Unformatted text preview: Philipp Eduard Anton von Lénárd von
(that’s a very long name!) By: Stacy Devino June 7, 1862– May 20, 1947 Born: Pressburg (today's Bratislava, Slovakia), Austria-Hungary Died: Messelhausen, Germany Received his Ph.D at the University of Heidelberg in 1886. 1892 worked as an assistant to Hertz at the University of Bonn 1894 was appointed Professor Extraordinary at the University of Breslau 1895 became Professor of Physics at Aix-la-Chapelle 1896 Professor of Theoretical Physics at the University of Heidelberg 1898 he was appointed Professor Ordinarius at the University of Kiel 1907 as the head of the Philipp Lenard Institute (University of Heidelberg ) Cathode Rays Cathode Nobel Prize in 1905 for Physics While working under Hertz, discovered While the “Lenard Window” where cathode rays could be observed in their “pure state” within the vacuum tube. He made it possible to study cathode He rays outside of the vacuum tube in their “pure state” by placing a piece of thin aluminum at the end rather than a quartz crystal. Allowed him to discover that cathode Allowed rays were actually streams of charged particles that were smaller than atoms or molecules (electrons) and the nature of how they create fluorescence. Why do I care?
Electrons!!! – They are represented everywhere in this course Quantum Theory!!! – his work was used by Einstein as a foundation TV!!! – CRT (cathode ray tube) sets are still the mainstream More Discoveries More UV light placed on a piece of UV metal causes electrons to be ejected. Energy of the incident light is Energy proportional to the number of electrons ejected, but not the kinetic energy of those electrons. “Lenard Effect” – when water Lenard droplets separate they cause the surrounding air to become ionized surrounding Invented a Photoelectric Cell Electrons must have a certain Electrons energy to become ionized through a gas gas Spectral lines produced by Spectral elements elements Why do I care? Photoelectric Effect!!! – Ejected electrons (lab ex. – MBE) Solar Panels!!! – Cheap Energy Ionization!!! – used to bind Air Purifiers!!! – My place smells good Spectral Lines!!! – allow you to detect elements quickly without real loss of subject matter Thin Line Thin • Hated all science not German and believed it stolen from Germans • Joined the Nationalist Socialist Party (NAZI) early in the regime • Preached that non-German physics were proponents of “Jewish Lies” • Denounced Einstein’s Relativity as “the Jewish Fraud” • Advisor to Adolf Hitler • Chief of Aryan Physics under the Nazis • Records show that he was actually born Jewish • Yes, even he was married • Brilliant and Delusional can be barely separated Awards and Publications Awards
Awards: Rumford Medal of the Royal Society in 1896 Matteucci Medal of the Italian Society of Sciences in 1896 Franklin Medal of the Franklin Institute in 1905 Nobel Prize for Physics in 1905 Publications: Ueber Kathodenstrahlen (1906) “Over cathode rays “ Ueber Ueber Aether und Materie (second edition 1911) “Over ethers and subject “ Ueber Probleme komplexer Molekuele (1914) “Problems of complex molecules” Probleme Quantitatives über Kathodenstrahlen (1918) “Quantitative over cathode rays” Quantitatives Ueber das Relativitätsprinzip (1918) “Over the relativity principle” Ueber Grosse Naturforscher (second edition 1930) “Large natural scientists” Grosse Deutsche Physik (1936-37, physics, 4 vols.) “German Physics” Deutsche Have a Laugh Today <End> ...
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- Winter '09
- cathode rays, Cathode rays Cathode, Philipp Lenard, Invented a Photoelectric Cell Electrons, Professor Ordinarius