Two Comparative Case Studies of $b$-quark and $c$-quark Physics

We discuss prospects for detecting the two charm-related phenomena of $D^0$-${\bar D}^0$ mixing and weak radiative decays of $D$ mesons ({\it e.g.} $D\to K^* + \gamma$). A general update of particle-antiparticle mixing for the pseudoscalar mesons is presented and the dynamics of mixing is reviewed, with application especially to the $D^0$-${\bar D}^0$ system. The radiative weak decays of $B$ mesons is then considered, and the problem of hadronic uncertainties is reviewed. Finally, the technique of calculating radiative weak decays for charm mesons is explained.