{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"6547b2f229d5aeea2f3b0e2ae9613ba3e0af36780b06dce70879ca3d92a85350","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["c036a904ef78114e976ed53a6b2fee8b062c2940aa55f97bbd485710272feeb8","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"346659d402e396217fb2c0f77220a0ad1dc09e2d55475042a0c3de723f4124ff","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":"2","parents":[],"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 $10^{9}\\ \\mathrm{dyn}/\\mathrm{cm}^2$ and testing the growth of the maxima toward a critical point.","problem_ref":"c036a904ef78114e976ed53a6b2fee8b062c2940aa55f97bbd485710272feeb8","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"ce824db3afd4f6f03548a00acbd2ae126c9062904e51b0b32dc478a1a884cd0b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"40699e265b0277cc801ebc907258e5dd4dd757629d94d6bd9e4c7806ab075e1e","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"WQYreIpOo8Jr7cjXPjuAuuJXykVgxsN40NUNXio4omnhCiv1yuuj0oELvVPov9ql5tHy_DUaRY_eWmTgokmvDg"},"schema":"pubphys.envelope/1"},"record_hash":"ce824db3afd4f6f03548a00acbd2ae126c9062904e51b0b32dc478a1a884cd0b","leaf_index":2630}