{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"fe3c9a3c154f0f67226828f3bd4579039274159f251b79872b8504666bd3bec4","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","d847a1866cc65d2d76744e2c1ee8ee83fa5fdd7343bf2a30f3c7e819d68e66b1"],"salt":"04bcb601b4170aa4058ba067a91a210aea2158f7761347ffd2b8187519a9fb8a","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"bio.glass-transition.growing-static-length","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Near the glass point, molecules rearrange in cooperating groups whose size grows on cooling. It is unknown whether a growing structural length that ordinary structure measurements cannot see controls how slow the liquid becomes.","posed_since":"","precise":"Determine whether the point-to-set length $\\xi_{\\mathrm{PTS}}(T)$ (radius of a cavity, with frozen particles outside it, beyond which the interior forgets the frozen boundary) and the dynamic heterogeneity length $\\xi_4(T)$ (from the four-point susceptibility $\\chi_4$) are linked to the relaxation time by $\\tau_{\\alpha} \\sim \\tau_0 \\exp(c \\xi^{\\psi} / T)$ with a single exponent psi over the range from the onset temperature to $T_g$. An answer gives $\\xi_{\\mathrm{PTS}}(T)$, $\\xi_4(T)$ and $\\tau_{\\alpha}(T)$ from equilibrium simulations below the experimental $T_g$ and either confirms the relation with a measured $\\psi$ or refutes it.","problem_ref":"d847a1866cc65d2d76744e2c1ee8ee83fa5fdd7343bf2a30f3c7e819d68e66b1","references":"","settled_by":"Equilibrium measurements of $\\xi_{\\mathrm{PTS}}$, $\\xi_4$ and $\\tau_\\alpha$ over enough decades of $\\tau_\\alpha$ to fix $\\psi$ with error bars, or to show that no single relation holds.","status_note":"Simulations to date reach point-to-set lengths of only a few particle diameters, so $\\psi$ is poorly constrained (2026).","title":"Does a growing static length control relaxation near $T_g$?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"73869bf3136849b506f4a88a8125aece21487bc33ac0e103dbfd7f81e65a9885","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e4fd0b4b12d408ec6f5f982f07b429475f003f9469dc64a8388321f1cf920023","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"WpL-iJj2gTfVSSTQmv7N8zBMOvY164QSP5Crx83gOFRamLdzQSdPDUqxWf5BMzChpu_dU8m8T74jBbSMKSN_CA"},"schema":"pubphys.envelope/1"},"record_hash":"73869bf3136849b506f4a88a8125aece21487bc33ac0e103dbfd7f81e65a9885","leaf_index":2570}