So you are saying that if we ever find a mean to travel in time we wouldn't be able to use it before a "x" period of time pass and we couldn't go back in time prior to "x" afterward?

I'm in no mean an expert, but I keep an interested eyes on all sciences (ok specially the wacky ones, lol) but I sure can prove you I can land a plane without an airport...it just might be rougher as in poping in dressed like today in 3000 BC.