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Is Time Travel Possible?
What physics says about one of science fiction’s favorite tropes
For as long as I can remember, I have always wondered what I might do differently if I could travel to the past.
Would I stay in academia instead of going to law school? Would I end a dying relationship sooner instead of trying to make it work long distance?
Where I had said “yes”, would I now say “no”? Where I went left, would I turn right instead?
For many of us, the life we haven’t lived glimmers with unfulfilled promise, even if only as a fantasy conjured by our imagination.
I’ve made choices that I’ve come to regret. Even if I believe there are no wrong choices, only life lessons, making a different decision still has some allure.
That fascination with redoing what has already happened is at the heart of much science fiction and, as much as it might surprise you, modern physics. (A brief caveat: I am not a physicist, so what follows is a layperson’s take based on reading countless articles and books. On the plus side, I won’t saddle you with any math equations.)
Physics doesn’t have a complete theory of time. We know time is relative, passing slower where there’s more gravity. But at the smallest level of reality, time disappears. As to…
