The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s).

This value is considered a fundamental constant of nature and is one of the most precisely measured physical quantities. It is denoted by the symbol ‘c’ and is a critical value in many areas of physics, including:

• Electromagnetism – The speed of light is the maximum speed at which all electromagnetic radiation, including visible light, can travel.

• Special Relativity – Einstein’s theory of special relativity is based on the constancy of the speed of light.

• Astrophysics – The speed of light is used to measure astronomical distances and the age of the universe.

• Quantum Mechanics – The speed of light appears in equations describing the behavior of subatomic particles and fields.

The speed of light in a vacuum is an absolute constant, meaning it does not depend on the motion of the light source or the observer. However, the speed of light can be slightly slower when traveling through materials like air, water, or glass due to the interaction with the medium.