Cosmology in medieval Islam empirical testing. His work thus marked a turning point in astronomy, which may be considered a "Scientific Revolution before the Renaissance". His rectified model was later adapted into a heliocentric model by Copernicus, which was mathematically achieved by reversing the direction of the last vector connecting the Earth to the Sun. In the published version of his masterwork, "De revolutionibus orbium coelestium", Copernicus also cites the theories of al-Battani and Averroes as influences. An area of active discussion in the Maragheh school, and later the Samarkand and Istanbul observatories, was the possibility of the Earth's rotation. Supporters of this theory
Planets of the Hainish Cycle current estimate. On the other hand, giant stars last 100 million years or so, which is much less time than Earth needed to evolve complex life. It is probable that the native humanoids are of Hainish origin, as are many other indigenous populations in the Hainish Cycle, descendents of genetically modified Hanish colonists from the ancient Hanish colonial epoch, similar to other planets in the cycle. This would account for the successful imbreeding, which should not be possible if they had evolved from completely different biospheres. In 1.5 million years, Eltanin will pass within 28 light years of Earth. At