1894-1966

Belgian mathematical physicist who formulated an early version of the "big bang" theory in which the universe was conceived to have evolved from a cataclysmic explosion of an immeasurably dense "primeval atom." Five years after Aleksandr Friedmann's 1922 work suggested the possibility of a contracting or expanding universe, Lemaître independently showed Albert Einstein's general field equations permitted an expanding universe solution. This expansion was confirmed with Erwin Hubble's 1929 announcement that galaxies recede from Earth with velocities directly proportional to their distance from Earth.