Kepler, Johannes (1571-1630)

A German savant considered as the founder of modern astronomy. A disciple of Copernicus’ system (the Earth is not the centre of the universe; it is a planet like any other, which gravitates around the Sun). He discovered the laws which govern the movements of the planets in an orbit in the form of an ellipsis. These three ‘Kepler’s Laws’ opened the way to Isaac Newton, who provided an explanation for them. Kepler also carried out important work in the field of optics: the definition of light rays, an explanation of the reflection of light and atmospheric refraction.