Proper noun
Sommerfeld (plural Sommerfelds)
A surname from German.
Arnold Sommerfeld identified this adiabatic invariant as the action variable of classical mechanics. Source: Internet
Because Sommerfeld had a sincere interest in his students and knew of Heisenberg's interest in Niels Bohr 's theories on atomic physics, Sommerfeld took Heisenberg to Göttingen to the Bohr-Festspiele (Bohr Festival) in June 1922. Source: Internet
In 1916, Arnold Sommerfeld added elliptical orbits to the Bohr model to explain the extra emission lines, but this made the model very difficult to use, and it still couldn't explain more complex atoms. Source: Internet
Further applying special relativity theory to the elliptic orbits, Sommerfeld succeeded in deriving the correct expression for the fine structure of hydrogen spectra (which happens to be exactly the same as in the most elaborate Dirac theory). Source: Internet
He received his doctorate in 1923, at Munich under Sommerfeld. Source: Internet
However, Sommerfeld stayed in his chair during the selection process for his successor, which took until 1 December 1939. Source: Internet