Determination of the Newtonian gravitational constant G with time-of-swing method.
We present a new value of the Newtonian gravitational constant G by using the time-of-swing method. Several improvements greatly reduce the uncertainties: (1) measuring the anelasticity of the fiber directly; (2) using spherical source masses minimizes the effects of density inhomogeneity and eccentricities; (3) using a quartz block pendulum simplifies its vibration modes and minimizes the uncertainty of inertial moment; (4) setting the pendulum and source masses both in a vacuum chamber reduces the error of measuring the relative positions. By two individual experiments, we obtain G = 6.673 49(18) x 10;{-11} m;{3} kg;{-1} s;{-2} with a standard uncertainty of about 2.6 parts in 10;{5}.
Luo
Jun
J
Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. junluo@mail.hust.edu.cn
Liu
Qi
Q
Tu
Liang-Cheng
LC
Shao
Cheng-Gang
CG
Liu
Lin-Xia
LX
Yang
Shan-Qing
SQ
Li
Qing
Q
Zhang
Ya-Ting
YT