[quote name='0r0d' timestamp='1357893867' post='5020236']
The Earth is not a perfect sphere, nor is it a perfectly rigid body with uniform density, or any of that. It sounds like you want math more suited to billiard balls, not planets.
[/quote]
Pretty darn close though. The earth is in fact smoother then a billiard ball, but it's slightly squashed at the poles.. not that much though, so you probably wouldn't notice it unless you are a professional pool player :)