Émilie du Châtelet Émilie du Châtelet Émilie du Châtelet , born Gabrielle Émilie le Tonnelier de Breteuil ( December 17 , 1706 – September 10 , 1749 ) was a French mathematician , physicist , and author . She researched the science of fire , publishing in 1737 a paper which foresaw what is today known as infra-red radiation and the nature of light . Her book Institutions de Physique ( “Lessons in Physics” ) appeared in 1740 ; it was presented as a review of new ideas in science and philosphy to be studied by her thirteen-year-old son , but it incorporated and sought to reconcile complex ideas from the leading thinkers of the time . In the year of her death she completed the work regarded as her outstanding achievement : her translation into French , with her own commentary , of Newton’s celebrated Principia Mathematica , including her derivation from its principles of mechanics the notion of conservation of energy . Today this is still the standard translation of the work into French . Early life Her father was Louis Nicolas le Tonnelier de Breteuil , the Principal Secretary and Introducer of Ambassadors to Louis XIV , whose position placed him at the center of social activity in the court , and thus gave the family great status . Her mother , Gabrielle Anne de Froulay , was brought up in a convent . Émilie de Breteuil was a rather awkward child , and so she was given lessons in fencing , riding , and gymnastics in an attempt to improve her coordination . She was remarkably well educated for the time , and by the age of twelve she was fluent in Latin , Italian , Greek and German . She received education in mathematics , literature , and even science as well . She also liked to dance , was a passable performer on the harpsichord , sang opera , and was an amateur actress . Marriage and liaisons On 20 June 1725 she married the Marquis Florent-Claude du Chastellet , and thus became Marquise du Chastellet ( the spelling Châtelet was introduced by Voltaire , and has now become standard ) . The Marquis was a military man and governor of Semur-en-Auxois in Burgundy . The marriage was arranged and they had little in common , but did not openly fight often. Émilie du Châtelet had three children , and , considering her marital responsibilities fulfilled , she and her husband agreed to live separate lives . In the upper classes of France at the time , it was standard for both the husband and wife to have a lover . Émilie du Châtelet had three love affairs before she met Voltaire . At the age of twenty-four , she had an affair with the Duc de Richelieu that lasted for a year and a half . The Duc was interested in literature and philosophy , and Châtelet was one of the few women who could converse with him on his own level . She read every book of consequence , attended the theater regularly , and enjoyed intellectual debate . Châtelet expressed an interest in Isaac Newton , and Richelieu encouraged her to take lessons in higher mathematics to better understand his theories . Châtelet invited Voltaire to live in her country house at Cirey in Lorraine , and she became his long-time companion ( under the eyes of her tolerant husband ) . There she studied physics and mathematics and published scientific articles and translations . Her translation of Newton 's Principia Mathematica is still regarded as the standard version in France . Her greatest discovery was the demonstration that the kinetic energy of an object is a function of the square of its velocity . Moreau de Maupertuis , a member of the Academy of Sciences , became Châtelet 's tutor in geometry . He was a mathematician , astronomer and physicist , and supported Newton 's theories , which were a topic of hot debate at the Academy . Châtelet 's last affair proved to be fatal . In her early 40s , she had an affair with the Marquis de Saint-Lambert and became pregnant . Fraught with premonitions of dying in childbirth , Châtelet bore the child , but died six days later from an embolism at the age of 43 . Voltaire declared that du Châtelet was `` a great man whose only fault was being a woman '' . References Bodanis , David ( 2006 ) . Passionate Minds : The Great Enlightenment Love Affair , London : Little Brown . ISBN 0316730858 . Ehman , Esther ( 1986 ) Madame du Chatelet : Leamington Spa : Berg . ISBN 0907582850 . Mitford , Nancy ( 1999 ) Voltaire in Love : New York : Carroll and Graff . ISBN 0786706414 . Zinsser , Judith ( 2006 ) Dame d'Esprit : A Biography of the Marquise du Chatelet : New York : Viking . ISBN 0670038008 . Zinsser , Judith and Hayes , Julie ( eds ) ( 2006 ) Emelie du Chatelet : Rewriting Enlightenment Philosophy and Science : Oxford : Voltaire Foundation . ISBN 0729408728 . ^ Agnes Scott bio ^ The Guardian 11 June 2006 . External links PBS.org – Châtelet 's role in E=mc² The scientist whom history forgot The Guardian article on Châtelet ( 8/2006 ) Gabrielle Émilie Le Tonnelier de Breteuil Marquise du Châtelet : Biography at the MacTutor History of Mathematics archive PhysicsWeb article : Emilie du Châtelet : the genius without a beard Categories : 1706 births | 1749 deaths | French nobility | French mathematicians | French physicists | French scientists | Women mathematicians | Women physicists In other languages : Deutsch | Español | Français | Galego | עברית | Polski | Svenska | 中文 