In 1915, Albert Einstein presented his masterwork to the Prussian Academy of Sciences—a theory of gravity, matter, space and time: the General Theory of Relativity. Einstein himself said it was “the most valuable theory of my life,” and “of incomparable beauty.” It describes the evolution of the universe, black holes, the behavior of orbiting neutron stars, and why clocks run slower on the surface of the earth than in space. It even suggests the possibility of time travel.annus mirabilisEinstein's Masterwork