Jonathan Zenneck | |
|---|---|
 Zenneck in 1951 | |
| Rector of theTechnical University of Munich | |
| In office 1925–1927 | |
| Preceded by | Walther von Dyck |
| Succeeded by | Kaspar Dantscher [de] |
| Personal details | |
| Born | Jonathan Adolf Wilhelm Zenneck (1871-04-15)15 April 1871 |
| Died | 8 April 1959(1959-04-08) (aged 87) |
| Scientific career | |
| Alma mater | University of Tübingen |
| Known for | Zenneck wave Oscilloscope |
| Awards | IRE Medal of Honor[1] (1928) Werner von Siemens Ring (1956) |
| Fields | Physics Electrical engineering |
| Doctoral advisor | Theodor Eimer |
Jonathan Adolf Wilhelm Zenneck (/ˈzɛnɛk/;German:[ˈjoːnatanˈtsɛnɛk]; 15 April 1871 – 8 April 1959) was a Germanphysicist andelectrical engineer.
Zenneck improved thecathode-ray tube by adding a second deflection structure at right angles to the first, which allowed two-dimensional viewing of a waveform. This two-dimensional display is fundamental to theoscilloscope.[2]
Zenneck was born inRuppertshofen,Württemberg.
In 1885, Zenneck entered theEvangelical-Theological Seminary inMaulbronn. In 1887, while in a Blaubeuren seminary, Zenneck learnedLatin,Greek,French, andHebrew. In 1889, Zenneck enrolled in theUniversity of Tübingen. At theTübingen Seminary, he studiedmathematics andnatural sciences. In 1894, Zenneck took the state examination in mathematics and natural sciences and the examination for his doctor's degree. His dissertation, supervised byTheodor Eimer, was ongrass snakeembryos.
In 1894, Zenneck conducted zoological research (Natural History Museum,London). Between 1894 and 1895, he served in the military.
In 1895, Zenneck left zoology and turned over to the new field of radio science, He became assistant toFerdinand Braun and lecturer at "Physikalisches Institut" inStrasbourg,Alsace.Nikola Tesla's lectures introduced him to the wireless sciences. In 1899, Zenneck started propagation studies ofwireless telegraphy, first over land, but then became more interested in the larger ranges that were reached over sea. In 1900 he started ship-to-coast experiments in the North Sea nearCuxhaven,Germany. in 1902 he conducted tests ofdirectional antennas. In 1905, Zenneck left Strasbourg since he was appointed assistant-professor at the Danzig Technische Hochschule and in 1906, he became professor of experimentalphysics in the Braunschweig Technische Hochschule. Also in 1906, Zenneck wrote "Electromagnetic Oscillations and Wireless Telegraphy", the then standard textbook on the subject). In 1909, he joinedBadische Anilin und Sodafabrik in Ludwigshafen to experiment with electrical discharges in air to produce boundnitrogen asfertilizer. In 1913, he became director of the newly createdPhysics Institute of theTechnische Hochschule München.
Zenneck analyzed solutions toMaxwell's equations describingelectromagnetic waves that are localized around an interface between a conducting medium and a non-conducting medium. In these solutions, the electric field strength decays exponentially in each medium as distance from the interface increases. These waves are sometimes calledZenneck waves and are relevant toground waves,radio waves that travel horizontally just above the ground. Zenneck analyzedplane wave solutions having this property; he also analyzed solutions with cylindrical symmetry having this property.[3][4]
AroundWorld War I, Zenneck served on the front-lines as acaptain in theMarines. However, in 1914, the German government sent him andKarl Ferdinand Braun to theUnited States astechnical advisor in a patent case involvingTelefunken. The USMarconi Company sued Telefunken for patent infringement, a case spurred by the British government in an attempt to shut down transatlantic wireless telegraph between the US and Germany.[5] The case stalled and event went moot when the United States entered the war, declaring Zenneck aPrisoner of War. He was dismissed only in 1920 when he could finally take over the professorship of experimental physics at theTechnische Hochschule München. In that time he resumed propagation studies, now withshortwaves and was first in Germany to study theIonosphere with vertical sounding at his station at Kochel/Bavaria. From the 1930s, Zenneck directed theDeutsches Museum inMunich, and rebuilt it afterWorld War II. Zenneck was awarded the 1928IRE Medal of Honor for his achievements in basic research on radio technology and for fostering academic and technical offspring he received theSiemens-Ring in 1956.
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