Uploads from Dr. Jorge S. Diaz

Currently Playing: When helium broke quantum theory

Buy me a coffee and support the channel: https://ko-fi.com/jkzero This episode follows over a decade of struggle to make sense of the helium atom: Bohr's coplanar ring atom, Debye's 1915 dispersion calculation, Sommerfeld's nuclear screening, and Landé's 1919 vector model of the atom. Helium was not solved by quantum mechanics until 1928, and not by a famous name, but by a Norwegian school teacher named Egil Hylleraas. [Related videos] ∘ Quantum theory of the nornal Zeeman effect https://youtu.be/DetAXY2cpzM ∘ Sommerfeld and the fine-structure constant https://youtu.be/H4ZnVpiQTDw ∘ Classical theory of dispersion https://youtu.be/HC0a33HnTuE ∘ Quantum theory of dispersion https://youtu.be/9hfQZMBQOiw ∘ The Stern-Gerlach experiment https://youtu.be/BDAzFIJu9_E ∘ Playlist video series on Quantum Physics https://www.youtube.com/playlist?list=PL_UV-wQj1lvVxch-RPQIUOHX88eeNGzVH [References] [1] N. Bohr, "On the Constitution of Atoms and Molecules: Part II - Systems Containing Only a Single Nucleus," Phil. Mag. 26, 476–502 (1913) [2] J.Franck & G. Hertz, "Messung der Ionisierungsspannung in verschiedenen Gasen," Verb. d. Deutsch. Phys. Ges. 15, 34-44 (1913) [3] J. Franck & P. Knipping, "Die Ionisierungsspannungeng des Heliums," Phys. Z. 20: 481-488 (1919) [4] N. Bohr, "On the Constitution of Atoms and Molecules: Part III - Systems Containing Several Nuclei," Phil. Mag. 26, 857–875 (1913) [5] P. Debye, "Die Konstitution des Wasserstoffmoleküls," Sitzungsb. Bayr. Akad. Wiss. Band 1, 1-26 (1915) [6] A. Sommerfeld, "Zur Quantentheorie der Spektrallinien," Ann. Phys. 51, 1-94 and 125-167 (1916) [7] A. Sommerfeld, "Die Drudesche Dispersionstheorie vom Standpunkte des Bohrschen Modelles und die Konstitution von H2, O2 und N2," Ann. Phys. 53:497-550 (1918) [8] M. Born & A. Landé, "Kristallgitter und Bohrsches Atommodell," Verh. DPG 20, 202-209 (1918) [9] M. Born & A. Landé, "Über die Berechnung der Kompressibilität der Alkali-Halogenidkristalle aus der Gitterenergie," Verh. DPG 20, 210–216 (1918) [10] A. Landé, "Das Serienspektrum des Heliums," Phys. Z. 20:228-234 (1919) [11] A. Landé, "Eine Quantenregel fiir die raumliche Orientierung von Elektronenringen," Verhl d. Dtsch. Phys. Ges., 21 , 585–588 (1919) [12] A. Sommerfeld, "Allgemeine spektroskopische Gesetze insbesondere ein magnetooptischer Zerlegungssatz," Ann. Phys. 63, 221 (1920) [13] D. C. Cassidy, "Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb," 2009 [14] E. A. Hylleraas, "Über den Grundzustand des Heliumatoms," Z. Phys. 48(7–8), 469–494 (1928) [15] E. A. Hylleraas, "Neue Berechnung der Energie des Heliums im Grundzustande, sowie des tiefsten Terms von Ortho-Helium," Z. Phys. 54(5–6), 347–366 (1929) [Credits] Periodic table by GSI Helmholtzzentrum für Schwerionenforschung Solar system, by Orrery under CC BY-SA 4.0 Átomo de Oro by G. Creador under CC BY 3.0 The three-body problem by Perosello under CC BY-SA 4.0 VFPt charges minus minus by Geek3 under CC BY-SA 4.0 James Frank, public domain Gustav Hertz, public domain Bonzenfreie Kolloquium by AIP A. Sommerfeld, public domain W. Lenz, public domain D. Hilbert, public domain U. Göttingen, public domain M. Born, public domain P. Debye, public domain M. Born in uniform by AIP A. Landé, public domain Wettermessungen, by the German Federal Archive, under CC-BY-SA 3.0 R. Ladenburg, public domain Red Cross WWI, public domain Crystallography diagrams, public domain U. Frankfurt, public domain W. Pauli, public domain W. Heisenberg, public domain W. Gerlach, public domain O. Stern, public domain E. Hylleraas, public domain Niels Bohr Institute Conference 1932 by AIP Egil Hylleraas, public domain AIP: American Institute of Physics, Emilio Segrè Visual Archives CC BY 2.5: https://creativecommons.org/licenses/by/2.5/deed.en CC BY 3.0: https://creativecommons.org/licenses/by/3.0/deed.en CC BY-SA 3.0: https://creativecommons.org/licenses/by-sa/3.0/deed.en CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/deed.en