Abstract
This paper describes goals of research and some example of recent results on the dynamics and the statistical mechanics of an ensemble of real particles that dissipates due to collision, i.e. ball-wall and ball-ball collisions, studied in micro-gravity. Special care is taken to study the limits of little interaction between the balls because of their small density number (Knudsen regime) and the limit of strong interaction when the mean free path between 2 ball-ball collision is less than the cell size. It turns out that the physics of these dissipative systems is non extensive and generates heterogeneities. The question of transporting and managing grains is asked, taking as an example the Maxwell's demon. Comparison with different limiting cases will be achieved, i.e. with dissipative billiard model and with the statistical mechanics of gas or of liquid.
