ABSTRACT
1.1 Overview
A measure of the advancement of a particular civilization may well lie in its ability to provide comprehensible answers to fundamental questions. Two examples of such fundamental questions are (1) What is the nature of the Universe and (2) What is the Universe made of? Seeking the answers to these questions defines the discipline of physical cosmology. While this discipline is a convolution of elementary particle theory, general relativity and astronomical observations, there is still room for elements of mysticism and imagination in our cosmological models. Indeed, history has taught us that humans have an insatiable appetite for grand ideas about the nature of the world. Furthermore, at any given time in history, everyone always thinks their world model is correct. Since the answers to our two posed questions continue to elude us, it is safe to say that no cosmological theory has yet proven to be entirely satisfactory. Hence one should expect, and even demand, continual revisions and challenges to any existing cosmological paradigm.
