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 doesn’t always travel at the speed of light. A new experiment reveals that focusing or manipulating the structure of light pulses reduces their speed, even in vacuum conditions. A paper ...

Let’s explore how constant this speed of light fundamental constant really is. One of the most fundamental physics facts is that the speed of light in a vacuum is constant for all observers. But can ...

We wouldn’t notice. Or we’d die. Depends on how much it changed. Relativity already tells us what would happen if the speed of light were to change, and the answer is nothing. Consider a stationary ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

The speed of light in a vacuum is the ultimate cosmic speed limit. Just getting close to it causes problems: the weird distortions of Einstein’s relativity kick in, so time slows down, lengths go up, ...

The speed of light is constant, or so textbooks say. But some scientists are exploring the possibility that this cosmic speed limit changes, a consequence of the nature of the vacuum of space. The ...

For science-fiction enthusiasts, that’s a bit depressing. Space is big, and while the speed of light is incredibly fast to us ...

One night over drinks at a conference in San Jose, Miles Padgett, a physicist at Glasgow University in Scotland, was chatting with a colleague about whether or not they could make light go slower than ...

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 ...