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A Great Invention of a Russian Scientist

Radio occupies one of the leading places among the greatest achievements of modern engineering. It was invented by Professor A. S. Popov, a talented Russian scientist, who demonstrated the first radio – receiving set in the world on May 7, 1895.

And it is on this day that the anniversary of the birth of the radio is marked.

By his invention Popov made a priceless contribution to the development of world science.

A. S. Popov was born in the Urals, on March 16, 1859. For some years he had been studying at the seminary in Perm, and then went to the University of St. Petersburg. In his student days he worked as a mechanic at one of the first electric power – plants in St. Petersburg which was producing electric lights for Nevsky Prospekt.

After graduating from the University in 1882, A. S. Popov remained there as a post – graduate at the Physics Department. A year later he became a lecturer in Physics and Electrical Engineering in Kronstadt. By this time he had already gained recognition among specialists as an authority in this field.

After Hertz had published his experiments proving the existence of electromagnetic waves, A. S. Popov thought of the possibility of using Hertz waves for transmitting signals over a distance. Thus the first wireless (radio) receiving set was created. Then Popov developed his device and on March 24, 1896 he demonstrated the transmission and reception of a radiogram consisting of two words: Heinrich Hertz. On that day the radio-telegraphy was converted from an abstract theoretical problem into a real fact.

A. S. Popov did not live to see the great progress of his invention. In the first decrees the Soviet Government planned the development of an industry for producing radio equipment, the construction of radio stations. All this was put into practice on a scale which had greatly surpassed plans for the radiofication of the country.

Popov’s invention laid the foundation for further inventions and improvements in the field of radio engineering. Since that time scientists all over the world have been developing the modern systems of radiotelegraphy, broadcasting, television, radiolocation, radio-navigation and other branches of radio-electronics.

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CHARLES COULOMB

CHARLES COULOMB (1736–1806), a member of the Paris Academy of Sciences, an outstanding French physicist in the period from 1785 to 1789 stated the law of electrostatic and magnetic interaction. His work in this field laid foundation for the future theoretic investigations in the electrostatics and magnetstatics.

Coulomb’s law is one of the principal laws of electrostatics. It established a relationship between the force of interaction of two static electric charges, their quantities, and the distance between them. According to Coulomb’s law the absolute value of the force of repulsion of two like charges or the force of attraction between two unlike charges e l and e 2, which size is much less than the distance between them, is inversely proportional to the square of the distance between them. He also stated the laws of rotation, dry friction, laws of interaction between magnetic poles. All these laws were named in honor of Ch. Coulomb.



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ANDRE MARIE AMPERE

ANDRE MARIE AMPERE (1775–1836) was an outstanding physicist and mathematician of French origin. He is one of the founders of modern electrodynamics. He was born in aristocratic family in Lyon. By the age of 14 he has read all the 20 volumes of «The Encyclopedia» by Diderot and D’Alambert. His scientific interests were very diverse.

In 1801 Ampere headed the Chair of Physics in Burge, in 1805 he became a teacher of physics at the Polytechnical School in Paris. Since 1814 he was elected Member of The Institute, which later transformed into the French Academy of Sciences. After 1824 he occupied the post of professor at the Ecole Normale in Paris.

Ampere’s studies on the effects of the electric current flow on the magnetic needle were his greatest contribution to physics. In 1820 in the report to the Paris Academy, he made the announcement of the so-called “Ampere Rule”, which is since used to define the deflection of the needle affected by the electric current. This led him to the discovery of interactions between electric currents. The fundamental laws of this interaction got his name.

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GEORGE SYMON OHM

GEORGE SYMON OHM (1784–1854) is a famous German physicist. In 1805 he entered the Erlangen University. Though he did not graduate from this University, he managed to write and defend a thesis in 1811. Later, he was a teacher at the gymnasiums of Gottstadt and Wamburg. Beginning from 1833 he became professor at the Polytechnical School in Nürenberg, and since 1849 – at the München University.

He is most famous for establishment of the general law of the electric circuit, stating the relation between resistance, electromotive force, and strength of the current in the electric circuit. The law was discovered experimentally and first formulated in 1826. Further investigations made use of this law. The unit of resistance was named after Ohm at the International Congress of Electricians in 1881.

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Date: 2015-12-24; view: 1341


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