| Philipp Lenard | |
 Philipp Lenard in 1900
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| Born | June 7, 1862 Pressburg, Kingdom of Hungary |
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| Died | May 20, 1947 (aged 84) Messelhausen, Germany |
| Nationality | Hungary Germany |
| Fields | Physics |
| Institutions | University of Breslau University of Aachen University of Heidelberg University of Kiel |
| Alma mater | University of Heidelberg |
| Doctoral advisor | Robert Bunsen |
| Known for | Cathode rays |
| Notable awards |  Nobel Prize for Physics (1905) |
Philipp Eduard Anton von Lénárd (June 7, 1862 – May 20, 1947) was a Hungarian-German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties. Events 1099 - The First Crusade: The Siege of Jerusalem begins Year 1862 was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common year starting on Monday ARTICLE TEXT BEGINS AFTER THESE COMMENTS - PLEASE READ 1 Please do not edit the lead without reading The Kingdom of Hungary (short form Hungary) was a considerable state in Central Europe that existed from 1001 to 1918 then from 1919 to 1946 Events 325 - The First Council of Nicaea &ndash the first Ecumenical Council of the Christian Church is held Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Hungary (Magyarország 'mɔɟɔrorsaːg) officially in English the Republic of Hungary ( Magyar Köztársaság, literally Magyar (Hungarian Republic Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. The University of Wrocław (Uniwersytet Wrocławski Universität Breslau Universitas Wratislaviensis is one of nine universities in Wrocław, Poland RWTH Aachen University is a large university located in Aachen, Germany. The Ruprecht Karl University of Heidelberg ( University of Heidelberg, Ruperto Carola, Heidelberg University, or simply Heidelberg) is a The University of Kiel ( German Christian-Albrechts-Universität zu Kiel, CAU) is a University in the city of Kiel, Germany Alma mater is Latin for "nourishing mother" It was used in Ancient Rome as a title for the mother Goddess, and in Medieval The Ruprecht Karl University of Heidelberg ( University of Heidelberg, Ruperto Carola, Heidelberg University, or simply Heidelberg) is a A doctorate is an Academic degree that indicates the highest level of academic achievement Robert Wilhelm Eberhard Bunsen (31 March 1811 &ndash 16 August 1899 was a German Chemist. Cathode rays (also called an electron beam or e-beam) are streams of Electrons observed in Vacuum tubes i The Nobel Prize in Physics (Nobelpriset i fysik is awarded once a year by the Royal Swedish Academy of Sciences. Events 1099 - The First Crusade: The Siege of Jerusalem begins Year 1862 was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common year starting on Monday Events 325 - The First Council of Nicaea &ndash the first Ecumenical Council of the Christian Church is held Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar. Hungary (Magyarország 'mɔɟɔrorsaːg) officially in English the Republic of Hungary ( Magyar Köztársaság, literally Magyar (Hungarian Republic Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. The Nobel Prize in Physics (Nobelpriset i fysik is awarded once a year by the Royal Swedish Academy of Sciences. Cathode rays (also called an electron beam or e-beam) are streams of Electrons observed in Vacuum tubes i He was also an active proponent of Nazi ideology. Nazism, which was a short name for National Socialism (Nationalsozialismus refers primarily to the Ideology and practices of the National Socialist German An ideology is a set of beliefs aims and Ideas especially in politics
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Early life and work
Philipp Lenard was born in Pressburg (today's Bratislava, Slovakia), Austria-Hungary, on July 7, 1862. ARTICLE TEXT BEGINS AFTER THESE COMMENTS - PLEASE READ 1 Please do not edit the lead without reading Slovakia (long form Slovak Republic; Slovak:, long form, is a Landlocked country in Central Europe with a population of over five million He studied under the illustrious Robert Bunsen and Hermann von Helmholtz, and obtained his doctoral degree in 1886 at the University of Heidelberg. Robert Wilhelm Eberhard Bunsen (31 March 1811 &ndash 16 August 1899 was a German Chemist. A doctorate is an Academic degree that indicates the highest level of academic achievement The Ruprecht Karl University of Heidelberg ( University of Heidelberg, Ruperto Carola, Heidelberg University, or simply Heidelberg) is a [1] After posts at Aachen, Bonn, Breslau, Heidelberg (1896-1898), and Kiel (1898-1907), he returned finally to the University of Heidelberg in 1907 as the head of the Philipp Lenard Institute.
His early work included studies of phosphorescence and luminescence and the conductivity of flames. Phosphorescence is a specific type of Photoluminescence related to fluorescence. Luminescence is also the title of an album by singer Anggun. Luminescence is Light not generated by high temperatures alone
Contributions to physics
Photoelectric investigation
As a physicist, Lenard's major contributions were in the study of cathode rays, which he began in 1888. Cathode rays (also called an electron beam or e-beam) are streams of Electrons observed in Vacuum tubes i Prior to his work, cathode rays were produced in primitive tubes which are partially evacuated glass tubes that have metallic electrodes in them, across which a high voltage can be placed. Cathode rays were difficult to study because they were inside sealed glass tubes, difficult to access, and because the rays were in the presence of air molecules. Lenard overcame these problems by devising a method of making small metallic windows in the glass that were thick enough to be able to withstand the pressure differences, but thin enough to allow passage of the rays. Having made a window for the rays, he could pass them out into the laboratory, or, alternatively, into another chamber that was completely evacuated. He was able to conveniently detect the rays and measure their intensity by means of paper sheets coated with phosphorescent materials. [2] These windows have come to be known as Lenard windows.
Lenard observed that the absorption of the rays was, to first order, proportional to the density of the material they were made to pass through. This appeared to contradict the idea that they were some sort of electromagnetic radiation. He also showed that the rays could pass through some inches of air of a normal density, and appeared to be scattered by it, implying that they must be particles that were even smaller than the molecules in air. He confirmed some of J.J. Thomson's work, which ultimately arrived at the understanding that cathode rays were streams of energetic electrons. Sir Joseph John “JJ” Thomson, OM, FRS (18 December 1856 &ndash 30 August 1940 was a British Physicist and Nobel laureate In conjunction with his and other earlier experiments on the absorption of the rays in metals, the general realization that electrons were constituent parts of the atom enabled Lenard to claim correctly that for the most part atoms consist of empty space.
As a result of his Crookes tube investigations, he showed that the rays produced by radiating metals in a vacuum with ultraviolet light were similar in many respects to cathode rays. A Crookes tube is an early experimental Discharge tube, invented by British physicist William Crookes and others around 1875 in which Cathode rays His most important observations were that the energy of the rays was independent of the light intensity, but was greater for shorter wavelengths of light.
These latter observations were explained by Albert Einstein as a quantum effect. Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical This theory predicted that the plot of the cathode ray energy versus the frequency would be a straight line with a slope equal to Planck's constant, h. This was shown to be the case some years later. The photo-electric quantum theory was the work cited when Einstein was awarded the Nobel Prize in Physics. This much embittered Lenard, who became a prominent skeptic of relativity and of Einstein's theories generally.
Meteorological contributions
Lenard was the first person to study what has been termed the Lenard effect in 1892. This is the separation of electric charges accompanying the aerodynamic breakup of water drops. It is also known as spray electrification or the waterfall effect. [3]
He conducted studies on the size and shape distributions of raindrops and constructed a novel wind tunnel in which water droplets of various sizes could be held stationary for a few seconds. A wind tunnel is a research tool developed to assist with studying the effects of air moving over or around solid objects He was the first to recognize that large raindrops are not tear-shaped, but are rather shaped something like a hamburger bun. [4]
"Deutsche Physik" and anti-semitism
Lenard is remembered today as a strong German nationalist who despised English physics, which he considered as having stolen their ideas from Germany. The term nationalism can refer to an Ideology, a sentiment, a form of Culture, or a Social movement that focuses on the Nation He joined the National Socialist Party before it became politically necessary or popular to do so. The, officially National Socialist German Workers' Party, ( abbreviated NSDAP) was a Political party in Germany between 1919 and 1945 During the Nazi regime, he was the outspoken proponent of the idea that Germany should rely on "Deutsche Physik" and ignore what he considered the fallacious and deliberately misleading ideas of "Jewish physics", by which he meant chiefly the theories of Albert Einstein, including "the Jewish fraud" of relativity. Nazism, which was a short name for National Socialism (Nationalsozialismus refers primarily to the Ideology and practices of the National Socialist German Deutsche Physik (literally "German Physics" or Aryan Physics was a Nationalist movement in the German Physics community Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical This page is about the scientific concept of relativity for philosophical or sociological theories about relativity see Relativism. An advisor to Adolf Hitler, Lenard became Chief of Aryan Physics under the Nazis. Hi and welcome to Wikipedia! Please understand that this article is frequently vandalized and vandalism is reverted immediately Aryan is an English word derived from the Sanskrit " Ārya " meaning "noble" or "honorable"
Lenard retired from Heidelberg University as professor of theoretical physics in 1931. The Ruprecht Karl University of Heidelberg ( University of Heidelberg, Ruperto Carola, Heidelberg University, or simply Heidelberg) is a Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. He achieved emeritus status there, but he was expelled from his post by Allied occupation forces in 1945 when he was 83. The Allies of World War II were the countries officially opposed to the Axis powers during the Second World War. Year 1945 ( MCMXLV) was a Common year starting on Monday (link will display the full calendar He died in 1947 in Messelhausen. Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar.
Honours and awards
- Royal Society Rumford Medal, 1896
- Italian Society of Sciences Matteucci Medal, 1896
- Franklin Institute Franklin Medal, 1905
Bibliography
- Lenard, Philipp (1906). The Royal Society of London for the Improvement of Natural Knowledge, known simply as The Royal Society, is a Learned society for science that was founded in 1660 Not to be confused with the Rumford Prize In 1796, Benjamin Thompson known as Count Rumford, gave $5000 separately to the Royal The Matteucci Medal was established to award Physicists for their fundamental contributions This article is about the science museum in Philadelphia For the Boston school see Benjamin Franklin Institute of Technology. This article is about the science museum in Philadelphia For the Boston school see Benjamin Franklin Institute of Technology. Über Kathodenstrahlen (On Cathode Rays) (in German).
- Lenard, Philipp. Über Aether und Materie (On Aether and Matter) (in German).
- Lenard, Philipp (1914). Probleme komplexer Moleküle (Problems of complex molecules) (in German).
- Lenard, Philipp (1918). Quantitatives über Kathodenstrahlen (in German).
- Lenard, Philipp (1918). Über das Relativitätsprinzip (On the Principle of Relativity) (in German).
- Lenard, Philipp (1921). Aether und Uraether (in German).
- Lenard, Philipp (1930). Grosse Naturforscher (in German).
- Lenard, Philipp (1933). Great Men of Science. London: G. Bell and sons. OCLC 1156317. The OCLC Online Computer Library Center is according to its website a "nonprofit membership computer library service and research organization dedicated to the public purpose
- Lenard, Philipp (1936). Deutsche physik in vier bänden (in German). J. F. Lehmann. OCLC 13814543. The OCLC Online Computer Library Center is according to its website a "nonprofit membership computer library service and research organization dedicated to the public purpose
References
- ^ Lénárd Fülöp
- ^ Philipp Lenard (1894). "Ueber Kathodenstrahlen in Gasen von atmosphärischem Druck und im äussersten Vacuum". Annalen der Physik 287 (2): 225-267. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ American Meteorological Society Glossary
- ^ Diameter of a Raindrop - the Physics Handbook
- Beyerchen, Alan, Scientists under Hitler: Politics and the physics community in the Third Reich (New Haven, CT: Yale University Press, 1977).
- Hentschel, Klaus, ed. Physics and National Socialism: An anthology of primary sources (Basel: Birkhaeuser, 1996).
- Walker, Mark, Nazi science: Myth, truth, and the German atomic bomb (New York: Harper Collins, 1995).
- Wolff, Stephan L. , "Physicists in the 'Krieg der Geister': Wilhelm Wien's 'Proclamation'", Historical Studies in the Physical and Biological Sciences Vol. 33, No. 2 (2003): 337-368. \
External links
| Persondata | |
|---|---|
| NAME | Lenard, Philipp |
| ALTERNATIVE NAMES | |
| SHORT DESCRIPTION | Hungarian-German physicist |
| DATE OF BIRTH | June 7, 1862 |
| PLACE OF BIRTH | Pressburg, Hungary |
| DATE OF DEATH | May 20, 1947 |
| PLACE OF DEATH | Messelhausen, Germany |
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