{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"136d8d18eef0076ab9fe80a6bc05a309440f346e78537551b5096f2ed17c8eb8","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"7143205ffadd621b3adaa0b0ebad85da7335ab04013e017fec967e96fa80e6ad","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"amo.quantum-equivalence-principle.atom-eotvos-1e15","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Two kinds of atoms dropped together should fall at exactly the same rate. Atom interferometers have checked this to about one part in $10^{12}$, while a satellite with solid masses reached one part in $10^{15}$.","posed_since":"","precise":"Dual-species atom interferometry (Rb-85/Rb-87, Asenbaum et al 2020) bounds the Eotvos parameter $\\eta$ at about 1e-12; MICROSCOPE bounds $\\eta(\\mathrm{Ti}, \\mathrm{Pt})$ at about 1e-15 (2022). Determine $\\eta$ for a pair of quantum test masses with uncertainty at or below 1e-15, for example in a $100\\,\\mathrm{m}$ class tower or in space.","problem_ref":null,"references":"","settled_by":"A dual-species interferometer result for $\\eta$ with total uncertainty below 1e-15 (MAGIS-100, AION, STE-QUEST class).","status_note":"","title":"Atom-interferometric test of universality of free fall at 1e-15","topic_ref":"1ef36fc0692a8bd1d924ba5b2faf894c475adb1314f3440a6281df6c8bcb9e1b"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1e7fc526b360e7a2a266805dd04cd294adce9d1561b67a65f94412af76c7f0a4","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"ca207501cf657bce5e4b59456ddd642398b27459b77368089110eddb7593a548","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"8NIrRHSLY3BiGC4T-bPmY3lCogLLpPFlE-QDEBPS5hpA4Ke3GhnfWY6Mah4L7wntjB5E6PLtJcsDCqGcS2FODw"},"schema":"pubphys.envelope/1"},"record_hash":"1e7fc526b360e7a2a266805dd04cd294adce9d1561b67a65f94412af76c7f0a4","leaf_index":448}