Refraction is the bending of light as it passes through different mediums, such as air, water, or glass. This occurs because light travels at different speeds in different mediums, causing it to change direction.
Snell's law of refraction is a mathematical equation that describes the relationship between the angle of incidence and the angle of refraction when light passes through different mediums. It is represented as n1sinθ1 = n2sinθ2, where n1 and n2 are the refractive indices of the two mediums and θ1 and θ2 are the angles of incidence and refraction, respectively.
The refractive index of a medium can be calculated by dividing the speed of light in a vacuum by the speed of light in the medium. This can also be represented as n = c/v, where c is the speed of light (3 x 10^8 m/s) and v is the speed of light in the medium.
The degree of refraction can be affected by the angle of incidence, the refractive indices of the two mediums, and the wavelength of light. The angle of incidence and the refractive indices determine the amount of bending, while the wavelength can affect the speed of light in a medium and thus the degree of bending.
Refraction and Snell's law have many practical applications, such as in the design of lenses for glasses or cameras, the functioning of optical fibers for communication, and the creation of prisms for splitting light into its different wavelengths. They are also important in understanding how light travels through the atmosphere, which affects the appearance of objects in the sky, such as rainbows and mirages.