Mathematician:Jules Henri Poincaré

Better known as Henri Poincaré.

French mathematician and philosopher.

Often referred to as "The last universalist", as he was the last one able to master the whole of mathematics at the time. (Since then the field has grown too large.)

Introduced the field of special relativity.

Nationality
French

History

 * Born: 29 April 1854
 * Died: 7 July 1912

Theorems and Definitions

 * Hilbert-Poincaré Series (with )
 * Poincaré Conjecture (now proven)
 * Poincaré-Bendixson Theorem (with )
 * Poincaré-Birkhoff-Witt Theorem (with and )
 * Poincaré Duality
 * Poincaré Group
 * Poincaré Half-Plane Model
 * Poincaré-Hopf Theorem (with )
 * Poincaré-Lindstedt Method (also known as the Lindstedt-Poincaré Method) (with )
 * Poincaré Map
 * Poincaré Metric
 * Poincaré-Steklov Operator (with )
 * Poincaré Symmetry
 * Poincaré's Last Geometric Theorem
 * Poincaré Plane
 * Poincaré-Bendixson Theorem (with )

Books and Papers

 * 1892–99: New Methods of Celestial Mechanics 3 volumes
 * 1894: On the nature of mathematical reasoning
 * 1895: Analysis situs
 * 1898: On the foundations of geometry
 * 1900: Intuition and Logic in mathematics
 * 1900: Sur les groupes continus
 * 1902: Science and Hypothesis
 * 1905: The Value of Science
 * 1905–06: Mathematics and Logic, I–III
 * 1905–10: Lessons of Celestial Mechanics
 * 1908: Science and Method
 * 1910: On transfinite numbers
 * 1912: Sur un théorème de géométrie (in which is presented what is now known as Poincaré's Last Geometric Theorem)

Notable Quotes

 * Though the source be obscure, still the stream flows on.


 * People have been shocked by this formula, and yet it is as good as life for life's sake, if life is but misery.


 * What we call objective reality is, in the last analysis, what is common to many thinking beings and could be common to all.


 * Mathematicians do not deal in objects, but in relations between objects; thus, they are free to replace some objects by others so long as the relations remain unchanged. Content to them is irrelevant: they are interested in form only.


 * The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living. Of course I do not here speak of beauty which strikes the senses, the beauty of qualities and appearances; not that I undervalue such beauty, far from it, but it has nothing to do with science; I mean that profounder beauty which comes from the harmonious order of the parts, and which a pure intelligence can grasp.

Also see

 * : Chapter $\text{XXVIII}$