Observed arrival · 2026-11-03
Not Flat: Earth geometry, calculated
A browser-based collection of calculations for horizons, celestial navigation, Earth curvature, and related geometry.
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- People exploring horizon geometry and Earth-based navigation
- Worth noticing
- Curvature, radar-horizon, and hull-down pages compare a spherical Earth with a plane; the site says they share one geometry module.
Field notes
Several pages make their assumptions legible: the curvature calculator separates drop below the horizontal from bulge above a chord, while horizon pages distinguish geometric results from refraction or a standard-atmosphere model. The site says its curvature, radar-horizon, and hull-down pages import one shared Earth-geometry module. Other examples range from a Syene–Alexandria stick measurement to a sextant sight that explicitly has no ephemeris.
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Editorial observations of this landing page, not a rating.
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✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
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