Measurement of Newton's Constant Using a Torsion Balance with Angular Acceleration Feedback

We measured Newton's gravitational constant G using a new torsion balance method. Our technique greatly reduces several sources of uncertainty compared to previous measurements: (1) It is insensitive to anelastic torsion fiber properties; (2) a flat plate pendulum minimizes the sensitivity due to the pendulum density distribution; (3) continuous attractor rotation reduces background noise. We obtain $G{{0ex}{0ex}}={{0ex}{0ex}}(6.674215±{}0.000092)×{}{10}^{{-}11}{m}³{kg}^{{-}1}{s}^{{-}2}$; the Earth's mass is, therefore, ${M}_{{}}{{0ex}{0ex}}={{0ex}{0ex}}(5.972245±{}0.000082)×{}{10}²⁴kg$ and the Sun's mass is ${M}_{{}}{{0ex}{0ex}}={{0ex}{0ex}}(1.988435±{}0.000027)×{}{10}³⁰kg$.