was jokingly told by Aristarchus that he should be charged with impiety. Ménage, shortly after the trials of Galileo and Giordano Bruno, amended an accusative (identifying the object of the verb) with a nominative (the subject of the sentence), and vice versa, so that the impiety accusation fell over the heliocentric sustainer. The resulting misconception of an isolated and persecuted Aristarchus is still transmitted today. In 499 CE, the Indian astronomer and mathematician Aryabhata propounded a planetary model that explicitly incorporated Earth's rotation about its axis, which he explains as the cause of what appears to be an apparent westward motion of the stars. He also believed that the orbits of planets are elliptical. Aryabhata's followers were particularly strong in South India, where his principles of the diurnal rotation of Earth, among others, were followed and a number of secondary works were based on them. Middle Ages Islamic astronomers Several Islamic astronomers questioned the Earth's apparent immobility and centrality within the universe. Some accepted that the Earth rotates around its axis, such as Al-Sijzi, who invented an astrolabe based on a belief held by some of his contemporaries "that the motion we see is due to the Earth's movement and not to that of the sky". That others besides al-Sijzi held this view is further confirmed by a reference from an Arabic work in the 13th century which states: "According to the geometers [or engineers] (muhandisīn), the earth is in constant circular motion, and what appears to be the motion of the heavens is actually due to the motion of the earth and not the stars". In the 12th century, Nur ad-Din al-Bitruji proposed a complete alternative to the Ptolemaic system (although not heliocentric). He declared the Ptolemaic system as an imaginary model, successful at predicting planetary positions but not real or physical. Al-Btiruji's alternative system spread through most of Europe during the 13th century. Mathematical techniques developed in the 13th to 14th centuries by the Arab and Persian astronomers Mu'ayyad al-Din al-Urdi, Nasir al-Din al-Tusi, and Ibn al-Shatir for geocentric models of planetary motions closely resemble some of the techniques used later by Copernicus in his heliocentric models. European astronomers Ptolemaic system The prevailing astronomical model of the cosmos in Europe in the 1,400 years leading up to the 16th century was the Ptolemaic System, a geocentric model created by the Roman citizen Claudius Ptolemy in his Almagest, dating