By Joan Cummins, Dramaturg

Born to a wealthy aristocratic family in Paris in 1706, Emilie du Châtelet was one of the few people in her time who could wrestle with the cutting-edge math of calculus. For a long time best known as the lover of Voltaire—the iconoclastic French dramatist, philosopher, and scientist—she was also extraordinary in her own right.
Having discovered the questions science posed about the nature of the universe, she never stopped searching for answers.

She also worked tirelessly on behalf of those she loved. Contentedly married to the Marquis du Châtelet, Emilie lobbied on behalf of his military career, educated their son herself, and organized an advantageous marriage for their daughter into the court of Naples. She also did her best to keep Voltaire out of prison for his screeds against the Church. All the while she furiously corresponded with other intellectuals, worked through the principles of Newtonian physics from the ground up, and was the first woman published by the prestigious Académie Royale des Sciences.
In 1749 she found herself unexpectedly pregnant again by her new young lover Saint-Lambert, and continued to work on her translation and commentary on Newton into the wee hours of the morning. She died due to complications from childbirth at the age of forty-two.
6 Cool Things to Know About Emilie du Châtelet
1. Emilie tackled historic scientific problems.
The major scientific debate afoot in the 1740s was between Isaac Newton’s system describing the motion of the universe (including gravity) and Gottfried Leibniz’s opposing views on how space, time, and force worked. They disagreed on God’s role in the function of the universe, the fundamental nature of matter, and whether force was “living” or “dead.” The two men were also engaged in a furious dispute over who had first claim to the invention of calculus, an argument Leibniz lost in the 1700s but is now considered to have been right about all along. Emilie du Châtelet waded directly into these debates and provided new insights into the function of the universe.
2. Emilie had a secret love affair…with Voltaire.

As a poet, scientist, and public intellectual, Voltaire was a lifelong critic of the hypocrisy and corruption he saw among the clergy and aristocracy in France. He drew on themes from classical stories and the history of France in his vast oeuvre of writing. Always volatile, he spent much of his life fleeing condemnation or returning to Paris more famous than before. After losing Emilie so early, Voltaire would go on to live another thirty years, befriending Benjamin Franklin, writing his most famous work, Candide, and briefly joining the Prussion court before his death in 1778.
3. Emilie helped change what it meant to even do science.
She insisted on using experimental results to back up her conclusions, and implemented Leibniz’s principle of sufficient reason. In essence, this principle refused to accept easy answers, and required a scientist to continue to seek explanations for why something worked one way and not another until you really got to the bottom of it. She also advocated for scientists to come up with hypotheses and then test them to determine whether they were true, an idea controversial in her day that today is the foundation of scientific work.
4. Emilie was a lover of knowledge.
In the early 1700s, the kind of work Emilie and her contemporaries were doing was bigger than “just” science. People were trying to figure out how the world worked, and the fields we today call science, ethics, math, and philosophy all overlapped. Philosophes (or philosophers in English—which has its roots in the Greek for “lover of knowledge”) could weigh in on gravity, human nature, political structures, religion and any number of other things.
5. Emilie fixed Newton’s physics.
Emilie took Newton’s work on the universe and improved upon it, incorporating Leibniz’s insights and her own. She found additional experimental proof for some of Newton’s assertions, and did the extensive calculus to back them up further (Newton himself used only geometric proofs in his major opus Principia). Emilie’s translation of Principia, accompanied by her commentary, is still today the authoritative version in French
6. Emilie contributed to our modern understanding of energy.
She argued in favor of force vive, which squared the speed of an object to determine its force (energy), against Newton’s insistence on plain multiplication (F=mv2 vs. F=mv). We now understand these two concepts to be kinetic energy and momentum respectively. This squaring of speed would reappear in Einstein’s famous formulation E = mc2, which explained that all matter everywhere included an astonishing amount of energy and reframed how we understand the universe.
Joan Cummins is dramaturg for Avant Bard’s production of Lauren Gunderson’s Emilie: La Marquise Du Châtelet Defends Her Life Tonight. A dramaturg, director, and teaching artist working in new plays and interactive theater, she is also a public historian, working to make history accessible to the public through interactive experiences and performance. Locally, she has worked with dog & pony dc, President Lincoln’s Cottage, The Welders, Signature Theatre, Pinky Swear Productions, the Historical Society of Washington, D.C., the Capital Fringe Festival, Ford’s Theater, and the Kennedy Center.