Nikolai Dmitrievich Papaleksi (20 November 1880 – 3 February 1947) was a physicist who pioneered radio technology and radio astronomy in the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

. He was involved in the discovery of radiowave emission by solar coronae in 1947.

Early life

Papaleksi was born in

Simferopol Simferopol () is the second-largest city in the Crimea, Crimean Peninsula. The city, along with the rest of Crimea, is internationally recognised as part of Ukraine, and is considered the capital of the Autonomous Republic of Crimea. However, ...

in a family that produced many military officers. His father was a battalion commander in the 51st Lithuanian Regiment and the family may have had origins in Greece. He was educated locally at then at

Poltava Poltava (, ; uk, Полтава ) is a city located on the Vorskla River in central Ukraine. It is the capital city of the Poltava Oblast (province) and of the surrounding Poltava Raion (district) of the oblast. Poltava is administratively ...

before he went to the Universities of Berlin and later

Strasbourg Strasbourg (, , ; german: Straßburg ; gsw, label=Bas Rhin Alsatian, Strossburi , gsw, label=Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the Eu ...

where he met L. I. Mandelshtam. Together they studied radiowaves under Carl Ferdinand Braun who headed the Institute of Physics. Papaleksi received his doctorate in 1904.

Career

In 1906 Mandelshtam and Papaleksi worked on the production of high frequency radio waves. The worked for a while with the

Telefunken Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" app ...

company. In 1914 Papaleksi moved back to Russia due to

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. He then worked on the production of gas

triodes A triode is an electronic amplifying vacuum tube (or ''valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's 190 ...

which came to be known as Papaleksi tubes. He worked on applications of radio communication for submarines, remote control and for home radio receivers. He became a professor at the National Polytechnic University of Odessa in 1922. He also collaborated with Mandelshtam on research at the St. Petersburg Radio Centre. He subsequently worked at the Lebedev Physics Institute and at the USSR Institute of Energy in Moscow. In 1946 he was involved in radiowave based determination of the distance from the earth to the moon. In 1947 he was involved in examining radiowave emissions from the sun and had organized an expedition to Brazil where a total solar eclipse was expected. Papaleksi died before the expedition could set out, but it was successful in demonstrating radiowave emission by solar coronae. The Lunar crater Papaleksi was named after him in 1970.

References

External links

Papaleksi tube
{{DEFAULTSORT:Papaleksi, Nikolai Dmitrievich 1880 births 1947 deaths Soviet physicists People from Simferopol Physicists from the Russian Empire