Empirical Earth · The Sky — Sun, Moon & Stars

The “conceptual” flat-earth simulator — neutral only because it measures nothing

The claim

“A flat-earth sky simulator is as valid as the globe — both are consistent projections of the same celestial sphere.”

What is true

For one observer looking only at directions, that really is projection-neutral, and so is a planetarium dome.

What is measured

The simulator proves what a planetarium proves, that one observer’s sky is a bundle of angles you can paint on any ceiling. It stays neutral by carrying no distances and admitting no second observer. Restore either and every measurement lands on the globe.

What would show this is wrong

a metric, multi-observer prediction the flat vault makes that the globe does not, which measurement then confirms: a second observer for whom a globe-hidden star is visible, a Sun that measurably changes width through the day, or an eclipse track that lands where a flat-Earth map puts it rather than where the globe does.

Sources

  1. Conceptual flat-earth simulator (AlanSpaceAudits). A browser-based, single-observer flat-earth astronomy sandbox built in three.js, deliberately unitless ( FE_RADIUS = 1 ), presenting a shar link
  2. Yi Xing’s meridian survey (724 CE). The Tang astronomer-monk Yi Xing, with Nangong Yue, ran the first large-scale geodetic survey, measuring the noon gnomon shadow and pole-star altitude at link
  3. Ptolemy on a spherical Earth, Almagest Book I (2nd c. CE). Ptolemy’s foundational treatise argues that the Earth is sensibly spherical and computes every planetary position on that basis. A link
  4. Oppolzer’s Canon of Eclipses (1887). Theodor Ritter von Oppolzer’s Canon der Finsternisse , published by the Imperial Academy of Sciences in Vienna, catalogs over 13,000 eclipses (8,000 sola link
  5. The Saros cycle and why it does not fix an eclipse’s path. Eclipses in a Saros series recur about every 18 years 11 days, but the extra ~8 hours turns the Earth roughly a third of a rotation link
  6. A data-driven flat-earth dome model, in its author’s words. This browser model plots the Sun, Moon, and stars on a flat north-polar projection using real heliocentric data: inclinations, axi link
  7. Conceptual flat-earth model (open source). Source at github.com/AlanSpaceAudits/conceptual_flat_earth_model ; one ephemeris feeds both flat and globe views, with a Ptolemaic engine and a thr link
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