Which phenomenon explains the bending of light as it passes through different media?

The bending of light as it passes from one medium to another is primarily explained by refraction. This phenomenon occurs due to the change in speed of light as it enters a medium with a different optical density. When light travels through air and then enters water, for example, it slows down, leading to a change in direction. This change in speed is influenced by the refractive index of the different materials, which quantifies how much the speed of light is reduced in a specific medium compared to its speed in a vacuum.

Refraction is essential in various applications, such as lenses in glasses and optical instruments, where it is used to focus or disperse light rays. Understanding refraction allows us to predict how light will behave as it transitions between different materials, and it highlights the fundamental principles underlying many optical phenomena. The bending of light is not due to reflection, which involves the bouncing back of light, nor diffraction, where light spreads around an obstacle or through an opening. Dispersion, on the other hand, refers to the separation of light into its constituent colors, which is a different phenomenon altogether.