History of the center of the Universe Sun at the center of our Solar System. The word comes from the Greek ( "helios" "sun" and "kentron" "center"). The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BCE by Aristarchus of Samos, but had received no support from most other ancient astronomers. Nicolaus Copernicus' major theory of a heliocentric model was published in "De revolutionibus orbium coelestium" ("On the Revolutions of the Celestial Spheres"), in 1543, the year of his death, though he had formulated the theory several decades earlier. Copernicus' ideas were not immediately accepted, but they did
Science and technology of the Han dynasty Han astronomers believed the Sun, Moon, and planets were spherical like balls or crossbow bullets. He also wrote that the Moon and planets produce no light of their own, are viewable to people on Earth only because they are illuminated by the Sun, and those parts not illuminated by the Sun would be dark on the other side. For this, Jing compared the Moon to a mirror illuminating light. In the 2nd century CE, Zhang Heng drew a similar comparison to Jing's by stating that the Sun is like fire and the Moon and planets are like water, since fire