An Experimental Determination of the Gravitational Constant at Distances Around Ten Meters

余秀桃(Hsou-Tao Yu) ； 倪維斗(Wei-Tou Ni) ； 胡錦城(Chin-Cheng Hu) ； 劉發祥(Fa-Hsiang Lru) ； 楊家祥(Chia-Hsiang Yang) ； 劉武男(Wu-Nan Liu)

《Chinese Journal of Physics》 16卷4期 (1978/12) Pp. 201-213

並列摘要

Long, Fuji, O'Hanlon, and others have speculated that the gravitational force between point masses in the Newtonian regime might not be exactly proportional to 1/r^2. Deviations from the inverse square law can be expressed in terms of a distance-dependent gravitational“”constant” G(r). Compilation of laboratory results show that the variation of G(r) in the range 5 cm ＜r＜ 1 m do not exceed 1%. From an analysis of planetary dynamics, Mikkelsen and Newman showed that G(r) is constant to within 0.03% in the range 10^4’km ＜r＜ 3x 10^8 km. But constraints on G(r) in the intermediate range 10m ＜r＜ 1 km are very poor. The purpose of this experiment is to experimentally determine G(r) at distances about ten meters. We use Worden gravimeter to measure the gravitational accelerations at fixed positions when the oil tank or swimming pool is full and when it is empty. The differences Δg give the vertical contributions to gravitational accelerations due to the materials contained in the oil tank or swimming pool when it is full. These, in turn determine G(r). Our main result is: at a distance of two meters from the oil tank (diameter=54.86 m, height=15.50 m) with oil level difference 11.86 m, the ratio of the observed Ag and the Newtonian prediction is 1.01~t0.13 (r. m. s. deviation). With the α-μ model of Wagoner, Fuji and O'Hanlon. G(r) is constrained by these experiments, e.g., G(1.5 m)=Go(1 10.18).