"Nothing can travel faster than light. But what if we switched the rules a little? Imagine a world where the speed of light ...

A person fires a starting pistol. A distant observer stood 200 metres away (measured using a 20 m tape measure or trundle wheel) records the time between seeing the flash of light from the ...

Refraction close refractionProcess by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens.

But in Earth-bound reality, traveling at the speed of light (299,792,458 meters per second, or 670,616,629 miles per hour, in a vacuum) in a clunky rocket is a physical impossibility.

On its surface, entanglement allows particles to communicate over vast distances instantly, apparently violating the speed of light. But while ...