{"id": "card_n_36048aaa9a1b", "kind": "note", "title": "Glottochronology — carbon-dating the words", "body": "Swadesh (1950s): a language's CORE vocabulary — the 100-200 most basic words (mother,\nwater, two, hand) — is replaced at a roughly constant rate, so its loss is EXPONENTIAL:\nretention r^t with r about 0.86 per millennium. Sealed: 74% remain after 2,000 years, a\n~4,595-year HALF-LIFE for basic vocabulary (https://narrowhighway.com/s/9c66f521565216319b7ab6cf3bca9314c18dfe3e9982b88459f714c61237c10f) — the identical decay math as carbon-14,\nwhich is why it is called linguistic dating. The linear misconception (lose the same NUMBER each\nera) sealed BROKEN (https://narrowhighway.com/s/e456b15c210b9675bfdb7813c725256cd2c52b267665b9cc4518a826c6019545): words decay by RATIO, like atoms, like a capacitor, like\neverything on the exponential spine. Honest grade: the METHOD is exact, the constant RATE is\nHEURISTIC and contested (borrowing and contact perturb it) — a trend, not a law, same class as\nthe Phillips curve on the boundary map.", "source": {"label": "Concordance assay — 2026-07-09", "url": "https://narrowhighway.com/s/9c66f521565216319b7ab6cf3bca9314c18dfe3e9982b88459f714c61237c10f", "ref": "language", "authority_tier": "engine_derived"}, "shelf": "science", "box": "language", "bands": ["glottochronology", "swadesh list", "lexicostatistics", "vocabulary decay", "half-life", "exponential", "linguistic dating", "heuristic"], "connections": [], "author": "engine", "created_at": "2026-07-10T02:06:03.344343+00:00", "updated_at": "2026-07-10T02:06:03.344343+00:00", "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "metrics": {"paperclips_count": 0, "helpful_count": 0, "not_helpful_count": 0, "cite_count": 0, "walks_through_count": 0, "flagged_count": 0}, "source_hash": "be323a83d792f2622682e455eade93b88305694bdbff936eee94c0aec5a39a6d"}