A Simple Pendulum Determination of the Gravitational Constant

TL;DR

This study used interferometry with a simple pendulum setup to measure the gravitational constant G, achieving a value consistent with the 1986 CODATA but differing from more recent measurements.

Contribution

It presents a straightforward pendulum-based interferometric method for determining G, providing results that align with older CODATA values and highlighting discrepancies with recent measurements.

Findings

Measured G as (6.67234 +/- 0.00014) x 10^-11 m^3 kg^-1 s^-2

Results agree with 1986 CODATA value

Results differ from recent G determinations

Abstract

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) x 10^-11 m^3 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) x 10^-11 m^3 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) x 10^-11 m^3 kg^-1 s^-2 [Rev. Mod. Phys. 80, 633 (2008)].