113 years ago today, on July 17, 1912 (June 4, 1912 in the lunar calendar), the French mathematician and physicist Paul Poincaré died. Poincaré, 1913 edition of "Last Thoughts" ("Last Thoughts") Cover photo Jules Henri Poincaré (translated as Poincaré, April 29, 1854 - July 17, 1912), commonly known as Henri Poincaré, one of France's greatest mathematicians, theoretical scientist and philosopher of science. Poincaré is widely regarded as a leading mathematician of the late 19th and early 20th centuries, the last person after Gauss to have a comprehensive knowledge of mathematics and its applications. He made many creative and fundamental contributions to mathematics, mathematical physics, and celestial mechanics. He proposed the Poincaré conjecture, one of the most famous problems in mathematics. In his study of the three-body problem, Poincaré became the first person to discover a chaotic deterministic system and laid the foundation for modern chaos theory. Poincaré was one step ahead of Einstein's work and drafted a simplified version of the special theory of relativity. The Poincaré group is named after him. Comments: The 20th century was a century of great development in science, and Poincaré was the leader among them.