{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2023:BUYKIAK3MGRVJKVOOGH457BM2B","short_pith_number":"pith:BUYKIAK3","canonical_record":{"source":{"id":"2305.10470","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"gr-qc","submitted_at":"2023-05-17T14:52:13Z","cross_cats_sorted":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"title_canon_sha256":"83a569f54683a1e8bf47caf40551f8283de3f7d62b45ead1d9a2a69fb227f525","abstract_canon_sha256":"bb2f02f8f635b0dfd043b5f63e9436e801cedc06fbf6beadf7e95eb98d5bfd60"},"schema_version":"1.0"},"canonical_sha256":"0d30a4015b61a354aaae718fcefc2cd056206c584073caf274c6c641cbd06091","source":{"kind":"arxiv","id":"2305.10470","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2305.10470","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"arxiv_version","alias_value":"2305.10470v1","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2305.10470","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_12","alias_value":"BUYKIAK3MGRV","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_16","alias_value":"BUYKIAK3MGRVJKVO","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_8","alias_value":"BUYKIAK3","created_at":"2026-07-05T06:11:23Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2023:BUYKIAK3MGRVJKVOOGH457BM2B","target":"record","payload":{"canonical_record":{"source":{"id":"2305.10470","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"gr-qc","submitted_at":"2023-05-17T14:52:13Z","cross_cats_sorted":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"title_canon_sha256":"83a569f54683a1e8bf47caf40551f8283de3f7d62b45ead1d9a2a69fb227f525","abstract_canon_sha256":"bb2f02f8f635b0dfd043b5f63e9436e801cedc06fbf6beadf7e95eb98d5bfd60"},"schema_version":"1.0"},"canonical_sha256":"0d30a4015b61a354aaae718fcefc2cd056206c584073caf274c6c641cbd06091","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T06:11:23.022185Z","signature_b64":"xVm+2asK2L/+smASrIyO3aLkK5XkEv6yiFLPWVbTAJ/AjrlkeKH8p3hpY2PRgMye+F4lC8jH8uEpQU1z2/kTCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0d30a4015b61a354aaae718fcefc2cd056206c584073caf274c6c641cbd06091","last_reissued_at":"2026-07-05T06:11:23.021772Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T06:11:23.021772Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2305.10470","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":"2026-07-05T06:11:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"W094LfLvkJfCyO4I8aejufLIb+P4k0dDX1IoR6mmeA6RN9HDyfFmmuUidDL6gsq1HzJ213s7kThqjU0m5Y4mAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T06:56:56.963997Z"},"content_sha256":"eb21f0b09b4ff4e39fb64953c8f2a73b54b5bd53a657a7ffe16975e06dd62628","schema_version":"1.0","event_id":"sha256:eb21f0b09b4ff4e39fb64953c8f2a73b54b5bd53a657a7ffe16975e06dd62628"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2023:BUYKIAK3MGRVJKVOOGH457BM2B","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Gravitational Machines","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","headline":"","cross_cats":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"primary_cat":"gr-qc","authors_text":"Freeman J. Dyson","submitted_at":"2023-05-17T14:52:13Z","abstract_excerpt":"A gravitational machine is defined as an arrangement of gravitating masses from which useful energy can be extracted. It is shown that such machines may exist if the masses are of normal astronomical size. A simple example of a gravitational machine, consisting of a double star with smaller masses orbiting around it, is described. It is shown that an efficient gravitational machine will also be an emitter of gravitational radiation. The emitted radiation sets a limit on the possible performance of gravitational machines, and also provides us with a possible means for detecting such machines if"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2305.10470","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2305.10470/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":"2026-07-05T06:11:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"3jS7PfCHXxWNSm+iQrJC+fUhwylj8rKFe2YDSOCeqbG/FimuQKy4ETSjUoQUPUg0xSY4vt1v+N4LTRd0cOOGDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T06:56:56.964538Z"},"content_sha256":"ee0f5bd7167650cf503491da9d4a25ceb96eca43fda957020384ffdf8eff5ac4","schema_version":"1.0","event_id":"sha256:ee0f5bd7167650cf503491da9d4a25ceb96eca43fda957020384ffdf8eff5ac4"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/BUYKIAK3MGRVJKVOOGH457BM2B/bundle.json","state_url":"https://pith.science/pith/BUYKIAK3MGRVJKVOOGH457BM2B/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/BUYKIAK3MGRVJKVOOGH457BM2B/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":"2026-08-04T06:56:56Z","links":{"resolver":"https://pith.science/pith/BUYKIAK3MGRVJKVOOGH457BM2B","bundle":"https://pith.science/pith/BUYKIAK3MGRVJKVOOGH457BM2B/bundle.json","state":"https://pith.science/pith/BUYKIAK3MGRVJKVOOGH457BM2B/state.json","well_known_bundle":"https://pith.science/.well-known/pith/BUYKIAK3MGRVJKVOOGH457BM2B/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2023:BUYKIAK3MGRVJKVOOGH457BM2B","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":"bb2f02f8f635b0dfd043b5f63e9436e801cedc06fbf6beadf7e95eb98d5bfd60","cross_cats_sorted":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"gr-qc","submitted_at":"2023-05-17T14:52:13Z","title_canon_sha256":"83a569f54683a1e8bf47caf40551f8283de3f7d62b45ead1d9a2a69fb227f525"},"schema_version":"1.0","source":{"id":"2305.10470","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2305.10470","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"arxiv_version","alias_value":"2305.10470v1","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2305.10470","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_12","alias_value":"BUYKIAK3MGRV","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_16","alias_value":"BUYKIAK3MGRVJKVO","created_at":"2026-07-05T06:11:23Z"},{"alias_kind":"pith_short_8","alias_value":"BUYKIAK3","created_at":"2026-07-05T06:11:23Z"}],"graph_snapshots":[{"event_id":"sha256:ee0f5bd7167650cf503491da9d4a25ceb96eca43fda957020384ffdf8eff5ac4","target":"graph","created_at":"2026-07-05T06:11:23Z","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/2305.10470/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"A gravitational machine is defined as an arrangement of gravitating masses from which useful energy can be extracted. It is shown that such machines may exist if the masses are of normal astronomical size. A simple example of a gravitational machine, consisting of a double star with smaller masses orbiting around it, is described. It is shown that an efficient gravitational machine will also be an emitter of gravitational radiation. The emitted radiation sets a limit on the possible performance of gravitational machines, and also provides us with a possible means for detecting such machines if","authors_text":"Freeman J. Dyson","cross_cats":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"gr-qc","submitted_at":"2023-05-17T14:52:13Z","title":"Gravitational Machines"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2305.10470","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:eb21f0b09b4ff4e39fb64953c8f2a73b54b5bd53a657a7ffe16975e06dd62628","target":"record","created_at":"2026-07-05T06:11:23Z","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":"bb2f02f8f635b0dfd043b5f63e9436e801cedc06fbf6beadf7e95eb98d5bfd60","cross_cats_sorted":["astro-ph.SR","physics.hist-ph","physics.pop-ph"],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"gr-qc","submitted_at":"2023-05-17T14:52:13Z","title_canon_sha256":"83a569f54683a1e8bf47caf40551f8283de3f7d62b45ead1d9a2a69fb227f525"},"schema_version":"1.0","source":{"id":"2305.10470","kind":"arxiv","version":1}},"canonical_sha256":"0d30a4015b61a354aaae718fcefc2cd056206c584073caf274c6c641cbd06091","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0d30a4015b61a354aaae718fcefc2cd056206c584073caf274c6c641cbd06091","first_computed_at":"2026-07-05T06:11:23.021772Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T06:11:23.021772Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xVm+2asK2L/+smASrIyO3aLkK5XkEv6yiFLPWVbTAJ/AjrlkeKH8p3hpY2PRgMye+F4lC8jH8uEpQU1z2/kTCg==","signature_status":"signed_v1","signed_at":"2026-07-05T06:11:23.022185Z","signed_message":"canonical_sha256_bytes"},"source_id":"2305.10470","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:eb21f0b09b4ff4e39fb64953c8f2a73b54b5bd53a657a7ffe16975e06dd62628","sha256:ee0f5bd7167650cf503491da9d4a25ceb96eca43fda957020384ffdf8eff5ac4"],"state_sha256":"f20c9502678f7169ed18c092c79820834fc1d13ba74c86c0623e7805cd3a1e68"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yvHW5oDA2bVEC5t49XWYwt50LNkRGIX6qwFVj6E1QltXsGFJLfUTswsHzyB+emcN0RoSa1ARc6Avb/fDMcxLCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-04T06:56:56.970438Z","bundle_sha256":"c8c2f50a4145b151d1e27a5f102e3cd64037bb03f26fec6785b0bc6e4bb24f73"}}