John von Neumann

John von Neumann (born Neumann János Lajos on December 28, 1903, in Budapest, Hungary; died February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, and engineer. His intellectual range was exceptionally broad, spanning pure and applied science, and he made fundamental contributions to mathematics, physics, economics, computing, and statistics. He helped establish the mathematical foundations of quantum mechanics, advanced functional analysis, and created game theory. He also introduced or formalized concepts such as cellular automata, the universal constructor, and the digital computer. His work on the structure of self-replication predated the discovery of DNA's structure.

During World War II, von Neumann worked on the Manhattan Project, developing the mathematical models for the explosive lenses used in implosion-type nuclear weapons. Before and after the war, he consulted for the Office of Scientific Research and Development, the U.S. Army's Ballistic Research Laboratory, the Armed Forces Special Weapons Project, and Oak Ridge National Laboratory. In the 1950s, he chaired several Defense Department committees, including the Strategic Missile Evaluation Committee and the ICBM Scientific Advisory Committee, and served on the Atomic Energy Commission, overseeing all atomic energy development in the country. Alongside Bernard Schriever and Trevor Gardner, he was instrumental in designing and developing the United States' first intercontinental ballistic missile programs. At the time, he was regarded as the nation's foremost expert on nuclear weaponry and the leading defense scientist at the U.S. Department of Defense.

Colleagues in physics, mathematics, and other fields praised his contributions and intellectual ability. His honors include a Medal of Freedom, and a crater on the Moon is named after him.

Von Neumann was born into a wealthy, non-observant Jewish family in Budapest, then part of Austria-Hungary. His birth name was Neumann János Lajos (the family name comes first in Hungarian; his given names correspond to John Louis in English). He was the eldest of three brothers, with younger siblings Mihály (Michael) and Miklós (Nicholas). His father, Neumann Miksa (Max von Neumann), was a banker with a doctorate in law who had moved to Budapest from Pécs in the late 1880s. His paternal grandfather and great-grandfather were born in Ond (now part of Szerencs), Zemplén County, northern Hungary. His mother was Kann Margit (Margaret Kann), whose parents were Kann Jákab and Meisels Katalin of the Meisels family. Three generations of the Kann family lived in spacious apartments above the Kann-Heller offices in Budapest; von Neumann's family occupied an 18-room apartment on the top floor.

On February 20, 1913, Emperor Franz Joseph elevated John's father to the Hungarian nobility for his service to the Austro-Hungarian Empire. The family received the hereditary appellation Margittai ("of Margitta," today Marghita, Romania), chosen in reference to Margaret, with a coat of arms depicting three marguerites. Neumann János thus became margittai Neumann János (John Neumann de Margitta), later changed to the German Johann von Neumann.

Von Neumann was a child prodigy. He, his brothers, and his cousins were taught by governesses. His father considered knowledge of languages beyond Hungarian essential, so the children were tutored in English, French, German, and Italian. Legend has it that by age eight he was familiar with differential and integral calculus, and by twelve he had read Borel's *La Théorie des Fonctions*. He also had a deep interest in history, reading Wilhelm Oncken's 46-volume world history series *Allgemeine Geschichte in Einzeldarstellungen*. One room in the apartment was converted into a library and reading room.

He entered the Lutheran Fasori Evangélikus Gimnázium in 1914, where Eugene Wigner, a year ahead, soon became his friend. Although his father insisted he attend school at the appropriate grade level, he agreed to hire private tutors for advanced instruction. At 15, von Neumann began studying advanced calculus under the analyst Gábor Szegő. On their first meeting, Szegő was so astonished by von Neumann's mathematical talent and speed that, according to Szegő's wife, he returned home with tears in his eyes. By age 19, von Neumann had published two major mathematical papers, the second giving the modern definition of ordinal numbers, superseding Georg Cantor's. Upon finishing gymnasium, he won the Eötvös Prize, a national mathematics award.

According to his friend Theodore von Kármán, von Neumann's father wanted him to go into industry and asked von Kármán to discourage him from mathematics. Von Neumann and his father decided chemical engineering was the best path. Since he knew little about it, he took a two-year, non-degree chemistry course at the University of Berlin, then passed the entrance exam for ETH Zurich in September 1923. Simultaneously, he entered Pázmány Péter University (then the University of Budapest) as a Ph.D. candidate in mathematics. For his thesis, he produced an axiomatization of Cantor's set theory. In 1926, he graduated as a chemical engineer from ETH Zurich and simultaneously completed his Ph.D. in mathematics.