Paper presented the 8-IX-06 in the Spanish society gravitation and relativity, international meeting (ERE2006). Mallorca

Einstein, in the equations of the General Relativity, departs from three premises: 1/ Equivalence between inertia, gravity and mass. 2/ Distortion of the space for the mass, and equivalence between mass and spatial distortion. 3/ Equivalence between gravity and uniformly accelerated motion. From this viewpoint conceptual and pre-relativist is where I have something to add. I try to postulate the braking effect as equivalent to gravity. Then results it make more understandable the gravity, the inertia, the uniformly accelerated motion and also the mass. In the present moment, at the end of the article, I add some considerations on mass, dark energy and dark matter specially.