Josef Karl Franz Otto Geitler, Ritter von Armingen (14 September 1870 – 20 June 1923) was an Austrian

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 ...

born in

Smíchov Smíchov () is, since 1922, a district and cadastral area of Prague, the capital of the Czech Republic, and is part of Prague 5. It is on the west bank of the Vltava river. History It was only on 22 February 1903, that Smíchov was elevated to ...

, today a district in

Prague Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...

. He is remembered for his investigations of

electromagnetic waves In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength, ran ...

. He studied in

and

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

, later obtaining his

habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excelle ...

at Prague. In 1906 he succeeded Alois Handl (1837-1915) as chair of

experimental physics Experimental physics is the category of disciplines and sub-disciplines in the field of physics that are concerned with the observation of physical phenomena and experiments. Methods vary from discipline to discipline, from simple experiments and o ...

at the University of Czernowitz. In 1919, when Czernowitz became a Romanian university, Geitler relocated to

Graz Graz () is the capital of the Austrian Federal states of Austria, federal state of Styria and the List of cities and towns in Austria, second-largest city in Austria, after Vienna. On 1 January 2025, Graz had a population of 306,068 (343,461 inc ...

, where he taught classes at the Technische Universität Graz. Among his scientific research were studies that explained differences between

x-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

and

cathode rays Cathode rays are streams of electrons observed in vacuum tube, discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to electrons emitte ...

. His best known publication was ''Elektromagnetische Schwingungen und Wellen'', ("Electromagnetic oscillations and waves") (1905).Google Books
Elektromagnetische Schwingungen und Well He was a cousin to physicist

Heinrich Hertz 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. Biography Heinri ...

(1857-1894). Among his students at Czernowitz was Wojciech Rubinowicz (1889-1974).

References

Scientists and mathematicians in Czernowitz University by Robert Rosner
(biographical information) * Parts of this article are based on a translation of an equivalent article at the

German Wikipedia The German Wikipedia () is the German-language edition of Wikipedia, a free and publicly editable online encyclopedia. Founded on 16 March 2001, it is the second-oldest Wikipedia edition (after the English Wikipedia). It has articles, ma ...

, namely: Österreichisches Biographisches Lexikon 1815-1950, Bd. 1, (Lfg. 5), S. 419 {{DEFAULTSORT:Geitler von Armingen, Josef Austrian physicists 1870 births 1923 deaths Scientists from Prague Academic staff of Chernivtsi University Physicists from Austria-Hungary