# John von Neumann

*A separate article covers Saint John Neumann, the American priest.*

**John von Neumann**(Neumann János) (December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician who made important contributions in quantum physics, set theory, computer science, economics and virtually all mathematical fields.

The oldest of three children, von Neumann was born *Neumann János* in Budapest to *Neumann Miksa* (Max Neumann), a banker, and *Kann Margit* (Margaret Kann). Growing up in a non-practicing Jewish family, von Neumann, nicknamed "Jancsi", showed incredible memory at an early age, being able to divide eight-digit numbers in his head at the age of six. He entered the Lutheran Gymnasium in 1911. In 1913, his father purchased a title, and Neumann János acquired the German name *von*, becoming János von Neumann.

He received his Ph.D in mathematics from the University of Budapest at the age of 23. He simultaneously learnt Chemistry in Switzerland,

Between 1926 and 1930 he was private lecturer in Berlin, Germany.

Von Neumann was invited to Princeton University in 1930, and was one of four people selected for first faculty of the Institute for Advanced Study, where he was a mathematics professor from its formation in 1933 until his death. During the Second World War, von Neumann contributed to the USA's Manhattan Project that built the first atomic bomb.

From 1936 to 1938 Alan Turing was a visitor at the Institute and completed a Ph.D. dissertation under von Neumann's supervision. This visit occurred shortly after Turing's publication of his 1934 paper "On Computable Numbers with an Application to the Entscheidungs-problem" which involved the concepts of logical design and the universal machine. Von Neumann must have known of Turing's ideas but it is not clear whether he applied them to the design of the IAS Machine ten years later.

Von Neumann was the father of game theory and published the classic book *Theory of Games and Economic Behavior* with Oskar Morgenstern in 1944. He conceived the concept of "MAD" (mutually assured destruction), which dominated American nuclear strategy in the Cold War.

Von Neumann dashed all hope of developing a deterministic quantum mechanics until his work was overturned by David Bohm, J.S. Bell, and others. He held a strong belief in the role of the observer in creating the collapse of the quantum wave function.

Von Neumann devised the von Neumann architecture used in most non-parallel-processing computers. Virtually every commercially available home computer, microcomputer and supercomputer is a von Neumann machine. He created the field of cellular automata without computers, constructing the first examples of self-replicating automata with pencil and graph paper. The term von Neumann machine also refers to self-replicating machines. Von Neumann proved that the most effective way large-scale mining operations such as mining an entire moon or asteroid belt can be accomplished is through the use of self-replicating machines, to take advantage of the exponential growth of such mechanisms.

In addition to his work on architecture, he is credited with at least one contribution the study of algorithms. Donald Knuth cites von Neumann as the inventor, in 1945, of the well known MergeSort algorithm, in which the first and second halves of an array are each sorted recursively and then merged together.

He also engaged in exploration of problems in the field of numerical hydrodynamics.

Von Neumann had a mind of great ingenuity and near total recall. He was an extrovert who loved drinking, dancing and having a good time. He had a fun-loving nature with a great love of jokes and humor. He died in Washington D.C.

The John von Neumann Theory Prize of the Institute for Operations Research and Management Science (INFORMS, previously TIMS-ORSA) is awarded annually to a individual (or sometimes group) who have made fundamental and sustained contributions to theory in operations research and the management sciences.

The IEEE John von Neumann Medal is awarded annually by the IEEE "for outstanding achievements in computer-related science and technology."

*This article was originally based on material from the Free On-line Dictionary of Computing and is used with permission under the GFDL.*