"There is meaning..." by AnonymousSeptember 24, 2008
Cuesta College, San Luis Obispo, CA
Latest scribbling on the lift-and-erase slate in the hallway, outside the office door.
20080928
Erasing slate: There is meaning...
"There is meaning..." by AnonymousSeptember 24, 2008
Cuesta College, San Luis Obispo, CA
Latest scribbling on the lift-and-erase slate in the hallway, outside the office door.
20080927
Erasing slate: COOKEE (sic)
"COOKEE (sic)" by AnonymousSeptember 15, 2008
Cuesta College, San Luis Obispo, CA
Latest scribbling on the lift-and-erase slate in the hallway, outside the office door.
20080921
Astronomy quiz question: inferior planets at midnight
Astronomy 210 Quiz 2, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] Why are Mercury and Venus never visible in the San Luis Obispo, CA sky at midnight?
(A) Mercury and Venus never exhibit retrograde motion.
(B) Mercury and Venus are too small to reflect enough sunlight.
(C) The orbits of Mercury and Venus are smaller than the orbit of the Earth.
(D) Mercury and Venus cannot exhibit gibbous phases.
Correct answer: (C)
Since the orbits of Mercury and Venus are smaller than the orbit of the Earth (making them inferior planets), they can never appear behind the Earth, with respect to the Sun, and thus cannot be overhead (or anywhere in the sky) at midnight for typical temperate latitudes such as for San Luis Obispo, CA.
Student responses
Section 70158
(A) : 9 students
(B) : 3 students
(C) : 42 students
(D) : 4 students
"Difficulty level": 75%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.76
Cuesta College, San Luis Obispo, CA
[4.0 points.] Why are Mercury and Venus never visible in the San Luis Obispo, CA sky at midnight?
(A) Mercury and Venus never exhibit retrograde motion.
(B) Mercury and Venus are too small to reflect enough sunlight.
(C) The orbits of Mercury and Venus are smaller than the orbit of the Earth.
(D) Mercury and Venus cannot exhibit gibbous phases.
Correct answer: (C)
Since the orbits of Mercury and Venus are smaller than the orbit of the Earth (making them inferior planets), they can never appear behind the Earth, with respect to the Sun, and thus cannot be overhead (or anywhere in the sky) at midnight for typical temperate latitudes such as for San Luis Obispo, CA.
Student responses
Section 70158
(A) : 9 students
(B) : 3 students
(C) : 42 students
(D) : 4 students
"Difficulty level": 75%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.76
20080920
Astronomy quiz question: heliocentric model of retrograde motion
Astronomy 210 Quiz 2, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] How does Copernicus' model explain the retrograde motion of a planet?
(A) The only perfect shape is a circle, and the only perfect motion is uniform motion.
(B) A planet slows down in its orbit when it is further from the sun, and speeds up in its orbit when it is closer to the sun.
(C) A planet moves around a circle that itself moves along an orbit around the Earth.
(D) A planet has a different orbital distance and speed around the sun from the Earth's orbital distance and speed around the sun.
Correct answer: (D)
Copernicus' model of planetary motion explains retrograde motion as a "lapping illusion" when planets in different orbits traveling at different speeds move past each other. Response (A) is Ptolemy's model of retrograde motion; response (B) is Kepler's second law; response (C) is based on Aristotle's first principles, but does not explain retrograde motion.
Student responses
Section 70158
(A) : 9 students
(B) : 11 students
(C) : 14 students
(D) : 18 students
"Difficulty level": 39%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.35
Cuesta College, San Luis Obispo, CA
[4.0 points.] How does Copernicus' model explain the retrograde motion of a planet?
(A) The only perfect shape is a circle, and the only perfect motion is uniform motion.
(B) A planet slows down in its orbit when it is further from the sun, and speeds up in its orbit when it is closer to the sun.
(C) A planet moves around a circle that itself moves along an orbit around the Earth.
(D) A planet has a different orbital distance and speed around the sun from the Earth's orbital distance and speed around the sun.
Correct answer: (D)
Copernicus' model of planetary motion explains retrograde motion as a "lapping illusion" when planets in different orbits traveling at different speeds move past each other. Response (A) is Ptolemy's model of retrograde motion; response (B) is Kepler's second law; response (C) is based on Aristotle's first principles, but does not explain retrograde motion.
Student responses
Section 70158
(A) : 9 students
(B) : 11 students
(C) : 14 students
(D) : 18 students
"Difficulty level": 39%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.35
20080919
Astronomy quiz question: geocentric model of retrograde motion
Astronomy 210 Quiz 2, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] How does Ptolemy's model explain the retrograde motion of a planet?
(A) The only perfect shape is a circle, and the only perfect motion is uniform motion.
(B) A planet has a different orbital distance and speed around the sun from the Earth's orbital distance and speed around the sun.
(C) A planet moves around a circle that itself moves along an orbit around the Earth.
(D) A planet slows down in its orbit when it is further from the sun, and speeds up in its orbit when it is closer to the sun.
Correct answer: (C)
Ptolemy's model of planetary motion used epicycles moving along deferents to explain the retrograde loops of planets. Response (A) is based on his (and Aristotle's) first principles, but in and of itself is not a model of retrograde motion; response (B) is Copernicus' heliocentric explanation of retrograde motion; and response (D) is Kepler's second law.
Student responses
Section 70160
(A) : 1 student
(B) : 2 students
(C) : 22 students
(D) : 8 students
"Difficulty level": 69%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.89
Cuesta College, San Luis Obispo, CA
[4.0 points.] How does Ptolemy's model explain the retrograde motion of a planet?
(A) The only perfect shape is a circle, and the only perfect motion is uniform motion.
(B) A planet has a different orbital distance and speed around the sun from the Earth's orbital distance and speed around the sun.
(C) A planet moves around a circle that itself moves along an orbit around the Earth.
(D) A planet slows down in its orbit when it is further from the sun, and speeds up in its orbit when it is closer to the sun.
Correct answer: (C)
Ptolemy's model of planetary motion used epicycles moving along deferents to explain the retrograde loops of planets. Response (A) is based on his (and Aristotle's) first principles, but in and of itself is not a model of retrograde motion; response (B) is Copernicus' heliocentric explanation of retrograde motion; and response (D) is Kepler's second law.
Student responses
Section 70160
(A) : 1 student
(B) : 2 students
(C) : 22 students
(D) : 8 students
"Difficulty level": 69%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.89
20080918
Astronomy quiz question: in the penumbra of the Moon
Astronomy 210 Quiz 2, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] An observer is located on the surface of the Earth, and this observer is also located in the penumbra of the Moon. What type of eclipse is seen by the observer?
(A) A total lunar eclipse.
(B) A partial lunar eclipse.
(C) An annular solar eclipse.
(D) A partial solar eclipse.
(E) A total solar eclipse.
Correct answer: (D)
Assuming that the umbra of the Moon never does pass over the observer (for which this would be response (E), a total solar eclipse), this will be only a partial solar eclipse. If the observer were in the "negative shadow" of the Moon (out past the umbra), then an annular solar eclipse would be observed (response (C)). Responses (A) and (B) correspond to the Moon itself being in the umbra or penumbra of the Earth, respectively.
Student responses
Section 70160
(A) : 5 students
(B) : 10 students
(C) : 0 students
(D) : 15 students
(E) : 3 students
"Difficulty level": 51%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.78
Cuesta College, San Luis Obispo, CA
[4.0 points.] An observer is located on the surface of the Earth, and this observer is also located in the penumbra of the Moon. What type of eclipse is seen by the observer?
(A) A total lunar eclipse.
(B) A partial lunar eclipse.
(C) An annular solar eclipse.
(D) A partial solar eclipse.
(E) A total solar eclipse.
Correct answer: (D)
Assuming that the umbra of the Moon never does pass over the observer (for which this would be response (E), a total solar eclipse), this will be only a partial solar eclipse. If the observer were in the "negative shadow" of the Moon (out past the umbra), then an annular solar eclipse would be observed (response (C)). Responses (A) and (B) correspond to the Moon itself being in the umbra or penumbra of the Earth, respectively.
Student responses
Section 70160
(A) : 5 students
(B) : 10 students
(C) : 0 students
(D) : 15 students
(E) : 3 students
"Difficulty level": 51%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.78
20080908
Astronomy quiz question: northwest setting Sun
Astronomy 210 Quiz 1, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] Which month would the Sun set in the northwest horizon, as seen by an observer in San Luis Obispo, CA?
(A) March or September.
(B) June.
(C) December.
(D) (None of the above choices, as it is not possible for the sun to set in the northwest horizon in San Luis Obispo, CA.)
Correct answer: (B)
In June (summer solstice), the Sun will rise northeast, pass the meridian very close to the zenith, and then set northwest. In March or September (vernal/autumnal equinoxes), the Sun will rise directly from the east and set in the west, while in December (winter solstice) the Sun will rise in the southeast, pass the meridian closer down towards the horizon, and eventually set southwest.
Student responses
Section 70158
(A) : 24 students
(B) : 27 students
(C) : 17 students
(D) : 7 students
"Difficulty level": 39%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
Cuesta College, San Luis Obispo, CA
[4.0 points.] Which month would the Sun set in the northwest horizon, as seen by an observer in San Luis Obispo, CA?
(A) March or September.
(B) June.
(C) December.
(D) (None of the above choices, as it is not possible for the sun to set in the northwest horizon in San Luis Obispo, CA.)
Correct answer: (B)
In June (summer solstice), the Sun will rise northeast, pass the meridian very close to the zenith, and then set northwest. In March or September (vernal/autumnal equinoxes), the Sun will rise directly from the east and set in the west, while in December (winter solstice) the Sun will rise in the southeast, pass the meridian closer down towards the horizon, and eventually set southwest.
Student responses
Section 70158
(A) : 24 students
(B) : 27 students
(C) : 17 students
(D) : 7 students
"Difficulty level": 39%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
20080907
Astronomy quiz question: zenith star set
Astronomy 210 Quiz 1, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] An observer in San Luis Obispo, CA observes a constellation located at the zenith. This constellation will:
(A) never set below the horizon, as it is a circumpolar constellation.
(B) eventually set somewhere near the southwest horizon.
(C) eventually set somewhere near the northwest horizon.
(D) (None of the above choices, as it is not possible for a constellation to be at the zenith in San Luis Obispo, CA.)
Correct answer: (C)
Using a starwheel, selecting any constellation (e.g., Lyra) that is at the zenith at its highest position, will eventually set on the northwest horizon. (For Lyra, it is at the zenith as it passes the meridian at 8:00 PM on August 25, and will set at 5:00 AM the next day.) Or from discussion on paths of the sun, objects that rise northeast will pass the meridian closer to the zenith, and set northwest, than objects that rise in the southeast, which will pass the meridian closer to the horizon, and eventually set southwest.
Some students may be confusing the hub of the starwheel (corresponding to the celestial north pole, near which Polaris lies) with the zenith (corresponding to the geometric center of the blue oval representing the visible portion of the celestial sphere above the horizon).
Student responses
Section 70158
(A) : 38 students
(B) : 10 students
(C) : 21 students
(D) : 6 students
"Difficulty level": 34%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
Cuesta College, San Luis Obispo, CA
[4.0 points.] An observer in San Luis Obispo, CA observes a constellation located at the zenith. This constellation will:
(A) never set below the horizon, as it is a circumpolar constellation.
(B) eventually set somewhere near the southwest horizon.
(C) eventually set somewhere near the northwest horizon.
(D) (None of the above choices, as it is not possible for a constellation to be at the zenith in San Luis Obispo, CA.)
Correct answer: (C)
Using a starwheel, selecting any constellation (e.g., Lyra) that is at the zenith at its highest position, will eventually set on the northwest horizon. (For Lyra, it is at the zenith as it passes the meridian at 8:00 PM on August 25, and will set at 5:00 AM the next day.) Or from discussion on paths of the sun, objects that rise northeast will pass the meridian closer to the zenith, and set northwest, than objects that rise in the southeast, which will pass the meridian closer to the horizon, and eventually set southwest.
Some students may be confusing the hub of the starwheel (corresponding to the celestial north pole, near which Polaris lies) with the zenith (corresponding to the geometric center of the blue oval representing the visible portion of the celestial sphere above the horizon).
Student responses
Section 70158
(A) : 38 students
(B) : 10 students
(C) : 21 students
(D) : 6 students
"Difficulty level": 34%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43
20080905
Solar system scribble
"Warning: not to scale" by D. T.Astronomy 210L
Fall Semester 2008
Cuesta College, San Luis Obispo, CA
This doodle was found on the back of a weekly current events quiz for introductory astronomy lab. Note that Pluto is not included with the rest of the planets!
20080904
Astronomy quiz question: Moon directly overhead
Astronomy 210 Quiz 1, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[Version 1]
[4.0 points.] What time is it when the waxing gibbous moon is highest overhead?
(A) 12 PM (noon).
(B) 3 PM (afternoon).
(C) 6 PM (sunset).
(D) 9 PM (evening).
(E) 12 AM (midnight).
(F) 3 AM (wee hours).
(G) 6 AM (sunrise).
(H) 9 AM (morning).
Correct answer: (D)
This is apparent once the Moon has been placed correctly in its orbit around the Earth, relative to the direction of sunlight on the Earth-Moon diagram. (Doing the "+/- 6 hour trick" results in this moon rising at (B) 3 PM, and setting at (F) 3 AM.)
Student responses
Section 70160
(A) : 0 students
(B) : 4 students
(C) : 0 students
(D) : 8 students
(E) : 0 students
(F) : 0 students
(G) : 0 students
(H) : 3 students
[Version 2]
[4.0 points.] What time is it when the waning gibbous moon is highest overhead?
(A) 12 PM (noon).
(B) 3 PM (afternoon).
(C) 6 PM (sunset).
(D) 9 PM (evening).
(E) 12 AM (midnight).
(F) 3 AM (wee hours).
(G) 6 AM (sunrise).
(H) 9 AM (morning).
Correct answer: (F)
This is apparent once the Moon has been placed correctly in its orbit around the Earth, relative to the direction of sunlight on the Earth-Moon diagram. (Doing the "+/- 6 hour trick" results in this moon rising at (D) 9 PM, and setting at (H) 9 AM.)
Student responses
Section 70160
(A) : 0 students
(B) : 2 students
(C) : 1 student
(D) : 3 students
(E) : 1 student
(F) : 8 students
(G) : 2 students
(H) : 0 students
"Difficulty level": 54%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.56
Cuesta College, San Luis Obispo, CA
[Version 1]
[4.0 points.] What time is it when the waxing gibbous moon is highest overhead?
(A) 12 PM (noon).
(B) 3 PM (afternoon).
(C) 6 PM (sunset).
(D) 9 PM (evening).
(E) 12 AM (midnight).
(F) 3 AM (wee hours).
(G) 6 AM (sunrise).
(H) 9 AM (morning).
Correct answer: (D)
This is apparent once the Moon has been placed correctly in its orbit around the Earth, relative to the direction of sunlight on the Earth-Moon diagram. (Doing the "+/- 6 hour trick" results in this moon rising at (B) 3 PM, and setting at (F) 3 AM.)
Student responses
Section 70160
(A) : 0 students
(B) : 4 students
(C) : 0 students
(D) : 8 students
(E) : 0 students
(F) : 0 students
(G) : 0 students
(H) : 3 students
[Version 2]
[4.0 points.] What time is it when the waning gibbous moon is highest overhead?
(A) 12 PM (noon).
(B) 3 PM (afternoon).
(C) 6 PM (sunset).
(D) 9 PM (evening).
(E) 12 AM (midnight).
(F) 3 AM (wee hours).
(G) 6 AM (sunrise).
(H) 9 AM (morning).
Correct answer: (F)
This is apparent once the Moon has been placed correctly in its orbit around the Earth, relative to the direction of sunlight on the Earth-Moon diagram. (Doing the "+/- 6 hour trick" results in this moon rising at (D) 9 PM, and setting at (H) 9 AM.)
Student responses
Section 70160
(A) : 0 students
(B) : 2 students
(C) : 1 student
(D) : 3 students
(E) : 1 student
(F) : 8 students
(G) : 2 students
(H) : 0 students
"Difficulty level": 54%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.56
Astronomy quiz question: starrise to starset time
Astronomy 210 Quiz 1, Fall Semester 2008
Cuesta College, San Luis Obispo, CA
[4.0 points.] A star that rises from the northeast horizon in San Luis Obispo, CA will take approximately how many hours until it sets in the northwest horizon?
(A) Less than 12 hours.
(B) More than 12 hours.
(C) (It cannot be determined how many hours the star will take to set, unless the season is known.)
(D) (None of the above choices, as it is not possible for a star to rise from the northeast horizon in San Luis Obispo, CA.)
Correct answer: (B)
Using a starwheel, selecting any star (e.g., Pollux) that rises from the northeast horizon, and finding the difference in times when it is on the northeast horizon, and eventually setting on the northwest horizon on the same/consecutive day(s) will result in more than 12 hours elapsed. (For Pollux, it rises at 2:00 AM on August 25, and will set at 5:30 PM later that same day.) Or from discussion on paths of the sun, objects that rise north of east will take longer than 12 hours to rise and set, compared to objects that rise directly in the east (exactly 12 hours); or objects that rise south of east (less than 12 hours).
Student responses
Section 70160
(A) : 12 students
(B) : 10 students
(C) : 8 students
(D) : 1 student
(no response) : 1 student
"Difficulty level": 38%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.44
Cuesta College, San Luis Obispo, CA
[4.0 points.] A star that rises from the northeast horizon in San Luis Obispo, CA will take approximately how many hours until it sets in the northwest horizon?
(A) Less than 12 hours.
(B) More than 12 hours.
(C) (It cannot be determined how many hours the star will take to set, unless the season is known.)
(D) (None of the above choices, as it is not possible for a star to rise from the northeast horizon in San Luis Obispo, CA.)
Correct answer: (B)
Using a starwheel, selecting any star (e.g., Pollux) that rises from the northeast horizon, and finding the difference in times when it is on the northeast horizon, and eventually setting on the northwest horizon on the same/consecutive day(s) will result in more than 12 hours elapsed. (For Pollux, it rises at 2:00 AM on August 25, and will set at 5:30 PM later that same day.) Or from discussion on paths of the sun, objects that rise north of east will take longer than 12 hours to rise and set, compared to objects that rise directly in the east (exactly 12 hours); or objects that rise south of east (less than 12 hours).
Student responses
Section 70160
(A) : 12 students
(B) : 10 students
(C) : 8 students
(D) : 1 student
(no response) : 1 student
"Difficulty level": 38%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.44
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