Definition:Speed of Light

Physical Law
The speed of light (in a vacuum) is a physical constant.

Nothing can travel faster.

It is usually denoted $$c$$, and its value is given as:
 * $$c = 299 \, 792 \, 458 \text { m s}^{-1}$$

exactly.

The meter is in fact defined in terms of the speed of light.

As the speed of light is at base a velocity, it has dimension $$L T^{-1}$$.