VERSION C

Write your name at the top of this quiz as well as on your answer sheet. WRITE YOUR VERSION ON YOUR ANSWER SHEET. Feel free to write or draw on the quiz.

Please put away all electronic devices. You will not need a calculator for this quiz. CHOOSE THE BEST ANSWER TO EACH QUESTION.

1. The astronomical term `The Observable Universe' refers to:
a) the portion of the Universe currently surveyed by modern telescopes.
b) the total extent of the Universe potentially observable by the Hubble Space Telescope.
c) all parts of space that are now within 13.7 billion years of the Milky Way.
d) all parts of space that have a lookback time of 13.7 billion years.
e) the total extent of the Universe observable without a telescope.

d) all parts of space that have a lookback time of 13.7 billion years.

2. The astronomical term `Lookback Time' refers to:
a) The age of the Milky Way.
b) The age of the Universe.
c) The time it took the light from an object to reach us.
d) The distance in light years to an object.
e) The time since the Big Bang.

c) The time it took the light from an object to reach us.

3. According to standard Big Bang theory, in the early Universe, what was the current order of the following four events, from first to last?
a) the end of pair production of protons; the end of pair production of electrons; the end of primordial nucleosynthesis; recombination.
b) the end of pair production of electrons; the end of pair production of protons; the end of primordial nucleosynthesis; recombination.
c) recombination; the end of pair production of electrons; the end of pair production of protons; the end of primordial nucleosynthesis.
d) the end of primordial nucleosynthesis; recombination; the end of pair production of protons; the end of pair production of electrons.
e) the end of primordial nucleosynthesis; recombination; the end of pair production of electrons; the end of pair production of protons.

a) the end of pair production of protons; the end of pair production of electrons; the end of primordial nucleosynthesis; recombination.

4. The Miller-Urey Experiment was an experiment designed to:
a) measure the density of matter in the Universe.
b) measure the deuterium abundance in the Universe.
c) measure the acceleration of the expansion of the Universe.
d) reproduce conditions on the young Earth, to create amino acids from simple chemical compounds.
e) search for radio signals from extraterrestrial civilizations.

d) reproduce conditions on the young Earth, which created amino acids from simple chemical compounds.

5. Before the early 1960's, what was a popular competing theory to the Big Bang theory?
a) The Big Burst.
b) The Recombination Theory.
c) The Steady State Theory.
d) The Inflationary Universe Model.
e) The Baryonic Theory.

c) The Steady State Theory.

6. Which of the following were abundant in the early Universe (the first 15 minutes after the Big Bang), but are very rare today?
a) free ⁴He nuclei.
b) free ³He nuclei.
c) free deuterium nuclei.
d) free protons.
e) free neutrons.

e) free neutrons.

7. According to standard cosmological models, as the Universe expanded and cooled with time during its very early stages, the separation of the strong force from the electroweak force caused:
a) The end of primordial nucleosynthesis.
b) The end of pair production of electrons and positrons.
c) The end of pair production of protons and anti-protons.
d) The production of heavy chemical elements such as carbon, nitrogen, and oxygen.
e) Inflation.

e) Inflation.

8. In addition to the expansion of the Universe and the cosmic microwave background, what else is considered strong evidence for the Big Bang Theory?
a) the relative abundances of iron, uranium, and plutonium in the Universe.
b) the relative abundances of ¹H, ²H, ³He, and ⁴He in the Universe.
c) the relative abundances of carbon, nitrogen, and oxygen in the Universe.
d) the relative abundance of ¹²C, ¹³C, and ¹⁴C in the Universe.
e) the relative abundances of magnesium, silicon, and iron in the Universe.

b) the relative abundances of ¹H, ²H, ³He, and ⁴He in the Universe.

9. In primordial nucleosynthesis, what is the primary end product of the reactions?
a) deuterium.
b) ⁴He.
c) iron.
d) carbon.
e) uranium.

b) ⁴He.

10. Protons and neutrons are:
a) Weakly-interacting massive particles (WIMPs).
b) Olber's Particles.
c) Baryons.
d) Non-baryonic matter.
e) Positrons.

c) Baryons.

11. The epoch of recombination is the time in the early Universe when the baryonic matter in the Universe became mostly neutral, as electrons combined with protons to form stable long-lived neutral atoms. According to standard cosmological models, recombination occurred approximately how long after the Big Bang?
a) 0.0001 seconds.
b) 1 minute.
c) 15 minutes.
d) 400,000 years.
e) 1 billion years.

d) 400,000 years.

12. According to a) observations of the deuterium abundance in the Universe, b) measurements of the velocity dispersions in galaxy clusters, and c) computer simulations of the formation of large scale structure in the early Universe, the dark matter in the Universe is likely:
a) baryonic matter.
b) non-baryonic weakly-interacting massive particles (WIMPs).
c) Jupiter-like planets.
d) white dwarfs.
e) red giant stars.

b) non-baryonic weakly-interacting massive particles (WIMPs).

13. In addition to helium, what other element was produced in small amounts by primordial nucleosynthesis?
a) Uranium.
b) Iron.
c) Oxygen.
d) Plutonium.
e) Lithium.

e) Lithium.

14. Arno Penzias and Robert Wilson were the first people to:
a) Discover that the Universe was expanding with time.
b) Discover that the Universe's expansion was accelerating with time.
c) Discover the first pulsar.
d) Detect the cosmic background radiation.
e) Predict the cosmic microwave background, based on theoretical calculations of the early Universe.

d) Detect the cosmic background radiation.

15. Olber's Paradox states:
a) Why is the density of baryonic matter in the Universe much less than the critical density?
b) Why are galaxy distances proportional to their recessional velocities?
c) If the Universe is infinite and filled with galaxies, why is the sky dark at night?
d) Why is the cosmic background radiation almost completely uniform in all directions?
e) Why is the Universe flat, or very close to being flat?

c) If the Universe is infinite and filled with galaxies, why is the sky dark at night?

16. Which moon in our solar system appears to have liquid methane lakes on its surface?
a) The Earth's Moon.
b) Jupiter's moon Europa.
c) Pluto's moon Charon.
d) Saturn's moon Titan.
e) Mars' moon Phobos.

d) Saturn's moon Titan.

17. Astronomers are very interested in determining the average density of matter in the Universe because it affects:
a) whether the Universe will expand forever, or if it will eventually contract back on itself.
b) how fast the Universe is decelerating with time.
c) the age of the Universe.
d) the shape of the Universe.
e) all of the above.

e) all of the above.

18. There are four known forces of nature. According to theoretical arguments, if the temperature is high enough, two or more of these forces unify into a single force. Which of the two forces of nature require the lowest temperature to unify? (in other words, as the early Universe expanded and cooled with time and the individual forces became distinct, which two forces were the last to separate?)
a) gravity and the strong force.
b) electromagnetism and gravity.
c) electromagnetism and the weak force.
d) gravity and the weak force.
e) the strong force and the weak force.

c) electromagnetism and the weak force.

19. A flat universe is:
a) a universe that will eventually collapse back on itself.
b) a universe with an overall density equal to the critical density.
c) a universe that is finite in space.
d) a universe that if you travel in a straight line long enough, you will eventually get back to the same point.
e) a universe with a density less than the critical density.

b) a universe with an overall density equal to the critical density.

20. According to standard Big Bang models, what important event occurred about 1 minute after the Big Bang?
a) Recombination.
b) Inflation.
c) The end of pair production of electrons and positrons.
d) Galaxy formation.
e) The formation of most of the carbon, oxygen, and nitrogen currently present in the Universe.

c) The end of pair production of electrons and positrons.