Categories: Biographical notes
Johannes Kepler (1571-1630) was an astronomer, astrologer, mathematician and philosopher born in what is now Germany. He is most famous for his three laws concerning planetary orbits. He was a major champion of the solar centred model of the world proposed by Copernicus, although he assisted the astronomer Tycho Brahe and also discussed his model of the structure of (what we call) the solar system. He made extensive use of observations of the changing position in the sky of Mars and used these to conclude that planets moved, not in circles as has long been assumed, but ellipses. He also produced a short study of snowflakes and considered how particles pack together in materials.
