Page "André-Marie Ampère" Paragraph 8

In September of 1820, Ampère ’ s friend and eventual eulogist François Arago showed the members of the French Academy of Sciences the surprising discovery of Danish physicist Hans Christian Ørsted that a magnetic needle is deflected by an adjacent electric current.

Ampère begun developing a mathematical and physical theory to understand the relationship between electricity and magnetism.

Furthering Ørsted ’ s experimental work, Ampère showed that two parallel wires carrying electric currents attract or repel each other, depending on whether the currents flow in the same or opposite directions, respectively-this laid the foundation of electrodynamics.

He also applied mathematics in generalizing physical laws from these experimental results.

The most important of these was the principle that came to be called Ampère ’ s law, which states that the mutual action of two lengths of current-carrying wire is proportional to their lengths and to the intensities of their currents.

Ampère also applied this same principle to magnetism, showing the harmony between his law and French physicist Charles Augustin de Coulomb ’ s law of magnetic action.

Ampère ’ s devotion to, and skill with, experimental techniques anchored his science within the emerging fields of experimental physics.