Like stretch marks left on skin that expanded too quickly or cracks embedded in freezing ice, cosmic strings are artifacts of ...

The curious minds at What If examine overwriting Einstein’s theory of relativity with time travel, imagining paradoxes, ...

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 ...

A trip through time has always sparked curiosity. The idea that you could step into a machine and emerge in the past or future has captured human imagination for generations. While science fiction ...

Predestination doesn’t waste time trying to explain the time travel technology, and it doesn’t need to, because it’s so coherent and straightforward, you naturally see that it makes sense right away.