People & Events|
Stanislaw M. Ulam (1909 - 1984)
One night in 1946, Stanislaw Ulam, a young mathematics professor was overwhelmed by a violent headache. When he tried to talk he found he could produce nothing but a meaningless mumble. He was rushed to a hospital where the surgeon drilled a hole in his skull and found his brain in an acute state of inflammation. The doctors applied penicillin liberally and Ulam lapsed into a coma.
The diagnosis was encephalitis. And Ulam's wife and friends worried that he would suffer permanent brain damage. But that was far from the case. The mathematician went on to produce some of his best work after his recovery. And, in fact, it was playing solitaire while convalescing, that Ulam first thought up the "Monte Carlo" method. Together with an old friend, mathematician John von Neumann, Ulam developed the procedure into an extremely useful calculating tool that enabled mathematicians to solve complicated problems by making approximations. It was put to almost immediate use by scientists working on nuclear weapons.
Ulam had first come to the United States from Poland for a few months in 1935 at von Neumann's invitation to work at the Institute of Advanced Studies in Princeton. He left his homeland for good in 1939 with his 16-year-old brother Adam. His father and uncle saw them off. It was the last time the brothers ever saw either men. Along with the rest of the Ulam family, they became victims of Hitler's holocaust.
In 1943 Ulam received a letter from physicist Hans Bethe offering him a job doing some war work. He remembers the letter was cryptic, "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 location was Los Alamos, New Mexico, the assignment: making an atomic bomb.
After a brief stint teaching at the University of Southern California, Ulam returned to the weapons laboratory at Los Alamos in 1946. And when President Truman announced in January 1950 that the United States was about to embark on an all-out effort to develop a hydrogen bomb, Ulam began calculating whether physicist Edward Teller's design for the superbomb would work. He comments: "We filled page upon page with calculations... I do not know how many man hours were spent on this problem."
Ultimately, Ulam and a fellow mathematician Cornelius Everett concluded that Teller's model was a "fizzle" and that it would never work. The results caused tensions between Ulam and Teller. But a year later Ulam accidentally came up with a new scheme that would prove to be a breakthrough, and he reluctantly took it to Teller. Teller recognized that, though there were problems with the idea, Ulam had hit on the solution. Together the two men converted it into a design for the superbomb that everyone at Los Alamos immediately recognized would work.
Their plan was to place an atom bomb inside a heavy shell that would also contain a capsule of hydrogen fuel. When the atom bomb exploded, in the fraction of a second before the whole assembly blew itself apart, the shell would confine the radiation from the atomic blast long enough to heat and compress the hydrogen fuel, setting off a fusion reaction. Central to Ulam's idea was the use of material surrounding the fuel capsule that would magnify the energy of the radiation.
Decades later physicist Hans Bethe wrote: "The new concept was to me, who had been rather closely associated with the program, about as surprising as the discovery of fission had been to physicists in 1939... Such miracles incidentally do happen occasionally in scientific history but it would be folly to count on their occurrence."