{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e4aeb5b3e7697b7817f329e1fd0820267b01a8c1b4336f59f1d2f17eb6e4f87f","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["6940f710bc7dec5b646561f27928a76523ff3ef5c6e6ea56b2754d0e8fb97837","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"60df91ab0a43a5e8b3959a86c1e1805690accd7e86e95794131b731dfe2b4e6a","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":"2","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":"6940f710bc7dec5b646561f27928a76523ff3ef5c6e6ea56b2754d0e8fb97837","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"01653b1eb5d42f43774985f0b8462e0f56b55422be120cbce08eca65b04e0d73","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"ab49f1bb75525b423640e83390b8f9f07b814957ae499e22e13e6e116227f9c8","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"jO9_w24X5zwxZPy0V6oRJQ9G6KjaC6jzPLm-GFkgnE5EpLUCllFmW01VNABtkDYGCjX5QM7W4IaKywAFWXNCDQ"},"schema":"pubphys.envelope/1"},"record_hash":"01653b1eb5d42f43774985f0b8462e0f56b55422be120cbce08eca65b04e0d73","leaf_index":2864}