This book provides an overview of topics in high energy, particle
and gravitational astrophysics, aimed mainly at interested undergraduates
and other readers with only a modest science background. Mathematics and
equations have been kept to a minimum, emphasizing instead the main concepts
by means of everyday examples where possible. I have tried to cover
and discuss in some detail all the major areas in these topics where significant
advances are being made or are expected in the near future, with discussions
of the main theoretical ideas and descriptions of the principal experimental
techniques and their results.