John Archibald Wheeler

John Archibald Wheeler was born in Jacksonville, Florida, in 1911, and earned his doctorate at Johns Hopkins University at the age of 21. He studied with Niels Bohr in Copenhagen, and in 1939 the two published the first quantitative theory of nuclear fission, modeling the splitting nucleus as a deforming liquid drop. During the Second World War he worked on the Manhattan Project and later on the hydrogen bomb, experiences that left a permanent mark on a man who otherwise spent his career on the most abstract reaches of physics.

From the 1950s onward, working at Princeton, Wheeler turned to general relativity at a time when the subject was a backwater — widely regarded as an elegant but sterile corner of physics with no living connection to experiment. Wheeler almost single-handedly revived it. He trained a generation of relativists, co-authored the monumental 1973 textbook 'Gravitation' (with Charles Misner and Kip Thorne), and insisted that Einstein's theory described real, dynamical objects rather than mathematical curiosities. His gift for naming was part of his physics: he coined or popularized 'black hole' (1967), 'wormhole', 'quantum foam', and the phrase 'a black hole has no hair'.

Wheeler's deepest conviction was that physics is ultimately about information and geometry. His slogan for general relativity — 'spacetime tells matter how to move; matter tells spacetime how to curve' — compresses the Einstein field equations into two clauses. Late in life he pursued the idea he called 'it from bit', the speculation that physical reality arises from yes-no questions, from information itself. His doctoral students included Richard Feynman, Kip Thorne, and Jacob Bekenstein, and through them his influence runs through much of twentieth-century physics.

He remained active into his nineties, moving from Princeton to the University of Texas at Austin and back, and died in 2008 at the age of 96. The no-hair theorem bears his fingerprint not because he proved it — that was the work of Israel, Carter, Hawking, and Robinson — but because he saw, before almost anyone, that gravitational collapse must produce something radically simple, and he found the words that made the idea unforgettable.