Of fundamental importance in almost all sciences is the concept of "event." The first object of this elementary study is to provide by a careful selection of materials an appropriate mathematical frame for this concept which specially includes the laws which the "watches," another important concept used frequently in this research, record the events. Armed, then, with this mathematics, the Gravitational Clouds Theory, a somewhat strange theory of gravitation concerning the role of the matter and energy in the universe, is proposed. This theory leads to miscellanies results some of which are:...