André-Marie Ampère
A self-taught genius who defined the relationship between electricity and magnetism, giving his name to the very unit of electrical current.
1775–1836 (age 61)·French physicist and mathematician·Birthday: January 20
Biography
André-Marie Ampère's mind was a storm of curiosity, largely self-fueled in the library of his family home in Lyon. Tragedy marked his early life—his father was guillotined during the French Revolution—but he immersed himself in mathematics and science. The pivotal moment came in 1820, when he learned of Hans Christian Ørsted's discovery that an electric current could deflect a compass needle. In a frenzy of experimentation and insight, Ampère formulated the mathematical laws of electromagnetism within weeks. He theorized that magnetism was electricity in motion, conceived of the solenoid as a tool to create magnetic fields, and even sketched early ideas for an electric telegraph. His work, compiled in his 'Memoir on the Mathematical Theory of Electrodynamic Phenomena,' was so foundational that James Clerk Maxwell later called him the 'Newton of electricity.' Ampère was a professor at the École Polytechnique, but his true classroom was the frontier of a new force that would power the modern world.
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André-Marie's Life & Times
The world at every milestone
1775Born
1780Started school
1788Became a teenager
1791Could drive
1793Could vote
1796Turned 21
1805Turned 30
1815Turned 40
1825Turned 50
1835Turned 60
1836Died at 61
Key Achievements
- Formulated Ampère's circuital law, a cornerstone of classical electromagnetism defining the relationship between electric currents and magnetic fields.
- Invented the solenoid, a coil of wire that produces a controlled magnetic field when electrified.
- Was the first to develop a theory that explained electrodynamic phenomena, which he detailed in his seminal 1827 memoir.
- His name was immortalized as the standard unit of electric current, the ampere (amp).
Did You Know?
He was largely self-taught, having read through the entire contents of his father's library by his early teens.
Ampère made significant contributions to chemistry, independently identifying the element fluorine (though he did not isolate it).
He experienced profound personal grief; his father was executed, and his first wife died young, after which he often struggled with depression.
Ampère held a chair in philosophy as well as physics, reflecting his wide-ranging intellectual pursuits.
“The future of science belongs to those who know how to interpret the facts and to deduce from them the laws which will allow us to foresee new facts.”
