Me and my friend have already decided that it is not possible to actually go back in time. We have done our research and come up with a way to slow things done for us so that we age at roughly half the rate the rest of the world will. Of course we have a problem with getting into space and being able to go very very fast(I'm talking vroom here) is going to be kinda tough. But like it was stated earlier, you can come back from space after what would have been aonly a couple of years for you, and everyone else would probably be dead, depending on how old you are that is. Good luck to anyone who tries doing this, it might be kinda hard, but only a little.