THE CORRESPONDENCE PRINCIPLE: "Über die Serienspektra der Elementeâ (Zeitschrift für Physik: Volume 2, pp. 423-469) Bohr, Niels German Language,Science & Technology

iv, 478 pp. 8vo. Gray cloth spine with gray patterned cloth covers. Some scuffing overall with a clean interior. Previous owner's name in ink on first free endpaper. Niels Bohr (1884-1962) first gives a name to the correspondence principle (â Korrespondenzprincipâ ) in a presentation to the Berlin Physical Society in 1920. The correspondence principle "says that for large orbits and for large energies, quantum calculations must agree with classical calculations." (https://en.wikipedia.org/wiki/Correspondence_principle) Also contains Otto Stern's article, â Eine direkte messung der thermischen molekulargeshwinidigkeitâ (â Direct measurement for the thermal molecular velocityâ ) on pp. 49-56.