Time feels like the most familiar thing in the world, yet it hides one of physics’ hardest questions: why do we only remember the past and never the future, and why do broken eggs not leap back into ...

Tourists of time all know one rule: never change the past. Whether it's preventing your own conception or handing the blueprints to a time machine to a younger version of yourself, generating a ...

Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that describe gravity, quantum fields and the structure of spacetime now allow ...

(via Sabine Hossenfelder) The Andromeda Paradox, originally from Roger Penrose, is a brain-melting thought experiment that brings up the question of whether the future is still open or already fixed ...