Re: Bulges

[igal@vms.huji.ac.il (Igal Galili)]

> > "Non-rotational bulges" are  not symmetrical, reflecting the profile of the
> > gravitational force gradient. The additions due to the centrifugal forces
> > make the bulges symmetrical.  This point usually is not mentioned by many
> > books, probably for the sake of simplicity, which could be understood.


> Now *there's* an interesting new piece of info for this thread. I
> suspected the two effects might combine to tend toward symmetry, but
> haven't yet had time to sit down to do the messy math. The field gradient
> effect would cause a bulge greater on the lunar side of the earth. The
> centrifugal effect would distort the equatorial bulge more on the opposite
> side. Does this make the resulting two-bulge shape close to symmetrical,
> or exactly symmetrical. If *exactly*, that's astounding, and *very*
> interesting.
>
>        -- Donald

        It is so qualitatively.  And the factual result we all know: the
buldges are almost equal.  I think it is quite sufficient in a conceptually
oriented presentation, just to satisfy the human curiousity in "the first
approximation".  As far as I know, the credit for this understanding should
be given to Ernst Mach.

 Igal.