John Archibald Wheeler (1911 - 2008) was an American physicist.
After receiving his Ph.D. from Johns Hopkins University, Wheeler worked at Danish physicist Niels Bohr's laboratory in Copenhagen before accepting a teaching position at Princeton University.
He joined the Manhattan Project in 1942, first at the University of Chicago's Metallurgical Laboratory and then with DuPont in Wilmington, Delaware. Wheeler was the leading physicist in residence at Hanford and is credited with solving the riddle of the B Reactor going dead a few hours after it started, an event that threatened to seriously delay the first production of plutonium.
Wheeler's Manhattan Project work was motivated by his brother Joe, an American soldier fighting in Italy. In 1944, Joe sent Wheeler a two-word postcard: "Hurry up." Tragically, Joe was killed in battle in October of 1944. His death had a profound impact on Wheeler's life and work.
In the early 1950s, Wheeler worked at Los Alamos, directing the group that produced the conceptual design for the first family of thermonuclear weapons. After a long career at Princeton, Wheeler joined the department of physics at the University of Texas at Austin. A gifted teacher, he oversaw many remarkable students during his career, including Richard Feynman and Katharine Way. He died on April 13, 2008, at the age of 96.
Early in his career at Princeton, in 1939, Wheeler and Bohr collaborated to develop the first general theory of the mechanism of fission, which included identifying the nuclei most susceptible to fission, a landmark accomplishment that helped make Wheeler, at age 28, world famous among nuclear physicists. Later in life, he became interested in astrophysics. He is often credited with coining the term "black holes."