  Astronomers measure distances to faraway galaxies and their velocities. They
do that in order to determine the expansion rate of the Universe. In Part I of
these lectures the foundations of the theory of the expansion of the Universe
was given. In this part we present the theory. A formula for the distance of
the galaxy in terms of its velocity is given. It is very simple:
$r(v)=c\tau/\beta\sinh\beta v/c$, where $\tau$ is the Big Bang time, $\beta
=\sqrt{1-\Omega_m}$, and $\Omega_m$ is the mass density of the Universe. For
$\Omega_m<1$ this formula clearly indicates that the Universe is expanding with
acceleration, as experiments clearly show.
