Chapter 25 presents an up-to-date discussion of important new topics in the study of galaxies as a whole.  It covers scales up to the size of the whole universe, or cosmology, the subject of Chapter 26.

I would subtitle it "Dark matter, the evolution of galaxies, and the largest-scale structures of the cosmos." 

We'll cover dark matter througly.

We'll only hit the high points of the evolution of galaxies and quasars.  This topic requires us to make use of results of relativistic redshifts.  I de-emphasized More Precisely 24-1 in the last chapter, but now you should go back and read it.  In class, I will use the definition z=(observed wavelength-emitted wavelength)/emitted wavelength.

In covering the largest-scale structures, which we'll do thoroughly, we will look at the texture of the universe. 

Review and Discussion:  All good.

Conceptual Self-Test: True or False/Multiple Choice:  Skip number 15.

Problems:  Neat problems for a more advanced course:  you can skip them.