Free Surface

Waves

Further information: Ocean surface wave and Airy wave theory

If the free surface of a liquid is disturbed, waves are produced on the surface. These waves are not elastic waves due to any elastic force; they are gravity waves caused by the force of gravity tending to bring the surface of the disturbed liquid back to its horizontal level. Momentum causes the wave to overshoot, thus oscillating and spreading the disturbance to the neighboring portions of the surface. The velocity of the surface waves varies as the square root of the wavelength if the liquid is deep; therefore long waves on the sea go faster than short ones. Very minute waves or ripples are not due to gravity but to capillary action, and have properties different from those of the longer ocean surface waves, because the surface is increased in area by the ripples and the capillary forces are in this case large compared with the gravitational forces. Capillary ripples are damped both by sub-surface viscosity and by surface rheology

Read more about this topic: Free Surface

Famous quotes containing the word waves:

“There is no sea more dangerous than the ocean of practical politics—none in which there is more need of good pilotage and of a single, unfaltering purpose when the waves rise high.”
—Thomas Henry Huxley (1825–95)

“With these I would be.
And with water: the waves coming forward, without cessation,
The waves, altered by sand-bars, beds of kelp, miscellaneous
driftwood,
Topped by cross-winds, tugged at by sinuous undercurrents
The tide rustling in, sliding between the ridges of stone,
The tongues of water, creeping in, quietly.”
—Theodore Roethke (1908–1963)