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Are the stars uniformly distributed in space? |
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2 | |
What is the Milky Way? |
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3 | |
Why is the sun considered to be located in the central disk of our galaxy? |
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4 | |
The earth undergoes three major motions through space. What are they? |
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5 | |
What are the properties of globular clusters? |
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6 | |
Both galactic nebulas and globular clusters occur in our galaxy. Distinguish between them. |
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7 | |
Distinguish between Population I and Population II stars. |
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8 | |
A number of elliptically shaped galaxies are known that seem to contain only Population II stars. Would you expect such galaxies to contain abundant gas and dust? |
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9 | |
Where is most of the interstellar gas in our galaxy located? What is its chief constituent? |
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10 | |
How can the rotation of a spiral galaxy be determined? Will this method work for all spiral galaxies? |
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11 | |
Are most galaxies smaller, larger, or about the same size as our galaxy? |
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12 | |
Do radio telescopes magnify anything? If not, why are larger and larger ones being built? |
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13 | |
List the three ways in which radio waves from space originate. |
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14 | |
Black holes with masses of millions of times that of the sun are believed to lie at the hearts of which objects in space? |
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15 | |
Why are radio-astronomical studies of the distribution of hydrogen in the universe of greater interest than studies of the distribution of other elements? |
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16 | |
What kind of evidence supports the belief that molecules of various kinds, including some fairly complex ones, exist in space? |
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17 | |
Cosmic-ray intensity varies around the world in a manner that is correlated with the earth's magnetic field. (a) Why is such a correlation plausible? (b) Account for the greater number of cosmic rays that reach the earth near the polar regions than near the equator. |
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18 | |
There is no day-night difference in cosmic-ray intensity. How does this observation bear on the possibility of a solar origin for cosmic rays? |
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19 | |
What do you think ultimately becomes of the protons and neutrons knocked out of atmospheric atoms by cosmic rays? |
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20 | |
Cosmic-ray primaries are mostly protons, but few protons are in the cosmic rays that reach the earth's surface. Why? |
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21 | |
What traps cosmic rays in our galaxy? |
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22 | |
What is Hubble's law? |
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23 | |
Why is the universe believed to be expanding? |
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24 | |
Why must the rate of expansion of the universe be slowing down? |
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25 | |
What is a quasar? |
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26 | |
The spectra of quasars exhibit red shifts, never blue shifts. Why does this suggest that quasars are not members of our galaxy? |
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27 | |
Why are quasars thought to be relatively small in size? |
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28 | |
What is the observational evidence in favor of the big bang? |
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29 | |
What are the origins of the helium found in the universe? |
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30 | |
Suppose the spectral lines of distant galaxies were shifted toward the blue end. What would this suggest about the universe? |
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31 | |
What is the observational evidence in favor of there being a great deal of dark matter in the universe? |
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32 | |
Distinguish between a closed and an open universe. How does the density of matter in the universe bear on the question of whether the universe is closed or open? What does present evidence suggest about the nature of the universe? |
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33 | |
Did the sun begin as a small body that grew to its present size, or as a large one that subsequently shrank? |
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34 | |
The sun and the giant outer planets contain hydrogen and helium in abundance; the inner planets, very little. Why? |
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35 | |
Would you summarize the most likely destiny for the earth as fire or ice? |
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36 | |
Why is it reasonable to suppose that many stars besides the sun have planets orbiting them? Why does it seem unlikely that spacecraft from the earth will ever visit other planetary systems? |
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37 | |
Why is it hard to detect the planetary systems of other stars? |
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38 | |
Did the planets come into being before, during, or after the formation of the sun? |
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