What is the index of refraction of vacuum?

The index of refraction of vacuum equal 1. By definition, the index of refraction is given by the formula n=c/v, where c is the speed of light in the vacuum and v the speed of light in the medium. If the medium is the vacuum then: n=c/c = 1. read more

The index of refraction of vacuum equal 1. By definition, the index of refraction is given by the formula n=c/v, where c is the speed of light in the vacuum and v the speed of light in the medium. If the medium is the vacuum then: n=c/c = 1. read more

The refractive index measures the phase velocity of light, which does not carry information. The phase velocity is the speed at which the crests of the wave move and can be faster than the speed of light in vacuum, and thereby give a refractive index below 1. read more

Refractive index or index of refraction is the ratio of speed of light in vacuum to its speed in a particular substance under consideration. The concept was invented in the year 1621, and is used in fiber optics, diamond industry, in manufacturing telescopes, etc. read more