Christiaan Huygens (1629-1695) was a prominent enlightenment-era physicist, mathematician, and inventor. He introduced the fundamental tenets of probability theory into the field of mathematics.
In 1657 Huygens published the first treatise on the mathematics of probability, in which he set forth the concept of expected value. All later applications of probability theory in the fields of pattern recognition, information theory, and machine intelligence can be traced back to this foundational work.
That same year, Huygens invented the pendulum clock, which revolutionized timekeeping and enabled much improved nautical navigation.
Huygens is responsible for many other advances in physics and science as well. He is best known for his formulation of the wave theory of light, and his discovery of the Orion Nebula and Saturn’s rings and its moon Titan.