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
Paris in the 16th century art, did not come until the very end of the century with the reign of Henry IV. Through the 16th century, there were only four bridges across the Seine, two on each bank, insufficient for the growing city and the amount of traffic they carried. The Paris bridges at the beginning of the 16th century were largely made of wood, and were frequently washed away in floods or knocked down by ice on the frozen river. The most important bridge was the Pont au Change, which had been built in 1304 under Philip le Bel, and was site where the