{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e8b665ca98e0e90f0e7c1a57631b750c8115b0a119b8cfcaa8da656ddc9ce2f9","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","60848fcc6e7dd814281e81cd02da7522c13d62ffd19f44653a61c8b90744fb32"],"salt":"40f3baef2b9c776f3a5e58f9335bf5b7d3a64a6e1662897557ec1952d85b3200","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":"1","parents":[{"note":"","parent_revision":"60848fcc6e7dd814281e81cd02da7522c13d62ffd19f44653a61c8b90744fb32","relation":"special_case"}],"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":null,"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":"b6cec0edf29a3e5b5b7b70395d6ca2460f15dfb7644125d881ab5595366caa14"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d847a1866cc65d2d76744e2c1ee8ee83fa5fdd7343bf2a30f3c7e819d68e66b1","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3fc73a35d40a50fe46de76631672837cd5fada26e2ffee0e3fcb4630f9d69585","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"t9azVwacNT3jFK5M8fNlUSWo-etzrNhTMX1TgmxgSMXdhAOd47T4ksA1vQRPCcz8OaxaToV0dzgQdM94NZeTCw"},"schema":"pubphys.envelope/1"},"record_hash":"d847a1866cc65d2d76744e2c1ee8ee83fa5fdd7343bf2a30f3c7e819d68e66b1","leaf_index":780}