What phenomenon describes the bending of light waves around obstacles and openings?

The bending of light waves around obstacles and openings is known as diffraction. This phenomenon occurs when light encounters an edge or a slit that is comparable in size to its wavelength. As the light waves pass through the opening or around the obstacle, they spread out and can interfere with one another, leading to patterns of light and dark regions known as diffraction patterns. This behavior is particularly noticeable with coherent light sources, such as lasers, and can be demonstrated through experiments showcasing how light behaves when it encounters sharp edges or slits.

Reflection refers to the bouncing of light off surfaces, while refraction is the change in direction of light as it passes from one medium to another with a different density, altering its speed. Dispersion involves the splitting of light into its constituent colors, typically seen when light passes through a prism. Each of these processes describes distinct interactions of light, but diffraction specifically addresses the bending of light waves around obstacles and openings, making it the correct choice for this question.