ABSTRACT
In this chapter, the role of galaxies in establishing the conditions necessary for life is explored in greater detail. In particular, the role galactic mass, size, and stellar constituents have in the formation of a potentially life-supporting environment is considered. Furthermore, the natures of dark matter and black holes are examined, and the special conditions these structures establish in a life-supporting galaxy are highlighted. The chapter also explores the circumstances that make our Milky Way galaxy unusual, and it concludes with a brief analysis of how several physical constants ultimately made life-supporting galaxies like ours possible.
