John Archibald Wheeler was an American theoretical physicist who was largely responsible for reviving interest in general relativity in the United States after World War II. Wheeler also worked with Niels Bohr in explaining the basic principles behind nuclear fission. One of the later collaborators of Albert Einstein, he tried to achieve Einstein's vision of a unified field theory. He is also known for having coined the terms black hole, quantum foam, and wormhole and the phrase "it from bit". For most of his career, Wheeler was a professor at Princeton University and was influential in mentoring a generation of physicists who made notable contributions to quantum mechanics and gravitation.