Question #a6abc

1 Answer
Apr 17, 2014

No, the index of refraction cannot be less than 1.

The index of refraction is a ratio, comparing the speed of light in a vacuum (#c = 3.00 x 10^8 m/s#) to the speed of light in another substance in which the light will slow down (and therefore, refract). This relationship is shown by the formula #n=c/v# where #n# is the index of refraction of the substance and #v# is the speed of light in whatever form of matter the light is traveling through.

Since light cannot travel faster in any substance than it does in a vacuum, the faster speed (c) is always in the numerator, making the ratio always larger than 1.