The Development of Physical Cosmology
This chapter introduces physical cosmology as the attempt to make sense of the large-scale nature of the material world by the methods of the natural sciences. It explains that physical cosmology operates under the special restrictions of astronomy, which is considered successful in sister fields, such as stellar astronomy and particle physics. It cites the substantial progress of cosmology as an enterprise in physical science, although the advances certainly have moved around considerable gaps in one's understanding. The chapter details how cosmology inherits from basic physics the more ancient and honorable tradition of attempts to understand where the world came from, where it is going, and why. It reviews believable evidence that the universe is expanding, the space between the galaxies opening up, and that this expansion traces back to a hot dense phase, the big bang.