{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"4c6cf864366a63f9ef5cdc836109465d677ce53541a23f08e71a1206c4f550ef","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"5256e91ac20721119ae68a4aa466723cc9841f16b33f5559708ce7743dbf453e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.hydrides.metallic-hydrogen-tc","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Because hydrogen atoms are so light their vibrations are fast, and theory predicts that metallic hydrogen could superconduct near or above room temperature.","posed_since":"1968","precise":"Determine whether metallic solid hydrogen (molecular or atomic phase, pressure above $\\sim 4\\,\\mathrm{Mbar}$) superconducts and measure $T_c(P)$; calculations give $T_c$ from about 100 K to above room temperature depending on phase and pressure. An answer is a resistive and magnetic transition at a calibrated pressure, or a bound excluding superconductivity above a stated temperature.","problem_ref":null,"references":"","settled_by":"Four-probe transport and magnetic measurements on metallic hydrogen in a diamond anvil cell showing a field-dependent transition.","status_note":"","title":"Does metallic hydrogen superconduct, and at what temperature","topic_ref":"d8f6a90ffa2d9797ae166bd4e51b07a319dd484720f9647530fc1647474424b6"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"6940f710bc7dec5b646561f27928a76523ff3ef5c6e6ea56b2754d0e8fb97837","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d928af8f60dd8fe9da8976ca89847a4a95eca25506c8dca2aee8df2fe6c08304","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"tnbd3w3xPjd2og_LCLG3Z8K1baT2z1qpRbSxVa3SHsjdXCS433RDr_2YQb6h3ciR2OB5TLTFJwW4cnLSt_cNDQ"},"schema":"pubphys.envelope/1"},"record_hash":"6940f710bc7dec5b646561f27928a76523ff3ef5c6e6ea56b2754d0e8fb97837","leaf_index":1034}