id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
grbs-11941	Huxley, George	Aristarchus of Samos and Graeco-Babylonian Astronomy	1964	9	.pdf	application/pdf	3550	200	74	His life cannot be dated exactly, but it is clear that he was already of mature age by 280 B.C., for Ptolemy states that the men around Aristarchus, that is to say his pupils, observed the summer solstice in that year, the 50th of the first Callippic period The date of the publication of Aristarchus's heliocentric theory is not known, but the doctrine was attacked by Cleanthes the Stoic land so must have been well known by 232 B.C., when Cleanthes died; but the helio­ centric hypothesis may have been formulated much earlier than that.	cache/grbs-11941.pdf	txt/grbs-11941.txt