{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"d3edfdcc4d37131330d9058ce72fbaa5121a5e0a2f9039d6f2ea7fee4e5894e9","created":"2026-10-03T07:17:53Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"fcc8f19d74a9332efa9eeb40b57b0c351300a91c0d17e15eb044f240c6613c86","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"amo.constant-variation.alpha-drift-today","kind":"well-posed","literature_status":"open","n":"1","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 |d ln(alpha)/dt| of order 1e-18 per year. Determine whether d ln(alpha)/dt is nonzero at the 1e-19 per year level using multi-year ratios of clocks with large differential sensitivity, including the Th-229 nuclear transition.","problem_ref":null,"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 1e-18, analyzed for a linear drift.","status_note":"","title":"Is $\\alpha$ drifting today at the $1e-19$ per year level?","topic_ref":"0d5d25a5bcd4a09341050ed67516a89341dcb76395d21eb07382fa82d8edaaf2"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"aef4ffa8ea03f4033d945b705644cde6be412685774696eb44ae2369320cec40","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"91c20d0e43fd94f5c86c4ac1e88a3d7257e62203b7aec953cb12251a47387e05","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"6QLYL9wREYDP0W2VpMUI60xvawi2A7Bq320b8cZ7FCq7rxiJARWYjKm2Mc-xLGRDKgxrgM4KfbxGZ3EuRnAyCw"},"schema":"pubphys.envelope/1"},"record_hash":"aef4ffa8ea03f4033d945b705644cde6be412685774696eb44ae2369320cec40","leaf_index":391}