{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"eba56dbc61ecdc81d3c5906d163291f3a6ab327cae25e506b23baebb0b9ead43","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"fc28c5f54a9a79843892874d1f374f3407b7bc6e3daafff1077c89754b330118","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cosmo.cosmic-dawn.edges-21cm","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"In 2018 the EDGES radio experiment reported a dip in the radio sky from hydrogen gas 180 million years after the Big Bang, twice as deep as theory allows. Another experiment did not see it.","posed_since":"2018","precise":"EDGES reported a flattened absorption profile centered at $78\\,\\mathrm{MHz}$ ($z \\sim 17$) with depth $\\sim 0.5\\,\\mathrm{K}$, at least twice the maximum in standard models without extra cooling or radio background. SARAS 3 (2022) found no such signal. Answer whether a global 21-cm absorption of that shape and depth exists, using an independent instrument with residuals below $\\sim 50\\,\\mathrm{mK}$.","problem_ref":null,"references":"","settled_by":"Independent global-signal measurements (REACH, LEDA, PRIzM, lunar far-side experiments) with different antennas and sites.","status_note":"SARAS 3 (2022) rejected the EDGES profile at about 95 percent confidence; no independent confirmation exists.","title":"Is the EDGES 78 MHz absorption trough a real cosmological signal?","topic_ref":"ea80801fd2eb5823d48bafd35c2c50fca035f01f2b6b883d55c93bfc64efc2da"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2c33adee2cf6eeb17711202ea3eba6916488dfa4adebabf6c9699129fecab5a1","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"f15f9a22564a2df2d29a249d0bd4eaf98c6d34da9807d695b7dbbb37478b6b8a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"EH6Yw6X2ovew1rg3BibEYaMWcqY3FNiUdg0WFr3xVJJbOpFEPtWVH0Lo-SQXWGsMLcYU3BYxdFZ1y3ASEfkvCQ"},"schema":"pubphys.envelope/1"},"record_hash":"2c33adee2cf6eeb17711202ea3eba6916488dfa4adebabf6c9699129fecab5a1","leaf_index":1230}