{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"370218d2f5a16a70e481513df258c89962f5422c0a310e8955f12b2afff6be83","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["1505e833e79f89b0470e69ae66964130d3b7976c65fa5488c5c3277221511966","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"a0d8153c373f73d5bd3bf63e7774cc649a42bc68e508f8424f86684937f26052","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"amo.constant-variation.quasar-alpha-dipole","kind":"phenomenon","literature_status":"contested","n":"2","parents":[],"plain":"Light from distant quasars passes through gas clouds that absorb at wavelengths set by $\\alpha$ at that place and time. Some analyses claimed $\\alpha$ differs slightly in opposite directions on the sky, while newer instruments see no change.","posed_since":"2011","precise":"Many-multiplet analyses of Keck and VLT spectra (Webb et al 2011) reported a dipole in $\\Delta \\alpha/\\alpha$ of order $10^{-5}$ across the sky at about $4\\sigma$; ESPRESSO measurements (Murphy et al 2022) found $\\Delta \\alpha/\\alpha = (1.3 \\pm 1.3\\,\\mathrm{stat} \\pm 0.4\\,\\mathrm{sys})\\,\\mathrm{ppm}$ toward HE0515-4414. Establish whether any spatial or redshift variation of $\\alpha$ exists at the $1\\,\\mathrm{ppm}$ level once wavelength-calibration, isotopic-abundance and blinding systematics are controlled.","problem_ref":"1505e833e79f89b0470e69ae66964130d3b7976c65fa5488c5c3277221511966","references":"","settled_by":"A blinded ESPRESSO, ANDES or ELT survey of many absorbers across the sky with sub-ppm per-system precision and laser-comb calibration.","status_note":"A 2024 reanalysis claimed a $7\\sigma$ difference between two absorbers toward HE0515-4414 if Mg isotopic abundances are terrestrial; this depends on the assumed isotope ratios and is disputed.","title":"Is there a spatial dipole in $\\alpha$ from quasar absorption spectra?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"eaa60b670998cdb9451b3d04aec093e19d3e1c12619f5418d12821e9ba6cb50f","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"79888a52d61ad010a52741f757ad09a33658daf2fea4624346879bdcdd9791cb","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"yhUvi5n4A_eoDvjp6zPR2xirq1za3s-cXeuOyXDSjflEK4AwZYudr3ag-JwBHY8HXIt3UiXoUyrGTCxLs1WfDw"},"schema":"pubphys.envelope/1"},"record_hash":"eaa60b670998cdb9451b3d04aec093e19d3e1c12619f5418d12821e9ba6cb50f","leaf_index":2212}