George David Birkhoff (March 21, 1884 – November 12, 1944) was an American mathematician. He is considered one of the top American mathematicians of his generation. He made valuable contributions to the theory of #differentialEquations, #dynamicalSystems, the #fourcolorProblem, the #threebodyProblem, and #generalRelativity. Today, Birkhoff is best remembered for the #ergodicTheorem. The #GeorgeDBirkhoffHouse, his residence in #CambridgeMassachusetts.