John von Neumann


John von Neumann : biography

28 December 1903 – 8 February 1957

Stochastic computing was first introduced in a pioneering paper by von Neumann in 1953. However, the theory could not be implemented until advances in computing of the 1960s.

Von Neumann also created the field of cellular automata without the aid of computers, constructing the first self-replicating automata with pencil and graph paper. The concept of a universal constructor was fleshed out in his posthumous work Theory of Self Reproducing Automata. Von Neumann proved that the most effective way of performing large-scale mining operations such as mining an entire moon or asteroid belt would be by using self-replicating machines, taking advantage of their exponential growth.

Von Neuman’s rigorous mathematical analysis of the structure of self-replication, preceded the discovery of the structure of DNA.

Beginning in 1949, Von Neumann’s design for a self-reproducing computer program is considered the world’s first computer virus, and he is considered to be the theoretical father of computer virology.Éric Filiol, , Birkhäuser, 2005, pp. 19–38 ISBN 2287239391.

Donald Knuth cites von Neumann as the inventor, in 1945, of the merge sort algorithm, in which the first and second halves of an array are each sorted recursively and then merged.

His algorithm for simulating a fair coin with a biased coin is used in the "software whitening" stage of some hardware random number generators.

Fluid dynamics

Von Neumann made fundamental contributions in exploration of problems in numerical hydrodynamics. For example, with R. D. Richtmyer he developed an algorithm defining artificial viscosity that improved the understanding of shock waves. It is possible that we would not understand much of astrophysics, and might not have highly developed jet and rocket engines without the work of von Neumann.

A problem was that when computers solved hydrodynamic or aerodynamic problems, they tried to put too many computational grid points at regions of sharp discontinuity (shock waves). The mathematics of artificial viscosity smoothed the shock transition without sacrificing basic physics.

Other well known contributions to fluid dynamics included the classic flow solution to blast waves,Neumann, John von, "The point source solution," John von Neumann. Collected Works, A. J. Taub (ed.), Vol. 6 [Elmsford, N.Y.: Permagon Press, 1963], pp. 219–237 and the co-discovery of the ZND detonation model of explosives.

Politics and social affairs

Von Neumann obtained at the age of 29 one of the first five professorships at the new Institute for Advanced Study in Princeton, New Jersey (another had gone to Albert Einstein). He was a frequent consultant for the Central Intelligence Agency, the United States Army, the RAND Corporation, Standard Oil, General Electric, IBM, and others.

Throughout his life von Neumann had a respect and admiration for business and government leaders; something which was often at variance with the inclinations of his scientific colleagues.Mathematical Association of American documentary, especially comments by Morgenstern regarding this aspect of von Neumann’s personality Von Neumann entered government service (Manhattan Project) primarily because he felt that, if freedom and civilization were to survive, it would have to be because the U.S. would triumph over totalitarianism from the right (Nazism and Fascism) and totalitarianism from the left (Soviet Communism).

As president of the von Neumann Committee for Missiles, and later as a member of the United States Atomic Energy Commission, from 1953 until his death in 1957, he was influential in setting U.S. scientific and military policy. Through his committee, he developed various scenarios of nuclear proliferation, the development of intercontinental and submarine missiles with atomic warheads, and the controversial strategic equilibrium called mutual assured destruction. During a Senate committee hearing he described his political ideology as "violently anti-communist, and much more militaristic than the norm". He was quoted in 1950 remarking, "If you say why not bomb [the Soviets] tomorrow, I say, why not today. If you say today at five o’clock, I say why not one o’clock?".Blair, p. 96.