{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f0a4a14461c357fb4dbe99faac8e0cfa55e38142504c7fd8b9afabaaa3139fcc","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"ceea4f33bf05aaa91b8088308a32447a6e12a38dde727c5f690fc805c93365a2","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"bio.chromatin-extrusion.chromatin-material-state","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Experiments disagree on whether chromatin flows like a thick liquid or holds its shape like a soft solid at scales below a micrometer. The answer decides how genes move and how mechanical forces reach the genome.","posed_since":"","precise":"Determine the frequency-dependent storage and loss moduli $G'(\\omega)$ and $G''(\\omega)$ of interphase chromatin in living mammalian nuclei at length scales $10^{-5}\\text{ to }10^{-4}\\,\\mathrm{cm}$ and times $10^{-2}\\text{ to }10^{3}\\,\\mathrm{s}$, and reconcile reports of liquid-like condensed chromatin with solid-like behavior. Answer: the classification by scale, with the moduli.","problem_ref":null,"references":"","settled_by":"Microrheology inside living nuclei with calibrated probes across the stated scales, cross-checked by response to applied force.","status_note":"A 2020 study (Strickfaden and co-workers) reported solid-like chromatin at the mesoscale, against liquid-like models; the dispute continues.","title":"Is chromatin in the nucleus a liquid, a gel or a solid?","topic_ref":"8ad1a941274484056fe235f47000030ee6a6486f2d2e01d87c8ec53a250ea12e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1631e4e8bc6053d448b51343c47985e129ab275704d14ff5b6878c1d16af170b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e8fb94f3594da745eef773956d6722afd30190b18c40f73f1b40359c424793c1","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"1PQtWeEYBH6Fr2ycO2r7KqOe8enijyUgxAXMvfGgjq39Y4k38FRaJa5_I5DjAkf1pIZjMJD7vYsHOn6mfUCKAQ"},"schema":"pubphys.envelope/1"},"record_hash":"1631e4e8bc6053d448b51343c47985e129ab275704d14ff5b6878c1d16af170b","leaf_index":738}