Hubble "Parameter"& acc. Universe I am a senior high student. And I am studying on SnIa. I recently read that SOME(maybe most) theory said that hubble's constant is not a CONSTANT, it's changing by time. But I wonder if there are something influent the data. (like "slection effect" .etc) ========================== But let's assume all the obs. data are fine and very precise. We can simply conclude that Hubble's constant varies by time and the universeis accelerating (In short, H of cepheid=70, H of near Ia=50, H of far Ia=30) So.... I have many question to ask. 0. The theory"hubble parameter is a value relate to time" is build on a "universe model" called (flat and ****...model), If anyone disagrees hubble parameter varies by time, does he either disagree this universe model? 1. If H really varies by time, can we ever measure the age of the universe by 1/h ? 2.If anyone disagrees that Hubble parameter varies by time, how does he describe the accelerating universe?(or he also disagree the accelerating universe) 3.And how do you explain this "calculated results" (H of cepheid=70, H of near Ia=50, H of far Ia=30) Despite the fact that what theory you support, it's welcome for you to give me ANY though of yours. ps. I have asked a prof. that he said that there are still some people think hubble is a CONSTANT that never change, but they still can't "find" any powerful evidences or theories to prove their stance. Thanks for your replyment!