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
Paris in the 16th century Protestants were killed in the streets by Catholic mobs. At the end of the century, Henry IV was able to return to Paris as King, and permitted Protestants to open churches outside the city. Urban innovation in Paris during the 16th century included the first street lighting, by candles.The first theater opened in Paris in 1548, and the first ballet performance took place at the French court in 1581. At the beginning of the 16th century Paris was officially the capital of France, but the King, Louis XI, had little trust in the Parisians, and resided in the chateaux of