Émilie du Châtelet
|Émilie du Châtelet|
Madame Du Châtelet at her Desk
by an unknown French artist
17 December 1706|
|Died||10 September 1749
|Known for||Advocacy of kinetic energy|
|Influences||Isaac Newton, Gottfried Leibniz, Willem 's Gravesande|
Gabrielle Émilie Le Tonnelier de Breteuil, marquise du Châtelet (17 December 1706 – 10 September 1749) was a French mathematician, 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. The translation, published posthumously in 1759, is still considered the standard French translation.
Early life 
Émilie du Châtelet was born on 17 December 1706 in Paris, the only daughter of six children. Three brothers lived to adulthood: René-Alexandre (b. 1698), Charles-Auguste (b. 1701), and Elisabeth-Théodore (b. 1710). Her eldest brother, René-Alexandre, died in 1720, and the next brother, Charles-Auguste, died in 1731. However, her younger brother, Elisabeth-Théodore, lived to a successful old age, becoming an abbé and eventually a bishop. Two other brothers died very young. Du Châtelet also had an illegitimate half-sister, Michelle, who was born of her father and Anne Bellinzani, an intelligent woman who was interested in astronomy and married to an important Parisian official.
Her father was Louis Nicolas le Tonnelier de Breteuil, a member of the lesser nobility. At the time of du Châtelet's birth, her father held the position of the Principal Secretary and Introducer of Ambassadors to King Louis XIV. He held a weekly salon on Thursdays, to which well-respected writers and scientists were invited.
Early education 
Du Châtelet's education has been the subject of much speculation, but nothing is known with certainty.
Among their acquaintances was Fontenelle, the perpetual secretary of the French Académie des Sciences. Émilie's father Louis-Nicolas, recognizing her early brilliance, arranged for Fontenelle to visit and talk about astronomy with her when she was 10 years old. Émilie's mother, Gabrielle-Anne de Froulay, was brought up in a convent, at the time the predominant educational institution available to French girls and women. While some sources believe her mother did not approve of her intelligent daughter, or of her husband's encouragement of Émilie's intellectual curiosity, there are also other indications that her mother not only approved of du Châtelet's early education, but actually encouraged her to vigorously question stated fact.
In either case, such encouragement would have been seen as unusual for parents of their time and status. When she was small, her father arranged training for her in physical activities such as fencing and riding, and as she grew older, he brought tutors to the house for her. As a result, by the age of twelve she was fluent in Latin, Italian, Greek and German; she was later to publish translations into French of Greek and Latin plays and philosophy. She received education in mathematics, literature, and science. Her mother Gabrielle-Anne was horrified at her progress and fought Louis-Nicolas at every step, once attempting to have Émilie sent to a convent.
Émilie also liked to dance, was a passable performer on the harpsichord, sang opera, and was an amateur actress. As a teenager, short of money for books, she used her mathematical skills to devise highly successful strategies for gambling.
On 12 June 1725, she married the Marquis Florent-Claude du Chastellet-Lomont.[note 1] Her marriage conferred the title of Marquise du Chastellet.[note 2] Like many marriages among the nobility, theirs was arranged. As a wedding gift, the husband was made governor of Semur-en-Auxois in Burgundy by his father; the recently married couple moved there at the end of September 1725. Du Châtelet was eighteen at the time, her husband thirty.
The Marquis Florent-Claude du Chastellet and Émilie du Châtelet had three children: Françoise Gabriel Pauline (born 30 June 1726), Louis Marie Florent (born 20 November 1727), and Victor-Esprit (born 11 April 1733). Victor-Esprit died as a toddler in late summer 1734, likely the last Sunday in August. In 1749 Émilie du Châtelet gave birth to Stanislas-Adélaïde du Châtelet (daughter of Jean François de Saint-Lambert). She was born on 4 September 1749. The infant died in Lunéville on 6 May 1751.
Resumption of studies 
In 1733, at the age of 26, du Châtelet resumed her mathematical studies. Initially, she was tutored in algebra and calculus by Moreau de Maupertuis, a member of the Academy of Sciences. Although mathematics was not his forte, Maupertuis had received a solid education from Johann Bernoulli, who also taught Leonhard Euler. By 1735, however, 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 
Du Châtelet and Voltaire may have met in her childhood at one of her father's salons; Voltaire himself dates their meeting to 1729, when he returned from his exile in London. However, their friendship began in earnest in May 1733, upon her re-entering society after the birth of her third child.
Du Châtelet invited Voltaire to live in her country house at Cirey-sur-Blaise in Haute-Marne, northeastern France, and he became her long-time companion (under the eyes of her tolerant husband). There she studied physics and mathematics and published scientific articles and translations. To judge from Voltaire's letters to friends and their commentaries on each other's work, they lived together with great mutual liking and respect.
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, at Lunéville, from a pulmonary embolism, at the age of 42. Her daughter died roughly eighteen months later.
Scientific research and publications 
Criticizing Locke 
In her writings, du Châtelet criticizes the empiricist philosophy of John Locke and maintains that we have to assume universal principles and innate laws, saying without such principles there is no chain of knowledge, no truth and no numbers, as two and two could make as well four as six.
Heat and light 
In 1737, Châtelet published a paper entitled Dissertation sur la nature et la propagation du feu, based upon 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.
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. (In classical physics, the correct formula is Ek = 1⁄2mv², where Ek is the kinetic energy of an object, m its mass and v its velocity.)
Translation and commentary on Newton's Principia 
In 1749, 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 of the notion of conservation of energy from its principles of mechanics. Published ten years after her death, today du Châtelet's translation of Principia Mathematica is still the standard translation of the work into French.
Other contributions 
Development of financial derivatives 
Much later in life, she once lost 84,000 francs (the equivalent of over US$1,000,000 in 2009)—some of it borrowed—in one evening at the table at the court of Fontainebleau, to card cheats. To quickly raise the money to pay back her huge debts, she devised an ingenious financing arrangement similar to modern derivatives, whereby she paid tax collectors a fairly low sum for the right to their future earnings (they were allowed to keep a portion of the taxes they collected for the King), and promised to pay the court gamblers part of these future earnings.
Biblical scholarship 
Du Châtelet wrote a critical analysis of the Bible, specifically the book of Genesis and those of the New Testament.
Discourse on happiness 
Du Châtelet also wrote a monograph, Discours sur le bonheur, on the nature of happiness, both in general and specialized to women.
Translation of the Fable of the Bees, and other works 
Du Châtelet translated The Fable of the Bees in a free adaptation. She also wrote works on optics, rational linguistics, and the nature of free will.
Support of women's education 
In her first independent work, the preface to her translation of the Fable of the Bees, du Châtelet argues strongly for women's education, particularly a strong secondary education as was available for young men in the French collèges. By denying women a good education, she argues, society prevents women from becoming eminent in the arts and sciences.
Although the classical mechanics of du Châtelet are not approached with the same accuracy as Einstein's concept of mass and velocity, in his famous equation for the energy equivalent of matter E = mc² (where c represents the velocity of light), modern biographers and historians continue to see a neat accord with the principle E ∝ mv² first recognised by du Châtelet from over 150 years before. It should be emphasized, however, that from a physical point of view, du Châtelet's principle is a correct assessment of the kinetic energy in classical mechanics, and is the first term in an expansion of Einstein's mass–energy equivalence.
A main-belt minor planet and a crater on Venus have been named in her honor, and she is the subject of two plays: Legacy of Light by Karen Zacarías and Emilie: La Marquise Du Châtelet Defends Her Life Tonight by Lauren Gunderson. The opera Émilie of Kaija Saariaho is about the last moments of her life.
Du Châtelet is often represented in portraits with mathematical iconography, such as holding a pair of dividers or a page of geometrical calculations. In the early nineteenth century, a French pamphlet of celebrated women (Femmes célèbres) introduced a possibly apocryphal story of du Châtelet's childhood. According to this story, a servant fashioned a doll for her by dressing up wooden dividers as a doll; however, du Châtelet undressed the dividers and intuited their purpose, making a circle with them.
- Dissertation sur la nature et la propagation du feu (1st edition, 1739; 2nd edition, 1744)
- Institutions de physique (1st edition, 1740; 2nd edition, 1742)
- Principes mathématiques de la philosophie naturelle par feue Madame la Marquise du Châtelet (1st edition, 1756; 2nd edition, 1759)
- Examen de la Genèse
- Examen des Livres du Nouveau Testament
- Discours sur le bonheur
- The Lomont suffix indicates the branch of the du Chastellet family; another such branch was the du Chastellet-Clemont.
- The spelling Châtelet (replacing the s by a circumflex over the a) was introduced by Voltaire, and has now become standard. (Andrew, Edward (2006). "Voltaire and his female protectors". Patrons of enlightenment. University of Toronto Press. p. 101. ISBN 978-0-8020-9064-5.)
- Hamel (1910: 370)
- Zinsser, pp. 19, 21, 22.
- Zinsser, pp. 16–17; for a quite different account, see Bodanis, pp. 131–134.
- Zinsser (2006: 26–29)
- Hamel (1910: 5).
- Zinsser, pp. 39 and 58.
- Zinsser, pp. 40 and 93.
- D. W. Smith, "Nouveaux regards sur la brève rencontre entre Mme Du Châtelet et Saint-Lambert." In The Enterprise of Enlightenment. A Tribute to David Williams from his friends. Ed. Terry Pratt and David McCallam. Oxford, Berne, etc.: Peter Lang, 2004, p. 329-343. See also Anne Soprani, ed., Mme Du Châtelet, Lettres d'amour au marquis de Saint-Lambert, Paris, 1997.
- Zinsser (2006: 278)
- Hagengruber (2011: 8-12)
- Hamel (1910: 286)
- Zinsser, pp. 25–26.
- McLellan, James E; Dorn, Harold (2006). Science and Technology in World History: An Introduction. Baltimore, MD: Johns Hopkins University Press. p. 368. ISBN 0-8018-8359-8.
- Zinsser (2006: 177)
- Ancestors of E=mc² Online essay from Public Broadcast Service, Arlington, VA
- Libretto of Émilie
- Zinsser, p. 13.
- Bodanis, David (10 October 2006). Passionate Minds: The Great Love Affair of the Enlightenment. New York: Crown. ISBN 0-307-23720-6.</ref>
- Ehman, Esther (1986) Madame du Chatelet: Leamington Spa: Berg. ISBN 0-907582-85-0.
- Hamel, Frank (1910). An Eighteenth Century Marquise: A Study of Émilie Du Châtelet and Her Times. London: Stanley Paul and Company. OCLC 37220247.
- Hagengruber, Ruth, editor (2011) Emilie du Chatelet between Leibniz and Newton. Springer. ISBN 978-94-007-2074-9.
- Mitford, Nancy (1999) Voltaire in Love: New York: Carroll and Graff. ISBN 0-7867-0641-4.
- Zinsser, Judith (2006) Dame d'Esprit: A Biography of the Marquise du Chatelet: New York: Viking. ISBN 0-670-03800-8 online review.
- Zinsser, Judith and Hayes, Julie, eds. (2006) Emelie du Chatelet: Rewriting Enlightenment Philosophy and Science: Oxford: Voltaire Foundation. ISBN 0-7294-0872-8.
|Wikimedia Commons has media related to: Émilie du Châtelet|
- O'Connor, John J.; Robertson, Edmund F., "Gabrielle Émilie Le Tonnelier de Breteuil Marquise du Châtelet", MacTutor History of Mathematics archive, University of St Andrews.
- "Emilie du Chatelet", Biographies of Women Mathematicians, Agnes Scott College
- The Portraits of Emilie du Chatelet at MathPages
- Voltaire and Emilie from the website of the Château de Cirey, accessed 11 December 2006.
- Correspondence between Frederick the Great and the Marquise du Châtelet Digital edition of Trier University Library (French and German text)
News media 
- Fara, Patricia (10 June 2006). "Love in the Library". The Guardian
- "The scientist that history forgot," The Guardian 15 May 2006.
- Object Lesson / Objet de Lux Article on Emilie du Châtelet from Cabinet (magazine)
- PhysicsWeb article: Emilie du Châtelet: the genius without a beard
- National Public Radio Morning Edition, 27 November 2006: Passionate Minds
- Women Scientists Today Link to CBC radio interview with author David Bodanis.
- Link to ARTE-Doku-Drama E = mc² – Einsteins große Idee. ARTE TV 26 April 2008, 12 March 2011.