Nicolaus Copernicus "Almagest" circa 150 CE; the Earth was the stationary center of the universe. Stars were embedded in a large outer sphere which rotated rapidly, approximately daily, while each of the planets, the Sun, and the Moon were embedded in their own, smaller spheres. Ptolemy's system employed devices, including epicycles, deferents and equants, to account for observations that the paths of these bodies differed from simple, circular orbits centered on the Earth. Copernicus' major work on his heliocentric theory was "Dē revolutionibus orbium coelestium" ("On the Revolutions of the Celestial Spheres"), published in the year of his death, 1543. He had
The Book of the Short Sun least "Locus: The Magazine of the Science Fiction & Fantasy Field" considered the three "Short Sun" volumes separately for annual "Best Novel" awards. The "Short Sun" of the title is an ordinary star, in contrast to the "Long Sun" of the Whorl where the narrator grew up. Most of the story takes place in a star system with two habitable planets, Blue and Green, which lend their names to the first two volumes. The Whorl of volume three's title is the generation ship setting of "Long Sun". The Tor hardcover editions (see table) were almost 1200 pages long in sum.