Cosmology 101 - The Study of the Universe

Cosmology is the scientific study of the large scale properties of the Universe as a whole. It endeavors to use the scientific method to understand the origin, evolution and ultimate fate of the entire Universe. This primer in cosmological concepts is organized as follows: The main concepts of the Big Bang theory are introduced in the first section with scant regard to actual observations. The second section discusses the classic tests of the Big Bang theory that make it so compelling as an apparently valid description of our universe. The third section discusses observations that highlight limitations of the Big Bang theory and point to a more detailed model of cosmology than the Big Bang theory alone provides. As discussed in the first section, the Big Bang theory predicts a range of possibilities for the structure and evolution of the universe. The final section discusses what constraints we can place on the nature of our universe based on current data, and indicates how WMAP furthers our understanding of cosmology. In addition, a few related topics are discussed based on commmonly asked questions. This site is hosted by the NASA Goddard Space Flight Center.