We all have some past events that we'd like to undo. These can be minor moments, such as a failed exam or an argument with friends, or world-changing incidents, such as the 2019 outbreak that led to ...

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 ...

This article is from Proof Positive, our friendly math newsletter that's delivered to your inbox every Tuesday afternoon. Sign up today and read it first. We all have some past events that we’d like ...

Most time travel movies don’t sweat the math — or, more accurately, the physics and/or quantum physics of how time travel might actually work. The writers and directors include the time travel ...