 In 1889 Poincaré won a prize from the King of Sweden for a question posed by Weierstrass on the stability of the solar system, that is, the three-body (or \(n\)-body) problem in classical mechanics. Despite a mathematical error that he discovered at the last moment (after questions raised by the Swedish mathematician Lars Edvard Phragmén) and frantically corrected, the work was important for its use of topology and as a founding document in chaos theory, for Poincaré showed that in general, the stability of such systems cannot be demonstrated. It is also in this context that he proved his famous recurrence theorem.