  This article is the written version of a talk delivered at the Workshop on
Nonlinear Dynamics and Fundamental Interactions in Tashkent and starts with an
introduction into quantum chaos and its relationship to classical chaos. The
Bohigas-Giannoni-Schmit conjecture is formulated and evaluated within
random-matrix theory. In accordance to the title, the presentation is twofold
and begins with research results on quantum chromodynamics and the quark-gluon
plasma. We conclude with recent research work on the spectroscopy of baryons.
Within the framework of a relativistic constituent quark model we investigate
the excitation spectra of the nucleon and the delta with regard to a possible
chaotic behavior for the cases when a hyperfine interaction of either
Goldstone-boson-exchange or one-gluon-exchange type is added to the confinement
interaction. Agreement with predictions from the experimental hadron spectrum
is established.
