The term glassy dynamics is often used to refer to the extremely slow relaxation observed in several types of many component systems. The time span needed to reach a steady, time independent, state will typically be far beyond experimentally accessible time scales. When melted alloys are cooled down they typically do not enter a crystalline ordered state. Instead the atoms retain the amorphous arrangement characteristic of the liquid high temperature phase while the mobility of the molecules decreases very many orders of magnitude. This colossal change in the characteristic dynamical time scales makes it impossible for a structural glass at low temperature to reach thermodynamic equilibrium . However, over short time scales the properties of glasses may appear to be time independent as in thermal equilibrium. Only when several orders of magnitude of time scales are covered is one able to resolve directly the slow change of measure macroscopic characteristic properties with time.