Heinrich Rudolph Hertz

Heinrich Rudolf Hertz (Hamburg, German Confederation, February 22, 1857-Bonn, German Empire, January 1, 1894) was a German physicist who discovered the photoelectric effect, the propagation of electromagnetic waves and the ways to produce and detect them. The unit of measurement for frequency, the hertz ("Hertz" in most languages), is named in his honor.

Childhood and youth

He belonged to a family of Jewish origin that had converted to Christianity in 1838. His father was a councilor in the city of Hamburg. Already in his childhood he showed that he had unusual abilities, since it is known that he read the classics in their original version (Plato and Greek tragedies). He also read Arabic, and his mother boasted that he was always at the top of the class. However, despite his demonstrated ability for studies, he was also very fond of practical activities, such as carpentry and the lathe, where he also He stood out for his skill. An anecdote relates how a craftsman who was teaching him to use the lathe exclaimed, upon learning of his nomination for the chair: "Too bad, because this boy would have become a good turner!"

Career

This taste for practical matters influenced his later decision to pursue engineering in Dresden, Germany. His self-acknowledged passion was physics, so he traveled to Berlin to study it with Gustav Kirchoff and with others. With a thesis on the rotation of spheres in a magnetic field, he obtained his doctorate in 1880, at the age of 23, and continued as a student of Hermann von Helmholtz until 1883, when he was appointed professor of theoretical physics at the University of Kiel. In 1885, he moved to the University of Karlsruhe, where he discovered how to produce and detect electromagnetic waves, which twenty years earlier had been predicted by James Clerk Maxwell.

Starting with Albert Abraham Michelson's experiment in 1881 (precursor to the Michelson and Morley experiment in 1887), which disproved the existence of the ether, Hertz reformulated Maxwell's equations to take the new discovery into account. He experimentally demonstrated that electromagnetic waves can travel through free air and vacuum, as James Clerk Maxwell and Michael Faraday had predicted, building himself a wave emitter and receiver in his laboratory. For the emitter, he used an oscillator, and for the receiver, a resonator. In the same way, he calculated the speed of travel of waves in the air and it was very close to the value established by Maxwell of 300,000 km / s. He focused on theoretical considerations and left the practical applications of his discoveries to others. Guglielmo Marconi used a Hertz article to build a radio transmitter, as Aleksandr Stepanovich Popov did the same with his coherer, a device that he adapted through the discoveries of Hertz, for the record of thunderstorms.^{[citation needed]}

He also discovered the photoelectric effect (later explained by Albert Einstein) when he noticed that a charged object loses its charge more easily when illuminated by ultraviolet light.^{[citation needed]}

Death

His brilliant career was cut short. Around 1889 he began to have serious health problems and, although they did not interfere with his work, he eventually died of Wegener's granulomatosis, at age 36, in Bonn, Germany. His nephew Gustav Ludwig Hertz was a Nobel Prize winner, and Gustav's son Carl Hellmuth Hertz invented medical ultrasonography.^{[citation needed ]}

The hertz or hertz (Hz)

Telecommunications owe their existence to this scientist and that is why, as a tribute, the scientific community gave his name to the unit of frequency (hertz or hertz), Hz, a decision made in 1930 by the Electrotechnical Commission International.

Acknowledgments

• The lunar crater Hertz carries this name in his honor.
• Likewise, the asteroid (16761) Hertz commemorates its name.

Works

• Ueber die Induction in rotirenden Kugeln (in German). Berlin: Schade. 1880.
• Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt (in German). Leipzig: Johann Ambrosius Barth. 1894.
• Schriften vermischten Inhalts (in German). Leipzig: Johann Ambrosius Barth. 1895.

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  Ueber die Induction in rotirenden Kugeln, 1880

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  Schriften vermischten Inhalts, 1895