Mathematician:Christiaan Huygens

Dutch mathematician, astronomer, physicist and horologist.

Studied the rings of Saturn and discovered its moon Titan.

Invented the pendulum clock.

Believed that light travels in waves, hence the Huygens-Fresnel Principle.

Nationality
Dutch

History

 * Born: 14 April 1629 in The Hague, Netherlands
 * Died: 8 July 1695 in The Hague, Netherlands

Theorems and Definitions

 * Huygens-Fresnel Principle (with Augustin-Jean Fresnel)
 * Parallel Axes Theorem (also known as the Huygens-Steiner Theorem, with Jakob Steiner)

Books and Papers

 * 1649: De iis quae liquido supernatant (About the parts above the water) (unpublished)
 * 1651: Cyclometriae
 * 1651: Theoremata de quadratura hyperboles, ellipsis et circuli (theorems concerning the quadrature of the hyperbola, ellipse and circle)
 * 1654: De circuli magnitudine inventa
 * 1656: De Saturni Luna observatio nova (About the new observation of the moon of Saturn)
 * 1656: De motu corporum ex percussione (published in 1703)
 * 1657: De ratiociniis in ludo aleae (translated by Frans van Schooten as Van reeckening in spelen van geluck)
 * 1659: Systema saturnium (on the planet Saturn)
 * 1673: Horologium oscillatorium sive de motu pendularium (theory and design of the pendulum clock)
 * 1673: De vi centrifuga (Concerning the centrifugal force)
 * 1684: Astroscopia Compendiaria tubi optici molimine liberata (compound telescopes without a tube)
 * 1685: Memoriën aengaende het slijpen van glasen tot verrekijckers (How to grind telescope lenses)
 * 1686: Kort onderwijs aengaende het gebruijck der horologiën tot het vinden der lenghten van Oost en West (How to use clocks to establish the longitude)
 * 1690: Traité de la lumière (Treatise on [the nature of] light)
 * 1690: Discours de la cause de la pesanteur (Discourse about gravity, possibly written in or around 1669)
 * 1691: Lettre touchant le cycle harmonique (concerning the 31-tone system)
 * 1698: Cosmotheoros (solar system, cosmology, life in the universe)
 * 1703: Opuscula posthuma (posthumous works), including:
 * De motu corporum ex percussione (Concerning the motions of colliding bodies: contains the first correct laws for collision, dating from 1656).
 * Descriptio automati planetarii (description and design of a planetarium)
 * Dioptrica (in which Snell's Law appears)
 * 1724: Novus cyclus harmonicus (after Huygens' death)
 * 1728: Christiani Hugenii Zuilichemii, dum viveret Zelhemii toparchae, opuscula posthuma ... or: Opera reliqua (about optics and physics)

Also see

 * , Chapter $\text {A}.17$