BUCKNELL UNIVERSITY

Astronomy 101- Quiz #6, Solution






1. A visible photon is emitted at time t=500,000 years after the big bang (just after the recombination of electrons and protons to form atoms). We may see this photon now as

a. an electron

b. a UV photon

c. a photon of 1 milimeter wavelength

d. a photon with the same frequency at which it was emitted.
 
 

2. From lab#8: If the universe is slowing down its expansion, then the Hubble time (1/H) is _________ its age.

a. an overestimate of

b. an underestimate of

c. an accurate measure of

d. not at all related to
 
 

3. The microwave background radiation spectrum is that of a black body radiation because

  1. the universe was black at t~500,000 years
  2. the universe was hot and dense at t~500,000 years
  3. the universe was hot and transparent at the time of elements nucleo-synthesis

    4.  

     
     
     
     

    4. The visual magnitude of spiral galaxy A is +14.3. The visual magnitude of the Andromeda galaxy, M31, is +4.3, and it is 0.7 Mpc away from us. How far is that galaxy?

    a. 7 Mpc

    b. 70 Mpc

    c. 700 Mpc

  4. 7000 Mpc
5. The "four pillars" of observational evidence for the big-bang theory are the microwave background radiation, the fluctuations in the radiation, the recession of galaxies and
  1. the fact that the night sky is black, which tells us that the universe is not infinitely large
  2. the isotropic (same in all directions) abundance of elements in galaxies
  3. the "flatness" of the universe
  4. the enormous size of the universe
6. Inflation may explain the fact that
  1. the universe is so nearly "flat"
  2. the universe is so close to its critical density
  3. a and b

 
 

7. The "steady state" model of the universe explains the creation of matter in terms of

  1. matter was always there and it just blew off from a single point
  2. matter was formed by means of "C-fields"
  3. matter was created from anti-matter
  4. matter was created from photons (pure energy)
8. We currently believe that the universe is made of indivisible particles that include
  1. electrons, neutrons, protons and neutrinos
  2. planets and stars
  3. quarks and electrons
  4. mesons and psisons
9. If the universe is closed than
  1. time will reverse itself once the universe reaches the turning point
  2. we may be able to see our own galaxy as it was billions of years ago
  3. the big bang MUST have had no initial time (no t=0, the no-boundary hypothesis).
  4. the universe is slightly left-handed, i.e. particles tend to spin to clockwise more than counterclockwise
10. This course covered the following topics:
  1. how stars affect the destiny of humans
  2. how the science that we do on earth explains what goes on in the universe
  3. how extra-terrestrial beings seeded the earth with life
  4. how Ran’s wardrobe could be improved.