3 Quotes by Arnold Sommerfeld

All integral laws of spectral lines and of atomic theory spring originally from the quantum theory. It is the mysterious organon on which Nature plays her music of the spectra, and according to the rhythm of which she regulates the structure of the atoms and nuclei.

If you want to be a physicist, you must do three things-first, study mathematics, second, study more mathematics, and third, do the same.

Mathematics is like childhood diseases. The younger you get it, the better.