‎"SOMMERFELD, ARNOLD. - SPATIAL QUANTIZATION AND FINE STRUCTURE - THE ATOMIC MODEL OF SOMMERFELD.‎
‎Zur Quantentheorie der Spektrallinien. (+) Fortzetzung. (2 Parts).‎

‎(Leipzig, Ambrosius Barth, 1918). Without wrappers in ""Annalen der Physik"", Vierte Folge, Bd. 51, No.17 a. 18. The entire issues offered. Pp. 1-124 a. pp. 125-236. Sommerfeld's papers: pp. 1-94 a. pp. 125-167. Punched in inner margins after cords. Clean and fine.‎

Reference : 43820

‎First appearance of Sommerfeld's main contribution to Quantum Theory, incorporating the ""Sommerfeld Model"" of the atom and his creation of a general theory of spectral lines based on quantum concepts.""In the winter Semester 1914/15 his topic was the Bohr model. He extended it considerably and was able to find a number of new results which were published early in 1916 (in the paper offered).The gist of Bohr's theory was the fact that it allowed only certain electron orbits. Sommerfeld tried to find the ""quantum conditions"" by which these orbits could be singled out from the classically allowed ones.""(Siegmund Brandt ""The harvest of a Century"", Episode 27, p. 110 ff.).""This extraordinary extension, enrichment, and precision of Bohr's theory by Sommerfeld contributed decisively to its rapid and widespread acceptance. Only five years after Bohr's first publicatuion Sommerfeld, recognizing that the mathematical development of thsi quantum-theoretical atomic model had reached a conclusion of sorts, undertook a comprehensive exposition of the field. His ""Atombau und Spektrallinien"", of which the first edition appeared late in 1919, immediately became the bible of atomic physics and its successive editions, appearing almost annually in the early 1920's, chronicled the progress of this field up to the eve of quantum mechanics.""(DSB XII, p. 529).The offered papers contains also 2 importent contribution in the same field by Sommerfeld's pupils: Paul S. Epstein ""Zur Quantentheorie"" pp. 168-188 and J. Stark: ""Der Träger der Haupt- un Nebenserien der Alkalien, alkalischen Erden und des Heliums"", pp. 220-236.‎