Re: Gravity waves (was seti@home is SORTA WORKING)

Joseph C Fineman (
Fri, 16 Jul 1999 17:27:30 -0400 (EDT)

On Thu, 15 Jul 1999, Brian Atkins wrote:

> Ocean/lake waves do not get their energy from gravity. They get it
> from sustained winds or from earthquakes. Tides are caused by
> gravity. Gravity may be necessary though for water wave formation
> (something has to pull the water down when the wind pushes it up)
> which is maybe what was being said.

The types of surface waves on liquids are not named after where the energy comes from, but after where the restoring force comes from. There are two extreme types:

Gravity waves (restoring force: gravity) in the limit of long wavelength
Ripples (restoring force: surface tension) in the limit of short wavelength

For intermediate wavelengths both effects are important.

Neither of the above is the same as a gravitational wave, which is the (so far undetected) oscillatory form of the gravitational field.

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