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
The Sun Saboteurs Earth Quarter"; and in the UK under the original title in the omnibus "Two Novels". In the future, Earth has been devastated by war and disease and supports only a primitive agrarian society. Most Earthmen live elsewhere, as émigrés on planets that are populated by alien species. The author suggests that the human species is the only one plagued by "original sin", i.e. by an innate tendency to lie, cheat, kill; aliens have come to accept these traits without understanding them. The story takes place among a group of humans in the "Earth Quarter", a ghetto on the planet Palu