Simple pendulum determination of the gravitational constant.

We determined the Newtonian constant of gravitation G by interferometrically measuring the change in spacing between two free-hanging pendulum masses caused by the gravitational field from large tungsten source masses. We find a value for G of (6.672 34±0.000 14)×10(-11)  m3  kg(-1)  s(-2). This value is in good agreement with the 1986 Committee on Data for Science and Technology (CODATA) value of (6.672 59±0.000 85)×10(-11)   m3  kg(-1)  s(-2) [Rev. Mod. Phys. 59, 1121 (1987)] but differs from some more recent determinations as well as the latest CODATA recommendation of (6.674 28±0.000 67)×10(-11)   m3  kg(-1)  s(-2) [Rev. Mod. Phys. 80, 633 (2008)].