  The cosmological vacuum, which is perfectly uniform, dominates by density
over all the forms of cosmic matter. It makes the Universe be actually more
uniform than it could be seen from the visible picture of the highly
non-uniform matter distribution, especially inside the observed cell of
uniformity (100-150 Mpc). This uniformity reveals itself in the structure of
the Hubble matter flow which extends over a giant range of cosmic space scales
-- from few Mpc to a thousand Mpc, -- preserving its kinematical identity.
According to Sandage (1999), this flow is mysteriously regular and quiet even
deep inside the cell of uniformity. An answer we propose to the question in the
title above is as follows: This is most probably because the flow is
dynamically controlled by the cosmological vacuum. An additional conjecture of
cosmological intermittency, that addresses a complex statistical structure of
initial chaotic perturbations, is also suggested in this context.
