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

On one hand, the speed of light is just a number: 299,792,458 meters per second. And on the other, it’s one of the most important constants that appears in nature and defines the relationship of ...

NORFOLK, Va. — A light year is exactly what it sounds like: the distance light travels in one year. If you need to get somewhere quick, you'd want to jump on this train because light travels through ...

Add Yahoo as a preferred source to see more of our stories on Google. Light, whether from a star or your flashlight, travels at 186,000 miles per second. Artur Debat/Moment via Getty Images My ...

Every generation grows up with starships that jump across galaxies in a heartbeat, but the real universe is far less forgiving than the screen. The same physics that lets GPS satellites work and ...

The glow from faster-than-light particles gives us a unique way to explore the universe. Nothing can travel faster than light — in a vacuum. But when light slows down, sometimes matter can blaze past ...