{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"5c1f4ad6a3536425c76bc7c916a5f43b9c78c69f5bda193cc6cf223513e43b3a","created":"2026-10-03T07:17:56Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1855e4b991f6a20c2e5cda6061d256d1e27ed31b462add3a4cb71a5d4a7071a1","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":"1","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 1e-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":null,"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":"e78bfe90db080ebe4f05460ebebe6c1ecd9eb9abbe035dcdb9122cce699033c5"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1c3364fad38a9264f1c1c63fc0d08ef074cdaf45e68af230cd54322df2d86c24","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"92bad16c36ac2fb7c49fb74f3f5c6446eff503ced10072327dbf26ff3d243c6a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"pFXs9zSNpw-98VNGfU2M4gYAgNzytapgRUN7HVahCLlZmOaXZjBpMW7KvR5nVEZmGH5d80P-g7Q7SbqTRzsXAQ"},"schema":"pubphys.envelope/1"},"record_hash":"1c3364fad38a9264f1c1c63fc0d08ef074cdaf45e68af230cd54322df2d86c24","leaf_index":729}