The speed of light in a vacuum that lies at the very core of the physics known to humankind as of now is approximately 299,792,458 meters per second or 186,282 mi per second. Popularly represented by symbol c, the speed of light helps define one of the prime tenets of the universe, as enunciated by Einstein in his theory of relativity.

Einstein also postulated that the speed of light is the maximum velocity beyond which no object with mass can travel.

Light speed is significant in the partnership of space and time and is an important factor in the equation 𝐸=𝑚𝑐2 in which mass is equal to energy.

This constant is also underlying to such technologies like GPS or telecommunication when precise calculations are needed. Also, the speed of light helps describe the universe since units of astronomical measurements, based on this speed, are light-years how far light can travel in a year.

Despite the steadiness of the light constant in the absence of any interaction, the speed of light can be changed by the medium through which it passes, and dimming down in water or glass due to the particle’s interaction.

Thus, the speed of light is not only a number, but the key to some of the major principles of modern physics and worldview.