Yes, the amplitude of a light wave can change during refraction. Refraction occurs when light waves pass from one medium to another, such as when light passes from air into a different medium like water or glass. During refraction, the speed of light changes as it travels through the different medium, and this change in speed can affect the amplitude of the light wave.
According to the laws of refraction, specifically Snell's law, the angle of incidence and the angle of refraction are related to the refractive indices of the two media and the speed of light in each medium. When light passes from a less dense medium to a more dense medium, it generally slows down and bends toward the normal, the line perpendicular to the surface of separation between the two media. Conversely, when light passes from a more dense medium to a less dense medium, it speeds up and bends away from the normal.
The change in speed of light during refraction can affect the amplitude of the light wave. According to the conservation of energy, the product of the amplitude and the square of the speed of light should remain constant. As the speed of light changes during refraction, the amplitude of the light wave can be altered to maintain this relationship.
In practical terms, refraction can lead to changes in the intensity or brightness of light. If the light wave is refracted towards the normal, the wavefronts can become more compressed, resulting in a higher amplitude and increased intensity. Conversely, if the light wave is refracted away from the normal, the wavefronts can spread out, leading to a lower amplitude and decreased intensity.
So, in summary, during refraction, the change in speed of light can result in a change in the amplitude of the light wave, which, in turn, can affect the intensity or brightness of the light.