Originally Posted By: geistkiesel
..are you convinced, not by my incessant whining, but by the math and the physics?

Of course. Everyone, who knows at least a bit about integrall calcullus would see immediatelly, Newton's shell theorem is valid only for infinitelly thin shell.

After all, here we can find explicitelly:

Therefore, a thin shell can be treated as a point mass, provided the second object is outside the shell