Sophie Germain: Kickass Mathematician

I recently read Simon Singh’s* fantastic book Fermat’s Last Theorem. Simon is a pro at delivering an absorbing history filled with colorful characters, and in this book one that stood out was Sophie Germain, a French mathematician. In honor of Ada Lovelace Day (already?? It seems to come earlier each year) I figured I’d tell you a little about her.

Sophie was born in Paris on April 1, 1776, a time when women weren’t seen as the mathematical sort. You and I were also born during a time like that, but at least we’d have had a slightly easier time getting into college to study it.

When the French Revolution started heating up, Sophie’s family locked her up in their house to keep her safe, at which point the 13-year old girl took an interest in mathematics. Supposedly, she was inspired by the story of Archimedes, who was so engrossed in a geometry problem he failed to notice that he was about to be murdered by a Roman soldier.

Taking advantage of her father’s extensive library, she taught herself math as well as Greek and Latin so she could study classical scholars. Her parents didn’t like all that book learnin’ (who would marry a girl like that?), so she studied at night until they took away her candles to keep her from reading after dark. She was so committed that eventually her parents gave in, and she became one of the most talented mathematicians in the world.

A man named Monsieur Le Blanc was studying math at the world-famous École Polytechnique, but he ultimately proved to be an uninspired and untalented mathematician. When he left the school for new adventures, Sophie took on his role at the school, using him as a pseudonym to get lecture notes and engage in correspondence with other scholars.

The world’s greatest mathematicians were impressed with M. Le Blanc’s work, and a few of them ended up discovering that Sophie was the real genius behind the name. The most interesting story is Sophie’s relationship with Carl Friedrich Gauss (whose work helped astronomers study Ceres). Gauss and “Le Blanc” had a long and fruitful correspondence, until word reached Sophie that Napoleon was preparing to invade Gauss’ Prussian hometown. Sophie was worried that Gauss would be killed, and so asked a general (who happened to be a family friend) to protect him.

Gauss was spared, and when the general informed him that he owed his life to one Sophie Germain, Abbot-and-Costello-like antics ensued. Eventually, it came out that Sophie was Le Blanc, and Gauss was blown away. He wrote:

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, [than] the predilection with which you have honored it.

Aww. Both mathematicians went on to do more great work. Sophie contributed to the effort to develop a proof for Fermat’s Last Theorem by using prime numbers, discovering (among other things) that if p is a prime number, then 2p+1 is also prime. the importance of prime numbers that fit the equation: if p is a prime number, then 2p+1 is also prime (thanks to Blake for pointing out that I screwed up my math facts!).

Sadly, Gauss fell out of touch with Sophie when he saw something shiny in another field of mathematics. Possibly hoping to make up for his poor correspondence later, he petitioned the University of Göttingen to grant her an honorary degree. Unfortunately, by the time they agreed to give it to her in 1831, Sophie lost a battle with breast cancer.

So there you have it – an awesome lady who fought hard to make great contributions to the world of mathematics. Happy Ada Lovelace Day!

*Update on Simon: he’ll be going to court against the chiropractors on May 7. Follow along on Facebook!

Rebecca Watson

Rebecca is a writer, speaker, YouTube personality, and unrepentant science nerd. In addition to founding and continuing to run Skepchick, she hosts Quiz-o-Tron, a monthly science-themed quiz show and podcast that pits comedians against nerds. There is an asteroid named in her honor.

Related Articles


  1. Question: Why on Earth hasn’t there been a biopic made of this story? I’m thinking a bit of a “Shakespeare in Love” thing, with Sophie Germain in the Gwyneth Paltrow role and Gauss as a sort of Shakespeare with whom she falls in love, though it CAN NEVER BE.

    Seriously, I smell an Oscar, or at least a Twoscar.

  2. Sophie Germain did kick-ass! :-)

    Here’s another kick-ass mathematician; Emmy Noether. Described by Einstein as “… the most significant creative mathematical genius thus far produced since the higher education of women began.”

    Emmy Noether connected symmetry and conservation laws in Physics; awesome!

  3. @Expatria:

    Gwyneth Paltrow played a female mathematics genius in Proof, one scene of which has her and Jake Gyllenhaal discussing Sophie Germain. It’s a bit of a macabre scene, with Paltrow asking Gyllenhaal if he knows any female mathematicians and Gyllenhaal, floundering, saying, “I think there’s one at Stanford” (or words to that effect).

  4. What a shame Gauss’s apparently egalitarian and forward thinking views were not more typical of the age.

    Nice piece of history. Thanks Rebecca!

  5. I’m curious how others read this.

    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.

    I want to put emphasis on “according to our customs and prejudices” and thus take the meaning to be something like “clearly our prejudices are wrong.” But I don’t think it says that, it looks more like “wow, you’re good at math, for a girl. Imagine how smart you’d have been if you were born a man.”

  6. @Rebecca: Agreed, it would be good to know if Grauss’s opinions were unique or more common then we think. We’ll likely never know because these types of discussions between like minded men and women of the day probably rarely made it into personal journals, diaries or letters that could be researched today.

  7. Awesome historical tidbit, Rebecca! Very cool that even those held down by the society of their time can make such a profound impact in their field of achievement, even if most of us nubes don’t often hear about them. Makes me wonder how many other relatively little-known people make their mark on history. Interesting…

  8. @Merkuto: But I don’t think it says that, it looks more like “wow, you’re good at math, for a girl. Imagine how smart you’d have been if you were born a man.”


    Except it unequivocally says nothing of the kind.

    The actual comment is: “women, according to our customs and prejudices, must “encounter more difficulties”. Gauss makes absolutely no intimation that women are less intelligent than men, or that the Madmoiselle is less intelligent than a man but rather acknowledges that her genius and character, already apparent in her work, is increased by the revelation of the great difficulties she must have faced.

    In other words, he’s saying that she’s way smarter than he thought she was when he thought she was a guy.

    Perhaps he is saying that similar genius in a man would have resulted in greater work, but that is an acknowledgment of a societal failure, not a sexist comment.

  9. According to the fun fact on this webpage: Sophie was also a crossdresser. I wonder if something got lost in translation from French to English? …Actually no, they do claim she dressed as a man So anyway, Sophie got a hotel and a street in Paris named after her. Gauss on the other hand has many small portraits of him floating around which are no longer in production:

    Maybe if Gauss had ever heard her say “The law of quadratic reciprocity” in her tres sexy French accent, they might have fallen in love. It’s worth noting that Gauss may have had Sophie on his mind when he was later studying differential geometry and became enamored of studying the curvature of hourglass shapes.

  10. @sethmanapio: Reading it again, I’d have to say I was wrong to think he might have meant it otherwise, but I do think there is a second, legitimate way to read that, though it wouldn’t be supported by the context.

    If you knew someone believed that women have trouble with math by nature, if they were to say “a person of [your] sex… must encounter infinitely more difficulties than men,” they would probably mean that those difficulties encountered are a natural weakness, even if they threw in “according to our customs and prejudices.” So, the sentence could be spoken with a very different intention by someone assuming the difficulties faced are natural, not social, and still use the exact same words. The context doesn’t support this interpretation, so I’m probably wrong to even bring up this other meaning that crossed my mind. But, it did, and I was curious if that way of reading it occurred to anyone else, or if anyone else had some more context to put this in.

  11. @Expatria: I didn’t know of Sophie Germain at the time I read the books, but in retrospect her story clearly inspired the character of Eliza in Neal Stephenson’s Baroque Cycle. Just replace Gauss with Liebniz (and make Sophie an escaped Turkish harem slave, etc., etc.), and it’s nearly the same story.

  12. @Joshua: I don’t think I’ve enjoyed reading a series of books more than I did the Baroque Cycle in the past fifteen years. His new book Anathem is of a similar standard.

  13. @Rebecca: Gauss came from pretty humble origins so it’s likely that his perspective as a non-nobleman in, what was in effect, an aristocrat’s world may have given him an insight that his mathematical peers might not have had into being a women in a man’s world.

    I think Gauss is saying to her that had she not had to run a marathon just to get to the starting line she would have achieved much more because he himself (being of humble origin) had been handicapped in a similar way.

    I suspect that, even then, a large proportion of men thought it was crazy that the potential of half the human race went unrealised. Strangely though, working class women worked then in the fields, mills and mines (removing women and children from mines in the 19thC was considered progress at the time), to the extent that they made up more than half of mill workers (and although paid less than men, were paid themselves for their own work rather wages going to their husbands) AND women had been in the vanguard of the French Revolution. So certainly at that time the role of women was “up for grabs” for the most talented women (if high-born)

    As an aside, Mary Wollstoncraft, authour of Vindication of the Rights of Women, is someone few people have heard of from the same era

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Back to top button
%d bloggers like this: