Discovery and exploration of the Solar System that moved through the sky. Although the Greek philosopher Aristarchus of Samos had speculated on a heliocentric reordering of the cosmos, Nicolaus Copernicus in the 16th century developed a mathematically predictive heliocentric system. His 17th-century successors, Galileo Galilei, Johannes Kepler, and Isaac Newton, developed a modern understanding of physics that led to the gradual acceptance of the idea that Earth moves around the Sun and that the planets are governed by the same physical laws that govern Earth. In more recent times, this led to the investigation of geological phenomena such as mountains and craters and seasonal meteorological phenomena such
The Dark Side of the Sun of CY Aquarii) settled by a joint party of phnobes and earth-humans. The planet is mostly water and marsh. Their wealth derives from both the chance discovery of "pilac", a safe death-immunity drug and "googoo", a fungal copier and regenerator of human tissue. The vegetation is blue. 52 different sentient species (including earth-humanity) exist in the novel. Chief among them are: The rest: The Dark Side of the Sun The Dark Side of the Sun is a science fiction novel by Terry Pratchett, first published in 1976. It is similar to the work of Isaac Asimov. According to Don D'Ammassa,