On This Day: Russian mathematician Grigori Perelman posts the first of three preprint texts with his proof of the

11/11 (2002): Russian mathematician Grigori Perelman posts the first of three preprint texts with his proof of the Poincaré conjecture. It remains the only of the Millennium Prize Problems in mathematics to be solved. He later refused both the prize money from Clay Mathematics Institute as well as the Fields Medal for his work.