{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"076da03738ee5f0d504860702179c8a0eff34e3a90eb492d39ccbc8c80055303","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["1c3364fad38a9264f1c1c63fc0d08ef074cdaf45e68af230cd54322df2d86c24","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"d4486067f5bfeb37dd5f7e7167924a707bc7418e0cca7b128b4777178db3e0cd","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"bio.amorphous-plasticity.silica-nanoductility","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"Window glass breaks in a brittle way, but microscope images in 2003 suggested that tiny cavities open ahead of a slowly moving crack, as in a metal. Later work found no such cavities, and whether glass is ductile at the nanometer scale is disputed.","posed_since":"2003","precise":"For slow stress-corrosion cracks in silica and aluminosilicate glasses, determine whether crack advance involves a plastic process zone with nanocavities of size about $10^{-6}$ cm ahead of the tip, or atom-by-atom bond rupture with a process zone of a few bond lengths. An answer gives the process-zone size and the fraction of fracture energy dissipated plastically, from in situ imaging or matched fracture-surface analysis and simulations with reliable silica potentials.","problem_ref":"1c3364fad38a9264f1c1c63fc0d08ef074cdaf45e68af230cd54322df2d86c24","references":"","settled_by":"In situ, nanometer-resolution imaging of a propagating crack tip in silica, or matched-surface topography with sub-nanometer resolution, consistent with large-scale atomistic simulations.","status_note":"Nanocavities reported by atomic force microscopy in 2003 (Celarie et al., Phys. Rev. Lett., https://doi.org/10.1103/PhysRevLett.90.075504) were not found by matched fracture-surface analysis in 2004 (Guin and Wiederhorn, https://doi.org/10.1103/PhysRevLett.92.215502).","title":"Is fracture of oxide glasses ductile at the nanometer scale?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"4de27caeb67991d2a66ed5df0724d468c64270c4fc6db96ae5ea5746d13c312c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"de2928f342695f61b441bc4a449d1e9a071db85aa491f462e140ee5ca594791a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"X5X9TkOiTtp8Km0JeFcDCoKPZKEoIzusn_4HSeEhvfuCPQ1AOmayJ4G9uK6rFDz_kdCn_oopGQOx6vCsdhOtBg"},"schema":"pubphys.envelope/1"},"record_hash":"4de27caeb67991d2a66ed5df0724d468c64270c4fc6db96ae5ea5746d13c312c","leaf_index":2556}