Re: double tide cause

[brian whatcott <inet@INTELLISYS.NET>]

At 03:04 9/2/01 -0400, John Denker wrote:

> The usual textbook discussion of tides tells you what the gravitational
> _potential_ looks like.
> /snip/ consider
> the case where the sun and moon are colinear with the earth, i.e. new moon
> or full moon.  The tides squash the potential into a prolate
> ellipsoid.  The potential bulges up at the point right under the moon and
> also bulges up at the antipodal point.  It "tightens its belt" on the ring
> of points 90 degrees away.
>
> Let us imagine, temporarily, a planet which is earth-like EXCEPT that it
> spins very slowly: slowly compared to the sloshing resonance frequency of
> all the oceans and bays, and also slowly compared to any viscous relaxation
> times.  On such a planet, the water would come to equilibrium and would map
> out the potential for us.

I found this visualization helpful to the intuition.
 Who could not grasp the conception of football poised
 to launch at the Moon?

Brian W


brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!