Giordano Bruno motion of the stars to be an illusion caused by the rotation of the Earth on its axis; he also preserved the notion of an immobile center, but it was the Sun rather than the Earth. Copernicus also argued the Earth was a planet orbiting the Sun once every year. However he maintained the Ptolemaic hypothesis that the orbits of the planets were composed of perfect circles—deferents and epicycles—and that the stars were fixed on a stationary outer sphere. Despite the widespread publication of Copernicus' work "De revolutionibus orbium coelestium", during Bruno's time most educated Catholics subscribed to the Aristotelian
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,