  Weinberg relation can be explained by Newton laws. It can also be transformed
into a relation between a gravitational cross section area, associated to a
gravitational mass m, and the product of two gravitational radii corresponding
to the mass m and to the mass M of the Universe. Using a physical similarity
process we propose a convective cascade mechanism to explain the structures
present in the Universe. The proposal includes the vacuum fluctuations as the
heating source for convection to take place. The fundamental Rayleigh number is
used with a value of 1100, as in the case of the granules observed in the sun
photosphere. Computer simulations results give structures that resemble a
configuration of the type of the Benard cells. We present the similarity of our
results with the actual structures in the Universe (masses and sizes).
