Posted: Mar 03, 2011 12:27 am
by CdesignProponentsist
Nautilidae wrote:

If I remember correctly, gravity is stronger at the center of a planet, not at its surface.

No. At the center you have the entire mass distributed equally around you. So the force is canceled like a marble at the bottom of a bowl.

...gravity is slight stronger at the poles of the Earth than at the Equator; the poles are closer to the core.

Yes. You are slightly closer to the core which is much more dense than the mantle, but it is still completely distributed below you whereas if you were IN the core, you would have it distributed all around you, again canceling out for a sum total of 0 gravitational force.

But it also is due to the rotation of the earth as well to a slightly lesser degree.