Einstein proposed that energy is equal to mass times this quantity squared.
Electromagnetic radiation pressure is inversely proportional to this quantity. The Lorentz factor can be found using an object's velocity and this quantity. Cherenkov radiation results when this value is exceeded, and its value through a particular medium constitutes a material's refractive index. The special theory of relativity states that this value is constant in all frames. Einstein proposed that energy is equal to mass times this quantity squared. For 10 points, name this quantity that is equal to about three million meters per second in a vacuum, often denoted c.
Electromagnetic radiation pressure is inversely proportional to this quantity.
speed of light [prompt on c before mention]