A model of a 3D unlimited and finished space is presented with the philosophic prejudgement that a physical space must be representable and cannot be a virtual mathematical abstraction. This representable 3D space has 3 radii of curvature and so, is multiconnected as predicted by the theorem of perelman-Poincaré. This model respects the basic principles of the physics (Occam, Maupertuis, Mach, ...) and does not question much of the content of the other models. Another way of seeing is given because: 1) this model avoids the problem of the 2 infinities;2) it gives an additional explanation to the expansion and to the value of the density always near the critical density;the homogeneity of the cosmos is easier to explain;3) the attraction is always attractive and it gives an explanation to the measure of the acceleration of the expansion estimated about 6 - 7 billion years and to the great attractor;4) it predicts the existence of many “ghosts” images, as the illusion of galaxies is older than Big Bang and these galaxies are more evolved when they are older, or for example a greater number of galaxies at a distance of about 2100 Mpc, what can be verified from the NASA/IPAC measurements of 348 galaxies of redshift <em>v</em> > 1/8<em>c</em>. Other deductions are verifiable, which should invalidate or confirm this model. In<strong> Appendix</strong>, a mathematical development deliberately simple is made to remain in a representable reality and locate any point in this space. This development can allow to make links with the spaces of Minkowski.