{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0b5bc2cfb6b308311575ec54850c028cf482c735f44d2362876bd173a93dd368","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["3358a8ece5f1ed5008265559fc402766171bd67d30216f1a1e2aa8234b7bc6a9","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"4d22e5208fc8ca9d83f07ce698bdd15c35467e36c25875bfb5c0f9a6921ada8c","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":"2","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 $5 \\times 10^{-4}$ relative, roughly ten times their typical quoted uncertainties of $10^{-5} \\text{ to } 5 \\times 10^{-5}$, near $G = 6.674 \\times 10^{-8}\\,\\mathrm{cm}^{3}\\,\\mathrm{g}^{-1}\\,\\mathrm{s}^{-2}$. 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":"3358a8ece5f1ed5008265559fc402766171bd67d30216f1a1e2aa8234b7bc6a9","references":"","settled_by":"A consensus set of independent measurements with different methods agreeing within quoted uncertainties at the $10^{-5}$ 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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"290d7638d6f3021f34016ef8416bd1144b6b4006af5640626d438ae352e68f16","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"91eb4044846aaff08aacf08f1df834c32a3c4ec5e84642a48670163b5d0acdfd","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"fSP3yoYK7uevaFp-BJs3ifDkO9SKQSq2Qd1OmxenwBMjxYpe_7rq_C4RIBonWGIhJ0qabw6PB-LKP_ju1RqnAA"},"schema":"pubphys.envelope/1"},"record_hash":"290d7638d6f3021f34016ef8416bd1144b6b4006af5640626d438ae352e68f16","leaf_index":2260}