John Archibald Wheeler (1911 – 2008) was an American theoretical physicist. He earned his doctorate at Johns Hopkins University and is best known for popularizing the term "black hole, as to objects with gravitational collapse already predicted during the early 20th century, for inventing the terms "quantum foam", "neutron moderator", "wormhole" and for hypothesizing the "one-electron universe". Stephen Hawking referred to him as the "hero of the black hole story".