摘要：Through reevaluating the physical significance of Hubble law, we propose the concept of spatial relativity and make two postulates: 1) Distance is equivalent to motion; 2) Hubble radius is constant. Such an approach can help us to develop the theory of relativity into a unified form, and further construct a simple and consistent cosmological model. It shows that, our universe can be treated as an eternal 3-dimensional ball with an edge never reached served by the physical horizon, whose inherent geometrical property will directly lead to Hubble law, rather than Doppler mechanism. Importantly, the presented model can provide us a unified scheme to deal with the cosmological problems, but without employing more extra assumptions. This will greatly change our understanding of the cosmic spacetime.
