Vita LOS ALAMOS 1943 Receives invitation to join the Manhattan Project 1944 February 4: Arrives in Los Alamos Joins Edward Teller's group in the Teller's group is transferred to COSMOS CLUB November 9, 1943 Dear Stan, Von Neumann wrote this letter to Stan in longhand. It is reproduced here in typewritten form to decrease its size and increase its legibility. I am very glad that Mr. Hughes and all he stands for'' have It is very interesting, too, It The project in question is exceedingly important, probably beyond all adjectives I could affix to it. and the theoretical (and other) physicists connected with it are probably the best group existing anywhere at this moment. does require some computational work, but there is no doubt, that everybody will be most glad and give you all the encouragement I can also assure you of my own you can wish in doing original research on the subject, for which there is ample opportunity. cooperation in this respect. The secrecy requirements of this project are rather extreme, and it will probably necessitate your and your families essentially staying on the premises (except for vacations) as long as you choose to be associated with it. If you want war work, this is probably a quite I may be able to give you a better idea orally, and I would be I don't see that from Germany need be broken before So you really count on a quite short war? a purely technical standpoint next fall.. Of course a collapse may come any day from now on for moral and political reasons, but I can't [know] how to judge that, without knowing much more about the present state and efficiency of the Nazi political machine. And there is still a year's worth of Asiatic war after that. It seems that Morgenstern's and my book on 'games'' will be out Best regards, and looking forward to seeing you soon---here or there''➖➖➖ as ever Von Neumann, circa 1950 During the late spring of 1943, I wrote to von Neumann about the possibility of war work... I received an official invitation to join an unidentified project that was doing important work, the physics having something to do with the interior of stars. The letter inviting me was signed by the famous physicist Hans Bethe. Finally I learned that we were going to New Mexico, to a place not far from Santa Fe. Never having heard about New Mexico, I went to the library and borrowed the Federal Writers' Project Guide to New Mexico. At the back of the book, on the slip of paper on which borrowers signed their names, I read the names of Joan Hinton, David Frisch, Joseph McKibben, and all the other people who had been mysteriously disappearing [from Madison] to hush-hush war jobs without saying where. I had uncovered their destination in a simple and unexpected fashion. It is next to impossible to maintain absolute secrecy and security in war time. [Upon my arrival at Los Alamos, Johnny] took me aside and... told me of all the possibilities which had been considered, of the problems relating to the assembling of fissionable materials, about plutonium (which did not yet physically exist even in the most microscopic quantities at Los Alamos). I remember very well, when a couple of months later I saw Robert Oppenheimer running excitedly down a corridor holding a small vial in his hand, with Victor Weisskopf trailing after him. He was showing some mysterious drops of something at the bottom of the vial. Doors opened, people were summoned, whispered conversations ensued, there was great excitement. The first quantity of plutonium had just arrived at the lab. It is one thing to know about physics abstractly. and quite another to have a practical encounter with problems directly connected with experimental data... I found out that the main ability to have was a visual, and also an almost tactile, way to imagine the physical situations, rather than a merely logical picture of the problems... Very few mathematicians seem to possess [such an imagination] to any great degree. Enrico Fermi Left to right: von Neumann, Feynman, Ulam at Bandelier, 1949 Strangely enough, the actual working problems did not involve much of the mathematical apparatus of quantum theory although it lay at the base of the phenomena, but rather dynamics of a more classical kind-kinematics, statistical mechanics, large-scale motion problems, hydrodynamics, behavior of radiation... Compared to quantum theory the project work was like applied mathematics as compared with abstract mathematics. [Edward] Teller, in whose group I was supposed to work, talked to me on that first day about a problem in mathematical physics that was part of the necessary theoretical work in preparation for developing the idea of a "super" bomb, as the proposed thermonuclear hydrogen bomb was then called... Teller's problem concerned the interaction of an electron gas with radiation... This was the first technical problem in theoretical physics I had ever tackled in my life... It was a messy little job. Edward was not satisfied with my rather elementary derivations. After this first work on Edward's problem, I spread out my interests to other related questions, one being the problem of statistics of neutron multiplication. This was more tangible for me from the purely mathematical side. I discussed such problems of branching and multiplying patterns with David Hawkins. A discussion with von Neumann... [in] early 1944 took several hours, and concerned ways to calculate the course of an implosion more realistically than the first attempts outlined by him and his collaborators. The hydrodynamical problem was simply stated, but very difficult to calculate-not only in detail, but even in order of magnitude ... In this discussion I stressed pure pragmatism and the necessity for attempting to get a heuristic survey of the general problem by simpleminded brute force-that is, more realistic, massive numerical work ... With the available computing facilities, the accuracy of the necessary numerical work could not be satisfactory. This was one of the first reasons for pressing for the development of electronic computers. Fermi was short, sturdily built, strong in arms and legs, and rather fast moving. His eyes, darting at times, would be fixed reflectively when he was considering some questions... He would try to elucidate other persons' thoughts by asking questions in a Socratic manner, yet more concretely than in Plato's succession of problems. I think he had a supreme sense of the important. He did not disdain work on the socalled smaller problems; at the same time, he kept in mind the order of importance of things in physics. This quality is more vital in physics than in mathematics, which is not so uniquely tied to "reality." Strangely enough, he started as a mathematician. Some of his first papers with very elegant results were devoted to the problem of ergodic motion. When he wanted to, he could do all kinds of mathematics. To my surprise, once on a walk he discussed a mathematical question arising from statistical mechanics which John Oxtoby and I had solved in 1941. [Fermi] could be also quite a tease. I remember his Italian inflections when he taunted Teller with statements like "Edward-a how com-a the Hungarians have not-a invented anything?" Clockwise from lower left: An unidentified person, Mark, Matthias, Ulam, Evans, Cowan, Metropolis Vita LOS ALAMOS 1945 July 16: Trinity Test September: Moves to Los Angeles as Associate Professor at University of Southern California 1946 January: Acute attack of encephalitis April: Attends secret conference at Los Alamos May: Returns to Los Alamos 1947 C. J. Everett joins the Laboratory Seminars on the Monte Carlo Method and hydrodynamical calculations Beginning of heuristic studies on electronic computing machines Ulam and Everett develop theory of multiplicative processes 1949 Russian atomic bomb test Truman directs AEC to proceed with work on the hydrogen bomb One thing that relieved the repetition and alternation of work, intellectual discussions, evening gatherings, social family visits and dinner parties, was when a group of us would play poker about once a week. The group included Metropolis, Davis, Calkin, Flanders, Langer, Long, Konopinski, von Neumann (when he was in town), Kistiakowski sometimes, Teller, and others. We played for small stakes; the naïveté of the game and the frivolous discussions laced with earthy exclamations and rough language provided a bath of refreshing foolishness from the very serious and important business that was the raison d'être of Los Alamos. The Trinity test, Hiroshima, V-J Day, and the story of Los Alamos exploded over the world almost simultaneously with the A-Bomb. Publicity over the secret wartime Project filled the newspapers and its administrative heads were thrown in the limelight. As I was reading [such items,] something else flashed through my mind, a story of a "pension" in Berlin before the war... One man was taking most of the asparagus that was on the platter. Whereupon another man stood up shyly and said: "Excuse me, Mr. Goldberg, we also like asparagus!" And the expression "asparagus" became a code word in our private conversations for trying to obtain an unduly large share of credit for scientific work or any other accomplishment of a joint or group character. Johnny loved this story ... We would plan to write a twenty-volume treatise on "Asparagetics through the Ages"... But levities like these could hardly alleviate the general feeling of foreboding upon entering into the era of history that would be called the Atomic Age. In early September of 1945, I went to Los Angeles to look for housing and to prepare our move from Los Alamos. It was a stormy day; on the walk from the bus to the house in Balboa the violent winds almost choked me. That same night I developed a fantastic headache ... The following night... I noticed that my speech was confused, that I was barely able to form words. I tried to talk ... but it was mostly a meaningless mumble-a most frightening experience ... A severe attack of brain troubles began, which was to be one of the most shattering experiences of my life... Many of the recollections of what preceded my operation are hazy. Thanks to what Françoise told me later I was able to put it together... She feared I was dying and made a frantic telephone call to the surgeon, who decided the operation should be performed immediately. This probably saved my life; the emergency operation relieved the severe pressure on my brain which was causing all the trouble... The illness was tentatively diagnosed as a kind of virus encephalitis. But the disquietude about the state of my mental faculties remained with me for a long time, even though I recovered speech completely. Stan and Everett in Madison, 1942 It was in 1949 ... that George Gamow, whom I had met briefly in Princeton before the war, came to Los Alamos for a lengthy visit... There was nothing dry about him. A truly "threedimensional" person, he was exuberant, full of life, interested in copious quantities of good food, fond of anecdotes, and inordinately given to practical jokes. Banach once told me, "Good mathematicians see analogies between theorems or theories, the very best ones see analogies between analogies." Gamow possessed this ability to see analogies between models for physical theories to an almost uncanny degree... It was along the great lines of the foundations of physics, in cosmology, and in the recent discoveries in molecular biology that his ideas played an important role. His pioneering work in explaining the radioactive decay of atoms was followed by his theory of the explosive beginning of the universe, the "big bang" theory (he disliked the term by the way), and the subsequent formation of galaxies. Shortly after President Truman's announcement directing the AEC to proceed with work on the H-Bomb, E. O. Lawrence and Luis Alvarez visited Los Alamos from Berkeley and started discussions with Bradbury and then with Gamow, Teller, and myself about the feasibility of constructing a "super." This visit played a part in the politics of this enterprise. Several different proposals of ideas existed on how to initiate the thermonuclear reaction, using fission bombs as starter. One of Gamow's was called "the cat's tail." Another was Edward's original proposal. Gamow drew a humorous cartoon with symbolic representations of these various schemes. In it he squeezes a cat by the tail, I spit in a spittoon, and Teller wears an Indian fertility necklace, which according to Gamow is the symbol for the womb, a word he pronounced "vombb." This cartoon has appeared among the illustrations in his autobiography, My World Line, published by The Viking Press in 1970. A first committee was formed to organize all work on the 'super' and investigate all possible schemes for constructing it. The committee's work was directed by Teller, as chairman, Gamow and myself... Both Gamow and I showed a lot of independence of thought in our meetings and Teller did not like this very much. Not too surprisingly, the original 'super' directing committee soon ceased to exist. Vita LOS ALAMOS UNIVERSITÉ DE PARIS FACULTÉ DES SCIENCES Année scolaire 1953-1954 M. S. M. ULAM, de l'Université de Californie, fera une conférence le Mardi 1 Juin 1954, à 18 heures, à l'Institut Henri Poincaré, 11, rue Pierre-Curie (Amphitheatre Darboux), sur le sujet suivant : At once Edward took up my suggestions, hesitantly at first, but enthusiastically after a few hours. He had seen not only the novel elements, but had found a parallel version, an alternative to what I had said, perhaps more convenient and generalized. From then on pessimism gave way Etudes heuristiques de divers problèmes mathématiques to hope... Teller lost no time in presenting these Hand calculations by Ulam and Ev- Results of calculations confirmed by Ulam suggests new approach to igni- Teller suggests a related approach 1951-52 Fall semester: Visiting Professor at Harvard Begins serious discussions of cellular 1952 Summer: Studies nonlinear systems with Fermi and Pasta sur les machines à calculer électroniques Still Teller kept on hinting that not enough work was being done on his original scheme for the ignition of the "super" ... In collaboration with my friend Everett one day I decided to try a schematic pilot calculation which could give an order of magnitude, at least, a "ballpark" estimate of the promise of his scheme... Before we started this calculation of the progress of a thermonuclear reaction (burning in a mass of deuterium or deuterium-tritium mixture), Everett and I had done a lot of work on probablility questions connected with the active assemblies of uranium and with neutron multiplications. We worked out a theory of multiplicative processes, as we called it. (Now the preferred name is "branching processes.") ... Our calculation ... threw grave doubts on the prospects of Edward's original approach to the initial ignition conditions of the "super." As the results of the von Neumann-Evans calculation on the big electronic Princeton machine slowly started to come in, they confirmed broadly what we had shown. There, in the course of the calculation, in spite of an initial, hopeful-looking "flare up," the whole assembly started slowly to cool down. Every few days Johnny would call in some results. "Icicles are forming," he would say dejectedly. ideas, perhaps with most of the emphasis on the second half of our paper, at a General Advisory Committee meeting in Princeton which was to become quite famous because it marked the turning point in the development of the H-bomb. Contrary to those people who were violently against the bomb on political, moral or sociological grounds, I never had any questions about doing purely theoretical work... I felt that one should not initiate projects leading to possibly horrible ends. But once such possibilities exist, is it not better to examine whether or not they are real? An even greater conceit is to assume that if you yourself won't work on it, it can't be done at all... When I reflected on the end results, they did not seem so qualitatively different from those possible with existing fission bombs. After the war it was clear that A-bombs of enormous size could be made. The thermonuclear schemes were neither very original nor exceptional. Sooner or later the Russians or others would investigate and build them. The Oppenheimer Affair, which grew out of the violent hydrogen-bomb debate-even though the animosity between Strauss and Oppenheimer had personal and perhaps petty origins-greatly affected the psychological and emotional role of scientists. |