28.02.2018 | Who discovered it: André Marie Ampère

Magnetic fields and electricity

He was a French physicist and mathematician, and worked as a professor in Lyon and Paris: André Marie Ampère was the founder of electrodynamics and one of the first to explain the science of electromagnetism. He laid the foundation for the construction of generators to produce power. The unit for electrical current strength is named after him, as is the staff cafeteria on the Axpo campus in Baden.

Electricity is a natural phenomenon. As early as 600 BC, Thales von Milet (see story) discovered electricity by means of experiments with amber.

In 1826, the French universal scholar André Marie Ampère came upon the relationship between electricity and magnetism that was the prerequisite for the subsequent invention of the generators used in almost all power plants worldwide to product electricity. In his magnum opus "Theory of Electrodynamic Phenomena" he provides empirical explanations for electricity and voltage. This laid the foundation for electrodynamics. A majority of today's modern life with generators, electro-motors, telecommunication and measuring devices are based on electrodynamics.

(Photo: istock)
The autodidact

But who was Andre Marie Ampère really? He was born near Lyon on 20 January 1775. As I child he exhibited an eagerness to learn although he did not have a traditional school education. Learning on his own, he focused on botany, and psychology. At 18 years of age he concentrated on mathematics, based on the textbooks of the Swiss mathematician Leonhard von Euler and also studied physics. He earned a living as a professor at various institutions in Lyon and Paris.

In 1820, Ampère became aware of the electricity and magnetic experiments by the Danish physicist Hans Christian Oersted. He repeated experiments and found out that two parallel wires carrying electric currents attract when the current flows in the same direction – and repel each other, when the current flows in different directions. Later he discovered that wire could be formed in rings, so-called coils.

The galvanometer

When electricity flows through a coil, a magnetic field is created. Its strength depends on how often the wire has been wound around the coil. Ampère constructed his own device, a galvanometer to measure electricity. He found out: Flowing electricity is the true cause of magnetism (Ampère's force law). And: The more windings a coil has, the stronger the magnetic field. This is the discovery of electromagnetism. Ampère was the first to give it this name and explained terms such as voltage and electricity.

André Marie Ampère: Honoured for his discoveries - also with a stamp (Photo: istock)

As a result Ampère, who according to Wikipedia was previously "merely a textbook footnote for his scientific work", entered the guild of prominent universal scholars of the 19th century.

Ampère died of pneumonia in Marseilles in 1836 at the age of 61. His grave is in the famous Paris cemmetary Montmartre. In Ampère's honour the unit for electrical current was named Ampere (A).

More information about the knowledge, research and life of André Marie Ampère is available in this video (Source: SWF).

Axpo presents important energy researchers, their inventions, and scientific findings in Energy dialogue online. Previous publications: Alessandro Volta

More articles for you

Show all

Energy politics

The consolidation bill is an important step towards implementing the energy transition

Further measures required to expand renewable energies

Read more

Renewable energy

What’s behind the electricity price increases

Basic electricity supply prices are rising

Read more

Energy politics

Higher renewable targets for 2030 & better tools to implement them?

Revision of the EU Renewable Energy Directive

Read more


Lots of expertise, pizza and the Axpo community in Baden

Engineering Power Conference 2023

Read more