Jean le Rond d'Alembert

Jean Le Rond d'Alembert (November 16, 1717 – October 29, 1783) was a French mathematician, mechanician, physicist and philosopher. He was also one of the editors of the Encyclopédie, an early French encyclopedia. D'Alembert's method for the wave equation is named after him.

Studies

D'Alembert first attended a private school. The chevalier Destouches left d'Alembert an annuity of 1200 livres on his death in 1726. Under the influence of the Destouches family, at the age of twelve d'Alembert entered the Quatre-Nations jansenist college (the institution was also known under the name Mazarin). Here he studied philosophy, law, and art, graduating as bachelier in 1735. In his later life, d'Alembert scorned the Cartesian principles he had been taught by the Jansenists: "physical premotion, innate ideas and the vortices".

Related Topics:
Annuity - Livre - 1726 - Jansenist - Philosophy - Law - Art - Bachelier - 1735 - Cartesian

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The Jansenists steered d'Alembert toward an ecclesiastical career, attempting to deter him from pursuits such as poetry and mathematics. Theology was, however, "rather unsubstantial fodder" for d'Alembert. He entered law school for two years, and was nominated avocat in 1738.

Related Topics:
Poetry - Mathematics - Theology - Avocat - 1738

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He was also interested in medicine and mathematics. Jean le Rond was first registered under the name Daremberg, but later changed it to d'Alembert. In July of 1739 he made his first contribution to the field of mathematics, pointing out the errors he had detected in L'analyse démontrée (published 1708 by Charles René Reynaud) in a communication addressed to the Académie des Sciences. At the time L'analyse démontrée was a standard work, which d'Alembert himself had used to study the foundations of mathematics.

Related Topics:
Medicine - Mathematics - 1739 - L'analyse démontrée - 1708 - Charles René Reynaud - Académie des Sciences

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In 1740, he submitted his second scientific work from the field of fluid mechanics Memoire sur le refraction des corps solides, which was recognized by Clairaut. In this work d'Alembert theoretically explained refraction. He also wrote about what is now called D'Alembert's paradox: that the force on a body immersed in an inviscid fluid is identically zero.

Related Topics:
1740 - Scientific - Fluid mechanics - Clairaut - Refraction - D'Alembert's paradox - Force - Inviscid - Fluid

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While he made great strides in mathematics and physics, d'Alembert is also famously known for incorrectly arguing in Croix ou Pile that the probability of a coin landing heads increased for every time that it came up tails. In gambling, the strategy of decreasing ones bet the more one wins and increasing one's bet the more one loses is therefore called the d'Alembert system, a type of martingale.

Related Topics:
Probability - Gambling - D'Alembert system - Martingale

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He suffered bad health for many years and his death was as the result of a bladder illness. As a known unbeliever, d'Alembert was buried in a common unmarked grave.

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In France, the fundamental theorem of algebra is known as the d'Alembert/Gauss theorem.

Related Topics:
France - Fundamental theorem of algebra - Gauss

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He also created his ratio test, a test to see if a function converges.

Related Topics:
Ratio test - Function

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See also D'Alembert's principle.

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