We've heard the argument about "If time travel is possible, why haven't we met anyone from the future." before. Well I heard somewhere that a scientist (IIRC) theorized that if Time Travel was possible it would only go as far back as the invention of the time machine. I think that doesn't make much sense. If there was indeed a time machine it should go as far back as anyone wants. I have a theory about why no one has met anyone from the future. I ask, what is this biggest problem with time travel in TV and movies? Changing the past in such a way that the future is completely screwed up. Go back in time and your parents may never meet and thus you are never born. Then you were never alive to go back in time and preventing your parents from meeting thus creating a paradox. I think time travel IF possible would be made paradox free. Think of it like being on ST:TNG's holodeck, yet none of the holograms can see/touch/hear/smell/taste you. You can walk around and take pictures of everything and study the people, but you are in all sense undetectable to them. This prevents you from tampering with the past. You could go see the fall of Rome, go see and hear the Gettysburg Address, ride on Titanic, etc. You could solve any of history's great mysteries, but you can't prevent any of the disasters. This solves the problem of never meeting a time traveler. They are existing just outside of our time, watching us. What are your thoughts?