{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f8371bc657083b95643d61e2ea3be982bafc6452084f5bbb722e73fa6fe7209a","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"bd929909dafbf3e0391cda2cf541f1852169a63fe2426f2066c68c63efcc2f5a","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"bio.glass-transition.stokes-einstein-breakdown","kind":"phenomenon","literature_status":"partially-resolved","n":"1","parents":[],"plain":"In ordinary liquids, how fast a molecule wanders is inversely proportional to the viscosity, the Stokes-Einstein relation. Near the glass point molecules wander much faster than this rule predicts, and a quantitative explanation is missing.","posed_since":"","precise":"Near $T_g$ in molecular liquids such as o-terphenyl, $D\\eta/T$ exceeds its high-temperature value by roughly two to three orders of magnitude (approximate), and $D\\sim \\tau_{\\alpha}^{-\\xi}$ with a fractional exponent reported near 0.75 to 0.85. Predict the magnitude, temperature dependence and exponent $\\xi$ from a theory of dynamic heterogeneity, and explain why rotational diffusion follows viscosity more closely than translational diffusion.","problem_ref":null,"references":"","settled_by":"A theory that predicts $D(T)$, $\\eta(T)$ and the decoupling exponent for a model liquid and agrees with simulations and with measurements on molecular glass formers.","status_note":"Attribution of the decoupling to dynamic heterogeneity is widely accepted qualitatively, but a quantitative prediction of the exponent is lacking (2026).","title":"Why diffusion decouples from viscosity near the glass transition","topic_ref":"b6cec0edf29a3e5b5b7b70395d6ca2460f15dfb7644125d881ab5595366caa14"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"eecb504f426a582467dec79553462615340b43d667827acd414ddb8b7fb19bc8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"41467f35e64e7af1a1ce04c1e8f7a03c99cbd9fb054de9ef9f7c4c342c878908","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Tari0qZU5JjB9ktyxnRdh4M-Yx8nQvEMgTYhkL9D3RM4q8VkY1txK06vTBBWsmS160J4_OmKdppSPRi8UDBcAw"},"schema":"pubphys.envelope/1"},"record_hash":"eecb504f426a582467dec79553462615340b43d667827acd414ddb8b7fb19bc8","leaf_index":781}