André-Marie Ampère (1775 - 1836) was a French physicist and mathematician who is regarded as one of the founders of the science of classical electromagnetism, which he named electrodynamics. [1] The SI unit of electric current, the ampere, is named in his honour.
Early life
André-Marie Ampère was born on 20 January 1775 in Lyon, France, into a prosperous merchant family. Largely self-educated, he read widely from his father's library and displayed an early aptitude for mathematics. His early life was marked by tragedy: his father, Jean-Jacques Ampère, was executed during the Reign of Terror in 1793. [2]
Academic career
Ampère taught mathematics and physics in Lyon before moving to Paris, where he was appointed a professor at the École Polytechnique. In 1808 he became an inspector general of the newly organised French university system, and he later held the chair of experimental physics at the Collège de France. He was elected a member of the French Academy of Sciences and a Foreign Member of the Royal Society.
Electrodynamics
In 1820 the Danish physicist Hans Christian Ørsted discovered that an electric current deflects a nearby compass needle. Within weeks Ampère extended these observations, demonstrating that two parallel wires carrying electric currents attract or repel one another depending on the direction of the currents. He formulated a mathematical relationship describing the magnetic force between current-carrying conductors, a result now known as Ampère's law. His 1827 memoir laid the theoretical foundations of the field he called electrodynamics. [1]
Legacy
Ampère died in Marseille on 10 June 1836. In recognition of his contributions, the ampere, the SI unit of electric current, was named in his honour, and his name is among the 72 inscribed on the Eiffel Tower. Made a Knight of the Legion of Honour, his pioneering work helped establish electromagnetism as a rigorous, quantitative branch of physics.
