Test of the inverse-square law of gravitation using the 300-m tower at Erie, Colorado

Gravity was measured at eight different heights on a 300-m meterological tower using LaCoste and Romberg gravimeters. The observed values were adjusted for tides, drift, and gravimeter screw errors, and tested for systematic effects due to tower motion. These results are compared with values predicted using Newton’s inverse-square law from surface gravity. The differences exhibit no systematic trends and their rms value is only 10×${10}^{\mathrm{-}8}$ m ${\mathrm{s}}^{\mathrm{-}2}$, well within the estimated errors of the experiment. This result places new constraints on the possible strength and range of any non-Newtonian force.