{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"bd42de97d9537a3f4a78a6e6e3235b5deead69e7477138b03ac726c259bd9a92","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"8b4a03e9d6e75fb25d5e20ba0e74df9aada7ddbe7bde1b0f49a3cb960ed531bc","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"astro.biosignatures.false-positives","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Oxygen and methane can sometimes be made by sunlight splitting water or by volcanic and rock-water chemistry, without life. A sign of life must be distinguishable from these.","posed_since":"","precise":"Enumerate and quantify abiotic pathways that produce detectable O2, O3 or CH4 plus CO2 disequilibrium on rocky planets: H2O photolysis with hydrogen escape, CO2 photolysis in dry atmospheres, serpentinization and volcanic outgassing. For each, derive spectral discriminants (CO, O4, H2O abundance, redox state) measurable by a Habitable Worlds Observatory-class telescope. The answer is a classified list with abundance ranges and discriminants.","problem_ref":null,"references":"","settled_by":"Coupled photochemical, geochemical and escape models over the plausible parameter range, with synthetic spectra at expected telescope resolution and signal to noise.","status_note":"","title":"Which non-biological processes can mimic oxygen or methane biosignatures?","topic_ref":"59b283291ab553a122fd70aabfbd2c1ce03ef623f8bb56636d5ec28be91c14ab"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fb842848d5f62fff9d1251605824309bcd8cc8db829286506c08e88b4a61758e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"edde092861480bf5d3daad412b1cc8ad30bd2d3083e5b91f3f30e4e999b0f4eb","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"a3lVJ1huauvuo3Q8oRdKdbKRm0i_jHwCqdHBnSnRJ4D-wOKz835GEXtCbGtmyu2DtiIWBZyKc0Fn5whtUcAoDQ"},"schema":"pubphys.envelope/1"},"record_hash":"fb842848d5f62fff9d1251605824309bcd8cc8db829286506c08e88b4a61758e","leaf_index":486}