We want to show here that it is possible to conceive a theory of gravitation built with very simple physical notions derived from the most classical mechanics. This is achieved by making the assumption that physical space is a granular fluid medium, constituted by “corpuscles” with infinitesimal energy and dimension and endowed with quantified cooperative properties. We will show that such a point of view can explain the principles on which Relativity is based and recover all its results. It also allow us to understand a quantum character for Newton's strength and shed some light on these mysterious "black objects”.