Vannevar Bush (March 11, 1890–June 30, 1974) was an American scientist.
Born in Chelsea, Massachusetts, Bush was educated at Tufts College, graduating in 1913. He joined the Department of Electrical Engineering at the Massachusetts Institute of Technology (MIT) in 1919, and was a professor there from 1923–32. He constructed a Differential Analyser, an analog computer that could solve differential equations with as many as 18 independent variables, based on Charles Babbage's Difference Engine. An offshoot of the Differential Analyser was the birth of digital circuit design theory by one of Bush's graduate students, Claude Shannon.
Bush was president of the Carnegie Institute of Washington in 1939 and in the same year appointed chair of National Advisory Committee for Aeronautics. In 1940, Bush became chairman of the National Defense Research Committee and in 1941 director of Office of Scientific Research and Development, which controlled the Manhattan Project. He recommended the creation of what would become the National Science Foundation. Bush was also a cofounder of the defense contractor Raytheon.
He invented the concept of what he called the memex in the 1930s, "a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility" and indicated what would become hypertext. His ideas were first published in the essay "As We May Think" in Atlantic Monthly in 1945. In the article, Bush predicted that, "Wholly new forms of encyclopedias will appear, ready made with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified." A few months later (November 19th 1945) Life magazine published an article with several ilustrations showing what a memex machine, and its companion devices, could look like.
Vannevar Bush plays an important role in many UFO conspiracy theories as the head of Majestic 12, an organization supposedly formed by Dwight Eisenhower to investigate and later cover up an alien crash in Roswell, New Mexico.
The Vannevar Bush Award was created by the National Science Foundation in 1980 to honor contributions to public service.
Vannevar Bush has an unfortunate eponym: vannevar  (http://catb.org/esr/jargon/html/V/vannevar.html) owing to his habit of overestimating technological challenges. He asserted that a nuclear weapon could not be made small enough to fit in the nose of a missile as in an ICBM. He also predicted "electronic brains" the size of the Empire State Building with a Niagara Falls-scale cooling system.
His name was pronounced Van-NEE-var. as in "receiver".