More than half a century has elapsed since the first confirmation of the violation of parity. Soon afterwards CP violation was discovered, and although the standard model seems to correctly describe both phenomena, the origin of the breaking of these symmetries is still not clear. A number of related issues remain open, such as the possible breaking of P and T by strong interactions, the role of fundamental discrete symmetries in cosmology, especially in lepto and baryogenesis, the high energy and high temperature behavior of these symmetries, to mention a few.
