Redetermination of the gravitational constant with the BIPM torsion balance at NIST

Abstract We report the first replication of a high-precision measurement of the gravitational constant, G . The experiment employed the torsion balance originally designed and constructed at the International Bureau of Weights and Measures (BIPM) approximately three decades ago. Using the same apparatus and geometry, with several modifications documented in this work, we determined G = ( 6.67387 ± 0.00038 ) × 10 − 11 m 3 kg − 1 s − 2 , corresponding to a relative standard uncertainty of 5.7 × 10 − 5 . The result is lower by 2.5 × 10 − 4 relative to the BIPM determination. This replication provides an independent verification of one of the most precise torsion-balance determinations of G and contributes to assessing the reproducibility limits of current experimental techniques in measurements of the gravitational constant.