Proposed null experiment to test the inverse square nature of gravitation

A null Cavendish experiment is proposed for testing the validity of the inverse square gravitational force law: one searches for spherically·symmetric excitations in a hollow spherical fluid-filled resonator in the presence of a mass quadrupole rotating at half the lowest resonant frequency of the fluid sphere. By Gauss' law, there is no nonstatic Newtonian coupling to the resonator. The experiment can be made sensitive enough to detect a Yukawa-type force with a strength less than 10^–3 G and a range on the order of 10 cm.