Class #11 (Feb. 12) Reading Questions - The Dark Side of the Universe

Chapter 8

1. Current observational results constrain to the total matter (plus energy) density of the universe to the range 0.1<Omega<10 where Omega=M_total/M_critical. Explain why this result strongly implies that Omega actually equals exactly one and thus, that the universe is "flat".

2. Explain the "horizon problem" (giving the experimental evidence for this "problem") and describe how the Inflationary Model solves this problem.

3. Explain the connection between the Standard Model of particle physics and the Inflationary Model of the universe.

4. Explain how detailed measurement of temperature variations in the cosmic background radiation (CMB) provide direct experimental evidence that the universe is "flat".

5. What is "dark energy" and what is the observational/experimental evidence for its existence.

Chapter 9

6. What is a type Ia supernova and why do these objects provide nearly "ideal standard candles"?

7. What "shocking" result was deemed the 1998 "Science Breakthrough of the Year" and what is the observational evidence for this result?

Your Question: Please give a well formulated question that you have regarding the material covered in this reading assignment.