Hermann Theodor Simon (1 January 1870, in

Kirn Kirn () is a town in the Bad Kreuznach (district), Bad Kreuznach Districts of Germany, district in Rhineland-Palatinate, Germany. It is the seat of the ''Verbandsgemeinde'' Kirner Land. Kirn is a Central place theory, middle centre serving an area ...

– 22 December 1918, in

Göttingen Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, t ...

) was a German

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

Biography

He studied physics at the Universities of

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

and

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

, earning his doctorate in 1894 under

August Kundt August Adolf Eduard Eberhard Kundt (; 18 November 1839 – 21 May 1894) was a German physicist known for developing Kundt's tube, an appartus used to measure the speed of sound in gases and solids. Early life Kundt was born in Schwerin, Meckle ...

with a thesis on the dispersion of

ultraviolet radiation Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of t ...

. Afterwards, he served as an assistant to

Eilhard Wiedemann Eilhard Ernst Gustav Wiedemann (1 August 1852, in Berlin – 7 January 1928, in Erlangen) was a German physicist and historian of science. He was the son of physicist Gustav Heinrich Wiedemann (1826–1899), and an older brother to Egyptologist Alfr ...

Erlangen Erlangen (; , ) is a Middle Franconian city in Bavaria, Germany. It is the seat of the administrative district Erlangen-Höchstadt (former administrative district Erlangen), and with 119,810 inhabitants (as of 30 September 2024), it is the smalle ...

, obtaining his habilitation in 1896. Two years later, he became an assistant to Eduard Riecke at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, then relocated to

Frankfurt am Main Frankfurt am Main () is the most populous city in the States of Germany, German state of Hesse. Its 773,068 inhabitants as of 2022 make it the List of cities in Germany by population, fifth-most populous city in Germany. Located in the forela ...

as director of the physics laboratory. In 1901 he returned to Göttingen as an associate professor and director of the department of

applied electricity Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

. In 1907 he was appointed as a full professor at the University of Göttingen. With Eduard Riecke, he was editor of the physics journal ''Physikalische Zeitschrift''. He discovered the "singing arc" phenomenon and reported it in 1898. Specifically, he found that the dominant frequency in the buzzing sound made by an electric arc light can be controlled by the voltage across the arc light, so that by varying the voltage, the arc can be made to "sing". His research led to a light telephone, with searchlight modulated by a microphone as the transmitter, and a photosensitive selenium cell as the receiver. SIL14-51634-0777

Selected writings

* ''Über Dispersion ultravioletter Strahlen'', 1894 - On dispersion of ultraviolet radiation (graduate thesis). * ''Über ein neues photographisches Photometrierverfahren und seine Anwendung auf die Photometrie des ultravioletten Spektralgebietes'', 1896 - Involving a new photographic photometric method and its application to the

photometry Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electr ...

of the ultraviolet spectral region. * ''Akustische Erscheinungen am electrischen Flammenbogen'', 1898 - Acoustic phenomena at the electric flame arc, Ann. Physik, Vol 300, No 2, pp233-242. * ''Elektrotechnisches Praktikum des Instituts für Angewandte Elektrizität der Universität Göttingen'', 1908 - Electrical engineering internship at the Institute of Applied Electricity, University of Göttingen. * ''Der elektrische lichtbogen: experimentalvortrag auf wunsch des wissenschaftlichen vereins zu Berlin gehalten am 11. januar 1911'', (1911) - The

electric arc An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma ( ...

: an experimental lecture.Google Books
(publications)

References

External links

* 1870 births 1918 deaths 20th-century German physicists People from Bad Kreuznach (district) Academic staff of the University of Göttingen {{Germany-scientist-stub