"Jeff" wrote in message
...
Making things overly complex is half the fun! Don't you find it
interesting that the oblateness is something you can observe?


It is interesting. I can also observe length deviations due to variations in
gravitational potential on the earths surface.

http://www.colorado.edu/GeolSci/Reso...ft/Gravity.htm


I wonder how frame dragging (Lens-Thirring) varies with latitude. Should see
it on the GPS.

http://www.phys.lsu.edu/mog/mog25/node11.html