Fénytörés

Fénytörés, also known as refraction, is a phenomenon that occurs when a wave, such as light or sound, passes from one medium to another with a different density or refractive index. This change in medium causes the wave to change direction, or bend, at the boundary between the two media. The amount of bending depends on the difference in refractive indices and the angle at which the wave approaches the boundary.

In the case of light, refraction is responsible for various optical effects, such as the bending of a pencil in water, the formation of rainbows, and the focusing of light by lenses. The refractive index of a medium is a measure of how much the speed of light is reduced when it enters that medium compared to its speed in a vacuum. For example, the refractive index of water is approximately 1.33, meaning light travels about 1.33 times slower in water than in a vacuum.

The law of refraction, also known as Snell's law, describes the relationship between the angles of incidence and refraction, as well as the refractive indices of the two media. It states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the refractive indices of the two media.

Refraction has numerous practical applications, including the design of lenses for eyeglasses and cameras, the creation of optical fibers for communication, and the development of optical instruments such as microscopes and telescopes. Understanding and controlling refraction is essential in various fields, including optics, physics, and engineering.