We write a non-relativistic Lagrangian for a hierarchical universe. The equ
ations of motion are solved numerically and the evolution of the fractal di
mension is obtained for different initial conditions. We show that our mode
l is homogeneous at the time of the last scattering, but evolves into a sel
f-similar universe with a remarkably constant fractal dimension. We also sh
ow that the Hubble law is implied by this model and make an estimate for th
e age of the universe.