Portrait of Nicolaus Copernicus (1473-1543), the Polish astronomer who first claimed that the Universe was centered around the Sun. From 1512, he developed a mathematical model for this heliocentric theory. This system contrasted with the thousand-year-old Earth-centered Ptolemaic system, to which the Roman Catholic church adhered. Copernicus feared persecution and delayed publication of his book, "The Revolution of the Heavenly Spheres," until 1543. The book was banned by the Roman Catholic church from 1616 until 1835.