Abstract
We present a new value of the Newtonian gravitational constant 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 with a standard uncertainty of about 2.6 parts in .
- Received 7 May 2006
DOI:https://doi.org/10.1103/PhysRevLett.102.240801
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