Light can be described both as a wave and as a particle (photon), depending on the context. When considering light as a wave, it exhibits properties such as frequency, wavelength, and speed. The relationship between these properties is described by the equation:
c = λν
where: c is the speed of light in a vacuum, λ (lambda) is the wavelength of the light, and ν (nu) is the frequency of the light.
According to this equation, the speed of light is constant, approximately 3.00 x 10^8 meters per second in a vacuum. However, the wavelength and frequency of light are inversely related: as the frequency increases, the wavelength decreases, and vice versa. This relationship is known as the wave-particle duality of light.
When light travels through different materials, such as air, water, or glass, its speed and wavelength can be affected. This phenomenon is called refraction. When light passes from one medium to another, its speed changes, resulting in a change in its direction and wavelength.
For example, when light enters a denser medium like water from air, it slows down, and its wavelength decreases. This change in wavelength is responsible for the bending of light at the interface between the two media. The degree of bending depends on the change in refractive index between the two media.
So, while the speed of light is constant in a vacuum, it can change when passing through different materials, leading to a change in wavelength. However, the frequency of light remains constant, as it is an inherent property of the light itself.