Alexander Friedmann (1888-1925). Russian physicist and mathematician, known for his pioneering theory that the universe was expanding, governed by a set of equations, known as the Friedmann equations. The cosmological model of general relativity would come to form the standard for both the Big Bang and Steady State theories. His work supports both theories equally. Was not until the detection of the CMB radiation that the Steady State theory was abandoned in favor of the Big Bang paradigm.