> My sketch of the Sun-Earth-Moon system assumes a heliocentric solar system, something that wasn’t known to the Greeks of the first century BCE.<p>I am not sure this is entirely accurate. According to Wikipedia:<p>> The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos,[1] who had been influenced by a concept presented by Philolaus of Croton (c. 470 – 385 BC). In the 5th century BC the Greek philosophers Philolaus and Hicetas had the thought on different occasions that the Earth was spherical and revolving around a "mystical" central fire, and that this fire regulated the universe.[2] In medieval Europe, however, Aristarchus' heliocentrism attracted little attention—possibly because of the loss of scientific works of the Hellenistic period.[b]<p>Source: <a href="https://en.m.wikipedia.org/wiki/Heliocentrism" rel="nofollow">https://en.m.wikipedia.org/wiki/Heliocentrism</a><p>Contrary to the recent revisionist version of the “dark ages”, they were pretty dark if you were a Greek of the Hellenistic period, an Athenian 5th century BC or a Roman the next 500-800 years. Loss of philosophical (locked in monasteries) and technical knowledge is common and Heliocentrism or the blood circulation system (Egyptians during the Ptolemy era had knowledge comparable to the one we will acquire again 18th century) are two prime examples.