On one hand, the speed of light is just a number: 299,792,458 meters per second. And on the other, it’s one of the most important constants that appears in nature and defines the relationship of ...

The universe has a speed limit, and it's the speed of light. Nothing can travel faster than light — not even our best spacecraft — according to the laws of physics. So, what is the speed of light?

The speed of light is one of the most famous constants in physics, yet it has never been directly measured in the way most people assume. All experiments rely on round-trip measurements and built-in ...

In Newtonian physics, gravity was thought to be instantaneous. But in Albert Einstein’s general theory of relativity, the speed of light, c, is the fastest possible speed for any interaction that ...

The principle of relativity, as initially described by Galileo, posits that the laws of physics remain consistent regardless of an observer's relative motion. Einstein's special relativity ...