Wave dispersion refers to the phenomenon where waves of varying frequencies travel at different speeds.

As a wave propagates through a medium, it interacts with the medium’s particles. This interaction causes the wave to decelerate, and the extent of this deceleration is influenced by the wave’s frequency. Specifically, waves with higher frequencies tend to interact more intensely with the medium, resulting in a greater reduction in speed compared to lower-frequency waves. Consequently, this variation in speed leads to the spreading out, or dispersion, of the wave as it moves.

Dispersion is particularly evident in waves that encompass a wide range of frequencies, such as white light. When white light passes through a prism, it separates into its constituent colors because each color corresponds to a different frequency, and thus each travels through the prism at a different speed.

The effects of dispersion are also significant in the behavior of waves as they traverse different media. For instance, sound waves travel faster in solids than in liquids. This difference arises because the particles in solids are more closely packed, facilitating greater interaction with the wave. As a result, higher-frequency components of the sound wave slow down less, thereby reducing the overall dispersion.

While dispersion can sometimes lead to undesirable outcomes, such as signal distortion in fiber optic communication, it can also serve beneficial purposes. For example, dispersion is harnessed in the design of lenses and prisms used in optical instruments, allowing for enhanced manipulation of light.