well, if you believe time travel to be one day possible, do you think "aliens" were ourselves living in the very far future? there have been sighting records of ufo's since the 1800's, and people have claimed to see some type of alien being before. what if their technology was so sophisticated that, unlike a time travel machine, they are able to move in time with their own made vehicles, or as we call them "ufos"? and they are able to come and visit themselves in the past. they might not be us in the future, but its just a thought. what do you think?