Arnold Sommerfeld

Sommerfeld, Arnold. Atombau undSpektrallinien. 3d ed. Braunschweig Teubner, 1922. 

Soon after Bohr developed his initial configuration Arnold Sommerfeld in Munich realized the need to characterize the stationary states of the electron in the hydrogen atom by. means of a second quantum number—the so-called angular-momentum quantum number, Bohr immediately applied this discovery to many-electron atoms and in 1922 produced a set of more detailed electronic configurations. In turn, Sommerfeld went on to discover the third or inner, quantum number, thus enabling the British physicist Edmund Stoner to come up with an even more refined set of electronic configurations in 1924. 

Photo 5 (left) Linus Pauling with Arnold Sommerfeld (on left). Sommerfeld, well-known professor of theoretical physics in the University of Munich, Germany, was an expert on an early form of quantum mechanics, the Bohr-Sommerfeld atomic model. The picture was taken on the occasion of Sommerfeld s visit to Caltech in 1928. Pauling studied quantum mechanics with Sommerfeld in 1926—1927, which is where Pauling got his start in the application of quantum mechanics to chemical bonding (Chapter 1) and to the calculation of molecular properties (Chapter 8). 

Ibid., preface to 1st ed. and Arnold Sommerfeld, Atomic Structures and Spectral Lines, trans. from 3d German ed., Henry Brose (London Methuen, 1923). 

Institut fur Physikalische Chemie, Technische Universitat Clausthal, Arnold-Sommerfeld-Str. 4, 38678 Clausthal-Zellerfeld, Germany... 

We conclude with a famous quotation attributed to the great theoretical physicist, Arnold Sommerfeld... 

Arnold Johannes Wilhelm Sommerfeld (1868-1951). James Clerk Maxwell (1831-1879). 

Linus Pauling arrived in Munich on April 20, 1926[1]. This was very much a case of being in the right place at the right time. He was going to spend one year at the Institute of Theoretical Physics which at the time was directed by Arnold Sommerfeld. For this purpose he had been awarded one of the very first fellowships of the John Simon Guggenheim Memorial Foundation. 

In telling this story it is apparent how much was new, fresh and young in 1926 Pauling, Cal Tech, Roscoe, the Guggenheim Fellowships, quantum theory, even Arnold Sommerfeld as far as the Royal Society was concerned ... 

The sums may be carried out with respect to the atomic positions in direct (real) space or to lattice planes in reciprocal space, an approach introduced in 1913 by Paul Peter Ewald (1888-1985), a doctoral student under Arnold Sommerfeld (Ewald, 1913). In reciprocal space, the structures of crystals are described using vectors that are defined as the reciprocals of the interplanar perpendicular distances between sets of lattice planes with Miller indices (hkl). In 1918, Erwin Rudolf Madelung (1881-1972) invoked both types of summations for calculating the electrostatic energy of NaCl (Madelung, 1918). 

Figure 4.4 A. diagram of the Bohr model of the hydrogen atom as shown by Arnold Sommerfeld in Atomic Structure and Spectral Lines. The radii of the pictured orbits n = 2 and w = 3 are four times and nine times larger than the radius = 1. Orbits forw = 4, 5, 6, and so on are even larger. Spectral lines originate when the atom passes from one energy state, w = 3, to others, n = 2 and n = 1, as pictured.

The quantum idea and the implications of relativity theory first met through the work of Arnold Sommerfeld in 1915. Sommer-feld (1868-1951), a professor of physics at the University of Munich, was well known for his contributions to physical research. He was also a renowned teacher. Many famous physicists of the twentieth cenmry, including Wolfgang PauH, Werner Heisenberg, and Hans Bethe studied under Sommerfeld and scores of physics students used his numerous textbooks. His book Atomic Structure and Spectral Lines (1919) was a primary reference for physicists interested in the atom. 

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