The universe comes with a built‑in speed cap, a hard limit that shapes everything from how stars shine to how cause and ...

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

The most distant galaxies in this deep field image from the James Webb Space Telescope appear as small, faint dots—and are receding from us faster than the speed of light due to cosmic expansion. If ...

The speed of light is the fastest anything can travel. What happens to a photon from a galaxy 25 million light years away on its journey toward Earth? When you purchase through links on our site, we ...

Deep frying a turkey can often times be incredibly dangerous. So why don’t we try a different cooking method? Let’s send our turkey up into space, and have it come for Earth while moving at the speed ...

Einstein’s claim that the speed of light is constant has survived more than a century of scrutiny—but scientists are still daring to test it. Some theories of quantum gravity suggest light might ...