Question

Question #a6abc

Answer 1

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.