Refractive index is a measure of the speed of light in a given material. This measure is used to compare the speed of light in different materials, such as water, glass, or diamond. The refractive index is determined by measuring the angle at which light passes through the material and comparing it to the angle at which light passes through a vacuum. The higher the angle, the higher the refractive index of the material. The refractive index is used to determine the properties of any given material, such as transparency and dispersion.
