Friedmann e a descoberta da expansão do universo
“I shall speak of the theoretical work of Einstein of Germany, de Sitter of Holland, Lemaitre of Belgium. For observational data I turn to the Americans Slipher, Hubble, Humason, recalling however that the vitally important datum of distance is found by a method which we owe to Hertzsprung of Denmark. … My subject disperses the…