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 ...

Scientists pushed photons across the universe to test the speed of light—and found Einstein’s cosmic speed limit still holds ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

We throw around terms like “light year” and “faster than light travel” frequently. But to really understand the scale it helps to feel how fast the speed of light is. The flight simulation video below ...

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 ...