André-Marie Ampère
André-Marie Ampère (Lyons 20 January, 1775 – Marseilles 10 June, 1836) was a French physicist and mathematician. His most important contribution was Ampere's law, which describes the relation between electric current and magnetic field. The unit of electric current ampere is named after him.
Biography
Although André-Marie did not receive a formal education—he was tutored by his farther—he was a child prodigy. At the age of thirteen he submitted his first mathematical paper. This work attempted to solve the problem of constructing a line of the same length as an arc of a circle.[1] However, the work was refused and André-Marie realized that he had to become better skilled in mathematics. So, he read d'Alembert's article on the differential calculus in the Encyclopédie and undertook a study of works by Leonhard Euler. He started to read the 1788 edition of Lagrange's Mécanique analytique and later claimed that he was able to repeat all the calculations in it.
Two years after the French Revolution of 1789 Ampère's father was beheaded by the Jacobins. The effect on André-Marie of his father's death was devastating. He gave up his studies of mathematics and only regained his taste for the sciences after he fell in love with his future wife, Julie Carron. They married in 1799 and their son Jean-Jacques was born in 1800. In 1802 Ampère was appointed teacher of physics and chemistry in Bourg-en-Bresse at the Bourg École Centrale. This was a difficult time for Ampère since Julie became ill and he had to leave her behind in Lyons. Nowadays Lyons and Bourg are seen as close (about 60 km), but in the beginning of the nineteenth century travel was difficult. While Ampère was in Bourg he found time to perform research in mathematics. He wrote Considérations sur la théorie mathématique du jeu [The Mathematical Theory of Games] in 1802. After his wife died in July 1803, Ampère decided to go to Paris.
He found a job as répétiteur d'analyse (tutor) in analysis at the École Polytechnique on 20 October 1804, where Augustin-Louis Cauchy was one of his students. Soon he embarked on a disastrous marriage with a girl named Jenny (1806). Before the birth of their daughter on 6 July 1807, the couple had separated. They were legally divorced in 1808 and Ampère was given custody of their daughter. Notwithstanding these private problems, Ampère was productive in mathematics. Among other things he wrote about variational calculus and about the rest term of the Taylor series (1806).
In 1809 he was promoted to professor of mathematical analysis at the École Polytechnique, a post he held until 1828. In the 1820s Ampère and Cauchy shared the teaching of analysis and both were critized heavily at times, because it was judged that they overloaded the future engineers by too much abstruse mathematics.
In 1814 Ampère summarized the functions he had fulfilled thus far together with his mathematical contributions[2], which he presented to the Institut de France in the same year. This was apparently a convincing résumé since it gained him election to the Institut in November 1814, when he defeated his former student Cauchy, who also applied for membership.
Also in 1814 he made independently the same discovery in chemistry[3] that Amedeo Avogadro made three years earlier, namely that the same volumes of different gases contain the same number of molecules. As happened to Avogadro's work, Ampère's discovery went largely unnoticed by the chemists of the time.
References
- ↑ A.-M. Ampère, Sur la rectification d'un arc quelconque de cercle plus petit que la demi-circonférence [On the rectification of an arbitrary arc smaller than half the circumference of a circle], July 8, 1788
- ↑ Notice des fonctions remplies et des principaux mémoires publiés ou lus à l'Institut et encore inédits, composés par A.M. Ampère. [Note on the functions fulfilled and the main memorandums published or presented at the Institut and not yet published, composed by A.M. Ampère
- ↑ Lettre de M. Ampère à M. le comte Berthollet sur la détermination des proportions dans lesquelles les corps se combinent d'après le nombre et la disposition respective des molécules dont les parties intégrantes sont composées, [Letter of mr. Ampère to mr. the count Berthollet on the determination of the proportions in which bodies combine according to the number and the suitability of the molecules of which the integral parts are composed] Annales de chimie, vol. 90 pp. 43-86 (1814).
Paul Jonathan Bruce, The History of Electromagnetic Theory, Ph.D. Thesis, University of Aberdeen, 2005.
(To be continued)