{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:UKMSXICECSJELGLVA2WTGVKXCV","short_pith_number":"pith:UKMSXICE","canonical_record":{"source":{"id":"1503.07804","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.pop-ph","submitted_at":"2015-03-15T17:19:47Z","cross_cats_sorted":["astro-ph.EP"],"title_canon_sha256":"c2b89aed50bc0d24ca9cea6c4a45146ac5ee944eda7d716de6995c88cf98903d","abstract_canon_sha256":"5b17cab3f62a6f2a534d62c66b49ab11d6ec72b748cb81340c767042576dcb5a"},"schema_version":"1.0"},"canonical_sha256":"a2992ba044149245997506ad3355571548c04b6052ecd1a1d24f19ab38268b0d","source":{"kind":"arxiv","id":"1503.07804","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.07804","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"arxiv_version","alias_value":"1503.07804v3","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.07804","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"pith_short_12","alias_value":"UKMSXICECSJE","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_16","alias_value":"UKMSXICECSJELGLV","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_8","alias_value":"UKMSXICE","created_at":"2026-05-18T12:29:44Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:UKMSXICECSJELGLVA2WTGVKXCV","target":"record","payload":{"canonical_record":{"source":{"id":"1503.07804","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.pop-ph","submitted_at":"2015-03-15T17:19:47Z","cross_cats_sorted":["astro-ph.EP"],"title_canon_sha256":"c2b89aed50bc0d24ca9cea6c4a45146ac5ee944eda7d716de6995c88cf98903d","abstract_canon_sha256":"5b17cab3f62a6f2a534d62c66b49ab11d6ec72b748cb81340c767042576dcb5a"},"schema_version":"1.0"},"canonical_sha256":"a2992ba044149245997506ad3355571548c04b6052ecd1a1d24f19ab38268b0d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:18:14.703868Z","signature_b64":"RBMmajtCQ2Y9PUdpbenqWgsvuzFNNgfARY2WQqxQb6Gcubjo/exu7n41Y3bV4DlFwOCctA832gC7eg89ojG3CA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a2992ba044149245997506ad3355571548c04b6052ecd1a1d24f19ab38268b0d","last_reissued_at":"2026-05-18T01:18:14.703334Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:18:14.703334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1503.07804","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:18:14Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Vqk/7CWvsuJoHHXmioiOBKFRdHCKrs9PvhrfTyzOab2vYnCLTFzy1UaFCFiMCIFeFJrGZcEDrcJamR9cz6hmDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T11:31:32.109705Z"},"content_sha256":"ef4aaae9150ddb3a466e85f92625199cfd44cf55f0414717d5cc192635e35d97","schema_version":"1.0","event_id":"sha256:ef4aaae9150ddb3a466e85f92625199cfd44cf55f0414717d5cc192635e35d97"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:UKMSXICECSJELGLVA2WTGVKXCV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Size Distribution of Inhabited Planets","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.EP"],"primary_cat":"physics.pop-ph","authors_text":"Fergus Simpson","submitted_at":"2015-03-15T17:19:47Z","abstract_excerpt":"Earth-like planets are expected to provide the greatest opportunity for the detection of life beyond the Solar System. However our planet cannot be considered a fair sample, especially if intelligent life exists elsewhere. Just as a person's country of origin is a biased sample among countries, so too their planet of origin may be a biased sample among planets. The magnitude of this effect can be substantial: over 98% of the world's population live in a country larger than the median. In the context of a simple model where the mean population density is invariant to planet size, we infer that "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.07804","kind":"arxiv","version":3},"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":"2026-05-18T01:18:14Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"R2dyly2GxJfJ+gNYuB0XEnZ3x/qv+aDHJyP8VQav5LxvAKrsGWkvvWqcb136EK1QvDZSzIh4pzZxU9iz9jIqDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T11:31:32.110050Z"},"content_sha256":"0114d6cadf15a0364ceec6957679c7ae5b4d96e7f0c43f2406b63a0db485a49e","schema_version":"1.0","event_id":"sha256:0114d6cadf15a0364ceec6957679c7ae5b4d96e7f0c43f2406b63a0db485a49e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/UKMSXICECSJELGLVA2WTGVKXCV/bundle.json","state_url":"https://pith.science/pith/UKMSXICECSJELGLVA2WTGVKXCV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/UKMSXICECSJELGLVA2WTGVKXCV/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":"2026-06-01T11:31:32Z","links":{"resolver":"https://pith.science/pith/UKMSXICECSJELGLVA2WTGVKXCV","bundle":"https://pith.science/pith/UKMSXICECSJELGLVA2WTGVKXCV/bundle.json","state":"https://pith.science/pith/UKMSXICECSJELGLVA2WTGVKXCV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/UKMSXICECSJELGLVA2WTGVKXCV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:UKMSXICECSJELGLVA2WTGVKXCV","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":"5b17cab3f62a6f2a534d62c66b49ab11d6ec72b748cb81340c767042576dcb5a","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.pop-ph","submitted_at":"2015-03-15T17:19:47Z","title_canon_sha256":"c2b89aed50bc0d24ca9cea6c4a45146ac5ee944eda7d716de6995c88cf98903d"},"schema_version":"1.0","source":{"id":"1503.07804","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.07804","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"arxiv_version","alias_value":"1503.07804v3","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.07804","created_at":"2026-05-18T01:18:14Z"},{"alias_kind":"pith_short_12","alias_value":"UKMSXICECSJE","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_16","alias_value":"UKMSXICECSJELGLV","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_8","alias_value":"UKMSXICE","created_at":"2026-05-18T12:29:44Z"}],"graph_snapshots":[{"event_id":"sha256:0114d6cadf15a0364ceec6957679c7ae5b4d96e7f0c43f2406b63a0db485a49e","target":"graph","created_at":"2026-05-18T01:18:14Z","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":"Earth-like planets are expected to provide the greatest opportunity for the detection of life beyond the Solar System. However our planet cannot be considered a fair sample, especially if intelligent life exists elsewhere. Just as a person's country of origin is a biased sample among countries, so too their planet of origin may be a biased sample among planets. The magnitude of this effect can be substantial: over 98% of the world's population live in a country larger than the median. In the context of a simple model where the mean population density is invariant to planet size, we infer that ","authors_text":"Fergus Simpson","cross_cats":["astro-ph.EP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.pop-ph","submitted_at":"2015-03-15T17:19:47Z","title":"The Size Distribution of Inhabited Planets"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.07804","kind":"arxiv","version":3},"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:ef4aaae9150ddb3a466e85f92625199cfd44cf55f0414717d5cc192635e35d97","target":"record","created_at":"2026-05-18T01:18:14Z","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":"5b17cab3f62a6f2a534d62c66b49ab11d6ec72b748cb81340c767042576dcb5a","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.pop-ph","submitted_at":"2015-03-15T17:19:47Z","title_canon_sha256":"c2b89aed50bc0d24ca9cea6c4a45146ac5ee944eda7d716de6995c88cf98903d"},"schema_version":"1.0","source":{"id":"1503.07804","kind":"arxiv","version":3}},"canonical_sha256":"a2992ba044149245997506ad3355571548c04b6052ecd1a1d24f19ab38268b0d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a2992ba044149245997506ad3355571548c04b6052ecd1a1d24f19ab38268b0d","first_computed_at":"2026-05-18T01:18:14.703334Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:18:14.703334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"RBMmajtCQ2Y9PUdpbenqWgsvuzFNNgfARY2WQqxQb6Gcubjo/exu7n41Y3bV4DlFwOCctA832gC7eg89ojG3CA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:18:14.703868Z","signed_message":"canonical_sha256_bytes"},"source_id":"1503.07804","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ef4aaae9150ddb3a466e85f92625199cfd44cf55f0414717d5cc192635e35d97","sha256:0114d6cadf15a0364ceec6957679c7ae5b4d96e7f0c43f2406b63a0db485a49e"],"state_sha256":"d8c96f24b50d36ee58cd9155ec0b84abc4b87bcf883803d8a5ae263c3d3b7809"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"RVv8CbHLaEweMkmOwteYWTcba9LDprJIU+9D395VqLFmHjXcnROdE51JImsYUOI/5u+k8Y5EDrMdk3KeHkM3Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T11:31:32.111996Z","bundle_sha256":"892b975217a3336f031d01ebd882fc13a96f3b31bac19518ed5e56eda4689a5b"}}