ljusrefraktion

Ljusrefraktion, or light refraction, is the bending of light as it passes from one medium to another. This phenomenon occurs because the speed of light changes depending on the medium it is traveling through. When light enters a denser medium, such as water or glass, it slows down and bends towards the normal, an imaginary line perpendicular to the surface. Conversely, when light exits a denser medium into a less dense one, like air, it speeds up and bends away from the normal.

The amount of bending is quantified by the refractive index of the medium, which is the ratio of the speed of light in a vacuum to the speed of light in that medium. A higher refractive index indicates that light travels slower in that medium and therefore bends more. This principle is described by Snell's Law, which mathematically relates the angles of incidence and refraction to the refractive indices of the two media.

Refraction is responsible for many everyday optical phenomena. For example, it makes a straw in a glass of water appear bent at the water's surface. It also plays a crucial role in the functioning of lenses, such as those in eyeglasses, cameras, and telescopes, allowing them to focus light and form images. The dispersion of light, where white light is split into its constituent colors (like in a prism), is also a form of refraction where different wavelengths of light are refracted at slightly different angles due to variations in refractive index with wavelength.