Here's why:
* Wave speed: Different wavelengths of light travel at slightly different speeds through a medium. This is why a prism can separate white light into its component colors, as each color (representing a different wavelength) bends at a different angle.
* Index of refraction: The index of refraction is a measure of how much a wave slows down when it enters a medium. Since different wavelengths travel at different speeds, they also have slightly different indices of refraction.
In summary, dispersion describes the phenomenon where the speed of light and the index of refraction within a material vary depending on the wavelength of the light. This leads to the separation of different colors when white light passes through a prism or other dispersive elements.
