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03:00It's 1820 and Ampère discovers the electromagnetics.
03:05André-Marie Ampère is the great scientist, born in Lyon, who discovered the electric current in 1820.
03:11The Newton of electricity, as the great physicist Maxwell had described it.
03:15At that time, electricity is still very little known and has no practical application.
03:21We know about electrical charges, those obtained by rubbing an amber or glass stick that attract straw fetuses, the cloud
03:29that produces lightning, those created by combining two metals in a conductive liquid.
03:33It is the battery the Italian Volta invented shortly before.
03:37We also know magnets like this magnesia stone, natural iron oxide, which orients at the surface of the earth in
03:44the needle of the compass, but we make no connection between electric charge and magnet.
03:49In 1819, the Danish physicist URSTED brings a wire connected to a Volta battery close to a magnetic mobile needle.
03:58Immediately, the needle deflects and leaves the pole on September 11th, 1820, the experiment is reproduced at the Paris Academy
04:08of Sciences.
04:08For Ampère, who attends, it is a shock, the stroke of genius that will give birth to electrodynamics, the science
04:16of interactions between electric currents.
04:18A week later, he sets out his fundamental hypothesis on the existence of electric currents in magnets, including for earth
04:26magnetism.
04:27Ampère announces that in the absence of earth magnetism, the needle would orient perpendicularly to the wire, and it demonstrates
04:34this by inventing a magnetic needle called astatic.
04:38He highlights and characterizes the electrodynamic forces between conductors.
04:45Ampère shows that the magnetic needle deviates similarly all along the wire, even very far from the battery.
04:53This characteristic property of the circuit as a whole is a quantity, the electric current.
04:59He is the first to clearly distinguish the basic concepts of voltage and current.
05:04André-Marie imagines using this property to build an electric telegraph that will become reality with the invention of the
05:12Morse code.
05:13In 1881, the Congress of Electricians paid homage to him by naming Ampères the International Current Unit.
05:21Ampère shows that the two wires wound in turn, spirals, or helices, behave exactly as two magnetic poles would.
05:30By placing with the physicist Arago a soft iron cylinder in the center of the helical wire, which he calls
05:36a solenoid,
05:37he discovers the temporary magnetization which is at the base of the electromagnet.
05:43Ampère also makes the rotation of a magnet around its axis, which already prefigures the electric motor.
05:50Finally, he defines the mathematical laws of interaction between two elementary conductors and deduces the formula for macroscopic conductors.
05:59This is the culmination in 1826 of his work on electrodynamics.
06:05Today, electrodynamics is present everywhere in the production and the use of electricity that enlightens us, nourishes, transports, cares for,
06:14and connects us.
06:32This is the financial tool for macroscopic conductors to the infinite resources for macroscopic conductors.
06:33Now, we watched the study of the American According ToWhat,
08:46The key theme of the symposium is power system transformation including active distribution.
08:53In this symposium, experts and scholars will exchange ideas and knowledge about state-of-the-earth
09:00technologies during technical sessions.
09:03And you can enjoy various social events like technical tour, company tour and gala dinner.
09:10Now, we are accepting your synopsis until 3rd September.
09:16We are looking forward to welcoming you in Kyoto next spring.
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