The speed of light remains one of physics’ firmest assumptions, but scientists still test whether it ever shifts under extreme conditions. A new review draws together decades of observations, ...

Every year, our planet makes one full trip around the Sun. And while that means we’re already moving at breakneck speeds, we’re about to ramp that speed up. Like, way up! Let’s turn Earth into a ...

Add Yahoo as a preferred source to see more of our stories on Google. A new review tightens limits on whether light changes speed in deep space, sharpening one of physics' most important tests.