André-Marie Ampère

Lore & Background

Ampère was born in Lyon to Jean-Jacques Ampère, a prosperous businessman, and Jeanne Antoinette Desutières-Sarcey Ampère. His father, an admirer of Rousseau, educated him at home using a well-stocked library, allowing Ampère to teach himself advanced mathematics by age 12. During the French Revolution, his father was guillotined in 1793 as part of Jacobin purges. Ampère married Julie Carron in 1799 and took his first regular job as a mathematics teacher that same year. After his wife's death in 1803, he moved to Paris, becoming a professor at the École Polytechnique in 1809 and later holding chairs at the University of Paris and the Collège de France. He was a member of the French Academy of Sciences and a lay Catholic who took the young Frédéric Ozanam into his family.

Reader's Guide

Ampère's most significant work began in September 1820, when François Arago showed the French Academy of Sciences Hans Christian Ørsted's discovery that a magnetic needle is deflected by an electric current. Ampère then developed a mathematical and physical theory of electromagnetism, demonstrating that parallel wires attract or repel depending on current direction. He formulated Ampère's law, which states that the mutual action of two current-carrying wires is proportional to their lengths and current intensities. He theorized an 'electrodynamic molecule' (forerunner of the electron), a hypothesis later confirmed by the Einstein–de Haas effect in 1915. His 1826 treatise coined the term electrodynamics and became the founding work of the field. The Monge–Ampère equation is named after him and Gaspard Monge. James Clerk Maxwell called Ampère 'the Newton of electricity.' The SI unit ampere is named after him, and his name appears on the Eiffel Tower.

Did You Know?

• Ampère coined the term solenoid and also invented the electrical telegraph.
• He constructed the term 'cinématique' (kinematic) from the Greek word for movement.
• His father was guillotined during the French Revolution in 1793.
• He was elected a Foreign Member of the Royal Society in 1827.

Notable Quotes (Wikiquote)

"Écoute les savants, mais ne les écoute que d'une oreille!...

Que l'autre soit toujours prête à recevoir les doux accents de la voix de ton ami céleste!" — André-Marie Ampère "Listen to learned men, but do so only with one ear !...

Let the other be always ready to receive the sweet accents of the voice of your heavenly Friend!" — André-Marie Ampère "André-Marie Ampère in: André-Marie Ampère: Enlightenment and Electrodynamics, Cambridge University Press, 1996, p. 158." — André-Marie Ampère "James Clerk Maxwell, A Treatise on Electricity and Magnetism (1873) quoted from 3rd edition (1892) Vol. 2, Ch. 3, p. 175." — André-Marie Ampère