Sophie Germain posed as Monsieur Le Blanc to trade mathematics with Gauss
Locked indoors as a teenager while revolution raged through Paris, Sophie Germain read how Archimedes died absorbed in geometry and decided the subject deserved her life. Barred from lectures as a woman, she wrote to Lagrange and Gauss under a dead student's name, and later became the first woman to win a Paris Academy prize.
Born on 1 April 1776 on the Rue Saint-Denis, the middle of three daughters of a prosperous merchant who sat in the États-Généraux of 1789, Germain was 13 when the Bastille fell. Stuck at home, she found Montucla's history of mathematics in her father's library and taught herself Latin and Greek to read Newton and Euler. Her parents thought mathematics unfit for a girl and took away her fire and warm clothes at night; she worked by candlelight wrapped in quilts, and her mother eventually helped her in secret.
When the École Polytechnique opened in 1794 it would not admit her, but its lecture notes were available to anyone. She sent Lagrange her work signed Antoine-Auguste Le Blanc, a former student, fearing the mockery aimed at women scientists. Impressed, he asked to meet the author and discovered the truth. Legendre later printed some of her number theory in a supplement to his book, calling it very ingenious.
Her letters to Gauss began on 21 November 1804 and included an attempt on Fermat's Last Theorem. When French troops occupied Braunschweig around 1807, she remembered Archimedes and asked a family friend, General Pernety, to check that Gauss was safe; the puzzled mathematician learned who Le Blanc really was three months later and answered with warm praise for her courage and genius. The correspondence faded by 1809, and they never met.
She then tackled the Academy's contest on Chladni's vibrating plates. Her 1811 entry lost, her 1813 attempt earned only an honourable mention, and Poisson published on elasticity without crediting her help. On 8 January 1816 her third paper, submitted under her own name, won; she skipped the ceremony. Even afterwards she could not attend Academy sessions until Joseph Fourier found her tickets. She died on 27 June 1831.
Source: Sophie Germain
