Andre Marie Ampere

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Andre Marie Ampere was a French physicist and mathematician and is known for being a founder of classical electromagnetism.

Engraving of Andre Marie Ampere


Personal Life

Andre Marie Ampere was born in January 20, 1775 to Jean-Jacques Ampère, a successful businessman, and Jeanne Antoinette Desutières-Sarcey Ampère. He also had two sisters. At a young age, he was very curious and sought out knowledge. He began to read books on mathematics, history, travels, poetry, philosophy, and the natural sciences. He began to gain more interest in mathematics at the age of 13 and at this time started to study physics as well. When Ampere was 14, the French Revolution began. His father was appointed as justice of peace of a small town near Lyon. However in 1972 and 1973, Ampere experienced tragic losses of his sister and father. Due to this, he stopped his studies for a year. In 1797, he was a private math tutor,

Education

His father believed very strongly in philosophy of Jean-Jacques Rousseau that young boys should not pursue formal education but learn "direct from nature." Ampere satisfied his desires to learn by reading books in his father's well-stocked library.

Scientific Contribution

Electromagnestism

In April 1820, Danish physicist Hans Christian Oersted found a connection between electricity and magnetism which we know as electromagnetism. A few months later, Francois Arago, a friend of Ampere, demonstrated Oersted’s electromagnetic effect to the French Academy in Paris. Ampere found Oersted’s electromagnetic discoveries interesting and began working on them himself. After rigorous experiments, Ampere was able to show 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. Having a lot of knowledge in both mathematics and physics, Ampere applied mathematics to generalize physical laws from the results of the experiments, and discovered the principle which is now known as “Ampere’s law”. His works provided a physical understanding of the electromagnetic relationship, allowing the theory of an “electrodynamic molecule” that served as the component element of both electricity and magnetism to form. After years of research and experimentation, Ampere published ‘Mémoire sur la théorie mathématique des phénomènes électrodynamiques uniquement déduite de l’experience’ (“Memoir on the Mathematical Theory of Electrodynamic Phenomena, Uniquely Deduced from Experience”) in 1827. The name of his discoveries became known as “Electrodynamics” was coined in this work which became known as its founding written document.

“Ever since I first heard of Oersted’s great discovery… of the action of electric current on a magnetized needle, I have thought about it constantly. All my time has been dedicated to writing a great theory about these phenomena… and attempting the experiments indicated by this theory, all of which succeeded.” -Ampere

Ampere's Circuital Law

Ampere’s circuital law relates the integrated magnetic field around a closed loop to the electric current passing through the loop. He also formulated Ampere's Law which states in its simplest form that two lengths of current-carrying wire is proportional to their lengths and to the intensities of their currents [math]\displaystyle{ \oint_C \mathbf{B} \cdot \mathrm{d}\boldsymbol{\ell} = \mu_0 \iint_S \mathbf{J} \cdot \mathrm{d}\mathbf{S} = \mu_0I_\mathrm{enc} }[/math]

Other Information

Fun Facts

  • His name is inscribed on the Eiffel Tower
  • He did not actually attend school because his father did not believe in formal education
  • Ampere which is a unit of measuring electric current was named in honor of him
  • He is credited for the invention of the astatic needle, a vital component of the modern astatic galvanometer

See also

Wikipedia page for Ampere's Law

Wikipedia page for Electromagnetism

Further reading

  • Ampère, André-Marie by Williams, L. Pearce in Dictionary of Scientific Biography 1
  • André-Marie Ampère by Hofmann, James R

External links

References