{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:VPHPFALCBTFDRHFI7ZSXJ3GKDV","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":"48aec909f7a1eccd781cbdb346071dd642c605736535562bef2beb5d631e60a5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2017-01-31T09:12:47Z","title_canon_sha256":"0eea209fd0cd275ecb65102f961e3f98074ba067a6fe2deddfee01d94746388f"},"schema_version":"1.0","source":{"id":"1701.08953","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1701.08953","created_at":"2026-05-18T00:51:38Z"},{"alias_kind":"arxiv_version","alias_value":"1701.08953v1","created_at":"2026-05-18T00:51:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1701.08953","created_at":"2026-05-18T00:51:38Z"},{"alias_kind":"pith_short_12","alias_value":"VPHPFALCBTFD","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_16","alias_value":"VPHPFALCBTFDRHFI","created_at":"2026-05-18T12:31:49Z"},{"alias_kind":"pith_short_8","alias_value":"VPHPFALC","created_at":"2026-05-18T12:31:49Z"}],"graph_snapshots":[{"event_id":"sha256:3888d083d85da27043c043b8f4dcacc86adbb7e5d86cd2933355592cd376d9b7","target":"graph","created_at":"2026-05-18T00:51:38Z","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"},"paper":{"abstract_excerpt":"Rampino & Caldeira (2015) carry out a circular spectral analysis (CSA) of the terrestrial impact cratering record over the past 260 million years (Ma), and suggest a ~26 Ma periodicity of impact events. For some of the impacts in that analysis, new accurate and high-precision (\"robust\"; 2SE<2%) 40Ar-39Ar ages have recently been published, resulting in significant age shifts. In a CSA of the updated impact age list, the periodicity is strongly reduced. In a CSA of a list containing only impacts with robust ages, we find no significant periodicity for the last 500 Ma. We show that if we relax th","authors_text":"22362 Lund, (2) Lund University, 8092 Zurich, Clausiusstrasse 25, Department of Geology, Institute of Geochemistry, Matthias M. M. Meier (1), Petrology, Sanna Holm-Alwmark (2) ((1) ETH Zurich, S\\\"olvegatan 12, Sweden), Switzerland","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2017-01-31T09:12:47Z","title":"A tale of clusters: No resolvable periodicity in the terrestrial impact cratering record"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1701.08953","kind":"arxiv","version":1},"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:e1ba675ffb0316882e977e7f9bf7a9db83e3844bf90fc1e5dd46593e17940f66","target":"record","created_at":"2026-05-18T00:51:38Z","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":"48aec909f7a1eccd781cbdb346071dd642c605736535562bef2beb5d631e60a5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2017-01-31T09:12:47Z","title_canon_sha256":"0eea209fd0cd275ecb65102f961e3f98074ba067a6fe2deddfee01d94746388f"},"schema_version":"1.0","source":{"id":"1701.08953","kind":"arxiv","version":1}},"canonical_sha256":"abcef281620cca389ca8fe6574ecca1d661bac210dcb649649e7d0967b907852","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"abcef281620cca389ca8fe6574ecca1d661bac210dcb649649e7d0967b907852","first_computed_at":"2026-05-18T00:51:38.810590Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:51:38.810590Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"dKmCfalX/A9RlCDMBHte0FjugkviXVeFHDMk7F5nV38u/LOsLAWL/Bp0sGUXZWiwrQyp8wO+kq17kVrArS/jBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:51:38.810939Z","signed_message":"canonical_sha256_bytes"},"source_id":"1701.08953","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e1ba675ffb0316882e977e7f9bf7a9db83e3844bf90fc1e5dd46593e17940f66","sha256:3888d083d85da27043c043b8f4dcacc86adbb7e5d86cd2933355592cd376d9b7"],"state_sha256":"63742b6f756ee2245a022da16367ab5c4ecd180ec308179cc889567d963e6a96"}