Luo Jun, Liu Qi, Tu Liang-Cheng, Shao Cheng-Gang, Liu Lin-Xia, Yang Shan-Qing, Li Qing, Zhang Ya-Ting
Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Phys Rev Lett. 2009 Jun 19;102(24):240801. doi: 10.1103/PhysRevLett.102.240801. Epub 2009 Jun 16.
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}.
我们通过摆动时间法给出了牛顿引力常数G的一个新值。多项改进措施极大地降低了不确定性：（1）直接测量纤维的滞弹性；（2）使用球形源质量使密度不均匀性和偏心率的影响最小化；（3）使用石英块摆简化了其振动模式并使惯性矩的不确定性最小化；（4）将摆和源质量都置于真空室内减少了测量相对位置的误差。通过两个独立实验，我们得到G = 6.673 49(18)×10⁻¹¹ m³ kg⁻¹ s⁻²，标准不确定性约为10⁵分之2.6。
