Copernicus' astronomical observation tables, 1543.
© Science Museum / Science & Society Picture Library
Tables from Polish astronomer Nicolaus Copernicus' pioneering text 'De revolutionibus orbium caelestium' ('On the revolution of heavenly spheres', 1543), which represents his complete work. In this text, Copernicus (1473-1543) describes his idea of a sun-centred universe, in which the Earth is merely one of the planets revolving around the Sun and rotating on its axis. Prior to Copernicus, the Earth was considered to be the stationary centre of the universe, as advocated by Ptolemy (c 90-168 AD).