What is the speed of light in a vacuum?

The speed of light in a vacuum is approximately 3.00 x 10^8 meters per second. This value is fundamental in physics and represents the maximum speed at which all energy, matter, and information in the universe can travel. It is a critical constant used in various equations, including Einstein's theory of relativity.

In a vacuum, light travels without interference from any medium, maintaining this high speed. The precision of this measurement is not just practical but also conveys significant implications in scientific disciplines, impacting everything from the structure of space-time to the behavior of electromagnetic radiation. Understanding this speed is essential for further studies in optics and physics, as it provides a baseline for discussing the effects of light in different media, such as air or water, where its speed changes due to refraction.