facts about peaceful uses of fission and fusion energy. Delegates from the United States, the Soviet Union, Britain, France, and Canada agreed to share and publish nuclear information that was not related to bombs. One of the American delegates at Geneva was Freddy de Hoffmann, a young scientist from Los Alamos. He understood that the Geneva agreement opened up the field of peaceful nuclear energy to private business. After the meeting, he resigned his position at Los Alamos and founded a nuclear start-up company which he called General Atomic. He raised enough money to rent a schoolhouse in San Diego for the summer of 1956 and to invite a big group of experts to sit in the schoolhouse for three months and decide what the new company should do. The group had roughly equal numbers of physicists, chemists, and engineers. I was one of the physicists. I arrived at the schoolhouse in June 1956 knowing nothing about nuclear reactors but eager to learn. I was housed with the other visitors in a big motel in La Jolla.

  My first impressions of La Jolla were unfavorable. It seemed to be a good place to take a holiday but a bad place to live. Abundant flowers that were actually real but looked artificial beause they were too brightly colored. Houses with big swimming pools but no books and no reading lights. Streets full of
big fast cars with few pedestrians. After we lived in La Jolla with our family for a few months, we began to like it better. There was a good public library where our children could borrow unlimited supplies of books. There was a good local hospital where one of our babies was born. The Scripps Institution of Oceanography was a world-class research center where we made lasting friendships. The famous Doctor Seuss, author of children’s books that our children loved, came in person to spend a morning with our son’s first-grade class, collecting ideas from the class for his next book. In the end we liked La Jolla so much that we bought an apartment there.

  WEDNESDAY, JUNE 20, 1956, LA JOLLA

  The work may turn out to be very exciting, or it may be a terrible flop. It is hard to say at present. In many ways it reminds me of Bomber Command. A group of us has been given the job of thinking up a nuclear reactor which shall be absolutely safe, so it can be played around with by untrained people and there can be no question of it blowing up. Such a reactor would be greatly in demand for hospitals and such places where they need a reactor but do not want to maintain a staff of physicists to take care of it. This is a clear enough assignment, and if we can do something along these lines, it will be exciting. On the other hand we have the feeling, as we did at Bomber Command, that we are remote from real life. Few of us know anything about the practical construction of reactors, and we do not have any experimental facilities here. So all we can do is to think up general ideas and follow them to a preliminary design stage. Perhaps something good will come out of it.

  Edward Teller was a famous Hungarian physicist who came to the United States in 1935 and became passionately involved in both the military and civilian applications of nuclear energy. He had two obsessions, the hydrogen bomb and civilian reactor safety. The hydrogen bomb obsession was well known to the public and made him generally unpopular. The reactor safety obsession was not so well known but equally important to Teller himself. He was chairman of the Reactor Safeguards Committee of the U.S. Atomic Energy Commission for many years. He was a friend of Freddy de Hoffmann at Los Alamos and was an enthusiastic supporter of Freddy’s venture into civilian nuclear technology. He came to General Atomic in 1956 because he saw it as an opportunity to build reactors far safer than any existing reactors. He believed passionately that nuclear energy could be a blessing to mankind if reactors were perceived by everybody as safe. It was not enough to solve the technical problems of safety. If nuclear energy were to be acceptable in the long run, it was necessary to make it visibly and obviously safe, so that we could operate a reactor in the middle of a city and insurance companies would not hesitate to insure it. When the visitors assembled at General Atomic, Edward Teller immediately took charge of the group working on the design of a safe reactor. He announced that our goal was to design a reactor so safe that we could hand it over to a bunch of high school kids to play with and they could not get hurt.

  JULY 15, 1956

  I am more deeply involved in nuclear reactors than I would have believed possible four weeks ago. There is lots to be done, and this is a good place to do it. Our group which is working on safe reactors has done so well that people are now being transferred into it from the two other groups (test reactors and ship reactors). I was responsible for most of the new ideas which gave us our lead. The rest came from Edward Teller who is also in our group. It is exciting and infuriating to work with Teller. I had often heard about scientists behaving like prima donnas, and now I know what it means. We had yesterday a long meeting at which I disagreed with him, and he was in a filthy temper. Finally he won the argument by threatening to leave the place if we would not do things his way. I did not know whether to laugh or cry, but it was clear that the best thing was to laugh and go along with him. I do not have to take this seriously. But I understand now what a misery he must have been for Oppenheimer at Los Alamos. Oppenheimer could not let him run the whole show his own way. I am glad I am not likely ever to be Teller’s boss.

  We are trying to design reactors which shall be intrinsically safe against blowing up or melting down, so that one can put them in hospitals or factories, and the neighbors will not be afraid of them. Our quarrels arise because I have a scheme which will take two or three years to develop and is very good, while Teller has a scheme which can be done with luck in one year but is not so good. Teller says, since this is a small company, we ought to drop everything else and work on his scheme to get it done as quickly as possible. We decided yesterday to do this. I am not particularly unhappy about it. I shall enjoy working on his scheme. But I am glad I put up a fight and made myself heard. It is astonishing how quickly one can become the world’s greatest expert on safe reactors. It is like Papa and his handbook of grenade fighting. I have never seen the inside of a reactor, and I did not even read about one till four weeks ago. Teller is in roughly the same situation. What makes me happy is that I have now an established reputation as a reactor expert, whether my ideas are ever adopted or not. I shall have to do nothing more, and invitations to consult with various companies will come flowing in. And I find this reactor business genuinely exciting. As time goes on, I begin to like this place better. Today I shall go down to Mexico and see my first bullfight.

  My father was a professional musician who volunteered to be a soldier when World War I broke out in 1914. He was quickly appointed grenade officer for his infantry unit, since nobody else wanted the job. He wrote the official handbook of grenade fighting (1915), never having seen a real grenade. His handbook was used by the entire British army thoughout the war, and also by the American army when the United States joined the war in 1917. He was thirty-one when he became the expert on grenade fighting, and I was aged thirty-two when I became the expert on safe reactors. All it takes to become an expert is a little common sense and a little imagination.

  AUGUST 12, 1956

  I am having a joyful time here. I seem to have made quite a dent in the atomic energy business and their security regulations. What I have done for this company seems to have impressed them. They are begging me to stay here and be the head of the theoretical division. They offer to do absolutely anything to make it agreeable to me. Luckily we had here for the last week a young man called Lewis Strauss, Jr., who happens to be the son of the Lewis Strauss who is the head of the whole AEC. Strauss Junior is a physicist, and I found him congenial and easy to talk to. The old Strauss is a firm Republican and would decide the question in favor of General Atomic if it ever came to his notice. Yesterday before he left to go back to Washington, young Strauss whispered in my ear, “We will have you cleared inside two weeks.” So I imagine the old-fashioned power of family influence will be brought into action on my side. Meanwhile I am amusing myself with reactors, and I find it absorbingly interesting to think about them. Probably this summer is a turning point in my life. I find the atomic energy business congenial, and also I am good at it. My real talent is perhaps not so much in pure science as in practical development. Just as Papa would never make music to himself in an ivory tower but always in the context of a particular group of people who would play it.

  SUNDAY, AUGUST 26, 1956, LA JOLLA

  You may like to hear the sequel to my quarrel with the AEC. A few days after my previous letter to you, the news came from Washington that I am cleared. But I am only cleared for one project, which is the most secret of all the things General Atomic is doing. The AEC has a logical explanation for this absurd situation. Their regulations say that secret information may be given to a foreigner only when this is necessary to the national defense. Obviously, if the information is not vital military information, it cannot be necessary to the national defense to give it to me. Therefore I can have the important military secrets but not the unimportant civilian secrets. It is the craziest joke I ever heard. A few days after the clearance, there came a telephone call from Los Alamos asking me to sign on with them as a consultant and to stay a week on my way home from here in September. The contract allows me to go to Los Alamos anytime I like. I have agr
eed to sign on.

  SEPTEMBER 20, 1956,

  THE LODGE, LOS ALAMOS, NEW MEXICO

  I finally managed to get here. Yesterday came the news that my clearance has been approved. I flew to Albuquerque in the evening and this morning took the little five-seater plane which comes up here. The trip from Albuquerque to here is marvelous, mountains and deserts glittering in the morning sun. The plane lands on a little mesa not much wider than the runway, perfectly flat on top and with a deep canyon on each side. From up above Los Alamos looks like a village, tiny among these vast distances. Most conveniently, I took the last of my fourteen rabies injections in La Jolla yesterday. I got through that very well. Now I have two days here, then on Saturday I fly east. Today I spent absorbing all the information I could at tremendous speed. My clearance is good for everything, all kinds of bombs included. I have done pretty well learning all this stuff in one day.

  The rabies injections were needed because I had been bitten by a stray dog in Mexico. In those days the injections were made from rabbit brains containing antibodies to the virus, so there was a risk that the brain tissue might cause an encephalitis as disabling as rabies. Edward Teller helped me to evaluate the risks of encephalitis and rabies with and without the injections. He advised me to take the injections.

  I never needed to worry about all the bomb secrets that I was carrying around in my head. Fortunately, there was always a clear separation between the secret stuff and the open science and the political activities that I was free to talk about. I did not worry whether my letters from Los Alamos to my parents might be read by some snooping security people. I did not know whether they were snooping, and I did not care. They had the right to snoop if they wished. There was never anything in the letters that came close to being secret.