Émilie du Châtelet By: Chanelle Grannum

Gabrielle Émilie Le Tonnelier de Breteuil, marquise du Châtelet was a French mathmatician, physicist, and author during the Age of Enlightenment.

Her crowning achievement is considered to be her translation and commentary on Isaac Newton's work Principia Mathematica. It was published in 1759, ten years after her death. Hers is still the standard translation in French.

Early Life and Education Born on December 27, 1706 in Parris, France The only daughter of six children; she also had an illegitimate half-sister Had tutors brought to the house for her and, as a result, she became fluent in Latin, Italian, Greek and German. She received education in mathematics, literature, and science.

Marriage She married Marquis Florent-Claude du Chastellet-Lomont on June 12, 1725 It was an arranged marriage As a wedding gift, the husband was made governor of Semur-en-Auxois in Burgundy by his father. Couple moved there at the end of September 1725. When they got married she was at the age of 18 when her husband was at the age of 30

Resumption of Studies In 1733, at the age 26, du Chatelet resumed her mathematical studies. She was tutored in algebra and calculus by Moreau de Maupertuis, a member of the Academy of Sciences. She was later taught by Leonhard Euler. By 1735, du Châtelet had turned for her mathematical training to Alexis Clairaut, a mathematical prodigy known best for Clairaut's equation and Clairaut's theorem.

Relationship with Voltaire They first met in 1729 but their friendship kindled in May of 1733 after she re-entered society after having her second child. Du Châtelet invited him to live in her country house at Cirey-sur-Blaise in Haute-Marne, north-eastern France, and he became her long-time companion (under the eyes of her tolerant husband).

Final Pregnancy and Death In May 1748, Du Châtelet began an affair with the poet Jean François de Saint-Lambert and became pregnant. In a letter to a friend, she confided her fears that she would not survive her pregnancy. On the night of 3 September 1749, she gave birth to a daughter, Stanislas-Adélaïde, but died a week later from a pulmonary embolism at the age of 42. Her daughter died about 18 months later.

Scientific Research and Publications Heat and Light In 1737, du Châtelet published a paper entitled Dissertation sur la nature et la propagation du feu, based on her research into the science of fire, that predicted what is today known as infrared radiation and the nature of light. Institutions de Physique Her book Institutions de Physique (“Lessons in Physics”) appeared in 1740 It was presented as a review of new ideas in science and philosophy 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.

Scientific Research and Publications Advocacy of kinetic energy In it, she combined the theories of Gottfried Leibniz and the practical observations of Willem 's Gravesande to show that the energy of a moving object is proportional not to its velocity, as had previously been believed by Newton, Voltaire and others, but to the square of its velocity. Translation and commentary on Newton's Principia In the year of her death, she completed the work regarded as her outstanding achievement: her translation into French, with her commentary, of Newton’s Principia Mathematica, including her derivation from its principles of mechanics, the notion of conservation of energy.

Work Cited Mandic, Sasha. "Emilie Du Chatelet." Agnes Scott College - A Private, Liberal Arts Women's College in Metropolitan Atlanta, Georgia. 2 July 210. Web. 22 Dec. 2010. <http://www.agnesscott.edu/lriddle/women/chatelet.htm>. Birkenstock, Jane M. "Gabrielle Emilie Le Tonnelier De Breteuil Du Chatelet - and Voltaire." Voltaire Residence / Residence of Voltaire. 7 Jan. 2009. Web. 22 Dec. 2010. <http://www.visitvoltaire.com/emilie_du_chatelet_bio.htm>. "Gabrielle Émilie, Marquise Du Châtelet-Laumont (1706-1749)." Oregon State University. Web. 22 Dec. 2010. <http://oregonstate.edu/instruct/phl302/philosophers/chatelet.html>.