Uniform gravitational field in an off-center spherical cavity
= Uniform gravitational field in an off-center spherical cavity
{title2=$g=-4\pi G\rho c/3$}
Remove a spherical void centered at $c$ from a uniform sphere centered at the origin. At points inside the void, <superposition> combines the sphere's interior field $-4\pi G\rho x/3$ with the removed sphere's field $+4\pi G\rho(x-c)/3$. Their sum is the displayed constant <Newtonian gravitational field>. A second removed mass outside this void adds a nonuniform contribution.