How big is Big G? Mystery deepens after ten-year effort to measure gravity’s strength

NEWS | 21 April 2026

By Elizabeth Gibney

The value of the constant that describes the gravitational pull between objects, Big G, continues to baffle scientists. A decade-long replication experiment1 that involved moving equipment across the Atlantic has resulted in a number that disagrees with previous results, and also differs from the current best estimate of G.

The new measurement gives important clues as to where the original experiment, conducted by researchers at the International Bureau of Weights and Measures (BIPM) in Paris and published in 2013, went wrong. But its failure to match the internationally agreed CODATA value has left physicists no closer to pinning down G’s true value.