Pith Number

pith:BL5OTQ3U

pith:2013:BL5OTQ3UR32DANXGOLFCKMDJ6I

not attested not anchored not stored refs pending

When does a physical system compute?

Dominic Horsman, Rob C. Wagner, Susan Stepney, Viv Kendon

arxiv:1309.7979 v3 · 2013-09-30 · cs.ET · physics.hist-ph · quant-ph

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{BL5OTQ3UR32DANXGOLFCKMDJ6I}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Receipt and verification

First computed	2026-07-05T06:02:43.282441Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

0afae9c3748ef43036e672ca253069f20cfcf662ad1fb3b41335530d88862968

Aliases

arxiv: 1309.7979 · arxiv_version: 1309.7979v3 · doi: 10.48550/arxiv.1309.7979 · pith_short_12: BL5OTQ3UR32D · pith_short_16: BL5OTQ3UR32DANXG · pith_short_8: BL5OTQ3U

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/BL5OTQ3UR32DANXGOLFCKMDJ6I \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 0afae9c3748ef43036e672ca253069f20cfcf662ad1fb3b41335530d88862968

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "d1fa84fe8c74beca2e7d423914baa9d4920b03889a97b4f5b9c664ccd3b9cf1a",
    "cross_cats_sorted": [
      "physics.hist-ph",
      "quant-ph"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.ET",
    "submitted_at": "2013-09-30T19:37:43Z",
    "title_canon_sha256": "1b35cd6b9840c46558a91098beeb7f71a2f18d0207b7973fce6e4cd26cad035f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1309.7979",
    "kind": "arxiv",
    "version": 3
  }
}