Orrery on display in Kassel at the Astronomisch-Physikalisches Kabinett and in Dresden at the Mathematisch-Physikalischer Salon. In "De revolutionibus orbium coelestium", published in Nuremberg in 1543, Nicolaus Copernicus challenged the Western teaching of a geocentric universe in which the Sun revolved daily around the Earth. He observed that some Greek philosophers had proposed a heliocentric universe. This simplified the apparent epicyclic motions of the planets, making it feasible to represent the planets' paths as simple circles. This could be modelled by the use of gears. Tycho Brahe's improved instruments made precise observations of the skies (1576–1601), and from these Johannes Kepler
Paris in the 16th century Paris in the 16th century During the 16th century, Paris was the largest city in Europe, with a population of about 350,000 in 1550. The 16th century saw the Renaissance arrive in Paris, expressed in the city's architecture, art and cultural life. The Kings of France returned to Paris from the Loire Valley. Paris. In 1534 Francis I became the first French king to make the Louvre his residence. Under King Francis I, the Renaissance style of architecture, imported from Italy, was widely used in churches and public buildings, replacing the gothic style. Paris landmarks built during the 16th century