ripples

Ripples are small, wave-like disturbances that propagate away from a local disturbance through a medium. They are most commonly observed on the surface of liquids such as water, where a disturbance like a dropped object, a gust of wind, or a moving object creates crests and troughs that spread outward and gradually dissipate.

In fluids, ripple behavior is governed by gravity and surface tension. Longer-wavelength disturbances are dominated by gravity and travel faster as wavelength increases, while very short wavelengths are governed by surface tension and move differently. Because the speed of a ripple depends on its wavelength, ripples are dispersive: different wavelengths travel at different speeds, causing wave trains to spread apart or compress as they propagate. Boundaries, depth changes, and environmental forces such as wind can reflect, refract, dampen, or modify ripple patterns, leading to complex interference and pattern formation.

Ripples have practical and scientific uses. Ripple tanks reproduce and study wave propagation in a controlled setting, helping researchers visualize concepts in hydrodynamics and acoustics. In geology, ripple marks on sedimentary rocks record past flow directions and conditions, offering clues about ancient environments. In everyday life, ripples appear on ponds and lakes and can reveal information about wind strength, object motion, or nearby disturbances.

See also: ripple tank, surface gravity wave, capillary wave, ripple marks, wave interference.