# How Fast Does Light Travel Meters Per Second?

## How fast does light travel in Metres per second?

The speed of light is sometimes referred to as the “cosmic speed limit”. Light travels in a vacuum at 186,282.4 miles per second or 299,792,458 meters/second. For simplicity, it is often said that these numbers are 186,000 miles per second, and 3.00 x 10^8 meters per second.

## How fast is 10% the speed of light?

“These technologies are advanced,” says Davis, “but they’re conventional physics and have been well-established since the dawn of the Atomic Age.” Optimistically, various propulsion systems based on fission and fusion concepts could theoretically accelerate a vessel up to 10% of the speed of light – a cool 62,000,000

## How fast does light travel in air?

Air has a refractive index of 1.0003 wavelengths. This means the speed of light in air is 299,700,000 meters per seconds (92,458 meters slower than c).

## How did they calculate the speed of light?

An early experiment to measure the speed of light was conducted by Ole Rømer, a Danish physicist, in 1676. Using a telescope, Ole observed the motions of Jupiter and one of its moons, Io. If Ole had known the diameter of the Earth’s orbit, he would have calculated a speed of 227,000,000 m/s. 