Philipp Lenard

Philipp Eduard Anton von Lenard (7 June 1862 – 20 May 1947) was a 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. Lenard was a nationalist and anti-Semite; as an active proponent of the Nazi ideology, he supported Adolf Hitler in the 1920s and was an important role model for the "Deutsche Physik" movement during the Nazi period. Notably, he labeled Albert Einstein's contributions to science as "Jewish physics".

Philipp Lenard
Phillipp Lenard in 1900
Philipp Lenard in 1900
Philipp Eduard Anton von Lenard

7 June 1862
Died20 May 1947 (aged 84)
CitizenshipHungarian[1] in Austria-Hungary (1862–1907),
German (1907–1947)
Alma materUniversity of Heidelberg
Known forCathode rays
AwardsMatteucci Medal (1896)
Rumford Medal (1896)
Nobel Prize for Physics (1905)
Scientific career
InstitutionsUniversity of Budapest
University of Breslau
University of Aachen
University of Heidelberg
University of Kiel
Doctoral advisorR. Bunsen
G. H. Quincke

Early life and work

Philipp Lenard was born in Pressburg (today's Bratislava), on 7 June 1862 in the Kingdom of Hungary. The Lenard family had originally come from Tyrol in the 17th century, and Lenard's parents were German-speakers (Carpathian Germans).[2] His father, Philipp von Lenardis (1812–1896), was a wine-merchant in Pressburg. His mother was Antonie Baumann (1831–1865).[3] The young Lenard studied at the Pozsonyi Királyi Katolikus Főgymnasium (today Gamča), and as he writes it in his autobiography, this made a big impression on him (especially the personality of his teacher, Virgil Klatt).[4] In 1880, he studied physics and chemistry in Vienna and in Budapest.[4] In 1882, Lenard left Budapest and returned to Pressburg, but in 1883, he moved to Heidelberg after his tender for an assistant's position in the University of Budapest was refused. In Heidelberg, he studied under the illustrious Robert Bunsen, interrupted by one semester in Berlin with Hermann von Helmholtz, and he obtained a doctoral degree in 1886.[5] In 1887 he worked again in Budapest under Loránd Eötvös as a demonstrator.[4] 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. In 1905, Lenard became a member of the Royal Swedish Academy of Sciences, and in 1907, of the Hungarian Academy of Sciences.[4]

His early work included studies of phosphorescence and luminescence and the conductivity of flames.

Contributions to physics

Photoelectric investigations

The dynamid atomic model, by Philipp Lenard, 1903
The dynamid atomic model, by Philipp Lenard, 1903

As a physicist, Lenard's major contributions were in the study of cathode rays, which he began in 1888. Prior to his work, cathode rays were produced in primitive, partially evacuated glass tubes that had metallic electrodes in them, across which a high voltage could be placed. Cathode rays were difficult to study using this arrangement, 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. These windows have come to be known as Lenard windows. He was able to conveniently detect the rays and measure their intensity by means of paper sheets coated with phosphorescent materials.[6]

Lenard observed that the absorption of cathode 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 eventually arrived at the understanding that cathode rays were streams of negatively charged energetic particles. He called them quanta of electricity or for short quanta, after Helmholtz, while J.J. Thomson proposed the name corpuscles, but eventually electrons became the everyday term.[7] 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. He proposed that every atom consists of empty space and electrically neutral corpuscules called "dynamids", each consisting of an electron and an equal positive charge.

As a result of his Crookes tube investigations, he showed that the rays produced by irradiating metals in a vacuum with ultraviolet light were similar in many respects to 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.[8]

These latter observations were explained by Albert Einstein as a quantum effect. 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. Suspicious of the general adulation of Einstein, Lenard became a prominent skeptic of relativity and of Einstein's theories generally; he did not, however, dispute Einstein's explanation of the photoelectric effect.

Lenard received the 1905 Nobel Prize for Physics in recognition of this work.

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.[9]

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. He was the first to recognize that large raindrops are not tear-shaped, but are rather shaped something like a hamburger bun.[10]

Deutsche Physik

Lenard is remembered today as a strong German nationalist who despised "English physics", which he considered to have stolen its ideas from Germany.[11][12][13] He joined the National Socialist Party before it became politically necessary or popular to do so. 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 (see also criticism of the theory of relativity). An advisor to Adolf Hitler, Lenard became Chief of Aryan physics under the Nazis.[14]

Some measure of Lenard's views on certain scientists may be deduced through examination of Lenard's book, Great Men in Science, A History of Scientific Progress, first published in 1933. The book was translated into English by Dr. H. Stafford Hatfield with an introduction by the famous scientist Edward Andrade of University College London (ironically, a Sephardic Jew himself) and was widely read in schools and universities after the Second World War. The individual scientists selected for inclusion by Lenard do not include Einstein or Curie, nor any other twentieth century scientist. Andrade noted that "A strong individuality like that of the writer of this book is bound to assert strongly individual judgements". The publisher included what now appears to be a remarkable understatement on page xix of the 1954 English edition: "While Professor Lenard's studies of the men of science who preceded him showed not only profound knowledge but also admirable balance, when it came to men of his own time he was apt to let his own strong views on contemporary matters sway his judgment. In his lifetime he would not consent to certain modifications that were proposed in the last study of the series".

Later life

Lenard retired from Heidelberg University as professor of theoretical physics in 1931. He achieved emeritus status there, but he was expelled from his post by Allied occupation forces in 1945 when he was 83. The Helmholtz-Gymnasium Heidelberg had been named the Philipp Lenard Schule from 1927 until 1945. As part of the elimination of Nazi street names and monuments it was renamed in September 1945 by order of the military government.[15] Lenard died in 1947 in Messelhausen, Germany.

Honours and awards

Cultural references

  • Lenard's criticism of the theory of relativity and his crusade against Einstein and his theories was covered in an episode of Dark Matters: Twisted But True, in a segment entitled "Einstein's Revenge".
  • The life of Lenard and the interrelationship between his work and that of Albert Einstein is the subject of the book The Man Who Stalked Einstein: How Nazi Scientist Philipp Lenard Changed the Course of History by Bruce J. Hillman, Birgit Ertl-Wagner and Bernd C. Wagner.
  • Lenard was portrayed by actor Michael McElhatton in the 2017 National Geographic anthology period drama television series Genius.[17]


  • Lenard, Philipp (1906). 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 (1931) (in German). Erinnerungen eines Naturforschers. New edition: Erinnerungen eines Naturforschers – Kritische annotierte Ausgabe des Originaltyposkriptes von 1931/1843 (Arne Schirrmacher, ed.). Springer Verlag, Heidelberg 2010, 344 pages, ISBN 978-3-540-89047-8, e-ISBN 978-3-540-89048-5.
  • Lenard, Philipp (1933). Great Men of Science. London: G. Bell and sons. OCLC 1156317.
  • Lenard, Philipp (1936). Deutsche Physik in vier Bänden (in German). J.F. Lehmann. OCLC 13814543.


  1. ^ "Lénárd Fülöp (1862–1947)". Sulinet (in Hungarian). Archived from the original on 2007-11-16.
  2. ^ Pöss, Ondrej (2012). "Karpatskí Nemci". In Myrtil Nagy (ed.). Naše národnostné menšiny. Šamorín: Fórum inštitút pre výskum menšín. pp. 9–12. ISBN 978-80-89249-57-2.
  3. ^ Neue deutsche biografie XIV, 1984 München
  4. ^ a b c d "Fizikai Szemle; ELEKTRON ÉS ÉTERFIZIKA: LÉNÁRD FÜLÖP (1862–1947)" (in Hungarian). Hungarian Academy of Sciences, Physical Sciences Section. 1997. p. 116. Written in Hungarian by the autobiography of the famous physicist: Philipp Lenard, Erinnerungen eines Naturwissenschaftlers, der Kaiserreich, Judenschaft und Hitler erlebt hat. Geschrieben September 1930 bis Mrz 1931 |first= missing |last= (help)
  5. ^ "Lénárd Fülöp". Retrieved 2013-07-13.
  6. ^ Philipp Lenard (1894). "Ueber Kathodenstrahlen in Gasen von atmosphärischem Druck und im äussersten Vacuum". Annalen der Physik. 287 (2): 225–267. Bibcode:1894AnP...287..225L. doi:10.1002/andp.18942870202.
  7. ^ "Lenard's Nobel lecture (1906)" (PDF). Retrieved 2010-08-25.
  8. ^ Wheaton, Bruce R. (1978). "Philipp Lenard and the Photoelectric Effect, 1889-1911". Historical Studies in the Physical Sciences. 9. pp. 299–322. doi:10.2307/27757381. JSTOR 27757381.
  9. ^ "American Meteorological Society Glossary". 2013-06-25. Archived from the original on 2012-02-05. Retrieved 2013-07-13.
  10. ^ "Diameter of a Raindrop – The Physics Hypertextbook". Retrieved 2013-07-13.
  11. ^ Anders Rydell (7 February 2017). The Book Thieves: The Nazi Looting of Europe's Libraries and the Race to Return a Literary Inheritance. Penguin. pp. 86–. ISBN 978-0-7352-2124-6.
  12. ^ Alexei Kojevnikov (2011). Weimar Culture and Quantum Mechanics: Selected Papers by Paul Forman and Contemporary Perspectives on the Forman Thesis. World Scientific. pp. 33–. doi:10.1142/7581. ISBN 978-981-4293-12-9.
  13. ^ Hugo Steinhaus (8 February 2016). Mathematician for All Seasons: Recollections and Notes, Vol. 2 (1945–1968). Birkhäuser. pp. 105–. ISBN 978-3-319-23102-0.
  14. ^
  15. ^ Geierhaas, Theo. "Schulgeschichte". Helmholtz-Gymnasium Heidelberg. Retrieved 4 March 2019 (in German).
  16. ^ Marie), Abbé Moigno (François Napoléon (1898). "Prix La Caze". Cosmos: Revue des Sciences et de Leurs Applications. 38 (678): 122.
  17. ^ "Genius – Chapter One". Retrieved 2017-05-06.


  • Beyerchen, Alan (1977). Scientists under Hitler: Politics and the physics community in the Third Reich. New Haven, CT: Yale University Press. ISBN 978-0300018301.
  • Cornwell, John (2003). Hitler's Scientists: Science, War and the Devil's Pact. Penguin Books. ISBN 978-0142004807.
  • Hentschel, Klaus, ed. (1996). Physics and National Socialism: An anthology of primary sources. Basel: Birkhaeuser. ISBN 978-3764353124.
  • Walker, Mark (1995). Nazi science: Myth, truth, and the German atomic bomb. New York: Harper Collins. ISBN 978-0306449413.
  • Wolff, Stephan L. (2003). "Physicists in the 'Krieg der Geister': Wilhelm Wien's 'Proclamation'". Historical Studies in the Physical and Biological Sciences. 33 (2): 337–368. doi:10.1525/hsps.2003.33.2.337.

External links

1862 in Germany

Events from the year 1862 in Germany.

1902 in science

The year 1902 in science and technology involved some significant events, listed below.

1947 in Germany

Events in the year 1947 in Germany.

Alfons Bühl

Alfons Bühl (1900–1988) was a German physicist. From 1934 to 1945, he was director of the physics department at the Technische Hochschule Karlsruhe.

Bruno Thüring

Bruno Jakob Thüring (7 September 1905 in Warmensteinach – 6 May 1989 in Karlsruhe) was a German physicist and astronomer.

Thüring studied mathematics, physics, and astronomy at the University of Munich and received his doctorate in 1928, under Alexander Wilkens and Arnold Sommerfeld. Wilkens was professor of astronomy and director of the Munich Observatory, which was part of the University. From 1928 to 1933, he was an assistant at the Munich Observatory. From 1934 to 1935, he was an assistant to Heinrich Vogt at the University of Heidelberg. Thüring completed his Habilitation there in 1935, whereupon he became an Observator at the Munich Observatory. In 1937, Thüring became a lecturer (Dozent) at the University of Munich. From 1940 to 1945, he held the chair for astronomy at the University of Vienna and was director of the Vienna Observatory. After 1945, Thüring lived as a private scholar in Karlsruhe.During the reign of Adolf Hitler, Thüring was a proponent of Deutsche Physik, as were the two Nobel Prize–winning physicists Johannes Stark and Philipp Lenard; Deutsche Physik, was anti-Semitic and had a bias against theoretical physics, especially including quantum mechanics. He was also a student of the philosophy of Hugo Dingler.

Conrad Weygand

Conrad Weygand (8 November 1890 – 18 April 1945) was Professor of Chemistry at the University of Leipzig.

In 1938 he put forward a method for the classification of chemical reactions based on bond breakage and formation during the reaction. The preparative part of his book, Organisch-Chemische Experimentierkunst, was translated into English and published as Organic Preparations by Interscience Publishers, Inc. in 1946.

His book about German chemistry introduces similar thoughts like there were presented by Philipp Lenard in his Deutsche Physik movement.

Enlisting as a commander of a Volkssturm unit, Conrad Weygand was killed in action on 18 April 1945 in Leipzig against US ground forces during the final battle for the city.

Crookes tube

A Crookes tube (also Crookes–Hittorf tube) is an early experimental electrical discharge tube, with partial vacuum, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were discovered.Developed from the earlier Geissler tube, the Crookes tube consists of a partially evacuated glass bulb of various shapes, with two metal electrodes, the cathode and the anode, one at either end. When a high voltage is applied between the electrodes, cathode rays (electrons) are projected in straight lines from the cathode. It was used by Crookes, Johann Hittorf, Julius Plücker, Eugen Goldstein, Heinrich Hertz, Philipp Lenard, Kristian Birkeland and others to discover the properties of cathode rays, culminating in J.J. Thomson's 1897 identification of cathode rays as negatively charged particles, which were later named electrons. Crookes tubes are now used only for demonstrating cathode rays.

Wilhelm Röntgen discovered X-rays using the Crookes tube in 1895. The term Crookes tube is also used for the first generation, cold cathode X-ray tubes, which evolved from the experimental Crookes tubes and were used until about 1920.

Deutsche Physik

Deutsche Physik (German: [ˈdɔʏtʃə fyˈziːk], lit. "German Physics") or Aryan Physics (German: Arische Physik) was a nationalist movement in the German physics community in the early 1930s. A pseudoscientific movement, it nonetheless won the support of many eminent physicists in Germany. The term was taken from the title of a 4-volume physics textbook by Nobel Laureate Philipp Lenard in the 1930s.

Deutsche Physik was opposed to the work of Albert Einstein and other modern theoretically based physics, which was disparagingly labeled as "Jewish physics" (German: Jüdische Physik).

Franklin Medal

The Franklin Medal was a science award presented from 1915 through 1997 by the Franklin Institute located in Philadelphia, Pennsylvania, U.S. It was founded in 1914 by Samuel Insull.

The Franklin Medal was the most prestigious of the various awards presented by the Franklin Institute. Together with other historical awards, it was merged into the Benjamin Franklin Medal, initiated in 1998.

Helmholtz-Gymnasium Heidelberg

Helmholtz-Gymnasium Heidelberg (HGH) is a state-funded gymnasium (secondary school) located on Rohrbacher Straße 102 in Heidelberg, Germany. Founded in 1835, it is now named Helmholtz-Gymnasium after Hermann von Helmholtz, but from 1927 until 1945 it was known as the Philipp Lenard Schule after Philipp Lenard. As of 2018, it had 891 pupils. In addition to its academic curriculum, it is designated by the German Olympic Sports Confederation as an "Eliteschule des Sports" (Elite Sports School).

Hermite (crater)

Hermite is a lunar impact crater located along the northern lunar limb, close to the north pole of the Moon. It was officially named in 1964 by the IAU. To the west is the crater Rozhdestvenskiy, and to the south are Lovelace and Sylvester. Grignard is located directly adjacent to the Southwest. From the Earth this crater is viewed nearly from the side, and it is illuminated by oblique sunlight.

This is a worn, eroded crater with a rugged outer rim that is notched and incised from past impacts. A crater overlies the southwestern rim, and the two formations have merged to share a common interior floor. A pair of small craters lies along the southern part of the rim, and a small crater is also attached near the northern end. The interior floor has been resurfaced, so that it forms a wide plain that is pock-marked by numerous tiny craterlets and low hills. There is a small crater on the floor near the northeastern wall.

In 2009, it was discovered by NASA's Lunar Reconnaissance Orbiter that Hermite is the coldest place recorded in the solar system, with temperatures at 26 kelvins (−413 °F, −247 °C). For comparison, Pluto's surface only gets down to about 43 kelvins (−382 °F, −229 °C).In 2008, the crater on the southwest margin of Hermite was named Lenard by the IAU, after Hungarian physicist Philipp Lenard.

Hungarians in Germany

There are around 120,000 Hungarians in Germany. Hungarians have emigrated here since the Middle Ages. However, after World War I, their number continues to grow at an increased pace. Today, around 75% of this population live in the states of Bavaria, Baden-Württemberg and Hessen.

Johannes Stark

Johannes Stark (German pronunciation: [joˈhanəs ʃtaʁk], 15 April 1874 – 21 June 1957) was a German physicist who was awarded the Nobel Prize in Physics in 1919 "for his discovery of the Doppler effect in canal rays and the splitting of spectral lines in electric fields". This phenomenon is known as the Stark effect.

Stark received his Ph.D. in physics from the University of Munich in 1897 under the supervision of Eugen von Lommel, and served as Lommel's assistant until his appointment as a lecturer at the University of Göttingen in 1900. He was an extraordinary professor at the University of Hannover from 1906 until he became a professor at RWTH Aachen University in 1909. In 1917, he became professor at the University of Greifswald, and he also worked at the University of Würzburg from 1920 to 1922.

A supporter of Adolf Hitler from 1924, Stark was one of the main figures, along with fellow Nobel laureate Philipp Lenard, in the anti-Semitic Deutsche Physik movement, which sought to remove Jewish scientists from German physics. He was appointed head of the German Research Foundation in 1933 and was president of the Reich Physical-Technical Institute from 1933 to 1939. In 1947, he was found guilty as a "Major Offender" by a denazification court.


Lenard may refer to:

Aldon Lewis Lenard (1921-2007), Canadian sports person

Alexander Lenard (1910-1972), Hungarian physician, writer and translator

Mark Lenard (1924-1996), American actor

Philipp Lenard (1862-1947), Hungarian-German physicist and winner of the Nobel Prize for Physics, 1905

Voshon Lenard (born 1973), American basketball player

Lenard (crater)

Lenard is a lunar impact crater located on the lunar far side near the northern pole. The crater forms some of the wall of the crater Hermite, and is located North of the craters Lovelace and Froelich. Lenard was adopted and named after Hungarian physicist Philipp Lenard by the IAU in 2008.

Matteucci Medal

The Matteucci Medal is an Italian award for physicists, named after Carlo Matteucci. It was established to award physicists for their fundamental contributions. Under an Italian Royal Decree dated July 10, 1870, the Italian Society of Sciences was authorized to receive a donation from Carlo Matteucci for the establishment of the Prize.

Matteucci MedalistsSource: Italian Society of Sciences

RWTH Aachen Faculty of Mathematics, Computer science, and Natural sciences

The Faculty of Mathematics, Computer science, and Natural sciences is one of nine faculties at the RWTH Aachen University. It comprises five sections for mathematics, computer science, physics, chemistry and biology. The Faculty was founded in 1880 and produced several notable individuals like Arnold Sommerfeld and Nobel laureates Philipp Lenard, Wilhelm Wien, Johannes Stark or Karl Ziegler. Peter Debye studied Physics at the RWTH Aachen and won the Nobel Prize in 1936. Furthermore, Helmut Zahn and his team of the Institute for textile chemistry were the first who synthesised Insulin.

The faculty cooperates with Forschungszentrum Jülich and the 4 Fraunhofer Institutes in Aachen. Several projects are assisted by the Deutsche Forschungsgemeinschaft and the European Union. Approximately 6,100 students are enrolled in the faculty.

Rudolf Tomaschek

Rudolf Karl Anton Tomaschek (23 December 1895 in Budweis, Bohemia – 8 February 1966, Breitbrunn am Chiemsee) was a German experimental physicist. His scientific efforts included work on phosphorescence, fluorescence, and (tidal) gravitation. Tomaschek was a supporter of deutsche Physik, which resulted in his suspension from his university posts after World War II. From 1948 to 1954, he worked in England for the Anglo-Iranian Oil Company (AIOC). In 1954, when AIOC became BP, he went to Germany and was president of the Permanent Tidal Commission.

Hungarian or Hungarian-American Nobel Laureates
Physiology or Medicine
Economic Sciences

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