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IWD: Sophie Germain

Today is International Women's Day and so I'm posting about a remarkable woman whom I recently learned about, the mathematician Sophie Germain.

Marie-Sophie Germain was born in Paris in 1776, the middle daughter of a wealthy silk merchant and was only thirteen years old when the French Revolution began. Sheltered at home by her family from the dangers outside, she took refuge in her father's library where she read of the death of Archimedes, too engrossed in the study of geometry to take notice of the Roman spearmen sacking his city.

The young girl was intrigued by a topic that could so absorb one's attention, and she undertook to teach herself mathematics as well as the Latin and Greek she needed to read the classic works of the field. Her parents forbade this pursuit, so Sophie crept from her bed to study in secret by night. When this defiance was noted her parents withdrew her heat, denied her candles, and even took away her clothing to keep their daughter in her bed but Sophie persisted, wrapping herself in her bedclothes and working at her desk with stolen candles. It was the discovery of Sophie asleep at her desk one morning, her inkpot frozen solid, that finally caused her parents to relent and allow her to continue her studies in greater comfort.

When she was eighteen (and like all French girls unable to study science at school) she managed to regularly obtain professors' notes from courses at the Ecole Polytechnique. Sophie followed along with the courses and boldly submitted comments and papers to the professors under the assumed name M. leBlanc. One of these professors, the brilliant Joseph-Louis Legrange, was impressed enough to request a meeting. leBlanc revealed her identity as a woman and Legrange, won over by Sophie's intelligence, continued to help her in her work.

A similar result occurred when Germain began corresponding as M. leBlanc with Carl Friedrich Gauss in Prussia, a man widely regarded as the greatest mathematician of his time. Gauss learned that his correspondent was a woman when Sophie prevailed upon her friend, French General Joseph-Marie Pernety to protect Gauss when Napoleon's armies invaded Gauss's home of Brunswick. Pernety complied, identified Gauss's protector as Sophie Germain and the connection was made with his friend Monsieur leBlanc. I am much taken by the ensuing correspondence:

Germain to Gauss, 1807:

In describing the honourable mission I charged him with, M. Pernety informed me that he made my name known to you. This leads me to confess that I am not as completely unknown to you as you might believe, but that fearing the ridicule attached to a female scientist, I have previously taken the name of M. LeBlanc in communicating to you those notes that, no doubt, do not deserve the indulgence with which you have responded.

Gauss to Germain:

But how to describe to you my admiration and astonishment at seeing my esteemed correspondent Monsieur Le Blanc metamorphose himself into this illustrious personage who gives such a brilliant example of what I would find it difficult to believe. A taste for the abstract sciences in general and above all the mysteries of numbers is excessively rare: one is not astonished at it: the enchanting charms of this sublime science reveal only to those who have the courage to go deeply into it. But when a person of the sex which, according to our customs and prejudices, must encounter infinitely more difficulties than men to familiarize herself with these thorny researches, succeeds nevertheless in surmounting these obstacles and penetrating the most obscure parts of them, then without doubt she must have the noblest courage, quite extraordinary talents and superior genius. Indeed nothing could prove to me in so flattering and less equivocal manner that the attractions of this science, which has enriched my life with so many joys, are not chimerical, the predilection with which you have honored it.
Sadly their association ended the next year when Gauss's research interests changed and he stopped responded to her letters.

Germain's research included important work in number theory on topics including prime numbers (a class of which bear her name) and Fermat's Last Theorem, as well as in the emerging field of solid mechanics, the physics of elasticity and vibration of solid objects, in which her contributions were a critical underpinning of the engineering of large structures such as modern skyscrapers and Paris's own Eiffel Tower.

She never married, and in 1831 she lost a two-year battle with breast cancer and died at the age of fifty-five. In the years preceding her death she and Gauss had renewed their correspondence. Gauss had convinced his employer, the University of Göttingen, to award Germain an honorary doctorate, the degree which she had long since earned but had never been able to receive. Her illness and eventually her death prevented her from traveling to Göttingen to receive her degree. The trip would also have marked the first time she and Gauss ever met.

For a long time Germain was overlooked by historians who denied her her place alongside the better known male giants of science and math, but in recent years she has achieved greater recognition. The net is rich with Sophie Germain information, and I referred to quite a few of these as I wrote this post. In addition to those linked above I recommend the following:

Addendum: Germain went by Sophie instead of Marie or Marie-Sophie because both her mother and one of her sisters were named Marie.


That is indeed a striking story -- thanks for sharing it!

This story is really great!It's unfair though she died without her merit of being a mathematician or a scientist. Thank god we live in the twenty first century and something like that could not take place. She should have been given her rightful title even if she was a women.

Hi! I am doing a project on famous Mathematicions in my math class and I chose Marie-Sophie Germain and I am looking all over the place to find info on her and this is the best site I have found yet! Thanks for helping my math grade!


I am doing a project in math too and I'd like to say thanks.

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