1 of 3 | Ancient Astronomy
The Aristotelean geocentric model of the universe, as developed by Claudius Ptolemy (90–168), was preeminent for over a thousand years. In this model, the Earth sat at the middle of the universe, heavy and stationary, made of the four terrestrial elements. It was surrounded by the planetary spheres, containing the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and finally the fixed stars, all made of one special light and shining element: aether. It included a complex system of orbits, epicycles and deferents, which precisely matched observed planetary movements and enabled accurate predictions of their future and past positions.
This geocentric model was supported by Biblical references like 1 Chronicles 16:30 and Psalm 104:5 (which say that the Earth is stationary) and Ecclesiastes 1:5 and Joshua 10:13 (which mention the movement of the sun). Thus the Ptolemaic model, matching observed planetary movements and supported by Scripture, was unassailable in Christian Europe for over a thousand years.
The geocentric model was challenged by Nicolaus Copernicus (1473–1543). He proposed a heliocentric model, in which the Sun was the centre of a Solar System, orbited by the Earth, all the planets, and the stars, with the Moon orbiting the Earth (which also rotated on its axis, and the axis moved).
This book and the next were both part of the Edward Hugh Norris Wilde bequest. His wife, Agnes Clay, was a Classics student here from 1886–1900, and a tutor from 1901–10.
Jean Bailly, Histoire de l’astronomie ancienne (Paris: De Bure, 1781). Briggs Room 520.9 1