Aristarchus On The Sizes and Distances

Aristarchus On The Sizes And Distances

On the Sizes and Distances (of the Sun and Moon) (Περὶ μεγεθῶν καὶ ἀποστημάτων ) is widely accepted as the only extant work written by Aristarchus of Samos, an ancient Greek astronomer who flourished circa 280–240 BC. This work calculates the sizes of the Sun and Moon, as well as their distances from the Earth in terms of Earth's radius.

A first printing of a Latin translation is found included in a compendium volume made by Giorgio Valla (Venice 1498). Frederico Commandino produced a commented edition in (1572).

However, since the time of Voltaire questions have existed as to whether the work is genuinely Aristarchus'. In 2009, it was revealed that misunderstanding the ancient angular unit "meros" appears to have introduced an error by a factor of 4 into several calculations, which explains the work's bizarre demands that central lunar eclipses last ½ a day, and that the Moon retrogrades against the stars every day. The testimony of Archimedes indeed disagrees on the solar diameter by a factor of 4. In 2011, it was first pointed out that the work's best-known data, its 87° half-Moon solar elongation-limit and 2° solar diameter, are mathematically incompatible with each other, given the precision of human vision.