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
Myth of the flat Earth flat Earth. The widely circulated engraving of a man poking his head through the firmament surrounding the Earth to view the Empyrean, executed in the style of the 16th century, was published in Camille Flammarion's "L'Atmosphère: Météorologie Populaire" (Paris, 1888, p. 163). The engraving illustrates the statement in the text that a medieval missionary claimed that "he reached the horizon where the Earth and the heavens met". In its original form, the engraving included a decorative border that places it in the 19th century. In later publications, some of which claimed that the engraving dates to the 16th century, the