Awasome Speed Of Light In Km S Scientific Notation Ideas. How far does light travel in 20 seconds? A light year is the distance light travels in one year.

As mentioned, the speed of light is the fastest speed in the universe, and it is always a constant in a vacuum. Its significance is far broader than its role in describing a property of electromagnetic waves. Light moves at an incredible 186,000 miles per second (300,000 kilometers per second), equivalent to almost 700 million mph (more than 1 billion km/h).