βοΈScience
The Speed of Light
Light travels at approximately 299,792 kilometers per second, fast enough to circle the Earth 7.5 times in one second.
About this fact
The speed of light in a vacuum, denoted as 'c', is a fundamental physical constant. It is the fastest speed at which all energy, matter, and information in the universe can travel. According to Einstein's theory of special relativity, as an object approaches the speed of light, its mass increases, its length contracts, and time dilates. This constant speed is crucial for many scientific calculations, including those in astronomy and particle physics, and forms the basis for defining units like the meter.