Here’s how it works. The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second — a universal constant ...

The universe is too vast to track distances on the scale of miles, so astronomers use light-years to convey the great lengths ...

On November 21, 1676, the Danish astronomer Ole Rømer discovered the speed of light. Before Rømer figured it out, scientists ...

If an object travels at a relative speed, which is a non-negligible fraction of the speed of light, with respect to an ...

Einstein’s special theory of relativity governs our understanding of both the flow of time and the speed at which objects can move. In special relativity, the speed of light is the ultimate speed ...

A series of new animations by a NASA scientist show just how zippy - and also torturously slow - the speed of light can be. Light-speed is the fastest that any material object can travel through ...

We know that measuring the speed of light with an Arduino is possible. It’s just that the implementation is hard. [Udo] hit upon the idea of pulsing a laser pointer and measuring the time of the ...

There are a number of ways to measure the speed of light. If you’ve got an oscilloscope and a few spare parts, you can build your own apparatus for just a few bucks. Don’t believe the “lies ...

Methods for measuring this universal constant have become more and more precise. Yet today there is considerable doubt about the true value. It may even have changed in the past 20 years ...

“Our technology can capture and visualize the actual propagation of light with the same dramatic, slowed-down detail,” says ...

In Newtonian physics, gravity was thought to be instantaneous. But in Albert Einstein’s general theory of relativity, the speed of light, c, is the fastest possible speed for any interaction that ...