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
Russian theoretical astrophysics
Igor Novikov
1935
Russian astrophysicist known for work on black holes and cosmology, and for the self-consistency principle that bears his name: if closed timelike curves exist, the only physical processes on them are those whose local solutions are globally consistent, so that paradoxical histories simply have probability zero. He collaborated with Kip Thorne's Caltech group on the physics of time machines in the late 1980s and 1990s.