The Grandfather Paradox
Travel back in time and stop your own grandparents from ever meeting. Then who was it that went back?
1943 (Barjavel's novel), with antecedents from the 1920s18 min read
British theoretical physics
David Deutsch
1953
Oxford physicist, a founder of quantum computation, and an outspoken advocate of the Everett interpretation. His 1985 paper defined the universal quantum Turing machine; his 1991 paper gave a consistency condition for quantum systems on closed timelike curves that removes the grandfather paradox at the cost of a branching, self-consistent density matrix.