André-Marie Ampère was a French physicist who is generally credited as one of the main discoverers of electromagnetism.
The ampere unit of measurement of electric current is named after him.
Ampère was born in Lyon, near his father's country house in Poleymieux and, as a child, took great delight in the pursuit of knowledge and is reported to have worked out long arithmetical sums by means of pebbles and biscuit crumbs before he knew the figures.
His father began to teach him Latin, but ceased on discovering the boy's greater inclination and aptitude for mathematical studies.
The young Ampère, however, soon resumed his Latin lessons, to enable him to master the works of Euler and Bernoulli.
In later life he was accustomed to say that he knew as much about mathematics when he was eighteen as ever he knew.
His reading embraced nearly the whole round of knowledge — history, travels, poetry, philosophy and the natural sciences.
When Lyons was taken by the army of the Convention in 1793 his father, who, holding the office of juge de paix, had stood out resolutely against the previous revolutionary excesses, was at once thrown into prison and died on the scaffold.
This left a profound impression on André-Marie's susceptible mind, and for more than a year he remained depressed.
His interest was aroused by some letters on botany that fell into his hands, and from botany he turned to the study of the classic poets, and to the writing of verses himself.
In 1796 he met Julie Carron, and an attachment sprang up between them that he naïvely recorded in a journal (Amorum) and they were married in 1799.
From about 1796 Ampère gave private lessons at Lyons in mathematics, chemistry and languages; and in 1801 he moved to Bourg, as professor of physics and chemistry, leaving his ailing wife and infant son (Jean Jacques Ampère) at Lyons.
She died in 1804, and he never recovered from the blow.
That year he was appointed professor of mathematics at the lycée of Lyons.
Jean Baptiste Joseph Delambre obtained for him a subordinate position in the polytechnic school at Paris,where he was elected professor of mathematics in 1809.
Here he continued to prosecute his scientific researches and his multifarious studies with unabated diligence.
He was admitted a member of the Institute in 1814.
It is on the service that he rendered to science in establishing the relations between electricity and magnetism, and in developing the science of electromagnetism, or, as he called it, electrodynamics, that Ampère's fame mainly rests.
On September 11, 1820 he heard of H. C. Ørsted's discovery that a magnetic needle is acted on by a voltaic current.
On the September 18 (of the same year) he presented a paper to the Academy, containing a far more complete exposition of that and similar phenomena.
He not only explained the electromagnetic phenomena already observed but also predicted many new ones.