Assignment 1
Concept Check
Due: Monday, 9 August 2010

Chapter 23:

• Page 618, Why do we see the Milky Way as a band of light across the night sky?
• Page 626, Can variable stars be used to map the structure of the Galactic disk?
• Page 629, Why do astronomers regard the disk and halo as different components of our Galaxy?
• Page 635, Why can't spiral arms simply be clouds of gas and young stars orbiting the Galactic center?
• Page 641, In what sense is dark matter dark?
• Page 645, What is the most likely explantion of the energetic events observed at the Galactic center?

Chapter 26:

• Page 713, In what sense and on what scale is the Universe homogeneous and isotropic?
• Page 717, Why does Hubble's Law imply a Big Bang?
• Page 729, When was the Cosmic Microwave Background formed?