{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2015:PWBMB32JFN7GMUWQZRIABDCQHX","short_pith_number":"pith:PWBMB32J","schema_version":"1.0","canonical_sha256":"7d82c0ef492b7e6652d0cc50008c503dc0e343701b6fcc7a21f4963bbb8baa7f","source":{"kind":"arxiv","id":"1502.07671","version":1},"attestation_state":"computed","paper":{"title":"South Pointing Chariot: An Invitation to Differential Geometry","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.DG"],"primary_cat":"math.HO","authors_text":"Stephen Sawin","submitted_at":"2015-02-24T22:19:18Z","abstract_excerpt":"We introduce the south-pointing chariot, an intriguing mechanical device from ancient China. We use its ability to keep track of a global direction as it travels on an arbitrary path as a tool to explore the geometry of curved surfaces. This takes us as far as a famous result of Gauss on the impossibility of a faithful map of the globe, which started off the field of differential geometry. The reader should get a view into how geometers think and an introduction to important early results in the field, but should need no more than a solid background in calculus (ideally through multivariable c"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1502.07671","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.HO","submitted_at":"2015-02-24T22:19:18Z","cross_cats_sorted":["math.DG"],"title_canon_sha256":"b645257734cc1bf17fa890f6ca3f04e850d998b3d39b97f3f17028eba1d80de5","abstract_canon_sha256":"18da0c54b6346185fcc39a2e812e259c3f3726f2b3e6992b0eb59797247a9433"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:26:03.155841Z","signature_b64":"QAIx+PSI2banRmlQQ/RoPh176z+WoGh36Vald66l+i+ESavYJ+wW7r/2EyVr1qhIu+614BLhaWO/6g4Yjr5pAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7d82c0ef492b7e6652d0cc50008c503dc0e343701b6fcc7a21f4963bbb8baa7f","last_reissued_at":"2026-05-18T02:26:03.155250Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:26:03.155250Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"South Pointing Chariot: An Invitation to Differential Geometry","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.DG"],"primary_cat":"math.HO","authors_text":"Stephen Sawin","submitted_at":"2015-02-24T22:19:18Z","abstract_excerpt":"We introduce the south-pointing chariot, an intriguing mechanical device from ancient China. We use its ability to keep track of a global direction as it travels on an arbitrary path as a tool to explore the geometry of curved surfaces. This takes us as far as a famous result of Gauss on the impossibility of a faithful map of the globe, which started off the field of differential geometry. The reader should get a view into how geometers think and an introduction to important early results in the field, but should need no more than a solid background in calculus (ideally through multivariable c"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.07671","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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1502.07671","created_at":"2026-05-18T02:26:03.155320+00:00"},{"alias_kind":"arxiv_version","alias_value":"1502.07671v1","created_at":"2026-05-18T02:26:03.155320+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1502.07671","created_at":"2026-05-18T02:26:03.155320+00:00"},{"alias_kind":"pith_short_12","alias_value":"PWBMB32JFN7G","created_at":"2026-05-18T12:29:37.295048+00:00"},{"alias_kind":"pith_short_16","alias_value":"PWBMB32JFN7GMUWQ","created_at":"2026-05-18T12:29:37.295048+00:00"},{"alias_kind":"pith_short_8","alias_value":"PWBMB32J","created_at":"2026-05-18T12:29:37.295048+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX","json":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX.json","graph_json":"https://pith.science/api/pith-number/PWBMB32JFN7GMUWQZRIABDCQHX/graph.json","events_json":"https://pith.science/api/pith-number/PWBMB32JFN7GMUWQZRIABDCQHX/events.json","paper":"https://pith.science/paper/PWBMB32J"},"agent_actions":{"view_html":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX","download_json":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX.json","view_paper":"https://pith.science/paper/PWBMB32J","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1502.07671&json=true","fetch_graph":"https://pith.science/api/pith-number/PWBMB32JFN7GMUWQZRIABDCQHX/graph.json","fetch_events":"https://pith.science/api/pith-number/PWBMB32JFN7GMUWQZRIABDCQHX/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX/action/timestamp_anchor","attest_storage":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX/action/storage_attestation","attest_author":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX/action/author_attestation","sign_citation":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX/action/citation_signature","submit_replication":"https://pith.science/pith/PWBMB32JFN7GMUWQZRIABDCQHX/action/replication_record"}},"created_at":"2026-05-18T02:26:03.155320+00:00","updated_at":"2026-05-18T02:26:03.155320+00:00"}