Alexander Alexandrovich Friedmann (also spelled Friedman or Fridman ; Russian: ??????´??? ??????´??????? ???´????) (June 16 [O.S.
4], 1888 – September 16, 1925) was a Russian and Soviet physicist and mathematician.
He is best known for his pioneering theory that the universe was expanding, governed by a set of equations he developed now known as the Friedmann equations.