Summary: Watching the sky, you can see the Sun, moon, planets and stars moving above Earth. It is very intuitive to imagine that you are standing still and the objects you are observing are moving above you and this was the view taken by geocentric models of the cosmos. A Greek model, which was dominant in many parts of the world for hundreds of years, had a spherical Earth at the centre of the universe, with the other heavenly bodies orbiting in perfect circles. This talk will outline problems and challenges to this model, and the developments which followed, through the theory of Copernicus, mathematical treatments by Kepler and Newton and questions of what drives planetary motion.
