{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"07364f8f0ba17a6c732dd996408819f465ea887e4651fe92bed5c4f4569384a9","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"bf2a5205e9a15d41220d40db7669c6983d50ed1d2a0421deadb939e6ebc4c5d2","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"amo.newtonian-g.measurement-spread","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"About a dozen top experiments, each claiming an error of a few parts in 100000, give values of G that spread by about 5 parts in 10000. Something in how G is measured is not understood.","posed_since":"","precise":"Laboratory determinations of G (torsion balances in time-of-swing, angular-acceleration and servo modes, beam balances, simple pendulums, atom interferometry) spread over about $5e-4$ relative, roughly ten times their typical quoted uncertainties of $1e-5 \\text{ to } 5e-5$, near $G = 6.674e-8\\,\\mathrm{cm}^{3}\\,\\mathrm{g}^{-1}\\,\\mathrm{s}^{-2}$. Identify the unaccounted systematic effects (or establish any genuine dependence of the measured G on method, material or geometry) that explain the excess scatter.","problem_ref":null,"references":"","settled_by":"A consensus set of independent measurements with different methods agreeing within quoted uncertainties at the 1e-5 level, together with an identified correction to the outliers.","status_note":"NIST published a 10-year blinded torsion-balance result in Metrologia in 2026 that lies about 235 ppm below the BIPM value obtained with the same apparatus design.","title":"Why laboratory values of G scatter beyond their stated uncertainties","topic_ref":"e5522d18821c2173b9833ad46620a1ae7d5f42c3c43509b22e231c630bb90895"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"3358a8ece5f1ed5008265559fc402766171bd67d30216f1a1e2aa8234b7bc6a9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e429f76af0d3fc1da911dce080cc60e8d561027b497dc592031a3b14578065e7","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"NCjqccX6BcUdpvbpGQwadTVyagPwwQbtvYYq-91ExCu5GE_U3rK1z7uev_RCdRhPtx1xh0pDSCpp7qNoH5FUAQ"},"schema":"pubphys.envelope/1"},"record_hash":"3358a8ece5f1ed5008265559fc402766171bd67d30216f1a1e2aa8234b7bc6a9","leaf_index":430}