{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2000:ZNO3ZFH57DW2HSEBN3TOSOK4EU","short_pith_number":"pith:ZNO3ZFH5","canonical_record":{"source":{"id":"astro-ph/0012420","kind":"arxiv","version":4},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2000-12-20T06:11:02Z","cross_cats_sorted":[],"title_canon_sha256":"3f9c62c9b53bf99d124c7783b152e59e7daa9635acaec93464d55bfca615377e","abstract_canon_sha256":"1d510bdbfe8336fd8d0e3a37ba1c1d694fc4d76d08d7652bb149ce482beb7be3"},"schema_version":"1.0"},"canonical_sha256":"cb5dbc94fdf8eda3c8816ee6e9395c253f81e90da30d5fa532bc95e318f74e14","source":{"kind":"arxiv","id":"astro-ph/0012420","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0012420","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0012420v4","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0012420","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_12","alias_value":"ZNO3ZFH57DW2","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_16","alias_value":"ZNO3ZFH57DW2HSEB","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_8","alias_value":"ZNO3ZFH5","created_at":"2026-07-04T15:48:02Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2000:ZNO3ZFH57DW2HSEBN3TOSOK4EU","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0012420","kind":"arxiv","version":4},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2000-12-20T06:11:02Z","cross_cats_sorted":[],"title_canon_sha256":"3f9c62c9b53bf99d124c7783b152e59e7daa9635acaec93464d55bfca615377e","abstract_canon_sha256":"1d510bdbfe8336fd8d0e3a37ba1c1d694fc4d76d08d7652bb149ce482beb7be3"},"schema_version":"1.0"},"canonical_sha256":"cb5dbc94fdf8eda3c8816ee6e9395c253f81e90da30d5fa532bc95e318f74e14","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T15:48:02.103710Z","signature_b64":"yGgbV417Yv0vRwP0hidSkBvSFUeW8RtP7u8iAMYjT2ghY/i7wUO4FUZrOcUEs5INXjOAyKucP3BERH1/tM4rBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"cb5dbc94fdf8eda3c8816ee6e9395c253f81e90da30d5fa532bc95e318f74e14","last_reissued_at":"2026-07-04T15:48:02.103334Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T15:48:02.103334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0012420","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T15:48:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qioG250jyuUk8lzQNJjDHJ0FmuxfR0S6YKqiwUdvuXoVg3wh2L7eCgG763+Qatz+OqnKAuOWy1JRFdmb0QnUCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T17:00:51.680209Z"},"content_sha256":"40d5ed007b02675a4ed404b8535556009da3bef9920c3cd8e4d779f1596c0647","schema_version":"1.0","event_id":"sha256:40d5ed007b02675a4ed404b8535556009da3bef9920c3cd8e4d779f1596c0647"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2000:ZNO3ZFH57DW2HSEBN3TOSOK4EU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Possible evidence for a variable fine structure constant from QSO absorption lines: systematic errors","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"C. W. Churchill (PSU), J. K. Webb (UNSW), J. X. Prochaska (OCIW), M. T. Murphy (UNSW), V. V. Flambaum (UNSW)","submitted_at":"2000-12-20T06:11:02Z","abstract_excerpt":"Comparison of quasar absorption spectra with laboratory spectra allow us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we present an analysis of Keck/HIRES spectra and report possible evidence suggesting that the fine structure constant, alpha, may have been smaller in the past: da/a = (-0.72 +/- 0.18) * 10^{-5} over the redshift range 0.5 < z < 3.5. In this paper we describe a comprehensive investigation into possible systematic effects. Most of these do not significantly influence our results. When we correct for those which do "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0012420","kind":"arxiv","version":4},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/astro-ph/0012420/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T15:48:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"s49wGsSA/ZgT7+78SSCt9aVVyw+z6IzWCLqlYGR+5yuKgZC/czodAZeq/ClP9/Co+D56WwTGABomQf4XxzuxAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T17:00:51.680593Z"},"content_sha256":"8fa2e6e7f027ec4d9b74fc17fcb130979be84b051459e82c9a5ee364de504322","schema_version":"1.0","event_id":"sha256:8fa2e6e7f027ec4d9b74fc17fcb130979be84b051459e82c9a5ee364de504322"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/bundle.json","state_url":"https://pith.science/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-06T17:00:51Z","links":{"resolver":"https://pith.science/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU","bundle":"https://pith.science/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/bundle.json","state":"https://pith.science/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ZNO3ZFH57DW2HSEBN3TOSOK4EU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2000:ZNO3ZFH57DW2HSEBN3TOSOK4EU","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"1d510bdbfe8336fd8d0e3a37ba1c1d694fc4d76d08d7652bb149ce482beb7be3","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2000-12-20T06:11:02Z","title_canon_sha256":"3f9c62c9b53bf99d124c7783b152e59e7daa9635acaec93464d55bfca615377e"},"schema_version":"1.0","source":{"id":"astro-ph/0012420","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0012420","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0012420v4","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0012420","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_12","alias_value":"ZNO3ZFH57DW2","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_16","alias_value":"ZNO3ZFH57DW2HSEB","created_at":"2026-07-04T15:48:02Z"},{"alias_kind":"pith_short_8","alias_value":"ZNO3ZFH5","created_at":"2026-07-04T15:48:02Z"}],"graph_snapshots":[{"event_id":"sha256:8fa2e6e7f027ec4d9b74fc17fcb130979be84b051459e82c9a5ee364de504322","target":"graph","created_at":"2026-07-04T15:48:02Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/astro-ph/0012420/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Comparison of quasar absorption spectra with laboratory spectra allow us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we present an analysis of Keck/HIRES spectra and report possible evidence suggesting that the fine structure constant, alpha, may have been smaller in the past: da/a = (-0.72 +/- 0.18) * 10^{-5} over the redshift range 0.5 < z < 3.5. In this paper we describe a comprehensive investigation into possible systematic effects. Most of these do not significantly influence our results. When we correct for those which do ","authors_text":"C. W. Churchill (PSU), J. K. Webb (UNSW), J. X. Prochaska (OCIW), M. T. Murphy (UNSW), V. V. Flambaum (UNSW)","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2000-12-20T06:11:02Z","title":"Possible evidence for a variable fine structure constant from QSO absorption lines: systematic errors"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0012420","kind":"arxiv","version":4},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:40d5ed007b02675a4ed404b8535556009da3bef9920c3cd8e4d779f1596c0647","target":"record","created_at":"2026-07-04T15:48:02Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"1d510bdbfe8336fd8d0e3a37ba1c1d694fc4d76d08d7652bb149ce482beb7be3","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2000-12-20T06:11:02Z","title_canon_sha256":"3f9c62c9b53bf99d124c7783b152e59e7daa9635acaec93464d55bfca615377e"},"schema_version":"1.0","source":{"id":"astro-ph/0012420","kind":"arxiv","version":4}},"canonical_sha256":"cb5dbc94fdf8eda3c8816ee6e9395c253f81e90da30d5fa532bc95e318f74e14","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"cb5dbc94fdf8eda3c8816ee6e9395c253f81e90da30d5fa532bc95e318f74e14","first_computed_at":"2026-07-04T15:48:02.103334Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T15:48:02.103334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"yGgbV417Yv0vRwP0hidSkBvSFUeW8RtP7u8iAMYjT2ghY/i7wUO4FUZrOcUEs5INXjOAyKucP3BERH1/tM4rBQ==","signature_status":"signed_v1","signed_at":"2026-07-04T15:48:02.103710Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0012420","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:40d5ed007b02675a4ed404b8535556009da3bef9920c3cd8e4d779f1596c0647","sha256:8fa2e6e7f027ec4d9b74fc17fcb130979be84b051459e82c9a5ee364de504322"],"state_sha256":"1dd371ac4bb55242d433ccfa016b8983b064270138a55d58286f95ac5b9353c9"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lnAWDPTEXVHLgtBwuvDHiRQd6mAA/URTr/h6XA3yY4MA6qBgXlywKMKndunh1VEKv26H67haKhMTDkJ2iwVlBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-06T17:00:51.682724Z","bundle_sha256":"8b429e5926d1b3162e3e1dd4420e37570863277c69d71fec4b628105efdde824"}}