Test of the gravitational inverse-square law at 0.4- to 1.4-m mass separations

Abstract

Using a superconducting gravimeter, we have measured the force on a spherical shell of Nb due to the presence of a spherical mass M that is periodically moved up and down on an elevator underneath the gravimeter. Over a distance range from 0.4 to 1.4 m Newton's inverse square law is verified to a precision of +I%. At a 95% confidence level, our data restrict the coupling constant a of a non-Newtonian Yukawa potential to be /a1 < 0.012G for Yukawa ranges from 0.2 to 2.0 m. PACS number(s1: 04.80. + z, 04.90. + e

Test of Theoretical Solid Earth and Ocean Gravity Tides

“…However, the signal-to-noise ratio for the tides measured by the absolute meter was such that the record lengths were not long enough to yield a calibration as accurate as the one used here. A repeat of this experiment by one or more of the groups owning both absolute and relative gravimeters should be able to equal or improve upon the accuracy of the calibration by Goodkind et al (1993). Using an applied acceleration, Richter et al (1995) report an accuracy of 0.02 per cent.…”

“…In order to compare the absolute value of the theoretical tides with the measured tides, absolute calibration of the gravimeters is needed. For the present work, this was obtained as a by-product of a prior experiment to test the gravitational inverse-square law (Goodkind et al 1993). In that experiment, a mercury-filled spherical steel shell weighing 323 865 f 100 g and a solid steel sphere weighing 184 441 f 1.0 g were placed, at different times, on a moveable platform under the gravimeter.…”

Superconducting Gravimetry

“…A similar calibration was done by Goodkind et al (1993) who used a moving mass system to test the inverse square law of Newtonian gravity. A spherical mass was moved vertically under the SG in a specially designed chamber; an accuracy of 0.09% was achieved for two different types of sphere material.…”

Tests of the Gravitational Inverse Square Law at Short Ranges

“…Several have used a torsion pendulum (Chen et al 1984;Panov and Frontov 1979;Spero et al 1980;Hoskins et al 1985). A test by Goodkind et al (1993) at UC San Diego measured the change of force exerted on a levitated superconducting niobium ball when a spherical mass was placed below it at a distance ranging from 0.4 to 1.4 meters. A test by Ogawa et al (1982) at the University of Tokyo measured the resonant response of a 1400 kg aluminum quadrupole gravity wave antenna to a 401 kg steel bar rotating at 30.4 Hz and placed at distances ranging from 2.6 to 10.6 meters.…”