The universe has a speed limit, and it's the speed of light. Nothing can travel faster than light — not even our best spacecraft — according to the laws of physics. So, what is the speed of light?

Earth never stops moving. Right now, as you read this, the planet beneath your feet is spinning at incredible speed. At the ...

Swipe Down for Full Video Story Imagine a tiny needle traveling toward Earth at the speed of light. At first glance, it might seem harmless, since it is so small. However, at such extreme speeds, even ...