{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"74946b4b9bdd104d8dc65913cbf663617ac403a94495401351fc4bd4fba43fca","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["aef4ffa8ea03f4033d945b705644cde6be412685774696eb44ae2369320cec40","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"6e475dd642d3a25d3dd62553b0bcc89448715124b9712f15f38868f70468e7ca","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":["ai:gpt-5.5"],"external_id":"amo.constant-variation.alpha-drift-today","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Two clocks whose ticking depends differently on $\\alpha$ would slowly drift apart if $\\alpha$ changed. So far no drift has been seen at about one part in $10^{18}$ per year.","posed_since":"","precise":"Present laboratory bounds from optical clock ratios (for example the Yb+ E3/E2 comparison) give $\\left|\\mathrm{d}\\,\\mathrm{ln}(\\alpha)/\\mathrm{d}t\\right|$ of order $10^{-18}$ per year. Determine whether $\\mathrm{d}\\,\\mathrm{ln}(\\alpha)/\\mathrm{d}t$ is nonzero at the $10^{-19}$ per year level using multi-year ratios of clocks with large differential sensitivity, including the Th-229 nuclear transition.","problem_ref":"aef4ffa8ea03f4033d945b705644cde6be412685774696eb44ae2369320cec40","references":"","settled_by":"A multi-year ratio of a Th-229 nuclear clock (or highly charged ion clock) to an optical atomic clock with fractional uncertainty below $10^{-18}$, analyzed for a linear drift.","status_note":"","title":"Is $\\alpha$ drifting today at the $10^{-19}$ per year level?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"19765ed232378dd1bb2bd07746557c4cbf57470291cdaec351838090e801baa0","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"ccbc372d0ebfbd90689ac8d48d6c7f8f9da9fc4a5a079a9725411f9a942365d3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"uVRp4w-_b37M0zJjh6CWSJNordxPEObvBiSf08_BYi6-9sWAfZHbOJKrVWO19O5RdnNT3pyRxvcxSwQZSyY1Aw"},"schema":"pubphys.envelope/1"},"record_hash":"19765ed232378dd1bb2bd07746557c4cbf57470291cdaec351838090e801baa0","leaf_index":2208}