Illustration of refractionRef: 80019161
Refraction. Computer artwork of a cherry in a glass of water. The cherry is demonstrating the concept of refraction. Light travels at different speeds through transparent media of different refractive indices, such as water (n=1.33) and air (n=1.00). When light from the cherry exits the water its angle of incidence with the water surface is increased. Since the brain assumes that light travels in straight lines, this leads it to believe that the cherry, when in the water, is in a different place from its true position.