After World War II, he returned to the faculty of the University of Chicago as an assistant professor. He came back to Los Alamos in 1948 to lead the group in the Theoretical Division that designed and built the MANIAC I computer in 1952 that was modeled on the IAS machine, and the MANIAC II in 1957. From 1957 to 1965 he was Professor of Physics at the University of Chicago and was the founding Director of its Institute for Computer Research. In 1965 he returned to Los Alamos where he was made a Laboratory Senior Fellow in 1980.
At Los Alamos, in the 1950s, a group of researchers led by Metropolis, including John von Neumann and Stanislaw Ulam, developed the Monte Carlo method. Generally speaking, the Monte Carlo method is a statistical approach to solve deterministic many-body problems. In 1953 Metropolis co-authored the first paper on a technique that was central to the method now known as simulated annealing. This landmark paper showed the first numerical simulations of a liquid. The algorithm for generating samples from the Boltzmann distribution was later generalized by W.K. Hastings to become the Metropolis-Hastings algorithm. He is credited as part of the team that came up with the name Monte Carlo method in reference to a colleague's relative's love for the casinos of Monte Carlo. Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. In statistical mechanics applications prior to the introduction of the Metropolis algorithm, the method consisted of generating a large number of random configurations of the system, computing the properties of interest for each configuration, and then producing a weighted average where the weight of each configuration is its Boltzmann factor,, where is the energy, is the temperature, and is the Boltzmann constant. The key contribution of the Metropolis paper was the idea that
Metropolis played the part of a scientist in the Woody Allen film Husbands and Wives.
Personal life
Metropolis had a son, Christopher, and two daughters, Penelope and Katharine. He was an avid skier and tennis player until his mid-seventies. He died at a nursing home in Los Alamos, New Mexico.
Anecdotes
In his memoirs, Stanislaw Ulam remembers that a small group, including himself, Metropolis, Calkin, Konopinski, Kistiakowsky, Teller and von Neumann, spent several evenings at Los Alamos playing poker. They played for very small sums, but: "Metropolis once described what a triumph it was to win ten dollars from John von Neumann, author of a famous treatise on game theory. He then bought his book for five dollars and pasted the other five inside the cover as a symbol of his victory." In another passage of his book, Ulam describes Metropolis as "a Greek-American with a wonderful personality."
