James Clerk Maxwell lived from 1831 to 1879, and was one of the great mathematicians and physicists of his time. He studied Saturn's rings and suggested that they were composed of solid particles. This theory was confirmed 100 years later by the Voyager 1 space probe. Maxwell is most famous for his equations linking electricity and magnetism. His revolutionary work led to the development of quantum physics in the early 1900's and to Einstein's theory of relativity. Maxwell also described the properties of gas molecules using statistics. His improvements to the kinetic theory of gases included showing that temperature and heat are caused only by molecular movement.