Dr. Albert Einstein writes out an equation for the density of the Milky Way on the blackboard at the Carnegie Institute, Mt. Wilson Observatory headquarters in Pasadena, Calif., on Jan. 14, 1931. Einstein achieved world reknown in 1905, at age 26, when he expounded his Special Theory of Relativity which proposed the existence of atomic energy. Though his concepts ushered in the atomic age, he was a pacifist who warned against the arms race. Einstein, who radically changed mankind's vision of the universe, won the Nobel Prize in physics in 1922. (AP Photo)