Selényi, Pál

(Dunaadony, November 17th, 1884 – Budapest, March 21st, 1954)

Selényi, Pál

Pál Selényi was one of the greatest and most versatile researchers of Hungarian experimental physics.

He obtained his degree in teaching and his doctorate at the faculty of mathematics and physics of the University of Sciences, Budapest, Web link then he studied in Berlin and Göttingen. After finishing his studies he started to work for the newly established Applied Physics Department of the University During World War I he was responsible for sound observation in the artillery, and in 1918 he was ordered to the university of Vienna to carry out acoustic examinations.

In his early works he studied the nature of light. A well-known result is his wide angle interference experiment answered the disputed questions of that time.

Selényi was a physicist with great technological interest. When Ignác Pfeifer organised the research laboratory of United Incandescent-Lamp and Electrical Co. Ltd., he employed

Selényi among the first ones. Selényi performed excellent work both in basic research and applied research.

In the Research Laboratory of Tungsram, with Imre Patai he constructed a simple device for measuring the thermal expansion of glass. He elaborated a method for determining the vacuum of a sealed lamp, and another method for detecting thorium in the filament of lamps. He was very much engaged in photo cells and light cells. He developed photo cells which are widely applied in the exposure-meters of cameras, and he also elaborated other applications, e.g. constructed a device for measuring the intensity of exposure, and a device for determining the colour of paprika.

Selényi's most important invention in industrial physics was the process of electrography. He produced pictures of good quality on waxed paper stretched on manually rotated roller, and he also developed a variant of this method suitable for displaying television pictures. He also constructed an oscillograph on the basis of the same principle and its advantage was that it recorded the picture in a simpler and quicker way than photographing the picture of a conventional oscillograph. His research in electrostatic picture recording gave the basis of xerography. Selényi earlier produced quality electrografic copies, published and patented fundamental ideas of electrography than C. F. Carlson to whom the invention is ascribed to.

In 1945 he was very enthusiastic to join the reviving scientific life. In 1950 he obtained the title of private professor and worked at the department of experimental physics of the University of Sciences.

On his initiative the Roland Eötvös Physical Society Web link organised the inter-school competition in physics for secondary schools.

He published more than hundred articles in the field of optics, vacuum technology, photometry and electrography.

Memberships: correspondent member of the Hungarian Academy of Sciences (1948), Web link co-president of the Roland Eötvös Physical Society (1952).

Honours: Zipernowski commemorative prize of the Electro-Technology Association (1934), first prize of the technical competition of the capital city of Budapest (1945), Kossuth prize (1952), the Roland Eötvös Physical Society founded a Selényi prize (1964).

Bibliography:
Selényi, P.: Gesammelte Arbeiten. Budapest, 1969