Andre-Marie Ampere was a French physicist and mathematician who was one of the founders of the science of classical electromagnetism. His name endures in everyday life in
the ampere, the unit for measuring electric current.
On September 18, 1820, introduced a new field of study, electrodynamics, devoted to the effect of electricity in motion, including the interaction between currents in adjoining conductors and the interplay of the surrounding magnetic fields. Constructed the first solenoid and demonstrated how it could behave like a magnet (the first electromagnet). Suggested the name galvanometer for an instrument designed to measure current levels.
Ampere, who was born into a prosperous bourgeois family during the height of the French Enlightenment, personified the scientific culture of his day. His father, Jean-Jacques Ampere, was a successful merchant, and
also an admirer of the philosophy of Jean-Jacques Rousseau, whose theories of education, were the basis of Ampere's education.
Rousseau argued that young boys should avoid formal schooling and pursue instead an "education direct from nature."
Ampere's father actualized this ideal by allowing his son to educate himself within the walls of his well-stocked library.
He used his access to the latest mathematical books to begin teaching himself advanced mathematics at age 12.
French Revolution brought new institutions of science that
ultimately became central to Andre-Marie Ampere's professional success. Ampere's maturation corresponded with
the transition to the Napoleonic regime in France, and he
found new opportunities for success within the technocratic structures favored by the new French emperor.
In 1802 Ampere produced ("Considerations on the Mathematical
Theory of Games"), a treatise on mathematical probability that he sent to the Paris Academy of Sciences in 1803.
In the following years Ampere engaged in a diverse array of scientific inquiries-writing papers and engaging in
topics ranging from mathematics and philosophy to chemistry and astronomy. Such breadth was customary among
the leading scientific intellectuals of the day.
Founding of Electromagnetism
In 1820 Ampere's friend and eventual eulogist Francois Arago demonstrated before the members of the French
Academy of Sciences the surprising discovery of Danish physicist Hans Christiaan oersted that a magnetic needle is deflected by an adjacent electric current. Ampere was well prepared to throw himself fully into this new line of research.
Ampere immediately set to work developing a mathematical and physical theory to understand the relationship
between electricity and magnetism. Extending oersted's experimental work, Ampere showed that two parallel
wires carrying electric currents repel or attract each other, depending on whether the currents flow in the same or
opposite directions, respectively. He also applied mathematics in generalizing physical laws from these
Most important was the principle
that came to be called Ampere'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
Ampere 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. Ampere's devotion to, and skill with, experimental
techniques anchored his science within the emerging
fields of experimental physics.
Ampere also offered a physical understanding of the
electromagnetic relationship, theorizing the existence of
an "electrodynamic molecule" that served as the constituent element of
electricity and magnetism. Using this physical understanding of electromagnetic motion, Ampere developed a
physical account of electromagnetic phenomena that was
both empirically demonstrable and mathematically predictive.
In recognition of his contribution to the making of modern electrical science, an
international convention signed in 1881 established the
as a standard unit of electrical measurement, along
with the coulomb
, and watt
, which are named,
respectively, after Ampere's
of Italy, Georg Ohm
of Germany, and James Watt of Scotland.
The 1827 publication of Ampere's brought to a close his feverish work over the previous
seven years on the new science of electrodynamics. The
text also marked the end of his original scientific work.
His health began to fail, and he died while performing a
university inspection, decades before his new science was
canonized as the foundation stone for the modern science