Stanisław Marcin Ulam ( ; 13 April 1909 – 13 May 1984) was a Polish and, later an American mathematician who made important contributions in advancing the understanding of nuclear physics and computer science. He participated in the Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method of computation, and championed nuclear pulse propulsion. In pure and applied mathematics, he proved a number of theorems and proposed several conjectures.

Born into a wealthy Polish Jewish family in Lemberg, Austria-Hungary, Ulam studied mathematics at the Lwów Polytechnic Institute, where he earned his PhD in 1933 under the supervision of Kazimierz Kuratowski and Włodzimierz Stożek. In 1935, John von Neumann, whom Ulam had met in Warsaw, invited him to come to the Institute for Advanced Study in Princeton, New Jersey, for a few months. From 1936 to 1939, he spent summers in Poland and academic years at Harvard University in Cambridge, Massachusetts, where he worked to establish important results regarding ergodic theory. On 20 August 1939, he sailed for the United States for the last time with his 17-year-old brother Adam Ulam. He became an assistant professor at the University of Wisconsin–Madison in 1940, and a United States citizen in 1941.

In October 1943, he received an invitation from Hans Bethe to join the Manhattan Project at the secret Los Alamos Laboratory in New Mexico. There, he worked on the hydrodynamic calculations to predict the behavior of the explosive lenses that were needed by an implosion-type weapon. He was assigned to Edward Teller's group, where he worked on Teller's "Super" bomb for Teller and Enrico Fermi. After the war he left to become an associate professor at the University of Southern California, but returned to Los Alamos in 1946 to work on thermonuclear weapons. With the aid of a cadre of female "computers" he found that Teller's "Super" design was unworkable. In January 1951, Ulam and Teller came up with the Teller–Ulam design, which became the basis for all thermonuclear weapons.

Ulam considered the problem of nuclear propulsion of rockets, which was pursued by Project Rover, and proposed, as an alternative to Rover's nuclear thermal rocket, to harness small nuclear explosions for propulsion, which became Project Orion. With Fermi, John Pasta, and Mary Tsingou, Ulam studied the Fermi–Pasta–Ulam–Tsingou problem, which became the inspiration for the field of nonlinear science. He is probably best known for realizing that electronic computers made it practical to apply statistical methods to functions without known solutions, and as computers have developed, the Monte Carlo method has become a common and standard approach to many problems.

Poland

Stanisław Marcin Ulam was born in Lemberg, Galicia, on 13 April 1909. At this time, Galicia was in the Kingdom of Galicia and Lodomeria of the Austro-Hungarian Empire, which was known to Poles as the Austrian partition. In 1918, it became part of the newly restored Poland, the Second Polish Republic, and the city took its Polish name again, Lwów. From 1931 until 1935, he traveled to and studied in Wilno (Vilnius), Vienna, Zürich, Paris, and Cambridge, England, where he met G. H. Hardy and Subrahmanyan Chandrasekhar. Fermi proposed to add to this force a nonlinear component, which could be chosen to be proportional to either the square or cube of the displacement, or to a more complicated "broken linear" function. This addition is the key element of the Fermi–Pasta–Ulam–Tsingou problem, which is often designated by the abbreviation FPUT.

In Colorado, where he rejoined his friends Gamow, Richtmyer, and Hawkins, Ulam's research interests turned toward biology. In 1968, recognizing this emphasis, the University of Colorado School of Medicine appointed Ulam as Professor of Biomathematics, and he held this position until his death. With his Los Alamos colleague Robert Schrandt he published a report, "Some Elementary Attempts at Numerical Modeling of Problems Concerning Rates of Evolutionary Processes", which applied his earlier ideas on branching processes to evolution. Except for sabbaticals at the University of California, Davis from 1982 to 1983, and at Rockefeller University from 1980 to 1984,

Impact and legacy

Ulam participated in the creation of a hydrogen bomb as part of the Los Alamos Laboratory nuclear project. From the publication of his first paper as a student in 1929 until his death, Ulam was constantly writing on mathematics. The list of Ulam's publications includes more than 150 papers.

thumb|An animation demonstrating the lucky number sieve. The numbers in red are lucky numbers.|alt=A square containing the numbers 1 to 120. Numbers are initially grey but go purple as they are eliminated; the lucky numbers then remain, and are highlighted in red.

The Monte Carlo method has become a ubiquitous and standard approach to computation, and the method has been applied to a vast number of scientific problems.

In 2021, German film director Thorsten Klein made a film adaptation of Ulam's autobiography, Adventures of a Mathematician.

In 2019, Polish entomologist Marcin Kamiński introduced the generic name Ulamus to honor Ulam's work. Ulamus belongs to the molluscan family Pteriidae.

Bibliography

  • (autobiography).

See also

  • (English title: Adventures of a Mathematician), biopic about Stanislaw Ulam, based on his autobiography.
  • List of Polish mathematicians
  • List of Polish physicists
  • List of things named after Stanislaw Ulam
  • Timeline of Polish science and technology

References

  • 1979 Audio Interview with Stanislaus Ulam by Martin Sherwin Voices of the Manhattan Project
  • 1965 Audio Interview with Stanislaus Ulam by Richard Rhodes Voices of the Manhattan Project
  • – 1976 lecture on The First International Research Conference on the History of Computing.