the assay office / record

The Shadow That Measured the World

Written 2026-06-22. Claims re-read against their sources on 2026-09-27: 11 checked, 5 confirmed, 6 wrong, 0 unverifiable. By claims-audit controls 2026-09-27 (audit agent + fix agent).

Claims

• WRONG Aristotle's On the Heavens argues the Earth is round because ships' hulls vanish before their masts
  https://classics.mit.edu/Aristotle/heavens.2.ii.html : II.14 gives the curved eclipse shadow and the shift of the stars (and a theoretical argument); the only ships in Book II are about the noise of the spheres; ships removed
• WRONG dek, meta and JSON-LD: the flat-Earth belief is a myth invented in 1828 by Washington Irving
  https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth : quotes James Hannam: the myth "appears to date from the 17th century ... But it gained currency in the 19th century"; Irving popularised it; every copy reworded
• WRONG Columbus thought Asia lay ~77 degrees west; "The true figure is about 180 degrees"
  https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth : 77 degrees confirmed (Morison); 180 degrees was the estimate "from Ptolemy onward"; the true distance to Japan is "about 20,000 km" against his 5,000, over 200 degrees of longitude from the Canaries; reworded
• MINOR Irving's scene of scriptural objections at Salamanca "never happened"
  https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth : the source calls it "a highly unlikely tale"; page now says historians judge it highly unlikely
• MINOR the experts who doubted him were "the Salamanca commission"
  https://en.wikipedia.org/wiki/Christopher_Columbus : "A council led by Isabella's confessor, Hernando de Talavera"; Salamanca is Irving's setting; body now names Talavera
• MINOR meta description: educated people had known the Earth was round for ~1,700 years
  public/strata/did-columbus-prove-earth-round/index.html : contradicts the page's own "nearly two thousand years" (Aristotle c. 350 BC to 1492 is about 1,840 years); meta now matches
• CONFIRMED the 5,000-stadia Alexandria to Syene distance was measured by professional pacers
  https://en.wikipedia.org/wiki/Earth%27s_circumference : the page's own cited source: 5,000 stadia "checked yearly by professional bematists" (Martianus Capella VI.598) and surveying trips "conducted by professional bematists" (Russo)
• CONFIRMED Eratosthenes got 250,000 stadia and rounded to 252,000
  https://en.wikipedia.org/wiki/Earth%27s_circumference : 250,000 from Cleomedes' figures; 252,000 per Pliny, possibly chosen for divisibility
• CONFIRMED Russell: "with extraordinary few exceptions no educated person ... from the third century B.C. onward believed that the Earth was flat"
  https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth : exact, the ellipsis standing for "in the history of Western Civilization"
• CONFIRMED Alexandria 31.20 N and Syene/Aswan 24.09 N, a gap of 7.11 degrees against his 7.2
  research/did-columbus-prove-earth-round/verify.mjs : recomputed by the verifier, 14/14 pass
• CONFIRMED the flat-Earth scene is Irving's 1828 Life and Voyages of Christopher Columbus, part-fictional
  https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth : "highly romanticized biography ... mistaken by many for a scholarly work", "a largely fictional account" of the commission

What was done

• [fixed] Aristotle credited with the ships'-hulls argument; removed from the timeline and facts.md; De Caelo II.14 linked in the sources; dated correction added
• [fixed] "invented in 1828 by Washington Irving" in frontmatter dek, meta description, JSON-LD, body intro and a relates note; now a 17th-century myth that Irving popularised in 1828; verifier label that asserted a "19th-century invention" reworded; dated correction added
• [fixed] "true figure is about 180 degrees" now says 180 was the accepted estimate from Ptolemy on and the true westward distance to Japan is over 200 degrees, about 20,000 km against his 5,000; facts.md too; dated correction added
• [fixed] reader: the check was named but not downloadable; the page's check list now says the research directory is in the repository and not served here (publishing it needs scripts/publish-checks.mjs, outside this layer's files, reported to the caller)
• [fixed] "It never happened" softened to the source's "highly unlikely tale"
• [fixed] "Salamanca commission" replaced by the royal commission led by Hernando de Talavera
• [declined] "measured by professional pacers" reported as unsupported; the page's own cited source, Wikipedia's Earth's circumference, says the 5,000 stadia were checked by professional bematists (pacers), citing Martianus Capella and Russo
• [fixed] meta "~1,700 years" now "nearly two thousand years", matching the dek