Conceived in 1904, the Poincaré conjecture, a puzzle that speaks to the possible shape of the universe and lies at the heart of modern topology and geometry, has resisted attempts by generations of mathematicians to prove or to disprove it. Despite a million-dollar prize for a solution, Russian mathematician Grigory Perelman, posted his solution on the Internet instead of publishing it in a peer-reviewed journal. This book "tells the story of the...