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title: "André-Marie Ampère"
chunk: 2/2
source: "https://en.wikipedia.org/wiki/André-Marie_Ampère"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:05:46.698183+00:00"
instance: "kb-cron"
---

=== Work in electromagnetism ===
In September 1820, Ampère's friend and eventual eulogist François Arago showed the members of the French Academy of Sciences the surprising discovery by Danish physicist Hans Christian Ørsted that a magnetic needle is deflected by an adjacent electric current. Ampère began developing a mathematical and physical theory to understand the relationship between electricity and magnetism. Furthering Ørsted's experimental work, Ampère showed that two parallel wires carrying electric currents attract or repel each other, depending on whether the currents flow in the same or opposite directions, respectively - this laid the foundation of electrodynamics. He also applied mathematics in generalizing physical laws from these experimental results. The most important of these was the principle that came to be called Ampère's law, which states that the mutual action of two lengths of current-carrying wire is proportional to their lengths and to the intensities of their currents. Ampère also applied this same principle to magnetism, showing the harmony between his law and French physicist Charles Augustin de Coulomb's law of electric action. Ampère's devotion to, and skill with, experimental techniques anchored his science within the emerging fields of experimental physics.
Ampère also provided a physical understanding of the electromagnetic relationship, theorizing the existence of an "electrodynamic molecule" (the forerunner of the idea of the electron) that served as the component element of both electricity and magnetism. Using this physical explanation of electromagnetic motion, Ampère developed a physical account of electromagnetic phenomena that was both empirically demonstrable and mathematically predictive. Almost 100 years later, in 1915, Albert Einstein together with Wander Johannes de Haas made the proof of the correctness of Ampère's hypothesis through the Einstein–de Haas effect. In 1826, Ampère published his magnum opus, Mémoire sur la théorie mathématique des phénomènes électrodynamiques uniquement déduite de l'experience (Memoir on the Mathematical Theory of Electrodynamic Phenomena, Uniquely Deduced from Experience), the work that coined the name of his new science, electrodynamics, and became known ever after as its founding treatise.
In 1827, Ampère was elected a Foreign Member of the Royal Society and in 1828, a foreign member of the Royal Swedish Academy of Science. Probably the highest recognition came from James Clerk Maxwell, who in his Treatise on Electricity and Magnetism named Ampère "the Newton of electricity".

== Honours ==
8.10.1825: Member of the Royal Academy of Science, Letters and Fine Arts of Belgium.

=== Legacy ===
An international convention, signed at the 1881 International Exposition of Electricity, established the ampere as one of the standard units of electrical measurement, in recognition of his contribution to the creation of modern electrical science and along with the coulomb, volt, ohm, watt and farad, which are named, respectively, after Ampère's contemporaries Charles-Augustin de Coulomb of France, Alessandro Volta of Italy, Georg Ohm of Germany, James Watt of Scotland and Michael Faraday of England. Ampère's name is one of the 72 names inscribed on the Eiffel Tower.
Many streets and squares are named after Ampère, as are schools, a Lyon metro station, a graphics processing unit microarchitecture, a mountain on the moon, an asteroid and an electric ferry in Norway.. A town in Brazil, Ampére, in the state of Parana, is named after Ampère.

== Writings ==
Considérations sur la théorie mathématique du jeu, Perisse, Lyon Paris 1802, online lesen im Internet-Archiv
André-Marie Ampère (1822), Recueil d'observations électro-dynamiques: contenant divers mémoires, notices, extraits de lettres ou d'ouvrages périodiques sur les sciences, relatifs a l'action mutuelle de deux courans électriques, à celle qui existe entre un courant électrique et un aimant ou le globe terrestre, et à celle de deux aimans l'un sur l'autre (in French), Chez Crochard, retrieved 26 September 2010
André-Marie Ampère; Babinet (Jacques, M.) (1822), Exposé des nouvelles découvertes sur l'électricité et le magnétisme (in German), Chez Méquignon-Marvis, retrieved 26 September 2010
André-Marie Ampère (1824), Description d'un appareil électro-dynamique (in French), Chez Crochard … et Bachelie, retrieved 26 September 2010
André-Marie Ampère (1826), Théorie des phénomènes électro-dynamiques, uniquement déduite de l'expérience (in French), Méquignon-Marvis, retrieved 26 September 2010
André-Marie Ampère (1883), Théorie mathématique des phénomènes électro-dynamiques: uniquement déduite de l'expérience (in French) (2nd ed.), A. Hermann, retrieved 26 September 2010
André-Marie Ampère (1834), Essai sur la philosophie des sciences, ou, Exposition analytique d'une classification naturelle de toutes les connaissances humaines (in German), Chez Bachelier, retrieved 26 September 2010
André-Marie Ampère (1834), Essai sur la philosophie des sciences (in German), vol. Bd. 1, Chez Bachelier, retrieved 26 September 2010
André-Marie Ampère (1843), Essai sur la philosophie des sciences (in German), vol. Bd. 2, Bachelier, retrieved 26 September 2010
Partial translations:

Magie, W.M. (1963). A Source Book in Physics. Harvard: Cambridge MA. pp. 446–460.
Lisa M. Dolling; Arthur F. Gianelli; Glenn N. Statile, eds. (2003). The Tests of Time: Readings in the Development of Physical Theory. Princeton: Princeton University Press. pp. 157–162. ISBN 978-0691090856..
Complete translations:

Ampère, André-Marie (2015). André Koch Torres Assis (ed.). Ampère's electrodynamics: analysis of the meaning and evolution of Ampère's force between current elements, together with a complete translation of his masterpiece: Theory of electrodynamic phenomena, uniquely deduced from experience (PDF). Translated by J. P. M. C Chaib. Montreal: Apeiron. ISBN 978-1-987980-03-5. Archived (PDF) from the original on 9 October 2022.
Ampère, André-Marie (2015). Mathematical Theory of Electrodynamic Phenomena, Uniquely Derived from Experiments. Michael D. Godfrey, Stanford University, (trans.).

== References ==

=== Notes ===

=== Citations ===

== Further reading ==
Williams, L. Pearce (1970). "Ampère, André-Marie". Dictionary of Scientific Biography. Vol. 1. New York: Charles Scribner's Sons. pp. 139–147. ISBN 978-0-684-10114-9.
Hofmann, James R. (1995). André-Marie Ampère. Oxford: Blackwell. ISBN 978-0631178491.
Duhem, Pierre Maurice Marie (9 September 2018). Ampère's Force Law: A Modern Introduction. Alan Aversa (trans.). doi:10.13140/RG.2.2.31100.03206/1 (inactive 21 October 2025). Retrieved 3 July 2019.{{cite book}}:  CS1 maint: DOI inactive as of October 2025 (link) (EPUB)

== External links ==

Ampère and the history of electricity – a French-language, edited by CNRS, site with Ampère's correspondence (full text and critical edition with links to manuscripts pictures, more than 1000 letters), an Ampère bibliography, experiments, and 3D simulations
Ampère Museum – a French-language site from the museum in Poleymieux-au-Mont-d'or, near Lyon, France
Ampere's Electrodynamics Includes complete English translation of Theory of Electrodynamic Phenomena
"Société des Amis d'André-Marie Ampère", a French society dedicated to maintain the memory of André-Marie Ampère and in charge of the Ampère Museum.
O'Connor, John J.; Robertson, Edmund F., "André-Marie Ampère", MacTutor History of Mathematics Archive, University of St Andrews
Catholic Encyclopedia on André Marie Ampère