Henri Poincare is known as the creator of topology and as a man who discovered the theory of analytic functions.

###### Childhood and youth

Jules Henri Poincare was born in the city of Nancy on April 29, 1854, with Leon Poincaré and Eugénie Lanois. His family was well-known and well-known, with a good income; his father was a teacher at the University of Lorraine. The cousin Henri Poincaré, Raymond Poincaré, was President of France from 1913 to 1920.

###### Education

In his childhood, Henri Poincare was an enthusiastic guy, who was enjoying math. Despite his poor vision and low concentration, he always managed to be the best in subjects related to science and mathematics. He won numerous competitions and won many awards, and in 1871 he graduated from the Lyceum with a bachelor’s degree in science and literature. In 1873, he entered the Polytechnic College, where he continued to study mathematics, and in 1874 published his first thesis, which was directed by Charles Hermite. Having successfully graduated from college in 1875, he entered the Mining School of Paris and received an engineering degree in 1879.

###### Career

Career Poincare began to develop from the very first year of work, when he was appointed mountain inspector in the north-eastern province of France, Vesoul. In 1879, he was sent to monitor the site of the disaster. He studied the scene and presented a scientific conclusion about the probable causes of the incident. Shortly after the end of the University of Paris, Poincaré was invited to take up the post of junior mathematics teacher at the University of Caen.

For a long time he worked at the University of Paris, occupying numerous posts in physical and mathematical faculties, sometimes also doing astronomy. In early 1880, Poincaré discovered that automorphic and elliptic functions belong to the same group of algebraic equations.

During the 1880s, Poincaré was engaged in the mechanics of celestial bodies, as a result of which he presented a treatise on his research. In 1887, he was engaged in the well-known “three-body problem”, in which he talked about the motion of gravitating bodies.

King of Sweden, Oscar II, awarded Poincaré, who managed to find a solution to the problem of the stability of the solar system. It was a standard example of classical mechanics, which eventually led to the discovery of the “theory of chaos.” Poincaré also contributed to

the creation of the special theory of relativity, which he worked with Hendrik Lorentz and Albert Einstein.

Despite his busy work on various aspects of science and mathematics, Poincaré did not leave the job of an engineer, and, eventually, in 1893, he was appointed chief engineer in the Mining Corps, after which in 1910 he was again promoted, to this time to the position of inspector.

Poincare worked with the “Bureau of Longitudes” of France, in which he was engaged in coordinating time around the world. In early 1895, Poincaré introduced new methods of topology and proposed a set of differential equations that contributed to the understanding of continuity theory. In 1899 he wrote a treatise titled “New Methods of Celestial Mechanics,” which was repeatedly reprinted. This treatise has become a kind of “bible” in the world of mathematics and celestial mechanics.

###### Achievements

For many years at the University of Poincare he made a great contribution to mathematics and science as a whole in the form of algebraic topology, the theory of relativity, the return theorem, the three-body problem, quantum mechanics, differential equations and much more. He inspired a large number of students who later also contributed to the development of mathematics and other disciplines. Some of his famous students are Dimitri Pompey, Tobias Danzig and Louis Bachelier.

###### Personal life

Poincaré married Louise Poulain d’Andesy at the beginning of 1881. The couple had four children.

During his life he received many awards and made a significant contribution to the development of the French Academy of Sciences and the British Royal Astronomical Society. And although Poincaré was completely absorbed in his work, he also devoted much time to his family.

###### Death and heritage

In the first half of 1912, Poincaré had problems with the prostate and had to undergo surgery on her. Poincaré died due to a clogged vessel on July 17, 1912 at the age of 58 years. Poincaré’s works have gained popularity all over the world. He wrote several books that for a long time did not allow him to forget his name. His work on thermodynamics, quantum physics, optics and fluid mechanics attracted many followers, for example, Maria Curie.

Many institutions and scientific meetings were named after Henri Poincaré: “The Henri Poincaré Institute” and the “Poincare Seminar”. In honor of his services and in memory of his legacy, one of the craters on the Moon was named in his honor.