Editing Quantum number (section)

===Nuclear quantum numbers===
With successful models of the atom, the attention of physics turned to models of the nucleus. Beginning with Heisenberg's initial model of proton-neutron binding in 1932, [[Eugene Wigner]] introduced [[isospin]] in 1937, the first 'internal' quantum number unrelated to a symmetry in real space-time.<ref name=Brown1987>{{Cite book |last=Brown |first=L.M. |chapter-url=https://archive.org/details/festivalfestschr0000unse/page/40/mode/2up?q=isospin |title=Festi-Val: Festschrift for Val Telegdi; essays in physics in honour of his 65th birthday; [a symposium ... was held at CERN, Geneva on 6 July 1987] |date=1988 |publisher=North-Holland Physics Publ |isbn=978-0-444-87099-5 |editor-last=Winter |editor-first=Klaus |location=Amsterdam |language=en |chapter=Remarks on the history of isospin |editor-last2=Telegdi |editor-first2=Valentine L.}}</ref>{{rp|45}}