Subject: conceptual3
From: Michele Gressman
Date: Tue, 27 Sep 2005 18:41:46 -0700 (PDT)
To: Larry Rudnick


1.

Correct Suppose that the planet Uranus were much brighter in the sky, so that it was as easily visible to the naked eye as Jupiter or Saturn. Which one of the following statements would most likely be true in that case?

Your Answer:

A week would have 8 days instead of 7.
  Correct. A week has 7 days because 7 objects that appear to move among the stars are visible to the naked eye: the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn. The names of the days of the week reflect their astronomical origin. If Uranus had been an 8th object visible to the naked eye, a week very likely would have 8 days.

2.

Incorrect Our standard hour is always the same amount of time (60 minutes, or 1/24 of a solar day). In contrast, the hour of ancient Egypt

Your Answer:

was always longer than the hour used today.

Correct Answer:

was longer than today's hour in the summer and shorter than today's hour in the winter.
  Sorry, try again.

3.

Incorrect What do the structures of Stonehenge, the Templo Mayor, the Sun Dagger, and the Big Horn Medicine Wheel all have in common?

Your Answer:

They all can be used as lunar calendars.

Correct Answer:

They were all used by ancient peoples for astronomical observations.
  The Sun Dagger cannot be used as a lunar calendar.

4.

Incorrect Ptolemy was important in the history of astronomy because he ____________

Your Answer:

was the first to create a model of the solar system that placed the Sun rather than the Earth at the center.

Correct Answer:

developed a model of the solar system that made sufficiently accurate predictions of planetary positions to remain in use for many centuries.
  His model was Earth-centered.

5.

Incorrect How did the Ptolemaic model explain the apparent retrograde motion of the planets?

Your Answer:

It held that sometimes the planets moved backwards along their circular orbits.

Correct Answer:

It held that the planets moved along small circles that moved on larger circles around the Earth, and that the combined motion sometimes resulted in backward motion.
  Try again.

6.

Incorrect When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?

Your Answer:

Copernicus placed the planets in the wrong order going outward from the Sun.

Correct Answer:

Copernicus used perfect circles for the orbits of the planets.
  Copernicus got the planetary order right.

7.

Incorrect All the following statements are true. Which one follows directly from Kepler's third law (p2 = a3)?

Your Answer:

Venus has a thicker atmosphere than Mercury.

Correct Answer:

Venus orbits the Sun at a slower average speed than Mercury.
  Kepler's laws do not consider planetary atmospheres.

8.

Incorrect Earth is farthest from the Sun in July and closest to the Sun in January. During which northern hemisphere season is Earth moving fastest in its orbit?

Your Answer:

Summer

Correct Answer:

Winter
  Earth actually moves slowest in Northern Hemisphere summer.

9.

Incorrect Galileo challenged the idea that objects in the heavens were perfect by ___________

Your Answer:

proving Kepler's laws were correct.

Correct Answer:

observing sunspots on the Sun and mountains on the Moon.
  Galileo did not prove or disprove Kepler's laws, though his discoveries lent them great support.

10.

Incorrect Which of the following is NOT one of the major hallmarks of science?

Your Answer:

Scientific explanations should be based solely on natural causes.

Correct Answer:

New scientific ideas are always based on small changes to old ideas and are never revolutionary.
  This is one of the major hallmarks of science, but the question asked for a statement that was NOT one of the hallmarks.

11.

Incorrect Which of the following is NOT part of a good scientific theory?

Your Answer:

A scientific theory must explain a wide variety of phenomena observed in the natural world.

Correct Answer:

A scientific theory cannot be accepted until it has been proven true beyond all doubt.
  This is indeed part of a good scientific theory, but the question asked for something that is not part of a good scientific theory.

12.

Incorrect The astrology practiced by those who cast predictive horoscopes can be tested by __________

Your Answer:

asking astrologers if it works.

Correct Answer:

comparing how often the predictions come true to what would be expected by pure chance.
  This would not be an objective test.


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