What was your last big discovery

Heinrich Rudolf Hertz

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With his discoveries, the German physicist laid the foundations for radio and television broadcasting. He taught at Kiel University from 1883 to 1885.


Heinrich Rudolf Hertz (1857-1894)
Heinrich Hertz was born on February 22nd, 1857 in Hamburg, the son of a lawyer and later senator. In 1876 he began studying engineering at the Dresden Polytechnic and after one semester did his one-year military service in Berlin. He then resumed his studies at the Technical University in Munich, but realized that "his skills lie more in the field of science than technology," writes Charlotte Schmidt-Schönbeck in her book on the history of physics at Kiel University . He moved to Munich University to study natural sciences. In 1878 he went to Berlin and continued his studies with such famous scholars as Hermann von Helmholtz (1821 to 1894) and Gustav Robert Kirchhoff (1824 to 1887). As a student, Hertz began working in the physics laboratory to solve price problems, which was widely recognized by Helmholtz. In the 5th semester he did his doctorate “On the induction of rotating spheres” and completed his exam magna cum laude. When he received his doctorate in 1880, he was just 23 years old. He then accepted an assistant position at the physics institute under the direction of Helmholtz and worked on problems of electrodynamics, mechanics and meteorology.

In 1883 Hertz moved to Kiel University as a private lecturer in mathematical physics. There he completed his habilitation with the thesis "Experiments on the glow discharge", which he had completed in Berlin. However, he was rarely satisfied during his time in Kiel. With his lectures, Hertz found little understanding among his students, and the experimental possibilities were few. Schmidt-Schönbeck quotes from his diary: “At first there is a lack of every nook and cranny, and everything is not so easy to get here in Kiel, God knows how long you can go for a piece of suitable platinum wire or a glass tube. Then having to do everything over the pathetic spirit lamp ... «His most important treatise from his time in Kiel was a theoretical study of electrodynamic problems. In addition, he also dealt intensively with hydrodynamic issues. In 1885, Hertz accepted a position as full professor of physics at the technical university in Karlsruhe. As head of a physics institute, all experimental resources were available to him there. From 1886 he carried out the experiments that made him world famous. "His greatest achievement was undoubtedly the experimental proof of the existence of electromagnetic waves," says Professor Holger Kersten from the Institute for Experimental and Applied Physics. "The most important classical field theory - the conception of electromagnetism according to Faraday and Maxwell - thus appeared as an independent field alongside classical particle physics and also opened up an undreamt-of triumph for many technical applications." The discovery of electromagnetic waves and the proof that they are like light behave and spread, brought Hertz great recognition among scientists worldwide. The societies and academies of science in Italy, France and Austria awarded him high honors. The Prussian government honored him with the Order of the Crown. His experiments with these waves later led to the development of the wireless telegraph, radio, television, and much more.

After the great success of Hertz in Karlsruhe, his teacher from Helmholtz would have liked to have him back in Berlin. Hertz decided, however, from the offers for professorships in Berlin, Bonn and Gießen for the University of Bonn as the future place of work. There he took over the management of the Physics Institute in 1889. Theoretical interests were at the forefront of his work in Bonn. He initially devoted himself to the system of Maxwell's equations and later, already suffering from health problems, worked on his last book on the theoretical foundation of mechanics. Plasma physicist Kersten describes his early death as a great loss: “When Hertz died of blood poisoning on January 1, 1894, a few weeks before his 37th birthday, physics lost one of the greatest hopes it had ever had . «His assistant Philipp Lenard (1862 to 1947) continued the work and published an edition of his collected works. Hertz was buried in his hometown of Hamburg in the Ohlsdorf cemetery. The Hamburg television tower (Heinrich Hertz Tower) and the Berlin Heinrich Hertz Institute, which belongs to the Fraunhofer Society, as well as numerous streets and places were named after him.

Kerstin Nees



Electromagnetic waves


98.3 or 102.4 - these numbers (in MHz) indicate the frequencies with which you can receive NDR2 or RSH in Kiel. The unit of frequency is Hertz (Hz) and is named after Heinrich Rudolf Hertz. In 1886, the German physicist succeeded for the first time in experimentally generating electromagnetic waves, the existence of which James Clerk Maxwell had predicted in his electromagnetic field theory in 1864.

The properties of electromagnetic waves examined and described by Hertz form the basis of radio technology. Radio waves are electromagnetic waves in a frequency range from 75 kHz to around 10 GHz, which are often used technically for the wireless transmission of speech, images and other data. Radio waves not only transmit speech and music to the radio, they are also used for television broadcasting and for making mobile phone calls.

Maxwell had predicted the existence of electromagnetic waves and described their properties as early as 1864, based on his theory of electricity and magnetism. In particular, he had calculated that its speed of propagation was equal to the speed of light. He also realized that light can be explained as an electromagnetic phenomenon, that is, that the light waves are electromagnetic waves of high frequency. Heinrich Hertz succeeded in experimentally generating electromagnetic waves that spread both along wires and freely in space. Guglielmo Marconi (1874 to 1937), K. Ferdinand Braun (1850 to 1918) and others then developed the technology of transmitting messages using free electromagnetic waves over great distances, from which modern radio and television technology developed. The Russian physicist Alexander Popow (1859-1906) achieved the first wireless communication over a distance of at least 250m in 1896. Marconi and Braun received the Nobel Prize in Physics together in 1909.

For further reading

  • Schmidt-Schönbeck, Charlotte: 300 years of physics and astronomy
    at Kiel University. Kiel 1965.
  • Lenard's work in Kiel

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