The speed of light is a fundamental constant, approximately 299,792,458 meters per second. It's the same for all observers and hasn't changed measurably over billions of years. Nothing can travel ...

Light is faster than anything else in the known universe, though its speed can change depending on what it's passing through. When you purchase through links on our site, we may earn an affiliate ...

In 1676, by studying the motion of Jupiter's moon Io, Danish astronomer Ole Rømer calculated that light travels at a finite speed. Two years later, building on data gathered by Rømer, Dutch ...

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 ...

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 ...

Imagine this: a tiny needle hurtling toward Earth at the speed of light. At first glance, it might sound like no big deal. After all, it’s just a needle. But in reality, a projectile moving this fast ...