{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b68b178b1b38424c132c668254f3d046d6b688672d52a92585cfaa2a4bba52e1","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["1e7fc526b360e7a2a266805dd04cd294adce9d1561b67a65f94412af76c7f0a4","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"903237e9eb81246677238544441d2a36da699fe4aaea6b76b3b4440c0afa22b7","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":"2","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 $10^{-12}$; MICROSCOPE bounds $\\eta(\\mathrm{Ti}, \\mathrm{Pt})$ at about $10^{-15}$ (2022). Determine $\\eta$ for a pair of quantum test masses with uncertainty at or below $10^{-15}$, for example in a $100\\,\\mathrm{m}$ class tower or in space.","problem_ref":"1e7fc526b360e7a2a266805dd04cd294adce9d1561b67a65f94412af76c7f0a4","references":"","settled_by":"A dual-species interferometer result for $\\eta$ with total uncertainty below $10^{-15}$ (MAGIS-100, AION, STE-QUEST class).","status_note":"","title":"Atom-interferometric test of universality of free fall at $10^{-15}$","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2e338ed3e05a0ce7966b8bb1d091f31b7795b30046bd5c58342f9394b73f3404","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d4f32d09f4ffbe0bbd77e52dc5421f21b42e376e6c08180bae47c775ad47749d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"7U9Pp1m5ZYAXoxtDZFfjAjQvk4h2iQs5-PagDrcKzovO1_qyw4zXI-dNiIw1_5DBHcc2Q7mHlk_dCDkrTsBaBg"},"schema":"pubphys.envelope/1"},"record_hash":"2e338ed3e05a0ce7966b8bb1d091f31b7795b30046bd5c58342f9394b73f3404","leaf_index":2278}