Stanislaw Marcin Ulam Biography

Stanislaw Marcin Ulam was one of the many gifted scientists involved in the effort to create a hydrogen bomb at the Los Alamos National Laboratory in New Mexico in the 1950s. As a professional mathematician, he was integral to the bomb development program because of his expertise in thermonuclear reactions and mathematical physics, which allowed him to solve the problem of how to start fusion in the hydrogen bomb. Along with John von Neumann, Ulam also invented the Monte Carlo method. In addition, his work on the new computers helped them become more flexible and useful.

Ulam, the son of a lawyer, was born in Lemberg, Poland, in the Austrian Empire (now Lvov, Ukraine) on April 13, 1909. When he was 10, he began attending the gymnasium (a classical college-preparatory school) in his hometown, and soon thereafter became interested in astronomy and physics. A brilliant boy, he became determined to understand Albert Einstein's theory of relativity, but when he realized he would need extensive knowledge of mathematics to accomplish his goal, Ulam directed his energies chiefly toward that subject.

Having taught himself much of the mathematics he knew, Ulam entered Lvov's Polytechnic Institute in 1927. He received his master's degree from the school in 1932 and his doctorate the following year. Ulam spent 1934 doing postdoctoral studies at Zurich, Vienna, and Cambridge University, after which he accepted von Neumann's invitation to work at the Institute for Advanced Studies (IAS) at Princeton University in 1935. He began lecturing there in 1936, and in 1939 decided to move to the United States. (Some of his close family members died soon afterward during the Holocaust.) Ulam also lectured at Harvard University until 1940, and then left the IAS and moved to the University of Wisconsin to serve as assistant professor of mathematics. He remained there until leaving for the Los Alamos lab in 1943 at the request of physicist Hans Bethe.

That same year, Ulam officially became an American citizen. At Los Alamos, he became intensely involved in the hydrogen (fusion) bomb program. Working with physicist Edward Teller, Ulam was credited with making huge progress toward creating a "superbomb" by suggesting that compression was the key element necessary for explosion and that the shock waves from an atomic (fission) bomb could produce that compression. He also showed how he could design the bomb so that the mechanical shock waves would be focused and promote quick ignition of the fusion fuel. Teller proposed instead that radiation, rather than mechanical, implosion be used to compress the fuel. This turned out to be the best solution, and led to the use of the "Teller-Ulam configuration" to build modern thermonuclear weapons.

Ulam left Los Alamos in 1946 to work briefly as professor of mathematics at the University of California, Los Angeles. Shortly after arriving there, he contracted encephalitis, which briefly rendered him unable to speak. His treatment succeeded, but afterward friends and colleagues found him a changed man. Apparently, Ulam's intellectual capacity had somehow been enhanced, although he seemed unable or at least reluctant to discuss the particulars of how he arrived at certain astonishing conclusions. While he rested in the hospital, von Neumann came to visit and the two mathematicians passed the time by playing solitaire. Ulam discovered the Monte Carlo method while doing so, and later developed it into an excellent calculation tool based on using approximations to solve complex problems. In fact, the method was so useful that Los Alamos scientists immediately adopted it for the national nuclear weapon program. Today, Monte Carlo is essential to applications in mathematical economy, weapons design, and operations research.

Returning to Los Alamos in 1946, Ulam served as staff member, research adviser, and group leader until 1967. He remained a consultant to the lab for the rest of his life, however. In the meantime, he published A Collection of Mathematical Problems in 1960 and continued to indulge his lifelong interest in set theory.

Two years prior to leaving Los Alamos, Ulam took a position at University of Colorado, Boulder as professor and chairperson of the Mathematics Department. He retained that post until 1975, publishing Sets, Numbers, and Universes in 1974 and his autobiography, Adventures of a Mathematician, in 1976. In the interim, he worked as a graduate research professor at the University of Florida from 1973 on and beginning in 1979 was professor of biomathematics at the University of Colorado Medical Center.

Ulam died in Santa Fe, New Mexico on May 13, 1984. He and his wife were married in 1941 and had one child. In his later years, Ulam continued to lecture around the world, but he also enjoyed writing and talking with friends.