Anton Sherwood wrote:

 > I don't see why not.

Because the earth isn't "pulled away" from the water. I know the 
analysis Larry is talking about. It's bogus. The center of the earth 
isn't pulled towards the moon and away from the water on the surface 
facing away from the moon, except for very vague and imprecise meanings 
of the word "pulled away". The explanation is sufficiently misleading 
that one can safely say it's wrong.

Consider, for example, the earth and moon on big sticks, held still. The 
centers wouldn't be going anywhere. The moon would still be pulling on 
the center of the earth, but all the water would be on the side with the 
  moon.

Now consider that the center of the earth follows the same path it would 
were there no tides. Clearly, the moon isn't pulling the center of the 
earth away from the water on the far side.

Plus, such an explanation doesn't account for tidal locking, wherein one 
face of the moon always points towards the earth, for example.

 > So if the Moon were a point mass Earth would not experience tides?
 > Bzzt, try again.

If the moon were a point mass the moon would not experience tides.
If the earth were a point mass, the earth would not experience tides.

The earth orbits the moon in the same path it would were it a point 
mass, so tides aren't caused by a change in the motion of the earth.

 > Newton showed that a spherically symmetric body - i.e. one whose 
density varies only with radius - produces the same g-field (outside its 
surface) as a point mass.

The water on the earth is not outside the surface of the earth. That's 
what I mean by "inside a system jazz".

-- 
   Darren New / San Diego, CA, USA (PST)
    Neither rocks nor slush nor salted rims
    shall keep us from our appointed rounds.

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