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
Against the Current: Essays in the History of Ideas published in 1973. In this essay, Berlin explains his theory of a Counter-Enlightenment. Berlin traces the ideology of figures such as Giambattista Vico, from their opposition to enlightenment ideals to the emergence of Romanticism and Existentialism. Against the Current: Essays in the History of Ideas Against the Current: Essays in the History of Ideas (1979) is a collection of essays by 20th century philosopher and historian Isaiah Berlin. The collection was edited by Henry Hardy, and featured an introduction by Roger Hausheer. The book collects previously published essays in which Berlin discusses the thoughts of 20th century ideologic dissenters who