Christiaan Huygens (The Hague, 1629 / The Hague, 1695) was a Dutch astronomer, physicist, mathematician and inventor. In astronomy, he perfected the telescope, explained the nature of the rings of Saturn, discovered Titan, studied the Orion Nebula (M42), and invented a micrometer to measure small angular distances. In other areas, he invented the modern pendulum clock, explained the wave nature of light, made important contributions to probability theory, and established the laws of collision between elastic bodies. He was a member of the Royal Society of London.
