Volume 25, 2000
S. E. Ney
Are Grandfathers an Endangered Species?
This paper aims to establish that time travel into the past is, at best, highly improbable. It does this by first establishing the causal dependency of identity relations for a person or object travelling into the past. The paper then goes on to show how hard it is to avoid a closed causal loop in time travel experiments, and the inherently contradictory nature of said loops. It then raises the question of how such loops could be avoided without affecting the identity requirements of the traveller, thus drawing the conclusion that while, strictly speaking, time travel has not been proved impossible, the combination of circumstance required to avoid contradiction is so unlikely as to render such activity highly improbable.