# John von Neumann (1903 - 1957)

John von Neumann was born Janos Lajos Margittai Neumann on December 28, 1903, in Budapest, Hungary. Raised in a non-practicing Jewish family, he had an incredible memory at an early age, being able to divide eight-digit numbers in his head at the age of six. He entered Lutheran Gymnasium in 1911; in 1913, his father purchased a title, and the family acquired the Austrian mark of nobility "von."

Von Neumann received his Ph.D. in mathematics from the University of Budapest at the age of 23. He simultaneously learned chemistry in Switzerland. Between 1926 and 1930, he was a private lecturer in Berlin, Germany. In 1930, the same year he married Mariette Koevesi and agreed to convert to Catholicism to placate her family, Princeton University invited him to lecture on mathematical physics. While at Princeton, the founders of the newly created Institute for Advanced Study asked him to accept a chair in mathematics. Dr. von Neumann became one of the original members of the prestigious institute, where he remained for the rest of his life.

In 1937, the same year von Neumann divorced his first wife, he became a naturalized citizen of the U.S. In 1938, he married Klara Dan, and he was awarded the Bocher Memorial Prize for his work in analysis.

In 1943, von Neumann began working on the Manhattan Project, where he tackled the immense calculations required for construction of an atomic bomb. Faced with that daunting task, he became interested in using machines for the calculation of numbers and the resolution of specific mathematical problems. During and after the war, his interest in computers grew, and he contributed extensively to the construction of the first modern computers. This work established principles on which today's computers are based. His primary area of interest, however, centered on game theory: the study of the conflict between two opponents seeking to arrive at two different goals, each wishing to beat the other.

One of von Neumann's signature achievements was his rigorous mathematical formulation of quantum mechanics in terms of linear operators on Hilbert spaces. He provided a rigorous foundation for quantum statistical mechanics and proposed a proof of the impossibility of hidden variables, showing that quantum mechanics was profoundly different from all previously known theories in physics.

He is also credited with at least one contribution to the study of algorithms. Donald Knuth cites von Neumann as the inventor, in 1945, of the well-known merge sort 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.

In 1955, President Eisenhower appointed von Neumann to the Atomic Energy Commission, and in 1956 he received its Enrico Fermi Award. He died from cancer on February 8, 1957, in Washington, D.C.