We throw around terms like “light year” and “faster than light travel” frequently. But to really understand the scale it helps to feel how fast the speed of light is. The flight simulation video below ...

A small but incredibly fast unwanted guest is about to swing past Earth at the speed of light. Yeah, this is the tiniest ...

In 1887, one of the most important experiments in the history of physics took place. American scientists Michelson and Morley ...

Physicists tested light speed using cosmic gamma-ray bursts. Study confirms Einstein's prediction that all light colors travel at same speed.

It takes light a single day to travel 16 billion miles. The Voyager 1 probe will need a little longer, just 49 years.

Editor’s note: Welcome to Just4Kids, a new feature with content from The Conversation for Kids, a nonprofit in which scholars answer kids’ questions about science, health and more, that will be ...

They recreate how a camera would see objects traveling at 99.9% of the speed of light, revealing surprising relativistic ...

As it heads out of the solar system never to return, the deep space probe Voyager 1 is headed for yet another cosmic ...

Earth’s days are not always exactly 24 hours, and recent measurements show unusual fluctuations. Some days are getting ...

Although the Earth completes one full rotation in 86,400 seconds on average, that spin fluctuates by a millisecond or two every day. Before 2020, the Earth never experienced a day shorter than the ...

The planet’s rotation fluctuates as it travels around the sun, and measurements suggest we’re losing more than a millisecond during the long days of summer. By Jacey Fortin This article was updated ...

This means that it would still take a little over four whole years of traveling at lightspeed to reach the red dwarf—not that ...