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Re: [Phys-l] A ball at the center of a planet

Bob LaMontagne wrote:

If the ball is a perfect sphere of finite size when at the center of the earth, then the center of the ball has zero net force acting on it - so it does nothing. A point on the surface of the ball has a weak but finite force on it pointing to the center of the ball and earth. Therefore, shouldn't a deformable ball therefore decrease in radius relative to deep space?

That same weak force is there in deep space (it is, after all, due to the mass of the ball itself), so why would there be any difference?

John Mallinckrodt
Cal Poly Pomona