I was wondering the feasbility of time travel. Has it been proven not possible? Has it been proven theortically possible? I have always been interested in time travel, even if it seems like science fiction, but was wondering from scientist, professors, etc, if it has been an 'unsolved' problem per se of theortical physics. Does anyone happen to know the name of the paradox where one is his own father, mother, self? It's a paradox of time travel with a bartender...who had an operation, and then loops through time and is his own mother, father, brother and sister!