  By means of a general classification of the different kinds of matter of
nature form a chain from the world of the subatomic particles to the large
bodies of the universe, the galaxies. Then, it proposes a new baryonic force
for the universe that is the fifth force which has been proposed in the
literature. It explains the universal expansion itself and shows why the
expansion must be slowing down at present. This force depends on the ratio of
the number of neutrons to the number of protons. Its potential for the Universe
is a well. At the bottom of the well the potential is of the form $kx^2$, where
$x$ is the separation among the bodies under consideration. It is suggested
that Nature has six fundamental forces which are unified in pairs and,
therefore, reduced to three at $t=0$. The condition for having a closed
universe is found. This new force, called superweak force in this paper,
explains also the evolution of galaxies and shows how the arms of spiral
galaxies(including barred spirals) are formed. The variation of the Hubble
constant with time is shown. It is shown that quarks are formed of prequarks
which may be the true elementary particles. The paper also gives a physical
explanation for quark confinement. The energies of baryon states are calculated
in a simple manner. The paper proposes the existence of four more bosons, one
for the superweak interaction and three for the superstrong interaction. The
six figures will be sent by mail upon request.
