PHY 111, Spring, 2006

Week 13
  Main Objectives

You should be able to explain:

bulletwhat is meant by "standard candles" and the "distance pyramid" and why all steps in the pyramid are not equally accurate
bulletwhat RR Lyrae stars are and how they are used to find distances
bullethow synchrotron radiation is produced and what kinds of objects emit this type of radiation
bulletWhy we think there may be supermassive black holes at the center of some galaxies
bulletwhat evidence we have that some galaxies may be colliding or exploding
bulletwhy stars are unlikely to collide when galaxies collide
bulletHubble's law and how it is related to the age of the universe
bulletwhat a quasar is and why they are important to our models of the history of the universe
bullethow we know quasars are small
bulletwhat Olber's paradox is and why it is important to our models of the history of the universe
bulletwhat the 3K background radiation is and why it is important to our of the history of the universe
bulletwhat evidence we have that galaxies are no longer being formed
bulletwhat the Big Bang model is and what evidence supports it

You should be able to compare and contrast :

bulletspiral, elliptical, and irregular galaxies
bulletSeyfert galaxies and normal galaxies
bulletactive galaxies and normal galaxies
Tuesday Discuss galaxies other than our own.

Outside of class: Read Chapter 17. Complete Chapter 17 Recall questions 9, 11, 15, 17, and 21 and Calculations 1, 3, and 5 to be turned in on Thursday.
Thursday Go over exam.  Discuss cosmology (the study of how the universe has changed over time).

Outside of class: Read Chapter 18. Read Ch. 7 sections 1-5.  Read Ch. 6 section 5.