{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:VS76PJFYC3UX4E2PJ4S3RA2Y5D","short_pith_number":"pith:VS76PJFY","canonical_record":{"source":{"id":"1608.03210","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2016-08-10T15:23:53Z","cross_cats_sorted":["cond-mat.soft"],"title_canon_sha256":"3bbd6dbdc4969a9477e7b9d61423b96bea66e5893cb786df319d4a60b3c60afb","abstract_canon_sha256":"694b507d0a5721cd1c3e3fb120dc0d0baa10b2e9e6cf64f386bb85cf019e7be8"},"schema_version":"1.0"},"canonical_sha256":"acbfe7a4b816e97e134f4f25b88358e8f362cb01498c80ca9d23fe18db4b3142","source":{"kind":"arxiv","id":"1608.03210","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1608.03210","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"arxiv_version","alias_value":"1608.03210v4","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1608.03210","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"pith_short_12","alias_value":"VS76PJFYC3UX","created_at":"2026-05-18T12:30:48Z"},{"alias_kind":"pith_short_16","alias_value":"VS76PJFYC3UX4E2P","created_at":"2026-05-18T12:30:48Z"},{"alias_kind":"pith_short_8","alias_value":"VS76PJFY","created_at":"2026-05-18T12:30:48Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:VS76PJFYC3UX4E2PJ4S3RA2Y5D","target":"record","payload":{"canonical_record":{"source":{"id":"1608.03210","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2016-08-10T15:23:53Z","cross_cats_sorted":["cond-mat.soft"],"title_canon_sha256":"3bbd6dbdc4969a9477e7b9d61423b96bea66e5893cb786df319d4a60b3c60afb","abstract_canon_sha256":"694b507d0a5721cd1c3e3fb120dc0d0baa10b2e9e6cf64f386bb85cf019e7be8"},"schema_version":"1.0"},"canonical_sha256":"acbfe7a4b816e97e134f4f25b88358e8f362cb01498c80ca9d23fe18db4b3142","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:52:49.827646Z","signature_b64":"bgTnWZFD+631RRDEXsVq1mqkJXafu0DEGoEtZCmgK6aWqoH8UIx7sB8C6FItkADk5RSk74Ez8EhKjCzImlR+DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"acbfe7a4b816e97e134f4f25b88358e8f362cb01498c80ca9d23fe18db4b3142","last_reissued_at":"2026-05-18T00:52:49.826893Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:52:49.826893Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1608.03210","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:52:49Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"o6RNvBLaIIFAMD158IFk/nI7oTEyNB7q1Ng5usuFwGPZ8qN0Y6B4AXOm3Obid2tCB/3r4a3Gb/xqsUUReqSpBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T02:37:06.321294Z"},"content_sha256":"0f5a0e7f4b899d57c9069ce145d568116c78c9cb48e869389613751a67008265","schema_version":"1.0","event_id":"sha256:0f5a0e7f4b899d57c9069ce145d568116c78c9cb48e869389613751a67008265"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:VS76PJFYC3UX4E2PJ4S3RA2Y5D","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Self-charging of identical grains in the absence of an external field","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.soft"],"primary_cat":"physics.comp-ph","authors_text":"Gerhard Wurm, Hans Herrmann, Nuno Ara\\'ujo, Ryuta Yoshimatsu, Troy Shinbrot","submitted_at":"2016-08-10T15:23:53Z","abstract_excerpt":"We investigate the electrostatic charging of an agitated bed of identical grains using simulations, mathematical modeling, and experiments. We simulate charging with a discrete-element model including electrical multipoles and find that infinitesimally small initial charges can grow exponentially rapidly. We propose a mathematical Turing model that defines conditions for exponential charging to occur and provides insights into the mechanisms involved. Finally, we confirm the predicted exponential growth in experiments using vibrated grains under microgravity, and we describe novel predicted sp"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1608.03210","kind":"arxiv","version":4},"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":"2026-05-18T00:52:49Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"a/nTx8UneHw2053nqCN5G/ScyBsmcVHudpdwrb008AyIWekvsoHCwLDKpFhFbtQfCktJTg3DK6bC3nlkc/tHAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T02:37:06.322023Z"},"content_sha256":"56d7baab6f6d91c3706e7ebe0adfb0203d52e6887fe7e94dbb0efd43b1f3473a","schema_version":"1.0","event_id":"sha256:56d7baab6f6d91c3706e7ebe0adfb0203d52e6887fe7e94dbb0efd43b1f3473a"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/bundle.json","state_url":"https://pith.science/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/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":"2026-05-22T02:37:06Z","links":{"resolver":"https://pith.science/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D","bundle":"https://pith.science/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/bundle.json","state":"https://pith.science/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VS76PJFYC3UX4E2PJ4S3RA2Y5D/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:VS76PJFYC3UX4E2PJ4S3RA2Y5D","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":"694b507d0a5721cd1c3e3fb120dc0d0baa10b2e9e6cf64f386bb85cf019e7be8","cross_cats_sorted":["cond-mat.soft"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2016-08-10T15:23:53Z","title_canon_sha256":"3bbd6dbdc4969a9477e7b9d61423b96bea66e5893cb786df319d4a60b3c60afb"},"schema_version":"1.0","source":{"id":"1608.03210","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1608.03210","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"arxiv_version","alias_value":"1608.03210v4","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1608.03210","created_at":"2026-05-18T00:52:49Z"},{"alias_kind":"pith_short_12","alias_value":"VS76PJFYC3UX","created_at":"2026-05-18T12:30:48Z"},{"alias_kind":"pith_short_16","alias_value":"VS76PJFYC3UX4E2P","created_at":"2026-05-18T12:30:48Z"},{"alias_kind":"pith_short_8","alias_value":"VS76PJFY","created_at":"2026-05-18T12:30:48Z"}],"graph_snapshots":[{"event_id":"sha256:56d7baab6f6d91c3706e7ebe0adfb0203d52e6887fe7e94dbb0efd43b1f3473a","target":"graph","created_at":"2026-05-18T00:52:49Z","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 investigate the electrostatic charging of an agitated bed of identical grains using simulations, mathematical modeling, and experiments. We simulate charging with a discrete-element model including electrical multipoles and find that infinitesimally small initial charges can grow exponentially rapidly. We propose a mathematical Turing model that defines conditions for exponential charging to occur and provides insights into the mechanisms involved. Finally, we confirm the predicted exponential growth in experiments using vibrated grains under microgravity, and we describe novel predicted sp","authors_text":"Gerhard Wurm, Hans Herrmann, Nuno Ara\\'ujo, Ryuta Yoshimatsu, Troy Shinbrot","cross_cats":["cond-mat.soft"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2016-08-10T15:23:53Z","title":"Self-charging of identical grains in the absence of an external field"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1608.03210","kind":"arxiv","version":4},"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":"sha256:0f5a0e7f4b899d57c9069ce145d568116c78c9cb48e869389613751a67008265","target":"record","created_at":"2026-05-18T00:52:49Z","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":"694b507d0a5721cd1c3e3fb120dc0d0baa10b2e9e6cf64f386bb85cf019e7be8","cross_cats_sorted":["cond-mat.soft"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2016-08-10T15:23:53Z","title_canon_sha256":"3bbd6dbdc4969a9477e7b9d61423b96bea66e5893cb786df319d4a60b3c60afb"},"schema_version":"1.0","source":{"id":"1608.03210","kind":"arxiv","version":4}},"canonical_sha256":"acbfe7a4b816e97e134f4f25b88358e8f362cb01498c80ca9d23fe18db4b3142","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"acbfe7a4b816e97e134f4f25b88358e8f362cb01498c80ca9d23fe18db4b3142","first_computed_at":"2026-05-18T00:52:49.826893Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:52:49.826893Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"bgTnWZFD+631RRDEXsVq1mqkJXafu0DEGoEtZCmgK6aWqoH8UIx7sB8C6FItkADk5RSk74Ez8EhKjCzImlR+DA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:52:49.827646Z","signed_message":"canonical_sha256_bytes"},"source_id":"1608.03210","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0f5a0e7f4b899d57c9069ce145d568116c78c9cb48e869389613751a67008265","sha256:56d7baab6f6d91c3706e7ebe0adfb0203d52e6887fe7e94dbb0efd43b1f3473a"],"state_sha256":"f2d778b8c7df9887e133e1793af6ad88d768665cdddf36bfccedbc87981f9b89"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MFIppYeJagbsIx9Q4WZCzNYA3CIxW/vs5EnRa/dKlSSo6ZjKAWAHZE/OuWi7xK3/cj3VkkSL1wH7DY/kQ1hiBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-22T02:37:06.325523Z","bundle_sha256":"37ef9f477ef1e2d186dc40edeea304ab199b38cc98e5e5d826d138ad7dd4e62c"}}