Stephen Hawking

(born Jan. 8, 1942, Oxford, Oxfordshire, Eng.) English theoretical physicist. He studied at the University of Oxford and later received his Ph.D. from Cambridge. He has worked primarily in the field of general relativity and particularly on the physics of black holes. In 1971 he suggested that numerous objects, formed after the big bang, each had as much as one billion tons of mass but the size of only a proton. These mini black holes are unique in being subject to both the laws of relativity, due to their immense mass and gravity, and the laws of quantum mechanics, due to their minute size. In 1974 he proposed that black holes evaporate by what is now known as Hawking radiation. His work greatly spurred efforts to delineate the properties of black holes. His work also showed the relationship of these properties to the laws of classical thermodynamics and quantum mechanics. Hawking's achievements, despite near-total paralysis from amyotrophic lateral sclerosis, have earned him extraordinary honours. His books include the best-selling A Brief History of Time (1988).