Assignment 11
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
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1. The expansion of the universe, according to astronomers, is:
a. a theory for which there is no observational evidence
b. a piece of established observational evidence which any theory of cosmology must include
c. a prediction of one theory of cosmology for which the evidence is very controversial
d. the opposite of what Hubble's Law describes
e. making all the planets in our solar system harder to reach, driving up NASA budgets
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2. The Hubble Time is:
a. a rough estimate of the age of the universe
b. the time since the beginning of the solar system
c. the period it takes for the scale of the universe to triple in size
d. the length of time a telescope in space can remain in orbit
e. part of a major beer company ad campaign
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3. Which of the following is pretty good evidence that the universe began with a Big Bang?
a. the fact that galaxies collide
b. the fact that stars explode
c. the fact that all the galaxies are moving toward us
d. the existence of a double star system like Cygnus X­1
e. the 3­degree background radiation
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4. Which of the following is the Earth not located in?
a. the solar system
b. the universe
c. globular cluster M­13
d. the Milky Way Galaxy
e. the Earth is located in all of the above
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5. In describing the universe using his equations of general relativity, Einstein assumed that it was isotropic (the same in all directions.) What recent observations have confirmed that the universe is isotropic on the large scale?
a. the discovery of pulsars
b. the discovery of cannibal galaxies
c. measurements of the 3­degree cosmic background radiation
d. measurements of neutrinos from Supernova 1987A
e. the discovery that there is really nothing very good on TV, no matter which way you point your dish (antenna)
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6. Which of the following statements about dark matter is FALSE:
a. it is observed to be a major part of the Milky Way
b. it is observed to be present in other groups of galaxies
c. astronomers have a pretty good idea what the dark matter is made of
d. we can detect its gravity, even though we can't see it
e. it may make up even more of the universe that the matter we can see
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7. The reciprocal of the Hubble constant (1/H) is a rough measure of the:
a. the period of a typical Cepheid variable
b. the distance to the last galaxies that formed
c. the age of the universe
d. the luminosity of a type I supernova explosion
e. the cost of building a telescope in space
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8. According to the models of the universe we discussed in this course, why do the galaxies move apart (why do we have Hubble's law)?
a. gravity is a repulsive force, once you get outside the Milky Way Galaxy
b. each galaxy has net charge on it, and they repel by the laws of electricity
c. supernova explosions happen more frequently on one side of each galaxy, giving the entire galaxy a push that moves it away from its neighbors
d. as a result of the Big Bang, space itself is stretching, and this stretching carries the galaxies away from each other
e. strong political and religious disagreements among the galaxies
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9. According to our modern theories, the geometry of the universe (all of space­time) may be curved or warped. This is a pretty bizarre notion; what other discovery in astronomy has helped us believe that space may be able to curve or warp?
a. supernova explosions and the elements they produce
b. how the light output of cepheid variables changes with time
c. the existence of dwarf elliptical galaxies
d. black holes
e. the error in the shape of the mirror on the Hubble Space Telescope
____ 10. According to our studies of the ages of the oldest stars we know, the age of the universe must be:
a. about the age of the Earth, 4.6 billion years
b. older than the Earth, but less than 10 billion years
c. about 13 ­ 14 billion years
d. about 100 billion years
e. you can't fool me, the age of the oldest stars is so great that the universe must be many thousands of billion years old or older
____ 11. The two scientists who first discovered the cosmic background radiation were:
a. Hubble and Humason
b. Einstein and Friedmann
c. Gamow and Alpher
d. Penzias and Wilson
e. Kirk and Spock
____ 12. Where in space did the expansion of the universe begin?
a. at the center of the Milky Way Galaxy; that's why all the other galaxies are moving away from us
b. near the center of the Virgo Supercluster of Galaxies
c. at a point so far away that only our largest telescopes can show us glimpses of it
d. everywhere at once
e. nowhere at all; new observations show that the universe is not expanding after all
____ 13. The model of the universe that involves an enormous increase of scale during a very short time in the early universe is called:
a. the flat universe model
b. the oscillating universe model
c. the primeval atom model
d. the inflationary universe model
e. the cosmic burp model
____ 14. Which of the following statements about the early universe (as envisioned by the standard model of cosmology) is FALSE?
a. as the universe expands, its temperature decreases
b. at the beginning, the temperature was hot enough to turn energy into matter
c. at the very beginning, the energies were so great that the universe was actually contracting for a while
d. at the beginning, the universe was not transparent to electro­magnetic radiation
e. at the very beginning, anti­matter (as well as matter) was present in significant quantities
____ 15. What is the strongest force in the universe:
a. gravity
b. the electromagnetic force
c. the weak nuclear force
d. the strong nuclear force
e. The Dallas Cowboys [put in your favorite local sports team here]
Assignment 11
Answer Section
MULTIPLE CHOICE
1. ANS: B
3. ANS: E
5. ANS: C
7. ANS: C
9. ANS: D
11. ANS: D
13. ANS: D
15. ANS: D