{"id": "card_works_astronomy", "kind": "verified", "title": "Kepler's law, and the pull between Earth and Moon", "body": "Kepler's third law binds a planet's period to its orbit (T² = a³); Newton's gravity gives the force holding the Moon — about 2 × 10²⁰ newtons.  Worked & sealed by the engine — T² = a³ for Earth (1 yr, 1 AU) · F = G·M·m/r² ≈ 1.98 × 10²⁰ N (Earth–Moon).  [HOLDS; open the seal to re-check.]", "source": {"label": "The Works — worked & sealed", "url": "https://narrowhighway.com/s/7036538f3a6188b5a1adb6c45d81d2fd4d0e4c8d3fa130558fcdaabd58b594bb", "domain": "astronomy", "authority_tier": "verified"}, "shelf": "the-works", "box": "physical", "bands": ["the-works", "physical", "astronomy", "astronomy"], "connections": [{"to_card_id": "card_spine_the-works", "relationship": "member_of", "evidence": "a member of the the-works shelf in the keeping"}, {"to_card_id": "card_k_floor_of_discovery", "relationship": "paves", "evidence": "A worked, engine-sealed demonstration — a paving-stone of the floor of reality."}, {"to_card_id": "card_v_ed81d928e2f5", "relationship": "demonstrates", "evidence": "A worked demonstration in the same field (astronomy)."}, {"to_card_id": "card_works_mechanics", "relationship": "adjacent", "evidence": "Neighbouring worked demonstrations in the same part of the volume."}, {"to_card_id": "card_works_thermo_carnot", "relationship": "adjacent", "evidence": "Neighbouring worked demonstrations in the same part of the volume."}], "author": "engine", "created_at": 0.0, "updated_at": 0.0, "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "generated": false, "subject": "Astronomy", "extra": {"seal_hash": "7036538f3a6188b5a1adb6c45d81d2fd4d0e4c8d3fa130558fcdaabd58b594bb", "cite_url": "https://narrowhighway.com/s/7036538f3a6188b5a1adb6c45d81d2fd4d0e4c8d3fa130558fcdaabd58b594bb", "demonstration_id": "works_astronomy", "verdict": "HOLDS"}, "presentation": {"glyph": "•", "kind_label": "physical", "by": "The Works — worked & sealed", "authority": "verified", "posted": "", "standing": "", "link": {"url": "https://narrowhighway.com/s/7036538f3a6188b5a1adb6c45d81d2fd4d0e4c8d3fa130558fcdaabd58b594bb", "host": "narrowhighway.com", "provider": "", "titled": "Kepler's law, and the pull between Earth and Moon", "waybill_line": "", "reach": "", "embed": ""}}, "neighbors": [{"id": "card_spine_the-works", "title": "The Works — sealed, worked demonstrations", "relationship": "on the shelf of", "why": "a member of the the-works shelf in the keeping", "href": "/card/card_spine_the-works", "resolved": true}, {"id": "card_k_floor_of_discovery", "title": "The Floor of Discovery — one floor, and by its design the fear of God", "relationship": "paves", "why": "A worked, engine-sealed demonstration — a paving-stone of the floor of reality.", "href": "/card/card_k_floor_of_discovery", "resolved": true}, {"id": "card_v_ed81d928e2f5", "title": "T² = a³ for Earth (1 yr, 1 AU) · F = G·M·m/r² ≈ 1.98 × 10²⁰ N (Earth–Moon)", "relationship": "demonstrates", "why": "A worked demonstration in the same field (astronomy).", "href": "/card/card_v_ed81d928e2f5", "resolved": true}, {"id": "card_works_mechanics", "title": "A 2 kg mass: the force to move it, the energy it carries", "relationship": "adjacent", "why": "Neighbouring worked demonstrations in the same part of the volume.", "href": "/card/card_works_mechanics", "resolved": true}, {"id": "card_works_thermo_carnot", "title": "The Carnot ceiling no engine can beat", "relationship": "adjacent", "why": "Neighbouring worked demonstrations in the same part of the volume.", "href": "/card/card_works_thermo_carnot", "resolved": true}]}