A bit of sad news for prospective time travelers — your efforts to change the past are futile, according toat the University of Queensland. The past is immutable, it seems. But that implies some good news, too, for even as these findings crush our hopes of changing history, they may also remove a barrier to journeying back in time.
, which states there is zero chance of an event occurring if it would change the past in any way — the universe simply forbids revision. But now it’s supported by the calculations of Fabio Costa, a theoretical physicist, and Germain Tobar, a Cambridge student pursuing a masters in mathematics, which wereThe results, Costa says, “are the stuff of science fiction.
But even as a pure thought experiment, time travel is plagued by challenges. The granddaddy of them all, aptly enough, is the grandfather paradox. The name originated with the famous scenario in which a person goes back in time to kill their own grandfather before he has children. If they succeed, they’ll never be born in the future; but in that case, who killed granddad? More abstractly, it refers to any change in the past that produces a logical inconsistency.