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

Scientists studying radiation from a distant gamma-ray burst have found that the speed of light does not vary with wavelength down to distance scales below that of the Planck length. They say that ...

The speed of light has been one of science’s most trusted markers of stability. For more than a century, the idea that light moves through space at a constant speed has supported some of physics’ most ...

There’s an adage coined by [Ian Betteridge] that any headline ending in a question mark can be answered by the word “No”. However, Lorentz invariance – the theory that the same rules of physics apply ...