Sample Old Exam 9

[2 pts] Star A has a measured parallax of 1 second of arc. Star B has a measured parallax of 2 seconds of arc. Which star is CLOSER to the Earth and Sun?
[2 pts] A solar eclipse will occur over the Caribbean on Feb 26, 1998. What will the phase of the moon be at the moment of the solar eclipse?
[2 pts] A light-year measures _____________.
[2 pts] What would be true about a star that lies at a distance of exactly one parsec?
[2 pts] Which year do our calendars measure, the tropical year or the sidereal year?
[2 pts] Which month is longer, the synodic month or the sidereal month?
[5 pts] Why do we have two different "months"?
[2 pts] In about 200 BCE, Eratosthenes used shadows in wells to measure ____________.
[2 pts] If tonight the moon is at Full Moon, what will the phase of the moon be on Friday September 26?
[6 pts] In summertime, the temperature is warmer than during the winter. Name two reasons why this is so.
[4 pts] The ecliptic plane is
[2 pts] Explain precession.
[5 pts] Why was it important that astronomers discovered and understood precesssion?
[8 pts] Name two basic observational phenomena related to the planets, observable by pre-telescopic cultures, that any cosmological theory must explain.
[2 pts] The Copernican Revolution represented a change in thinking from a _____________ universe to a _____________ universe.
[9 pts] List three fundamental changes (that are astronomical in nature) in how we must think about the Earth, if we change our mode of thinking from the pre-Copernican to the post-Copernican world view.
[9 pts] List three fundamental changes (that are astronomical in nature) in how we must think of the stars, the planets and/or the heavens, if we change our mode of thinking from the pre-Copernican to the post-Copernican world view.
[6 pts] It is the year 1550 and you believe Copernicus. Consequently, the laws of physics as they've been understood since the time of Aristotle don't work anymore. Name one problem that the Copernican Revolution raises for our understanding of physics and explain why there is a problem to be solved.
[10 pts]A scientific theory must be logically falsifiable. So, ignoring technological issues, what obvious test could you conduct in the year 1543 to determine whether the Copernican model of the universe is right? What answer would you expect to obtain (in 1543)? Why? How would you interpret your measurements?
[6 pts] In the Earth's elliptical orbit, the Earth is closest to the Sun in early January and furthest from the Sun in early July. What effects, if any, would you expect the changing Earth-Sun distance to have on the seasons in the southern hemisphere compared to those in the northern hemisphere.
[6 pts] A process called nutation, caused by the gravitational attraction of other planets and the moon for the Earth, causes the tilt of the Earth's rotation axis to rock back and forth from 21 degrees to 24 degrees with a period of 41,000 years. How, if it all, would nutation affect the seasons? Provide sufficient justification for your answer.
[6 pts] According to Webster's 7th Collegiate Dictionary, definition #2 for day is "the period of the Earth's rotation on its axis." Is this a good working definition for us Earthlings? Explain or defend your answer.