Genesis of the Monte Carlo Algorithm for Statistical Mechanics

(June 2, 2003) I fear that 50 years is a bit long for expecting much from the originators of the rst applications of a technique. Mici Teller and Nick Metropolis are dead. Edward Teller and Arianna Rosenbluth are too in rm to travel. It is not easy for me either, but in the hope of learning something about the last 50 years of progress from our crude beginnings, I am glad to be here, and I will try to give you my subjective history of the development and motivations of the rst papers on the topic. The period 1949-1952 here at Los Alamos 50 years ago was of course a time of great excitement as the successful concept for a hydrogen bomb had been proposed by Teller, and was being eshed out by the members of the small theory group. We worked 60 hours or more per week trying to understand the physics of the interactions of radiation and matter under these extreme conditions, and how the explosion/implosion/ explosion would evolve. A key issue was of course the equation of state which was the origin of my interest in the subject. At this time the rst electronic computers were just coming into being, and until the end of 51 the work was mainly analytic, supplemented by some implosion codes on the punchcard IBM machines. Nonetheless by this time our crude results, supplemented by the successful Greenhouse tests, led to a high degree of con dence that the Mike shot in Nov.52, the rst HBomb, would succeed, in fact was quite overdesigned. Still as the new computers nally came on line it was obviously necessary to do the most detailed possible calculations .For the next few months my rst wife, Arianna, and I devoted ourselves to this task and she in particular became one of the rst and most skillful adepts at this new game. Let me recall the state of computers in those days. The driving force in the US was of