a paradox concerning the implications of time travel, expressed by the idea that a hypothetical time traveller could potentially go back into the past and (deliberately or inadvertently) kill his or her grandfather, thus preventing the time traveller’s existence and the possibility of having travelled back into the past in the first place; cf. time paradox n.
Suppose I can travel back into time, let me say 200 years; and I visit the homestead of my great great great grand-father, and am able to take part in the life of his time. I am thus enabled to shoot him, while he is still a young man and as yet unmarried. From this it will be noted that I could have prevented my own birth.]
He is one of the few who have realized that if one travels in time, he would not remain stationary relative to the earth, but would stay in the same spot in space, while the sun (with the earth following) departed, until the machine were shut off. This would remove the killing-of-grandfather paradox.]
‘I can't see that anything can ever be done about time—I always think of the “Grandfather Paradox”—remember?’ ‘Yes, I know it by heart…. Time-travel is impossible, because a man could travel back in time, inadvertently kill his grandfather, and thus prevent himself from ever having been born!’
The Grandfather Paradox is basic to any discussion of time travel… We will call any such interference with the past, especially self-cancelling interference, a Grandfather Paradox.
Considerations like the grandfather paradox have caused many people…to conclude that any solutions to the equations of general relativity that allow such travel into the past must be ruled out.
She had a hunch he was simply convincing himself that they couldn’t kill the scientists. Because destroying the scientists from Einstein to Teller would be a modified grandfather paradox. Without those people, there would be no time travel.
Last modified 2021-01-03 04:36:39
In the compilation of some entries, HDSF has drawn extensively on corresponding entries in OED.