# Mathematician:Christiaan Huygens

## Contents

## Mathematician

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.

Developed an improved method of grinding lenses for telescopes.

Noticed a surface feature of Mars, and from there determined the length of a Martian day.

Introduced the concept of expectation.

Established the laws of impact for elastic bodies, refuting the erroneous work of Descartes in his $1644$ work *Principia Philosophiae*.

Made the first detailed study of the evolute and involute of a curve in the plane.

Served as a mentor to young Gottfried Wilhelm von Leibniz.

Investigated protozoology in order to repeat the work of Antonie Philips van Leeuwenhoek.

Left extensive manuscripts which, had they been published, may well have brought the science of microbiology forward by two centuries.

For one thing, he anticipated the work of Louis Pasteur.

Deduced the laws of reflection and refraction.

Explained the reason behind the double refraction of Iceland Spar.

Estimated the distance of the star Sirius as being $27 \, 664$ times as far away from Earth as the sun.

This was inaccurate, but no better estimate was forthcoming for another century.

## Nationality

Dutch

## History

- Born: 14 April 1629 in The Hague, Netherlands
- 1663: Elected Fellow of Royal Society of London
- 1666: Moved to Paris at the urging of Jean-Baptiste Colbert
- 1669: Presented to the Royal Society a correct statement on the laws of impact of elastic bodies
- 1681: Returned to The Hague, as Paris was becoming intolerant of Protestants
- 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)

Results named for **Christiaan Huygens** can be found here.

## Publications

- 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*De iis quae liquido supernatant*(About the parts above the water) (unpublished) - 1651: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)

### Posthumous Publications

- 1698:
*Cosmotheoros*(solar system, cosmology, life in the universe) - 1703:
*Opuscula posthuma*, 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 the Snell-Descartes Law appears)

- 1724:
*Novus cyclus harmonicus* - 1728:
*Christiani Hugenii Zuilichemii, dum viveret Zelhemii toparchae, opuscula posthuma ...*or:*Opera reliqua*(about optics and physics)

## Notable Quotes

*The world is my country, and science is my religion.*

## Also known as

Some sources give his first name in the Latinised form: **Christian Huygens**.

## Sources

- John J. O'Connor and Edmund F. Robertson: "Christiaan Huygens": MacTutor History of Mathematics archive

- 1937: Eric Temple Bell:
*Men of Mathematics*... (previous) ... (next): Chapter $\text{V}$: "Greatness and Misery of Man" - 1937: Eric Temple Bell:
*Men of Mathematics*... (previous) ... (next): Chapter $\text{VII}$: Master of All Trades - 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): A List of Mathematicians in Chronological Sequence - 1991: David Wells:
*Curious and Interesting Geometry*... (previous) ... (next): A Chronological List Of Mathematicians - 1992: George F. Simmons:
*Calculus Gems*... (previous) ... (next): Chapter $\text {A}.17$: Huygens ($\text {1629}$ – $\text {1695}$) - 1992: George F. Simmons:
*Calculus Gems*... (previous) ... (next): Chapter $\text {B}.21$: The Cycloid - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): A List of Mathematicians in Chronological Sequence - 1998: David Nelson:
*The Penguin Dictionary of Mathematics*(2nd ed.) ... (previous) ... (next): Entry:**Huygens, Christiaan**(1629-95) - 2008: David Nelson:
*The Penguin Dictionary of Mathematics*(4th ed.) ... (previous) ... (next): Entry:**Huygens, Christiaan**(1629-95) - 2014: Christopher Clapham and James Nicholson:
*The Concise Oxford Dictionary of Mathematics*(5th ed.) ... (previous) ... (next): Entry:**Huygens, Christiaan**(1629-95)