André-Marie Ampère was born in Lyon, France, on 20 January 1775. His father, Jean-Jacques Ampère, was a prosperous man who owned a home in Lyon and a country house in Poleymieux-auMont-d'Or, where he was a local government official, which is only 10 km from Lyon.
In his early years the Ampère family spent most of the year in Lyon but the summer months were spent at their country home. However, in 1782 the Poleymieux-auMont-d'Or home became their main residence since André-Marie's father wished to spend more time on his son's education. Only a short time in winter was spent at Lyon where André-Marie's father saw to his business interests.
Despite not attending a school, André-Marie had an excellent education. His father taught him Latin and French literature and several branches of science. He was never required to study anything, but his father knew how to inspire in him a desire to know. Before being able to read, the young Ampère's greatest pleasure was to listen to passages from Buffon's natural history.
Ampère read articles from L'Encyclopédie, many of which he could recite in full in later life. It appears that Ampère read the Encyclopédie starting at volume 1 and reading the articles in alphabetical order. Whether this was the seed for Ampère's later desire for classification in all subjects is hard to say.
He always felt very confident in his own abilities and he began to develop his own mathematical ideas very quickly. Ampère had no contacts with anyone with any depth of mathematical knowledge so it is not surprising that he felt that his ideas were original.
While still only 13 years old Ampère submitted his first paper to the Académie de Lyon but since Ampère had not studied calculus the paper was not found worthy of publication. Shortly after writing the article Ampère read an article on differential calculus in the Encyclopédie and realised that he must learn more about mathematics and took lessons from a monk in Lyon.
His life was soon shattered. The French Revolution began with the storming of the Bastille on 14 July 1789 but the effect on the Poleymieux region was not very great at first. The city of Lyon refused to carry out instructions from Paris and the city was besieged for two months. On the fall of the city Jean-Jacques Ampère, who was a Justice of the Peace in Lyon at that time, was arrested for issuing an arrest warrant for the Jacobin Chevalier who had then been put to death.
Ampère's father went to the guillotine and his death was devastating to the young man. He gave up his studies for 18 months such was his sorrow. He met a girl, Julie, who he fell deeply in love with and started to return to his old self. They were engaged to be married in 1797 and Ampère decided he better show that he could earn a living so began tutoring mathematics in Lyon. He married Julie in 1799 and they had a son, who they called Jean-Jacques in honour of his father, in 1800.
Ampère continued tutoring mathematics until 1802 when he was appointed professor of physics and chemistry at Bourg École Centrale. This was a difficult time for Ampère because Julie became ill and he had to move to Bourg leaving her at Poleymieux.
Fortunately, after a year in Bourg, Ampère was able to move closer to Poleymieux, being appointed to a mathematics position at the Lycée in Lyon. His time spent in Lyon was difficult due to the continuing decline in his wife's health.
Julie died in July 1803 and Ampère was left with feelings of guilt for he had lived apart from her during much of their short marriage. His depression contributed to his decision to take the earliest opportunity to leave Lyon for new surroundings in Paris. Later he would regret this decision; his friends in Lyon, who attempted to fill the emotional void left by Julie's death, were painfully missed.
In 1804 he was appointed répétiteur (basically a tutor) in analysis at the École Polytechnique. Without a formal education or qualifications his appointment is surprising but shows that his potential was recognised. His life did not improve and he embarked on a disastrous marriage to Jenny on 1 August 1806 but, before the birth of their daughter on 6 July 1807, the couple were living apart and were not on speaking terms. They were legally separated in 1808 and Ampère was given custody of their daughter Albine.
Between 1809 and 1828 he held posts at the École Polytechnique. During this time he worked on a wide variety of topics. Although a mathematics professor, his interests included, in addition to mathematics, metaphysics, physics and chemistry. In 1811 he suggested that an anhydrous acid prepared two years earlier was a compound of hydrogen with an unknown element, analogous to chlorine, for which he suggested the name fluorine. In mathematics he worked on partial differential equations. He also worked on the theory of light, and was a strong advocate of the wave theory of light, agreeing with Fresnel, who became a good friend of Ampère's and lodged at Ampère's home from 1822 until his death in 1827.
In the early 1820s, Ampère attempted to give a combined theory of electricity and magnetism after hearing about experimental results by the Danish physicist Hans Christian Ørsted. Ampère formulated a circuit force law and treated magnetism by postulating small closed circuits inside the magnetised substance. Ampère's most important publication on electricity and magnetism was published in 1826. It is called Memoir on the Mathematical Theory of Electrodynamic Phenomena, Uniquely Deduced from Experience and contained a mathematical derivation of the electrodynamic force law and describes four experiments. Ampère's theory became fundamental for 19th century developments in electricity and magnetism. Faraday discovered electromagnetic induction in 1821 and, after initially believing that he had himself discovered the effect in 1822, Ampère agreed that full credit for the discovery should go to Faraday.
Ampère was appointed to a chair at Université de France in 1826 which he held until his death.
Given the tragedy in Ampère's life it might have been hoped that his children would bring him some happiness. His son certainly achieved fame as a historian and philologist who studied the cultural origins of western European languages. He was appointed to a chair of history of foreign literature at the Sorbonne in 1830. However his relationship with his father was a difficult one.
Ampère had an even more difficult time with his daughter. She married one of Napoleon's lieutenants in 1827 but he was an alcoholic and the marriage was soon in trouble. Ampère's daughter fled to her father's house in 1830 and, some days later, Ampère allowed her husband to live with him also. This proved a difficult situation, led to police intervention and much unhappiness for Ampère.
Ampère died June 10, 1836 in Marseilles and was buried in the Montmartre Cemetery in Paris. When Gustave Eiffel built his famous Eiffel Tower in Pairs in 1889, he included the names of 72 prominent French scientists on plaques around the first section at the base of the structure. The name of André-Marie Ampère is included in that distinguished memorial.
The ampere, the unit for measuring electric current, was named in honor of Ampère. In the past, an ampere was understood as the force generated between parallel electrically charged wires, but as scientific knowledge evolves over time, the definition of ampere sometimes changes slightly also. The modern definition of ampere describes the ability of a specified current to deposit a precise amount of a substance on an electrode during electrolysis.