{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e6af3f02e768bc27ad8b84d0c43d5ecb3fe1de425e3659fc77837a571f351b74","created":"2026-10-03T07:17:58Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","7634b50edcbbf83ae2f2e94062090f3ca3a29492f52eba44d36c9538b21bda62","a1cb891d6d5f9723a2901a04f187ba4d539a0a66b5982d5154cf11e0dc2e6ac4"],"salt":"df2cce9c7c950933c466ba100c1682a7fb4a4cc58d4d7363a892bcb608b11543","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"bio.supercooled-water.ambient-response-maxima","kind":"well-posed","literature_status":"contested","n":"1","parents":[{"note":"Widom-line test of ambient maxima is a sharper version of anomaly origin","parent_revision":"7634b50edcbbf83ae2f2e94062090f3ca3a29492f52eba44d36c9538b21bda62","relation":"special_case"},{"note":"","parent_revision":"a1cb891d6d5f9723a2901a04f187ba4d539a0a66b5982d5154cf11e0dc2e6ac4","relation":"special_case"}],"plain":"Measurements on tiny falling droplets of supercooled water found peaks in compressibility near 229 K at ordinary pressure. Whether these peaks are a sign of a critical point at higher pressure or have another cause is not settled.","posed_since":"","precise":"X-ray scattering on evaporatively cooled micro-droplets (2017) reported maxima of the isothermal compressibility $\\kappa_{T}$ and correlation length near 229 K at 1 bar. Determine whether these maxima lie on a Widom line (locus of response-function maxima emanating from an LLCP) by measuring $\\kappa_{T}(T)$ and the correlation length along several isobars up to about $1e9\\ \\mathrm{dyn}/\\mathrm{cm}^2$ and testing the growth of the maxima toward a critical point.","problem_ref":null,"references":"","settled_by":"Isobaric measurements showing the response maxima growing and converging toward a critical point, or remaining finite and inconsistent with an LLCP.","status_note":"A 2026 ultrafast X-ray experiment (You et al., Science 2026) reported critical behavior near 210 K, consistent with the Widom-line reading, but isobaric tracking of the maxima toward the critical point has not been done.","title":"Are water's compressibility maxima at 1 bar a Widom line","topic_ref":"b1cabd44310015cc3941b7af0461d416e3c8ad464f6c3ad6f6fdbf54214bd97e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c036a904ef78114e976ed53a6b2fee8b062c2940aa55f97bbd485710272feeb8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"38b7d9a25711054b4b5230204cb064f6e04991b59cf8f2bc823bd4ed18fccd7d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"y5BiZWRHfHjFKsfWE2sb91jRfIa2lVYMHJCdaOnxd9NV7c7WwbnZ4aRpoAS2ZdQcmo37hg0q8r6cY8rX4-GiDQ"},"schema":"pubphys.envelope/1"},"record_hash":"c036a904ef78114e976ed53a6b2fee8b062c2940aa55f97bbd485710272feeb8","leaf_index":873}