yo i read in a einstien book all about time travel that he beleives time can be 'folded'. by what he means by that i have no clue. but I'm one of the people who think anything is possible givin the right circumstances. so to say it is impossible is kinda silly to me maybe humans dont have the tech but who is to say that on the billions of planets around the billions of stars there isnt a more intelligent race that is trying to time travel that might have a better understanding of it.

another thought is that if time is jsut a dimension (the 4th) we can already travel on three of them why should we only be limited to them?