Seventy-two names are engraved on the Eiffel Tower's iron lattice, a permanent tribute to the scientists whose work made it possible. The mathematician whose foundational theory of elasticity helped hold the structure up is not among them, because she was a woman. This episode follows Sophie Germain from a Paris bedroom during the Revolution, where her 13-year-old self read of Archimedes dying too absorbed in geometry to notice a soldier's sword and decided mathematics must be the most interesting subject in the world. Her parents confiscated her candles, her fire, and her warm clothes to freeze her out of studying; she smuggled in candles, wrapped herself in quilts, and was found asleep at her desk beside an inkhorn frozen solid.

Barred from the École Polytechnique, she obtained lecture notes through a loophole and submitted work under the ...