Portrait of the Polish astronomer Nicolaus Copernicus, 1473-1543. Copernicus recognised that the cosmology proposed by Ptolemy over a thousand years before was becoming inadequate to explain the motion of the celestial bodies. He developed in full mathematical detail a new cosmology in which the Sun was at the centre of the Universe with planets and stars orbiting about it in circular orbits. Copernicus, fearing religious persecution, hesitated to reveal his ideas but in 1543 they were published in his book De Revolutionibus Orbium Celestium, The Revolution of the Heavenly Spheres. His book was banned by the Church from 1616 until 1835.