Heinrich Rudolf Hertz ( ; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism.
The unit of frequency, cycle per second, was named the "[in his honor. ==Biography== Heinrich Rudolf Hertz was born in 1857 in Hamburg, then a sovereign state of the German Confederation, into a prosperous and cultured Hanseatic family.
He died at the age of 36 in Bonn, Germany in 1894, and was buried in the Ohlsdorf Cemetery in Hamburg. Hertz's wife, Elisabeth Hertz (née Doll; 1864–1941), did not remarry.
Hertz's daughters never married and he has no descendants. ==Scientific work== ===Electromagnetic waves=== In 1864 Scottish mathematical physicist James Clerk Maxwell proposed a comprehensive theory of electromagnetism, now called Maxwell's equations.
Maxwell proposed that light consisted of electromagnetic waves of short wavelength, but no one had been able to prove this, or generate or detect electromagnetic waves of other wavelengths. During Hertz's studies in 1879 Helmholtz suggested that Hertz's doctoral dissertation be on testing Maxwell's theory.
With an idea on how to build an apparatus, Hertz now had a way to proceed with the "Berlin Prize" problem of 1879 on proving Maxwell's theory (although the actual prize had expired uncollected in 1882).
In 1880, Hertz obtained his PhD from the University of Berlin, and for the next three years remained for post-doctoral study under Helmholtz, serving as his assistant.
With an idea on how to build an apparatus, Hertz now had a way to proceed with the "Berlin Prize" problem of 1879 on proving Maxwell's theory (although the actual prize had expired uncollected in 1882).
In 1883, Hertz took a post as a lecturer in theoretical physics at the University of Kiel.
In 1885, Hertz became a full professor at the University of Karlsruhe. In 1886, Hertz married Elisabeth Doll, the daughter of Max Doll, a lecturer in geometry at Karlsruhe.
In 1885, Hertz became a full professor at the University of Karlsruhe. In 1886, Hertz married Elisabeth Doll, the daughter of Max Doll, a lecturer in geometry at Karlsruhe.
Hertz did produce an analysis of Maxwell's equations during his time at Kiel, showing they did have more validity than the then prevalent "action at a distance" theories. After Hertz received his professorship at Karlsruhe he was experimenting with a pair of Riess spirals in the autumn of 1886 when he noticed that discharging a Leyden jar into one of these coils produced a spark in the other coil.
This experiment produced and received what are now called radio waves in the very high frequency range. Between 1886 and 1889 Hertz conducted a series of experiments that would prove the effects he was observing were results of Maxwell's predicted electromagnetic waves.
He did not further pursue investigation of this effect, nor did he make any attempt at explaining how the observed phenomenon was brought about. ===Contact mechanics=== In 1886–1889, Hertz published two articles on what was to become known as the field of contact mechanics, which proved to be an important basis for later theories in the field.
They had two daughters: Johanna, born on 20 October 1887 and Mathilde, born on 14 January 1891, who went on to become a notable biologist.
Starting in November 1887 with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz sent a series of papers to Helmholtz at the Berlin Academy, including papers in 1888 that showed transverse free space electromagnetic waves traveling at a finite speed over a distance.
In 1887, he made observations of the photoelectric effect and of the production and reception of electromagnetic (EM) waves, published in the journal Annalen der Physik.
Starting in November 1887 with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz sent a series of papers to Helmholtz at the Berlin Academy, including papers in 1888 that showed transverse free space electromagnetic waves traveling at a finite speed over a distance.
During this time Hertz conducted his landmark research into electromagnetic waves. Hertz took a position of Professor of Physics and Director of the Physics Institute in Bonn on 3 April 1889, a position he held until his death.
This experiment produced and received what are now called radio waves in the very high frequency range. Between 1886 and 1889 Hertz conducted a series of experiments that would prove the effects he was observing were results of Maxwell's predicted electromagnetic waves.
They had two daughters: Johanna, born on 20 October 1887 and Mathilde, born on 14 January 1891, who went on to become a notable biologist.
During this time he worked on theoretical mechanics with his work published in the book Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt (The Principles of Mechanics Presented in a New Form), published posthumously in 1894. ===Death=== In 1892, Hertz was diagnosed with an infection (after a bout of severe migraines) and underwent operations to treat the illness.
Today radio is an essential technology in global telecommunication networks, and the transmission medium underlying modern wireless devices. === Cathode rays === In 1892, Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil (such as aluminium).
Heinrich Rudolf Hertz ( ; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism.
During this time he worked on theoretical mechanics with his work published in the book Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt (The Principles of Mechanics Presented in a New Form), published posthumously in 1894. ===Death=== In 1892, Hertz was diagnosed with an infection (after a bout of severe migraines) and underwent operations to treat the illness.
He died at the age of 36 in Bonn, Germany in 1894, and was buried in the Ohlsdorf Cemetery in Hamburg. Hertz's wife, Elisabeth Hertz (née Doll; 1864–1941), did not remarry.
In 1909, Braun and Marconi received the Nobel Prize in physics for their "contributions to the development of wireless telegraphy".
But they are there." Asked about the applications of his discoveries, Hertz replied, "Nothing, I guess." Hertz's proof of the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around 1910 when the term "radio waves" became current.
Roberts (JKR) used this theory as a basis while calculating the theoretical displacement or indentation depth in the presence of adhesion in 1971.
Toporov published another theory in 1975, which came to be known as the DMT theory in the research community, which also recovered Hertz's formulations under the assumption of zero adhesion.
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