Marie-Sophie Germain was born in April, 1776. Because she grew up during the years of the French Revolution, Sophie’s parents kept her inside for safety. She turned to her father’s library for entertainment, and in particular, his books about mathematics. The author writes:
“As cries for equality echoed from the roof tiles, she cherished how math could make sense of the world.”
Sophie taught herself Latin and Greek so she could read the works of mathematicians in other languages.
Sophie’s parents tried to dissuade Sophie from her fascination with math, since it was not thought to be an appropriate preoccupation for females. They confiscated her candles and her warm clothes, so she would stay in bed at night. But as the author interjects frequently in the text, “nothing stopped Sophie.”
After her parents found her one morning wrapped in blankets next to a pot of ink that had frozen solid, they relented, and Sophie resumed her studies in the open.
[British popular science author Simon Singh writes for PBS in an article about Sophie that there were math texts for women, but since it was believed that women were only interested in romance, one author of such a text “attempted to explain Newton’s discoveries through the flirtatious dialogue between a Marquise and her interlocutor. The interlocutor outlines the inverse square law of gravitational attraction, whereupon the Marquise gives her own interpretation on this fundamental law of physics. ‘I cannot help thinking … that this proportion in the squares of the distances of places … is observed even in love. Thus after eight days absence, love becomes 64 time less than it was the first day.’”]
In 1794, when Sophie was 18, the École Polytechnique opened. As a female, Sophie was not allowed to attend, but the new system of education made lecture notes available to any who requested them. Students were required, however, to submit written observations about what they learned. Sophie obtained the lecture notes and began sending her work to Joseph Louis Lagrange, a faculty member and famous mathematician. She signed her papers “Monsieur Le Blanc,” fearing, as she later explained, “the ridicule attached to a female scientist.” When Lagrange read the outstanding work of M. Le Blanc, he requested a meeting, and thus Sophie was forced to disclose her true identity. Fortunately, Lagrange was not put off that Sophie was a female, and he became her mentor.
The author writes, “news of the girl prodigy rippled through Paris.” Sophie was invited to dinner parties mainly so others could gawk at her. “Still,” Bardoe writes, “nothing stopped Sophie.”
Under her pen name, still masquerading as a male, Sophie wrote to famous mathematicians outside of Paris about her findings. Some only wrote back until they discovered that Mr. Le Blanc was a woman. But of course, nothing stopped Sophie.
The brilliant German mathematician and physicist Carl Friedrich Gauss was impressed that M. Le Blanc was a female. He wrote to Sophie:
“How can I describe my astonishment and admiration on seeing my esteemed correspondent M. le Blanc metamorphosed into this celebrated person … when a woman, because of her sex, our customs and prejudices, encounters infinitely more obstacles than men in familiarising herself with [number theory’s] knotty problems, yet overcomes these fetters and penetrates that which is most hidden, she doubtless has the most noble courage, extraordinary talent, and superior genius.” [Nick Mackinnon, “Sophie Germain: Or Was Gauss a Feminist?,” The Mathematical Gazette, Vol 74, No. 470 (Dec 1990) online here.]
Sophie’s correspondence with Carl Gauss inspired much of her subsequent work but when he switched his field of interest from theory to applied mathematics, he no longer bothered to return Sophie’s letters.
Still, Sophie went on to do pioneering work in math, winning the grand prize from the Paris Academy of Sciences for her essay on elasticity theory. Her work on “Fermat’s Last Theorem” provided a foundation for mathematicians exploring the subject for hundreds of years after. In addition, as Bardoe points out, her work on vibration patterns “made it possible to build the Eiffel Tower in Paris and modern skyscrapers and lengthy bridges all over the world.”
On June 27, 1831, she died from breast cancer at age 55. At the centenary of her life, a street and a girls’ school were named after her. The Academy of Sciences established the Sophie Germain Prize in her honor.
After her death, Gauss wrote – in words we might find amusing today:
“She proved to the world that even a woman can accomplish something worthwhile in the most rigorous and abstract of the sciences and for that reason would well have deserved an honorary degree.” (Nick Mackinnon, citation above)
Illustrations by Barbara McClintock, adding to her usual warm watercolors with markers, gouache, and collage, are full of numbers, equations, and thoughts that swirl around Sophie’s head.
Back matter includes more about Sophie’s life and about math, a selected bibliography, an author’s note, and an illustrator’s note.
Evaluation: Two themes of the book stand out. One is the power of perseverance, especially when girls are told they can’t or shouldn’t do something commonly associated with males, an attitude which is not entirely absent even today. The second is that math is a thing of beauty, that “mathematicians use numbers as poets use letters – as a language to question, explore, and solve the secrets of the universe.” Both of these messages are important ones for the recommended audience of age 6 and up. I certainly could have used similar encouragement and support as a young girl. The introduction to life during the French Revolution is also a plus, and may inspire further research by readers.
Published by Little, Brown and Company, 2018