{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:QO5MUJAFOASNYFU3XUXWFHMAGI","short_pith_number":"pith:QO5MUJAF","canonical_record":{"source":{"id":"1310.3134","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2013-10-11T14:11:21Z","cross_cats_sorted":[],"title_canon_sha256":"75e5cc46773cfeb4acd9deff9fbe67cacafe6aea88743d276035ca41b4eebf45","abstract_canon_sha256":"48b5ff43d550bbe62d0bd23ae7abb0d066e41e4a7e6f0b0d70e15ae6752373b1"},"schema_version":"1.0"},"canonical_sha256":"83baca24057024dc169bbd2f629d80323fd714fdb97bc5ea675d7fc1330c4d7b","source":{"kind":"arxiv","id":"1310.3134","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.3134","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"arxiv_version","alias_value":"1310.3134v2","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.3134","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"pith_short_12","alias_value":"QO5MUJAFOASN","created_at":"2026-05-18T12:27:57Z"},{"alias_kind":"pith_short_16","alias_value":"QO5MUJAFOASNYFU3","created_at":"2026-05-18T12:27:57Z"},{"alias_kind":"pith_short_8","alias_value":"QO5MUJAF","created_at":"2026-05-18T12:27:57Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:QO5MUJAFOASNYFU3XUXWFHMAGI","target":"record","payload":{"canonical_record":{"source":{"id":"1310.3134","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2013-10-11T14:11:21Z","cross_cats_sorted":[],"title_canon_sha256":"75e5cc46773cfeb4acd9deff9fbe67cacafe6aea88743d276035ca41b4eebf45","abstract_canon_sha256":"48b5ff43d550bbe62d0bd23ae7abb0d066e41e4a7e6f0b0d70e15ae6752373b1"},"schema_version":"1.0"},"canonical_sha256":"83baca24057024dc169bbd2f629d80323fd714fdb97bc5ea675d7fc1330c4d7b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:02:56.938086Z","signature_b64":"QlUTHOXvmzc/qW7LrewFsr6phOGUKtxbQexRm1/UBruyx7DE8gdosIjSDqeV0s3cNRn1/MUUdE4pMGPqBXAhDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"83baca24057024dc169bbd2f629d80323fd714fdb97bc5ea675d7fc1330c4d7b","last_reissued_at":"2026-05-18T03:02:56.937349Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:02:56.937349Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1310.3134","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T03:02:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SQfuxzmTEYalo8LfW4JDjL2Zjvbgspua3nPNvlvrCUo6LDxFWGn1610uHdKtDaYsDCoRUdlco09laJ/pWbLiAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:28:28.309775Z"},"content_sha256":"247bfa6c6d74a25577821b778359dbe78cdcd6d95e90e336aac71dd87471ec65","schema_version":"1.0","event_id":"sha256:247bfa6c6d74a25577821b778359dbe78cdcd6d95e90e336aac71dd87471ec65"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:QO5MUJAFOASNYFU3XUXWFHMAGI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Collisional Model for Granular Impact Dynamics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.soft","authors_text":"Abram H. Clark, Alec J. Petersen, Robert P. Behringer","submitted_at":"2013-10-11T14:11:21Z","abstract_excerpt":"When an intruder strikes a granular material from above, the grains exert a stopping force which decelerates and stops the intruder. Many previous studies have used a macroscopic force law, including a drag force which is quadratic in velocity, to characterize the decelerating force on the intruder. However, the microscopic origins of the force law terms are still a subject of debate. Here, drawing from previous experiments with photoelastic particles, we present a model which describes the velocity-squared force in terms of repeated collisions with clusters of grains. From our high speed phot"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.3134","kind":"arxiv","version":2},"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":"2026-05-18T03:02:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XdoEMLwE0UKDifJQmqbFeJrHoh+UZ3meHRw9VYuueNJH9Ef8XyyTp6Dvv/sp6+9LyfucK18mlbu8FVm9NknTBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:28:28.310430Z"},"content_sha256":"e28099bebf8d87197c097ba557a58a1d9e8977d25d4b97c8d8d86b068f6a461c","schema_version":"1.0","event_id":"sha256:e28099bebf8d87197c097ba557a58a1d9e8977d25d4b97c8d8d86b068f6a461c"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/bundle.json","state_url":"https://pith.science/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/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":"2026-05-30T06:28:28Z","links":{"resolver":"https://pith.science/pith/QO5MUJAFOASNYFU3XUXWFHMAGI","bundle":"https://pith.science/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/bundle.json","state":"https://pith.science/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QO5MUJAFOASNYFU3XUXWFHMAGI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:QO5MUJAFOASNYFU3XUXWFHMAGI","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":"48b5ff43d550bbe62d0bd23ae7abb0d066e41e4a7e6f0b0d70e15ae6752373b1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2013-10-11T14:11:21Z","title_canon_sha256":"75e5cc46773cfeb4acd9deff9fbe67cacafe6aea88743d276035ca41b4eebf45"},"schema_version":"1.0","source":{"id":"1310.3134","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.3134","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"arxiv_version","alias_value":"1310.3134v2","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.3134","created_at":"2026-05-18T03:02:56Z"},{"alias_kind":"pith_short_12","alias_value":"QO5MUJAFOASN","created_at":"2026-05-18T12:27:57Z"},{"alias_kind":"pith_short_16","alias_value":"QO5MUJAFOASNYFU3","created_at":"2026-05-18T12:27:57Z"},{"alias_kind":"pith_short_8","alias_value":"QO5MUJAF","created_at":"2026-05-18T12:27:57Z"}],"graph_snapshots":[{"event_id":"sha256:e28099bebf8d87197c097ba557a58a1d9e8977d25d4b97c8d8d86b068f6a461c","target":"graph","created_at":"2026-05-18T03:02:56Z","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":"When an intruder strikes a granular material from above, the grains exert a stopping force which decelerates and stops the intruder. Many previous studies have used a macroscopic force law, including a drag force which is quadratic in velocity, to characterize the decelerating force on the intruder. However, the microscopic origins of the force law terms are still a subject of debate. Here, drawing from previous experiments with photoelastic particles, we present a model which describes the velocity-squared force in terms of repeated collisions with clusters of grains. From our high speed phot","authors_text":"Abram H. Clark, Alec J. Petersen, Robert P. Behringer","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2013-10-11T14:11:21Z","title":"Collisional Model for Granular Impact Dynamics"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.3134","kind":"arxiv","version":2},"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":"sha256:247bfa6c6d74a25577821b778359dbe78cdcd6d95e90e336aac71dd87471ec65","target":"record","created_at":"2026-05-18T03:02:56Z","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":"48b5ff43d550bbe62d0bd23ae7abb0d066e41e4a7e6f0b0d70e15ae6752373b1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2013-10-11T14:11:21Z","title_canon_sha256":"75e5cc46773cfeb4acd9deff9fbe67cacafe6aea88743d276035ca41b4eebf45"},"schema_version":"1.0","source":{"id":"1310.3134","kind":"arxiv","version":2}},"canonical_sha256":"83baca24057024dc169bbd2f629d80323fd714fdb97bc5ea675d7fc1330c4d7b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"83baca24057024dc169bbd2f629d80323fd714fdb97bc5ea675d7fc1330c4d7b","first_computed_at":"2026-05-18T03:02:56.937349Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:02:56.937349Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"QlUTHOXvmzc/qW7LrewFsr6phOGUKtxbQexRm1/UBruyx7DE8gdosIjSDqeV0s3cNRn1/MUUdE4pMGPqBXAhDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T03:02:56.938086Z","signed_message":"canonical_sha256_bytes"},"source_id":"1310.3134","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:247bfa6c6d74a25577821b778359dbe78cdcd6d95e90e336aac71dd87471ec65","sha256:e28099bebf8d87197c097ba557a58a1d9e8977d25d4b97c8d8d86b068f6a461c"],"state_sha256":"c6994105df821fd14b93b5037d7939e78dd3662272ba19d804f91950f4875324"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Pr3+mhPVBCYqJnUoOxKpw5zZ+uizA/3SqRSs44l35JFqV6kNkxizrRzzfmiht/IdNoPVcWPY5WDqY/LjWYKnAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T06:28:28.313943Z","bundle_sha256":"f273f7e5073274b958b5ad93c8d8be931b387c1f520bc697f6348aab7836df57"}}