{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"db46554f272001aa81e53d12f8a60bb4b3397973e8a91513bf1423d474d1d4e9","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["758593ddd21934f5cafd29de60d162dd327db8579db4b33708c8bb9394fd068a","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"0f81512a1c61b8c7730e80ed5da53cda7d2b54e5f8129c59bf16e6b9d2a0038e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cosmo.cosmic-magnetism.seed-origin","kind":"phenomenon","literature_status":"open","n":"2","parents":[],"plain":"Dynamos in galaxies can amplify a weak magnetic field, but they need a starting seed. The seed could come from the early universe or from the first stars and galaxies.","posed_since":"","precise":"Galaxies and clusters host fields of $\\sim 10^{-6}$ G coherent over $\\sim 10\\,\\mathrm{kpc}$, amplified by dynamos from seeds $B_{\\mathrm{seed}}$. Identify the origin of the seeds: Biermann battery in the first collapsed structures ($\\sim 10^{-20}$ G), inflationary magnetogenesis, or first-order phase transitions. An answer identifies the origin through the void field strength, coherence length and helicity, which differ between scenarios.","problem_ref":"758593ddd21934f5cafd29de60d162dd327db8579db4b33708c8bb9394fd068a","references":"","settled_by":"Measured strength, coherence length and helicity of void fields compared with the predictions of each scenario.","status_note":"","title":"Were cosmic magnetic seed fields primordial or astrophysical?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c560798868159f80c5b802ad565cc97f3f73f44d7c0d7cf242e3eabc9892b55c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c933677930e0c60c4a3ee3f52ebbc0f2f060311853ea25adfe206a05e7cff029","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"qMYhZEpFUnqUP9cVLEiI1Z4WHkYy9jNGmfa9RsYa61XJszUQPFbNreOslWKtxPL5-TfUfhNzxzanp8vdVFbxDw"},"schema":"pubphys.envelope/1"},"record_hash":"c560798868159f80c5b802ad565cc97f3f73f44d7c0d7cf242e3eabc9892b55c","leaf_index":3120}