Re: Bulges

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

> I agree that your potential approach is a superior way to do this. I'm
> curious, though, what you get as an answer when you consider the case
> where the two bodies are *not* rotating. I predict you will get the result
> that there are two opposing tidal bulges even in that case, simply from
> the gravitational force gradient. Therefore textbooks shouldn't imply that
> rotation is the *sole* cause of the bulges. However, it would be
> interesting to compare the size of the non-rotational bulges, with the
> size of them when the system is rotating, to see which cause is the
> predominant one for the bulges.
>
>        -- Donald

        Please, excuse my intrusion.  There is an interesting point here.
"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.

Igal.