Ampère, Adré Marie

1995/08/02 Azkune Mendia, Iñaki - Elhuyar Fundazioa | Kaltzada, Pili - Elhuyar Zientziaren Komunikazioa

• Biografiak

(1775-1836)

This physicist and mathematician first saw in Lyon the light of this world on January 22, 1775. His father, a retiree trader, was murdered by guilotina during the French revolution when the Republicans took over the city in 1793. André-Marie suffered a deep depression.

Since childhood he tried to learn on his own literature, natural sciences, philosophy, mathematics, etc. He had great mathematical ease and by the thirteen years had written a treatise on conical cuts.

In 1801 he was appointed professor of Bourg to teach Physics and Chemistry. In 1802, using the calculation of odds, he published a paper on the theory of the game.

In 1804 his wife died, recently married. He had to undergo a new depression.

However, he continued to teach physics and chemistry at Bourg and in 1809 he taught mathematics at the École Polytechnique in Paris. In 1814 he was appointed a member of the Academy of Sciences in mathematical matters.

But he also took care of chemistry. In a letter sent to Berthollet in 1814, for example, it was indicated that all gases of equal pressure, volume and temperature have the same number of molecules. It should be clarified that this hypothesis, although Ampérez did not know it, was made by Avogadro a year earlier.

However, he made his greatest advances in the field of physics. When in 1820 the Paris Academy of Sciences announced the discovery of Oersted, an electric current driver diverting the compass, Ampère and Arago began to work. A week later, Ampérez verified that the deviation of the needle was produced according to what is now known as "right hand rule" or "cork cork cork cork". The right hand is placed by grabbing the driver, the thumb marks the direction of the current and the other fingers indicate the north pole of the magnet. According to the standard, the magnet will deviate in the direction of the fingers. It was the beginning of the concept of magnetic field force lines.

To apply the rule of the right hand it was necessary to determine the direction of the electric current. According to Franklin's ideas, it seemed normal to consider that the direction of the current goes from the pole positive to the negative, since they thought that the positive pole had too much electric fluid and the negative insufficient. The Ampère also considered this direction, although today it is known that the electrons go from the negative to the positive pole.

According to Ampère, to see the magnetic attractions and repulsions, the presence of magnets and iron powders was not necessary. He placed two parallel conductors, which one could approach or move away. When the two threads had the electric current in the same sense, they attracted each other, and when they had the current in the opposite direction, they repented. Ampère also investigated the magnetic fields created by the current through the circular thread. Next to the Aragon, the cylindrical spiral thread would behave like a magnet with electric current. The spiral-shaped yellow is called solenoid.

If the electric current could divert the magnetic needle, measuring the deviation at a graduated scale, the amount or current intensity could be analysed. Ampère first applied high level mathematics to electrical and magnetic phenomena and it can be said that he is the creator of a field called electromagnetism.

In 1823 he published a theory on the characteristics of the magnet. He said there were small electric currents that circulated continuously through the magnet. That is why it can also be considered as the precursor of electronic theory, although scientists of the time of the Ampère did not pay much attention to this idea.

Ampère, at the end of his life, began to classify all human knowledge, leaving him unfinished in his Essay on the Philosophy of Sciences.

He used for the first time the words "current" and "voltage", as he distinguished between intensity and difference of potential, and the electric telegraph is also invented by him.

Currently the intensity of the electric current is measured in amps in honor of the French physicist.

He died almost without glory in Marseilles on June 10, 1836.