Wave refraction refers to the bending of waves as they transition from one medium to another.

When waves encounter a boundary between two different media, such as air and water, their speed and direction change, leading to refraction. The degree of bending is influenced by both the angle at which the waves approach the boundary and the difference in wave speed between the two media.

If waves approach the boundary perpendicularly, they will not undergo refraction and will continue traveling in a straight line. However, when waves approach at an angle, they will bend either towards or away from the normal line, which is an imaginary line drawn perpendicular to the boundary.

Specifically, when waves transition from a medium with a higher speed to one with a lower speed—such as from air to water—they bend towards the normal. Conversely, when waves move from a slower medium to a faster one, like from water to air, they bend away from the normal.

The phenomenon of wave refraction has significant implications in the natural world. For instance, it can lead to the focusing or spreading of waves and can cause waves to break at angles relative to the shore. Therefore, understanding wave refraction is essential for predicting and managing the effects of waves in coastal environments.