2.10 Heliocentric Model
As we mentioned in section 8 above, by the efforts of St. Aquinas, the Catholic Church was convinced that Aristotelian philosophy is compatible with theology, and they decided to adopt Ptolemy’s geocentric model as a theological principle, and considered scientists who criticized this model as heretics. Therefore, the Polish scientist Nicolai Copernicus (1473-1544 AD) circulated his heliocentric model anonymously, and his book De Revolutionibus Orbium Caelestrium (On the Revolutions of the Heavenly Orbs), was not published until 1543, just one year before his death. In this model, Copernicus postulated that the Sun and the stars are stationary and the Earth and the planets circulated around the Sun in circular orbits.
The Copernican model marked the beginning of modern astronomy and scientific revolution. It is certainty a remarkable departure from the Ptolemaic system that prevailed for many centuries. Copernicus may have been aware that Aristarchus had already proposed a heliocentric theory, as we mentioned in section 3 above, and he cited him in an early manuscript of his book before it was published, but there is no evidence that he had knowledge of its specific details. Some scholars suggested recently the possible transmission of earlier Islamic heliocentric models to Europe, after they discovered some of them are mathematically identical to those of Copernicus. In particular, the Damascene astronomer Ibn al-Shatir (1304-1375 AD), working at the Umayyad Mosque, wrote a major book entitled Kitab Nihayat al-Sul fi Tashih al-Usul (A Final Inquiry Concerning the Rectification of Planetary Theory). The theory of Ibn al-Shatir was identical with that of Copernicus, except for trivial differences in parameters, as we also briefly discussed in section 3 above.