The french **Jules Henri Poincaré** He was born on April 29, 1854 and died on July 17, 1912. He was a famous mathematician, physicist and philosopher of science, being described as the last "universalist" capable of understanding and contributing to all fields of mathematical discipline.

He was born in Nancy, France, the son of an influential family in society at the time. His father was a professor at the University of Nancy and his uncle Antoine an engineer. Several members of his family became known, both in politics and in intellectual life in France, notably cousin Raymond Poincare, president of France during the First World War.

His mathematical skills began to be seen while still studying at the Nancy High School (renamed Henri Poincaré High School in his honor), where he entered in 1862 and spent 11 years. During this time, he was one of the most outstanding students, having disputed and won the first prize in the *general concours*, a competition among the most prominent students in the French Lycees.

From 1873 to 1875 he studied at the Polytechnic School and in 1875 he joined the National Higher School of Minas (*Ecole des Mines*). In 1879 he obtained his doctorate in mathematical sciences with a thesis on differential equations. His work was done under the guidance of Hermite and was part of Gabriel Darboux banking, known for his work with non-Euclidean geometry.

In 1881 he became professor at the University of Paris, taking over the chair of mathematical physics, where he remained until his death on July 17, 1912.

Henri Poincaré has published, throughout his life, more than 500 works, including books and articles, as well as his lecture notes. His thinking has influenced mathematics, mathematical physics, and philosophy, from function theory and topology, to a particular way of thinking about the world and its logic.

In the field of mechanics, he elaborated several works on the theories of light and electromagnetic waves, developing, along with the physicist Albert Einstein, the theory of restricted relativity (also known as special relativity). Prior to his thirties, he developed the concept of automorphic functions, which he used to solve second-order linear differential equations with algebraic coefficients.

Poincaré's conjecture was one of the most challenging unsolved problems of algebraic topology, being solved only in 2003 by the Russian mathematician Grigori Perelman, more than a century after his proposition. He was also the first to consider the possibility of chaos in a deterministic system in his work on planetary orbits. This work was of little interest until he began the modern study of chaotic dynamics in 1963. In 1889 he was awarded for his work on the problem of the three bodies.

In 1895 he published his *Analysis situs*, a systematic treatise on topology. Other of his most important works include the three volumes of *The new methods of celestial mechanics* (*Les méthodes nouvelles of the celestial mechanism*), published between 1892 and 1899, and Lessons in Heavenly Mechanics (*Celestial celery lecons*, 1905). He has also written numerous works of scientific dissemination that have reached great popularity, such as *Science and hypothesis* (1902), *The value of science* (1904) and *Science and method* (1908).

Within applied mathematics, he has studied numerous problems in optics, electricity, telegraphy, capillarity, elasticity, thermodynamics, quantum mechanics, relativity theory, and cosmology.

In 1912, Poincaré underwent surgery for a prostate problem and subsequently died of an embolism on July 17, 1912, at the age of 58.