Historical cosmologies. 17th-century diagram of four historical models of planetary orbits. The geocentric system of 2nd-century Greek astronomer Ptolemy is at right. The smaller diagrams show the heliocentric 1543 model (upper left) of Polish astronomer Nicolaus Copernicus (1473-1543), the geo-heliocentric 1570s model (lower left) of Danish astronomer Tycho Brahe (1546-1601), and the heliocentric 1644 model (upper centre) of French mathematician Rene Descartes (1596-1650). At lower centre is the theory of Descartes concerning the boundlessness of the universe. Titled 'The Figure of the World', these diagrams were published in 1650.