Andre Marie Ampere

French physicist and mathematician, developed the connection between electricity and magnetism


His father was a wealthy merchant in Lyon. Ampere had a passion for mathematics and a photographic memory. A librarian informed him that the works of great scientists like Euler and Bernoulli were in Latin, so he learned Latin by age 12. At the age of 18 his life was torn apart by the French Revolution when his father was guillotined because he was a Justice of the Peace in the ancient regime. When Ampere was 28, his first wife died during childbirth, so much pain at an early age. In his early career, he study several subjects like philosophy, psychology and chemistry. He independently arrived at Avogadro number.

Wire and a Magnet

In 1819, Hans Christian Orsted, placed a magnet needle next to a current carrying wire and the needle defected. This discovery indicated that there was a connection between electricity and magnetism. When Ampere learned of the discovery, he too examined it further and created a right hand rule for determining the direction in which the needle deflected.

Electromagnetism Discoveries

He also examine the force between two parallel wires that carry current and he also wondered what would happen if the wire was in a cirle, this lead to the discovery of a current carrying coil called a Solenoid. This device was used Joseph Henry to develop the long distance electric telegraph.

Ampere Law

He noticed that the deflection in Orsted’s needle could be used as a meter of the flow of current in the wire, this formed the basis of a galvanometer. One of his main discoveries was to relate the magnetic force between two wires to the product of the current in the wires and the inverse of the distance between them.

The Reward

Ampere died of pneumonia in 1836 at the age of 61 and was rewarded by Lord Kelvin when he suggested that the standard measure for current should be measured in Amperes. This is still the situation today and you can learn more about amps in our measurement section. After the pain of losing his father and wife at an early age his attitude to life can be summed up in his epitaph Tandem Felix which translates to “Happy at Last”.

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