The discussion centers on justifying the statement that as an object descends into the Earth, only the mass beneath it influences gravitational force, while the mass above exerts no force. This concept is rooted in Newton's shell theorem, which states that a uniform spherical shell of mass exerts no net gravitational force on objects located inside it. Gauss's law supports this by indicating that only the mass enclosed within a Gaussian surface contributes to the gravitational field. Therefore, as one goes deeper, the gravitational effects of the layers above cancel out, leaving only the mass below to exert force. This illustrates the relationship between Gauss's law and the shell theorem effectively.
