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STANISLAW ULAM, THEORIST ON HYDROGEN BOMB
Stanislaw M Ulam, who has been described as one of the greatest contemporary mathematicians and who played a key role in developing the hydrogen bomb, died Sunday in Santa Fe, N.M., after apparently suffering a heart attack. He was 75 years old. Early in the development of a design for the hydrogen bomb at Los Alamos National Laboratory in New Mexico, Dr. Ulam and Dr. Edward Teller ran into a stumbling block so critical that the feasibility of such a weapon seemed in doubt. They were unable to devise a way, using the energy of an atomic explosion, to create conditions sufficiently like those in the core of the sun to initiate the fusion of hydrogen atoms and release the devastating energy of the proposed bomb. Solution Came in a Dream It was in a dream, Dr. Ulam later reported, that a solution came to him. Although Dr. Teller is often referred to as ''father'' of the hydrogen bomb, some physicists regard Dr. Ulam's role as essential. Details of what is now known as the Teller-Ulam solution are still classified by the Government.
In 1979 the Government sought to bar The Progressive, a magazine in Wisconsin, from publishing a partial description of the method. Elements of it, the magazine asserted, had already been disclosed in an article by Dr. Teller for the Encyclopedia Americana. The Government finally dropped its attempt after other publications printed similar material.
At Los Alamos, to predict what might happen in complicated situations, such as atomic chain reactions, Dr. Ulam developed a form of analysis that uses computer-generated random numbers to obtain a solution based on probabilities. Now widely used, it is known as the Monte Carlo method.
Invitation From von Neumann
Stanislaw Marcin Ulam was born April 3, 1909, in Lvov, Poland, now part of the Soviet Union. He displayed an early gift for mathematical wizardry, and at the age of 28, after obtaining master's and doctoral degrees at the Polytechnic Institute in Lvov, he was invited by the great mathematician, John von Neumann, to join the Institute for Advanced Study in Princeton, N.J. From 1936 to 1940 he was a lecturer in mathematics at Harvard University. In 1943, after serving as assistant professor at the University of Wisconsin and becoming an American citizen, he was recruited by von Neumann for the atomic bomb effort at Los Alamos, remaining there as an adviser until 1967. Meanwhile, he held visiting professorships at the University of Southern California, Harvard and the Massachusetts Institute of Technology.
In 1965 he joined the University of Colorado, serving both as professor in and chairman of the mathematics department. At his death he was professor of biomathematics at that university's medical school. Among his specialties, in addition to Monte Carlo analysis, were set theory, mathematical logic and topology. He was the author of several books, including Adventures of a Mathematician, describing in a personal way the many prominent mathematicians and scientists with whom he worked. He is survived by his wife, Françoise, a daughter and granddaughter.
Walter Sullivan
May 15, 1984 © New York Times