## 1629 – Huygens – bio

Christiaan Huygens was born in 1629 in The Hague, Netherlands (then known as the Dutch Republic) and was an astronomer, mathematician and physicist. He advanced the art of grinding lenses and building telescopes and in 1655 discovered that Titan was a moon of Saturn and in the next year became the first to propose that Saturn was surrounded by flat rings. In 1656, he made the first known drawing of the Orion nebula and also designed and patented the first pendulum clock in order to provide the more accurate timekeeping required for astronomical observations. He used geometrical methods to describe the arc of a pendulum, which were early forms of calculus. In 1657, he published the first book on probability. In 1659, he created the term, “centrifugal force” and described the circular motion involved. In 1678, Huygens argued for a wave theory of light, which was later confirmed by Young and expanded upon by Fresnel.

PRECURSOR:

**-0325 – Euclid**

0078 – Heng

**1452 – Da Vinci**

**1564 – Galileo**

CONCURRENT:

**1588 – Mersenne**

**1596 – Descartes**

**1601 – Fermat**

**1608 – telescope**

**1623 – Pascal**

**1627 – Boyle**

1635 – Hooke

**1642 – Newton**

**1646 – Leibniz**

SUBSEQUENT:

1693 – Harrison

**1707 – Euler**

**1773 – Young**

**1781 – Poisson**

1788 – Fresnel

**1791 – Faraday**

1819 – Foucault