The universe is the largest system of all. It consists of elementary
particles bound together by gravitational, electromagnetic and nuclear
forces. Its structural hierar- chy in space (from atomic nuclei to
supergalaxies) and its evolutionary sequence (from the fireball to the
diversity of present forms) is governed by the properties of elementary
particles and their interactions. This book is an attempt to interpret
the structure and evolution of the universe in terms of elementary
particles and of their interactions. This book is intended to present a
background for students in astronomy and related sciences, such as
geophysics, meteorology, plasma physics, chemistry, nuc- lear physics,
space sciences and some others. The universe forms a general framework
fo: all the phenomena studied by these sciences. It was possible to
squeeze an extensive range of topics from various disciplines into one
book of acceptable size only under some severe limitations: (a) no
references are given; (b) arguments are shortcut; (c) quantities are
often expressed in the order of magnitude; and (d) formulae have been
limited to a minimum. Often more hypo- theses or theories exist for a
phenomenon. We have chosen only one. The preference for a theory or
hypothesis may be personal and the theory itself may later prove
incorrect. But, many theories about a particular phenomenon would cover
many pages and might lead to confusing effects.