A geophysical experiment on Newton's inverse-square law

Abstract

A geophysical experiment consisting of the measurements of the gravitational effect produced by a large water mass was performed in order to verify the Newton's law. The use of a superconducting gravimeter, the detailed analysis of the local tidal perturbation, the precise topographic and geological surveys lead to a precision of about 0.1% in the final result. The ratio between the measured and the expected gravitational effect differs from 1 by more than 9 standard deviations. This may be explained by adding to the Newtonian potential a Yukawa repulsive term. The experimental result leads to constraints for the relationship between the relative magnitude (alpha)of the new term and the range (lambda) of the interaction. In the region 20 m < lambda > 500m, alpha ranges from 2.6% to 1.3%.