![\"NIST](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/04\/d41586-026-01284-3_52310484.jpg\"\/)
<\/p>\n <\/p>\n
Stephan Schlamminger (left) and colleague Vincent Lee with the equipment used to measure big G.Credit: R. Eskalis\/NIST<\/p>\n
The value of the constant that describes the gravitational pull between objects, Big G, continues to baffle scientists. A decade-long replication experiment1<\/a> 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.<\/p>\n 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<\/a>, went wrong. But its failure to match the internationally agreed CODATA value<\/a> has left physicists no closer to pinning down G\u2019s true value.<\/p>\n Is gravity quantum? Experiments could finally probe one of physics\u2019 biggest questions<\/p>\n <\/a><\/p>\n The work is \u201csoul draining\u201d, says Stephan Schlamminger, a physicist at the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, who led the latest work. But he says he is driven by the challenge. \u201cIt must be possible for humans to measure this number.\u201d<\/p>\n Studies of G have also often had to be a side hustle for scientists because, although it describes the strength of gravity, its value is rarely needed in practice. Most applications, such as calculating the motions of planets, only require the value of G multiplied by a mass, such as that of the Sun, and measurements can determine the combined value to high precision.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/04\/d41586-026-01284-3_51396734.jpg\"\/)
<\/p>\n