{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:Z6HYRGFNON5J7KSIKMXNL3OUVG","short_pith_number":"pith:Z6HYRGFN","canonical_record":{"source":{"id":"1901.06260","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2019-01-17T06:31:21Z","cross_cats_sorted":[],"title_canon_sha256":"2d12bb33ee267ef4c41b8030f1cada8028603fc19e79cc05bc44da91735967d0","abstract_canon_sha256":"f197c3c9768ea32ecdf5929901d54864b753fcffec87efe88ff9d39c4e3dfedc"},"schema_version":"1.0"},"canonical_sha256":"cf8f8898ad737a9faa48532ed5edd4a9acae1edf0b0872f45ac2e470af2c2804","source":{"kind":"arxiv","id":"1901.06260","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.06260","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"arxiv_version","alias_value":"1901.06260v1","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.06260","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"pith_short_12","alias_value":"Z6HYRGFNON5J","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"Z6HYRGFNON5J7KSI","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"Z6HYRGFN","created_at":"2026-05-18T12:33:33Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:Z6HYRGFNON5J7KSIKMXNL3OUVG","target":"record","payload":{"canonical_record":{"source":{"id":"1901.06260","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2019-01-17T06:31:21Z","cross_cats_sorted":[],"title_canon_sha256":"2d12bb33ee267ef4c41b8030f1cada8028603fc19e79cc05bc44da91735967d0","abstract_canon_sha256":"f197c3c9768ea32ecdf5929901d54864b753fcffec87efe88ff9d39c4e3dfedc"},"schema_version":"1.0"},"canonical_sha256":"cf8f8898ad737a9faa48532ed5edd4a9acae1edf0b0872f45ac2e470af2c2804","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:56:01.580455Z","signature_b64":"E7tX6+PlPnT8e35KF33FqYAIDuC9ZTduYExaR5MLGFOysMfqViQyHBso8A/Qx/FvP2FYQs7YMwvcsP6oTxNCBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"cf8f8898ad737a9faa48532ed5edd4a9acae1edf0b0872f45ac2e470af2c2804","last_reissued_at":"2026-05-17T23:56:01.579876Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:56:01.579876Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1901.06260","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:56:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UsiEjjSwxnuHvxpOHX2Ef6e3Karip59tQK0/1cGXvbJHWrJCASc8TXeAJEiKXN8sgMK0dpfptcnwaZhwt8oUAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-29T22:47:59.715644Z"},"content_sha256":"e320e87603f41b651de1d57aa6de6a7a00be2a85431141799d2331d3f1107406","schema_version":"1.0","event_id":"sha256:e320e87603f41b651de1d57aa6de6a7a00be2a85431141799d2331d3f1107406"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:Z6HYRGFNON5J7KSIKMXNL3OUVG","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Throwing $\\pi$ at a wall","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.class-ph","authors_text":"D. Dobie, M. Z. Rafat","submitted_at":"2019-01-17T06:31:21Z","abstract_excerpt":"We discuss a method for calculating $ \\pi $ using elastic collision between two masses $ M $ and $ m $, with $ X = m/M = 10^{2(1-d)} $ where $ d $ is an integer, and a wall. The total number of collisions between $ M $, $ m $ and the wall corresponds to the first $ d $ digits of $ \\pi $."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.06260","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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":"2026-05-17T23:56:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hKofYl1amfA+GCOnr2YlrmzFnrA3nQZOu5w4FZ9rsJIkvzbxNOurQN/B35XmDhaTgQxN1TgTWXiWPKrYWoSdCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-29T22:47:59.716045Z"},"content_sha256":"ffc955f8bcb1c29af0a92ce49baa5de6272f49910a57e024832d0af150289228","schema_version":"1.0","event_id":"sha256:ffc955f8bcb1c29af0a92ce49baa5de6272f49910a57e024832d0af150289228"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/bundle.json","state_url":"https://pith.science/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/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":"2026-05-29T22:47:59Z","links":{"resolver":"https://pith.science/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG","bundle":"https://pith.science/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/bundle.json","state":"https://pith.science/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/state.json","well_known_bundle":"https://pith.science/.well-known/pith/Z6HYRGFNON5J7KSIKMXNL3OUVG/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:Z6HYRGFNON5J7KSIKMXNL3OUVG","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":"f197c3c9768ea32ecdf5929901d54864b753fcffec87efe88ff9d39c4e3dfedc","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2019-01-17T06:31:21Z","title_canon_sha256":"2d12bb33ee267ef4c41b8030f1cada8028603fc19e79cc05bc44da91735967d0"},"schema_version":"1.0","source":{"id":"1901.06260","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.06260","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"arxiv_version","alias_value":"1901.06260v1","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.06260","created_at":"2026-05-17T23:56:01Z"},{"alias_kind":"pith_short_12","alias_value":"Z6HYRGFNON5J","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"Z6HYRGFNON5J7KSI","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"Z6HYRGFN","created_at":"2026-05-18T12:33:33Z"}],"graph_snapshots":[{"event_id":"sha256:ffc955f8bcb1c29af0a92ce49baa5de6272f49910a57e024832d0af150289228","target":"graph","created_at":"2026-05-17T23:56:01Z","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":"We discuss a method for calculating $ \\pi $ using elastic collision between two masses $ M $ and $ m $, with $ X = m/M = 10^{2(1-d)} $ where $ d $ is an integer, and a wall. The total number of collisions between $ M $, $ m $ and the wall corresponds to the first $ d $ digits of $ \\pi $.","authors_text":"D. Dobie, M. Z. Rafat","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2019-01-17T06:31:21Z","title":"Throwing $\\pi$ at a wall"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.06260","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:e320e87603f41b651de1d57aa6de6a7a00be2a85431141799d2331d3f1107406","target":"record","created_at":"2026-05-17T23:56:01Z","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":"f197c3c9768ea32ecdf5929901d54864b753fcffec87efe88ff9d39c4e3dfedc","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2019-01-17T06:31:21Z","title_canon_sha256":"2d12bb33ee267ef4c41b8030f1cada8028603fc19e79cc05bc44da91735967d0"},"schema_version":"1.0","source":{"id":"1901.06260","kind":"arxiv","version":1}},"canonical_sha256":"cf8f8898ad737a9faa48532ed5edd4a9acae1edf0b0872f45ac2e470af2c2804","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"cf8f8898ad737a9faa48532ed5edd4a9acae1edf0b0872f45ac2e470af2c2804","first_computed_at":"2026-05-17T23:56:01.579876Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:56:01.579876Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"E7tX6+PlPnT8e35KF33FqYAIDuC9ZTduYExaR5MLGFOysMfqViQyHBso8A/Qx/FvP2FYQs7YMwvcsP6oTxNCBA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:56:01.580455Z","signed_message":"canonical_sha256_bytes"},"source_id":"1901.06260","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e320e87603f41b651de1d57aa6de6a7a00be2a85431141799d2331d3f1107406","sha256:ffc955f8bcb1c29af0a92ce49baa5de6272f49910a57e024832d0af150289228"],"state_sha256":"9f74457333ebccd312e9a6ab2118aafad2c6c127f11dd81c1cda88907aa440dd"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hcvidALp3+ezdDysxSkGwmGyNmPPu+xlN5ZhZzkGmA/B+ZrjcvW0bXQSo2ESVg4/VPY8KAy2g5puUmlH2nJsCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-29T22:47:59.718687Z","bundle_sha256":"d13e979fffda476060bb931bbe376f82e1436db23b9d0ed7a395d716b8402ca2"}}