http://www-gap.dcs.st-and.ac.uk/~history/Biographies/Friedmann.html You may have heard people say that we live in a Friedmann universe. Why do they say that instead of saying "deSitter universe" or "Lemaître universe" didnt these other people also come up with an expanding universe solution to Einstein's 1915 equation? all these various universe you hear about are just special solutions to the Einstein Equation of Gen Rel. I don't happen to know the historical details so maybe someone can sort it out for us and explain. I don't think Friedmann had connections. Maybe he was just better looking than the other guys. There is a picture of him on that biography webpage I put a link to. It is possible that he has precedence because he found out MORE than the other guys. Or maybe he was the one who wrote down a particularly beautiful EQUATION (called the "Friedmann equation") which is a child ot the 1915 Einstein Equation and involves an elegant simplification that makes it easy to solve which the Einstein Equation is not. Or maybe he is more famous than them because he devised a DISTANCE FUNCTION, called the "Friedmann metric", for using in that universe. Or maybe the other guys actually did all that too, with the simplified equation and the metric, and history is simply unfair to them. In any case the date for Alexandr Friedmann finding his universe is 1922 and he was living in Saint Petersburg, Russia (which happened to be called something else at the time) if anybody wants to take the trouble to give us the full story on this it would be good I like George Lemaître because he went to Rome one time for the express purpose of telling the Pope not to confuse the singularity of his theory with anything to do with creation or God. Singularities do not exist in nature. A singularity is a place where a theory fails to compute, so it is a purely manmade thing in a manmade theory. Singularities often go away as theories get improved. Well George Lemaître was a serious Roman Catholic so he was quite embarrassed when he heard people confusing his singularity with creation or some other act of God. He requested an audience with the pope and advised him not to mix things up like that. the pope agreed and made an official statement soon afterwards saying people should not mix up theology with big bang theory, which seems like what a sensible pope should say. So George Lemaître is admirable and very much OK too. But for some reason Friedmann just slightly takes precedence. Or is it just alphabetical order?