What is the Cosmological Principle? How does it relate to ideas from the Copernican revolution?
Define isotropic and homogeneous? How are these terms different from each other?
What is Olber's paradox?
Why can't the universe be infinitely large and unchanging in time?
How does the idea of universal expansion result form Hubble's law and the Cosmological Principle?
Define open, flat, and closed universes. How does these ideas represent the three possible future for our universe?
How does the average density of the universe relate to the curvature of the universe? How is the curvature of the universe related to the future fate of the universe?