The Big Bang

May 19, 1942
Cambridge, England

In my second year as an undergraduate at Cambridge, I registered for national service. I was in the Home Guard, which was supposed to help the army defeat the Germans in case of an invasion. In 1940 the threat of an invasion had been real, but in 1942 the Germans were heavily engaged in Russia, and nobody took the threat of an invasion seriously. It was lucky that we never had to do any real fighting. The Home Guard required me to take part in occasional night exercises. The invasion became more and more unlikely as the years went by, but the exercises continued until the end of the war. They helped to sustain the wartime spirit that made England a friendlier country during the war years.

I went on the exercise on Saturday after all. We sat in the parade ground till ten p.m., when my section set out for Grantchester on bicycles. The idea was to stop the Welsh Fusileers from capturing Cambridge, so we were stationed near a bridge at Grantchester; two men to demolish the bridge and the rest to give protection to them. We took up a very halfhearted defensive position on the roadside, lying along the hedge, and waited for orders to demolish the bridge, or the arrival of the enemy. We had a beautiful notice saying Bridge Demolished and a small piece of explosive to make a bang. Of course, as always when I am on an exercise, the enemy never came anywhere near Grantchester, though they overran about a third of Cambridge. We stayed under that hedge from eleven p.m. till eleven a.m. It was impossible to take enough clothes to be able to keep warm, though the weather was quite fine. Last night I spent at the hut fire-watching. I was out from twelve till two-thirty but slept pretty well the rest of the time. Fortunately the weather was again good. But this military activity does take up a great deal of energy when they have night operations.

January 24, 1943
Cambridge, England

The Germans bombed London heavily in 1940–1941 and less heavily with V-1 cruise missiles and V-2 rockets in 1944–1945. During the years 1942–1943 there was very little bombing. Occasionally a few bombers would come over and drop a few bombs, probably to reassure the German home population, who were suffering from the growing British and American bombing of Germany. One of the token raids on London happened in January 1943.

I wish I had been in London for the air raid; there is nothing that makes me so happy as a display of fireworks. It seems they have given up the idea of a Baedeker raid on Cambridge, which is a pity. I bought yesterday a set of War and Peace in Russian, the first I have seen in England, published in Moscow in 1941. Rather a wartime production I am afraid, but still readable and with quite large print. I shall settle down to it one day, not in the near future. It is 1,927 pages long. It costs eighteen roubles in Russia, and a pound in England, the difference being several hundred percent; I do not know where the money goes. It says they published 100,000 copies of the edition in 1941–42, evidently as in England there was a great demand for it. I read the concluding paragraphs, which point the moral of the whole work, that human affairs can only be understood by a belief in complete dependence on Providence. They have not, I am glad to say, been interfered with.

August 13, 1947
British Army on the Rhine, Münster

…More valuable than any of the amusements laid on for us are the conversations which occur from time to time. I will describe two of these which made a deep impression on me. First, a gathering of five men including myself; one from the Nineteenth Light Infantry (the most famous division) of the Afrika Corps, one from the motor-torpedo-boat section of the German navy in the North Sea, one from the U-boat service, one from RAF Transport Command, and one from RAF Bomber Command. We began talking about the war years, and the different views which we had of the events of that time; gradually we drifted towards personal reminiscences. I said very little, but the Germans soon became warmed to their subject and unburdened their hearts without restraint. I have seldom found the Germans so genuinely and obviously happy; a description by the U-boat sailor of what happens when a petrol tanker is torpedoed was given with the most single-minded enthusiasm. It reminded me vividly of the descriptions we used to read at Bomber Command of successful incendiary attacks, and of the elation we felt when such attacks succeeded. It is ironic that when finally enemies meet and come together as friends, they should still be able to entertain each other with such stories….

December 7, 1947
Cornell University, Ithaca, New York

Yesterday I had a talk with [Hans] 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 [J. Robert] Oppenheimer, and that Oppenheimer would be glad to look after me. When I first went to see [Rudolf] 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 fairly 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 [the Institute of Advanced Study in] Princeton. So one could hardly ask for anything better than to go to him.

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 [Philip] 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.

October 10, 1948
Institute for Advanced Study Princeton, New Jersey

There is one consideration involved in this question of physics versus astronomy which I did not mention when I wrote before. It might have been supposed until recently that, as nuclear physics was a subject in which secrecy was having a seriously hampering effect on research, at least astronomy would have the advantage of being free from this. However, it turns out that the kind of fundamental nuclear physics which I am doing at present is completely free and likely to remain so, since it is quite impracticable to use it for predicting the behaviour of matter in bulk. On the other hand, it is just in the borderline between physics and astronomy that the most delicate problems involved in constructing superpowerful atomic bombs arise, and in this field I imagine are the most jealously guarded secrets. A superbomb is probably more like a nova (new star) than anything else we can see, so the time may come when telescopes become more important military weapons than piles [nuclear reactors].

November 14, 1948
Institute for Advanced Study Princeton, New Jersey

…Oppenheimer is in California this weekend, talking to people there. He returns on Tuesday. It is no wonder he is such a nervous wreck, with all this gadding around. The wonder is rather that he manages to keep as clear-headed as he does. I have been observing rather carefully his behaviour during seminars. If one is saying, for the benefit of the rest of the audience, things that he knows already, he cannot resist hurrying one on to something else; then when one says things that he doesn’t know or immediately agree with, he breaks in before the point is fully explained with acute and sometimes devastating criticisms, to which it is impossible to reply adequately even when he is wrong. If one watches him, one can see that he is moving around nervously all the time, never stops smoking, and I believe that his impatience is largely beyond his control. On Tuesday we had our fiercest public battle so far, when I criticised some unwarrantably pessimistic remarks he had made about the Schwinger theory. He came down on me like a ton of bricks and conclusively won the argument so far as the public was concerned. However, afterwards he was very friendly and even apologised to me. When life is like this, the great thing is to keep a sense of proportion and avoid becoming a nervous wreck like Oppy. So far I think I am succeeding, but you should not be surprised when I write melancholic letters occasionally.

November 25, 1948
Institute for Advanced Study Princeton, New Jersey

Last night the Oppenheimers gave their Thanksgiving party, a stand-up supper for about one hundred guests, mostly the institute and its wives. The party was quite enjoyable as such things go. The young physicists kept pretty much to themselves, and I did not speak to many people outside our circle. There were, however, two exceptions to this rule. First, it was a farewell party for T.S. Eliot, who is returning to Europe to receive his Nobel Prize and go home. Most of the time he was surrounded with elderly and distinguished people in a small drawing room apart from the main crowd; our physicist group was in the main room lamenting the fact that none of us had been brazen enough to go and talk to the great man. This conversation immediately fired the light of ambition in Cécile’s eyes, and she said, “Well, you are a lot of cowards; I’ll go and fetch him out for you.”¹ So she went into the little room where the elderly and distinguished people were, came out a few seconds later with a grinning Eliot in tow, and introduced us to him one by one. After this there was a brief period of rather embarrassed conversation, which was made easier by the fact that Eliot has a sense of humour and some experience in dealing with such situations. Then Cécile returned him to the little room.

All this time Oppy was rushing around, resplendent in black tie and dinner jacket, making sure he met and spoke to everybody. He is a first-rate host and looked happier than I have seen him ever. When he spoke to me, it was to give me the recipe for some delicious Mexican savories that were being served with the supper. (He is an expert cook.) Then he rushed off to the next conversation, which might have been on any subject from football to cuneiform texts. This kind of evening is probably the nearest he ever gets to being relaxed. Mrs. Oppy I also met. She is quick-witted on a much more human level. She struck me as a friendly, direct young person, with no airs and entirely unspoiled by greatness.

The queerest and maddest part of the evening came at the end. People were then trying ineffectively to dance in the constricted space available. I was suddenly seized upon by an absurd and very drunken little woman, who ordered me to dance with her. As she is a pathetic-looking creature with a disfiguring scar on her face, I could not decently reject her. So I danced around with her for about twenty minutes, she evidently not minding how badly I danced. At the end of this she was getting so wild and jumping about so that it made me very uncomfortable, and I finally succeeded in returning her to her husband. The husband, who is a solemn and frightened-looking little man, was standing around by himself miserably while all this went on. He did not seem to talk to anybody all the evening. It makes me feel sick just to think of the horror of the lives these two people may be living. Evidently the reason the wife seized upon me for a partner is that I am the only one of the young men at the party whom she had met before. The name of the husband (I wonder if you guessed it) is Kurt Gödel.

The horror of this scene was real, but Adele Gödel was rarely drunk, and she was a good wife for Kurt when she was sober.

June 20, 1956
La Jolla, California

I spent the summer of 1956 in La Jolla working for General Atomic, a start-up company founded in 1955 by Freddy de Hoffmann, a young scientist from Los Alamos, to build and sell fission reactors in the commercial market.

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.

May 24, 1959
La Jolla, California

For the academic year 1958–1959 I took a leave of absence from the Institute for Advanced Study to work at the General Atomic Laboratory in La Jolla on Project Orion, a nuclear bomb–propelled spaceship that we thought could fly to Mars and the satellites of Jupiter and Saturn. It did not turn out to be feasible.

Yesterday we had a beautiful supper-picnic on the beach. A lot of our friends were there and also Niels Bohr and his wife. Old Bohr was here for the official celebrations when the laboratory was dedicated last week. Bohr stayed another week to talk to people and enjoy the scenery. For about half an hour Bohr talked to me alone as we walked up and down the beach. It was a tantalizing experience, as his voice is almost too low to hear, and each time a wave broke, his wisdom was irreparably lost. I learnt a lot about his struggles during the war to convince Roosevelt and Churchill that the atomic bomb was not something they could keep in their pockets. He believed then that the Russians would soon be making their own bombs and that the only chance to avoid a catastrophe was to bargain with Russia immediately for an abandonment of secrecy on both sides. Of course, he failed to convince Roosevelt and Churchill. But he said he had General [Jan] Smuts and Lord Halifax on his side.

I was glad that Bohr was enthusiastic about our spaceship. He thinks of it as something with which one may once again try to make a reasonable bargain with Russia. Of course, the difficulties now are in some ways greater than they were in 1944. But at least the secrecy problem is not so obsessive as it was then. The politicians have learned that secrets do not stay secret forever, and one can talk much more freely than in 1944. The problem is that we do not have much to offer Russia in return for opening up their country to us. I do not have much hope that we can solve the problems of war and peace this way. But I am glad if we try. Bohr encouraged me a lot.

August 28, 1963
Washington, D.C.

I would like to write to you about today’s events while they are fresh in my mind.² I stopped work at eleven a.m. and walked from the State Department down to Constitution Avenue a few blocks away. The broad avenue was completely cleared of traffic and full of people. I walked to the end of the avenue where the march was beginning, then joined the people and walked with them to the other end where they arrived at the Lincoln Memorial. I found it profoundly moving to be marching with all these people. Just for once to be seeing history made instead of only reading and writing about it. The march was quiet. No music and no stamping of feet. Just people strolling down the avenue in their own time.

Each group of people carried banners saying where they came from. Occasionally there would be some shouting and cheering when a group came by from one of the really tough places, Birmingham, Alabama, or Albany, Georgia, or Prince Edward County, Virginia. Most of these people from the Deep South had never been away from their homes before, and they had never had anybody to cheer for them. It must have been quite an experience for them to see so many friends all together. There was an interesting difference between the northern and the southern people. The northerners were mostly rather well-dressed family people, husbands and wives, many of them union members who were brought to Washington by their unions. The southerners were much younger, most of them hardly more than children, and they looked like the hope of the future with their bright faces and gay clothes. Of course, in the bad southern states a man with family responsibilities cannot afford to be put in jail, so it is necessarily the young who must carry on the fight. Some of these southern groups sang their freedom songs very beautifully while the northerners listened.

The march along Constitution Avenue started at eleven and went on for three hours without stopping. They said 250,000 people came. I would guess they were about 80 percent northern negro, 10 percent northern white, 10 percent southern negro. The weather was kind, a temperature of eighty-two with cool breeze and sunny sky. All the people there were enjoying the outing. They had been told to leave their children at home, and that made it different from an ordinary holiday crowd. It was quite relaxed, but very serious in the underlying mood.

From two till four they had the official speeches at the Lincoln Memorial. It was very effective to have the huge figure of Lincoln towering over the speakers. The speeches were in general magnificent. All the famous negro leaders spoke, except James Farmer, who sent a message in writing from a Louisiana jail. The finest of them was Martin Luther King, who talks like an Old Testament prophet. He held the whole 250,000 spellbound with his biblical oratory. I felt I would be ready to go to jail for him anytime.

I think this whole affair has been enormously successful. All these 250,000 people behaved with perfect good temper and discipline all day long. And they have made it unmistakeably clear that if their demands are not promptly met, they will return one day in a very different temper. Seeing all this, I found it hard to keep the tears from running out of my eyes.