לוח שנה משולב

When we approach a physical problem, numerically or analytically, our first aim is to understand the most probable, 'typical' situation. There are, however, rare events that take place with small probability but are, for some reason, important. The examples are many, ranging from chemical reactions (which take place through improbable 'activation' processes), to rare trajectories in turbulent systems (that may give a burst of drag to your car) or in planetary systems, events that make our solar system lose Mercury. Furthermore, when we think of glasses as systems that are "chaotic in space" (amorphous), we realize that the 'ideal glass state' is also a rare event, and may be analised in an analogous way. From the numeric point of view, the problem is that observing an improbable event takes a long waiting time ... so that one has to develop new methods.