I will not come late to class

Anonymous, Cuesta College, San Luis Obispo, CA

But apparently cheap tricks like this works...on some level.

"Centrifugal absorption reciprocating" van

Centrifugal Absorption Reciprocating
Originally uploaded by Frauenfelder.

Physics 8A learning goal M2.1

The wondrous incongruity of it all!

"Let's Find Out About Air"

guvnor, Children's Books Photoshop Phriday contest
SomethingAwful.com

Astronomy 10 learning goal Q4.1, Q4.5, Q5.3, Q5.4

Oddly amusing in this absurd mash-up that these children find studying air itself fascinating. Hopefully astronomy students will be directed to consider properties of "air" itself, as properties of the atmosphere will ultimately lead to a discussion on escape velocities, rms speeds, global warming, volcanism, sedimentation, plate tectonics, runaway greenhouse and runaway refrigerator effects.

The original book cover is delightfully even more surreal!

http://artlabo.ocnk.net/product/247

Assessment: discussion participation rubric

The NASA Center for Astronomy Education (CAE) hosts a listserver discussing astronomy teaching and learning, moderated by Gina Brissenden. Recent posting:

The following table lists the criteria for posted in response to a topic on the discussion forum. The posted response should be with complete sentences and correct grammar. These will be graded according to the following:

• 90-100: A-Level participation
  
  • The conclusion or opinion is relevant to the discussion topic.
    
  • The answer is insightful & synthesizes basic concepts.
    
  • You have stated reasons and evidence to support your conclusion or opinion.
    
  • The answer and supporting evidence is clearly stated.
    
  
  
• 80-89: B–Level participation
  Same as A-Level participation, except that:
  
  • The answer is notably lacking one of the items listed for an A level response.
    
  
  
• 70-79: C–Level participation
  Same as B–Level participation, except that:
  
  • The answer is notably lacking two of the items listed for A-Level response.
    
  
  
• 60-69: D-Level participation
  Same as C–Level participation, except that:
  
  • The answer is notably lacking three of the items listed for A- Level response.
    
  
  
• 59 and below: F–level participation
  
  • Failure to turn in the work
    

--Jean Hurrle, Kankakee River Valley Forest Preserve District

This rubric is a good example of a subtractive scale, where students understand that they will receive a certain grade for performing at a certain level (the Astronomy 10 grading rubrics (introductory general-education astronomy) and Physics 8AB grading rubrics (university physics, calculus-based) at Cuesta College are more specific, but similar to this rubric, stress transparency and objectivity for the benefit of the instructor, as well as the students.

Supergiant simulation

Emergent surface intensity of a supergiant (*.mpg)
From Numerical simulations of a red supergiant
Bernd Freytag, Centre de Recherche Astronomique de Lyon and Uppsala Astronomical Observatory

Astronomy 10 learning goal M3.2

Computer simulation over several months of the outer layers of a supergiant, such as Betelgeuse, between its main sequence phase, and inevitable type II supernova explosion.

Astronomy quiz question: oldest white dwarfs

Astronomy 10 Quiz 12, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q12.3

[3.0 points.] Which one of the following choices best describes characteristics expected of the oldest white dwarfs in the disk of the Milky Way?
(A) On the verge of undergoing type Ia supernova explosions.
(B) Dim luminosities and cool surface temperatures.
(C) Extremely metal-rich absorption spectra.
(D) Extremely redshifted absorption spectra.
(E) Extremely low mass.

Correct answer: (B).

White dwarfs are the degenerately packed cores of giants, after the outer layers have been shed during the planetary nebula phase. Since there is no more energy source for an isolated white dwarf, it will gradually cool off and become dimmer in luminosity, according to the Stefan-Boltzmann law (luminosity proportional size times temperature^4), where size remains constant.

Student responses
Section 4136
(A) : 5 students
(B) : 16 students
(C) : 7 students
(D) : 5 students
(E) : 2 students

Section 5076
(A) : 1 student
(B) : 13 students
(C) : 6 students
(D) : 5 students
(E) : 1 student

Astronomy clicker question: whence cosmic background radiation?

Astronomy 10, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q12.4

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the start of their learning cycle:

[0.3 points.] What is the cosmic background radiation?
(A) Photons that have always existed, even before the start of the big bang.
(B) Photons from the very start of the big bang.
(C) Photons from about 400,000 years after the start of the big bang.
(D) Photons from the end of gravitational deceleration (start of dark energy acceleration).

Correct answer: (C).

It was too hot for protons and electrons to form atoms in the early universe, until approximately 400,000 years after the start of the big bang. Since atoms scatter light less efficiently than separate protons and electrons, when the universe made this "recombination" or "decoupling" transition from an opaque to a much more transparent state, photons were effectively freed from this time forward. However, any photons from earlier, back to the start of the big bang, were effectively lost.

Student responses
Section 5076
(A) : 5 students
(B) : 7 students
(C) : 1 student
(D) : 6 students

Astronomy clicker question: expanding universe evidence

Astronomy 10, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q12.2

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the start of their learning cycle:

[0.3 points.] How do we know that the universe is expanding?
(A) The distance from the Sun to the Earth is increasing.
(B) The speed of light is slowing down.
(C) Distant galaxies appear to be moving away faster than nearby galaxies.
(D) Distant galaxies appear to be much younger than nearby galaxies.

Correct answer: (C)
Distant galaxies appear to be much younger than nearby galaxies, due to the finite speed of light, and not because the universe is expanding. Distances within the Milky Way remain constant, due to gravitational interactions. However, distant galaxies are receding faster than nearby galaxies, as described by Hubble's law, which demonstrates that space (between all galaxies) is expanding.

Student responses
Section 4136
(A) : 1 student
(B) : 4 students
(C) : 14 students
(D) : 10 students

Student responses
Section 5076
(A) : 2 students
(B) : 7 students
(C) : 10 students
(D) : 4 students

Astronomy clicker question: metal-rich stars

Astronomy 10, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q11.5

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the start of their learning cycle:

[0.3 points.] Which type of stars is more abundant in "metals" (elements heavier than hydrogen and helium) in their outermost layers?
(A) Extremely old stars that formed a long time ago.
(B) Young stars that formed very recently.
(C) (Both (A) and (B) would have equal amounts of elements heavier than hydrogen and helium in their outer layers.)
(D) (Neither (A) nor (B), as there cannot be elements heavier than hydrogen and helium in the outer layers of stars.)

Correct answer: (B).

Extremely old stars that formed a long time ago would have mainly hydrogen in their outer layers (while their cores steadily produce metals through its supergiant phase), and after undergoing type II supernova explosions, the metals from the cores of these stars would be incorporated with hydrogen into next generation of younger stars. Thus metals are produced by previous generation stars to be inheirited by the next generation stars.

Student responses
Section 4136
(A) : 8 students
(B) : 10 students
(C) : 8 students
(D) : 9 students

Student responses
Section 5076
(A) : 4 students
(B) : 1 student
(C) : 6 students
(D) : 8 students

Astronomy quiz question: novae and type Ia supernovae

Astronomy 10 Quiz 8, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q10.3

[Version 1]

[3.0 points.] Which one of the following choices best describes a close-pair (mass-exchanging) binary system that can have many cycles of nova explosions?
(A) A massive main sequence star and a red dwarf.
(B) A black hole and a white dwarf.
(C) A supergiant and a white dwarf.
(D) A supergiant and a black hole.
(E) Two red dwarfs.

Correct answer: (C)
The hydrogen shed from a supergiant will form a degenerate layer around a white dwarf companion, and this outer layer will undergo fusion, producing a nova explosion.

Student responses
Section 4136
(A) : 6 students
(B) : 0 students
(C) : 26 students
(D) : 1 student
(E) : 0 students

[Version 2]

[3.0 points.] Which one of the following choices best describes a close-pair (mass-exchanging) binary system that can have a type Ia supernova explosion?
(A) A massive main sequence star and a red dwarf.
(B) A black hole and a white dwarf.
(C) A supergiant and a white dwarf.
(D) A supergiant and a black hole.
(E) Two red dwarfs.

Correct answer: (C)

When the hydrogen shed from a supergiant quickly forms a thick degenerate layer around a white dwarf companion (or the alternate theory is that this transfer has been going on for prolonged time over many nova explosion cycles), then the entire white dwarf will undergo fusion, producing a type Ia supernova explosion.

Student responses
Section 5076
(A) : 0 students
(B) : 2 students
(C) : 15 students
(D) : 1 student
(E) : 0 students

Astronomy midterm question: comparing stars using blackbody radiation laws

Astronomy 10 Midterm 3, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q8.3

[Version 1]
[15 points.] Consider the following statement: "If two stars have the same brightness, the star with the lower temperature will be bigger." Discuss whether this statement is true or not, and support your answer using Wien's law and/or the Stefan-Boltzmann law.

Solution and grading rubric:

• p = 15/15: Correct.
  Wien's law: peak wavelength is inversely proportional to temperature, size is not a factor. The Stefan-Boltzmann law: luminosity (brightness) proportional to size * (Temperature)^4, such that two stars can have the same brightness if the smaller star were hotter, and the larger star were cooler.
  
• r = 12/15:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  
• t = 9/15:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. At least recognizes that the Stefan-Boltzmann law is applicable, but argument is garbled.
  
• v = 6/15:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  
• x = 3/15:
  Implementation/application of ideas, but credit given for effort rather than merit. Agrees or disagrees with statement with no discussion.
  
• y = 1.5/15:
  Irrelevant discussion/effectively blank.
  
• z = 0/15:
  Blank.
  

Grading distribution:
Section 4136
p: 21 students
r: 2 students
t: 7 students
v: 7 students
x: 2 students
y: 0 students
z: 0 students

[Version 2]
[15 points.] Consider the following statement: "If two stars have the same color, the brighter star will be bigger." Discuss whether this statement is true or not, and support your answer using Wien's law and/or the Stefan-Boltzmann law.

Solution and grading rubric:

• p = 15/15:
  Correct. Wien's law: temperature is inverserly proportional to peak wavelength, which is related to color. Since both stars have the same color, then they must have the same temperature. The Stefan-Boltzmann law: luminosity
  (brightness) proportional to size * (Temperature)^4, such that the smaller star must be dimmer, and the larger star must be cooler, given that they are the same size.
  
• r = 12/15:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Uses the Stefan-Boltmann law correctly, but the temperature is assumed to be the same (or implied), not explicitly derived from applying Wien's law.
  
• t = 9/15:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. At least recognizes how the Stefan-Boltzmann law and Wien's law are applicable, but argument is garbled.
  
• v = 6/15:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  
• x = 3/15:
  Implementation/application of ideas, but credit given for effort rather than merit. Agrees or disagrees with statement with no discussion.
  
• y = 1.5/15:
  Irrelevant discussion/effectively blank.
  
• z = 0/15:
  Blank.
  

Grading distribution:
Section 5076
p: 7 students
r: 3 students
t: 6 students
v: 4 students
x: 0 students
y: 0 students
z: 0 students

Astronomy current events question: Gliese 581's super earth, part 2

Astronomy 10L, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events (skytonight.com, from Sky & Telescope magazine), and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

[0.2 points.] How was the recently discovered planet orbiting the red dwarf star Gliese 581 discovered? Circle your answer below.
(A) From the repetitive wobbles that the planet gravitationally exerts on Gliese 581.
(B) From the amount of light blocked by the planet as it passes in front of Gliese 581.
(C) From the amount of bright light emitted by the very hot planet, compared to the dim cool light emitted from Gliese 581.
(D) From deciphering ancient hieroglyphics in a newly discovered tomb in Egypt.
(E) From deciphering ancient glyphs from a previously overlooked Mayan codex.

Correct answer: (A).

Student responses
Section 4137
(A) : 13 students
(B) : 3 students
(C) : 5 students
(D) : 1 student
(E) : 0 students

Section 4138
(A) : 11 students
(B) : 5 students
(C) : 3 students
(D) : 0 students
(E) : 0 students

Section 4139
(A) : 10 students
(B) : 6 students
(C) : 1 student
(D) : 0 students
(E) : 0 students

Note that choices (A)-(C) are all used to find extrasolar planets. The one student who picked the nonsense choice (D) admitted to selecting it blindly at random.

Astronomy current events question: Gliese 581's super earth, part 1

Astronomy 10L, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events (skytonight.com, from Sky & Telescope magazine), and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

[0.2 points.] What is most significant about the recently discovered planet orbiting the red dwarf star Gliese 581? Circle your answer below.
(A) It is about to burned up by Gliese 581, as it is so close that its orbit around it is already only 13 days long.
(B) It is about to be swallowed up by Gliese 581 as the red dwarf becomes a giant.
(C) It may be an extremely old Earth-like planet, and thus may harbor an advanced technological civilization.
(D) It may be an Earth-like planet in its first stages of formation, with the correct conditions for carbon-based life.
(E) It may be an Earth-like planet at the right distance to have water in liquid form.

Correct answer: (E).

Student responses
Section 4137
(A) : 0 students
(B) : 0 students
(C) : 1 student
(D) : 1 student
(E) : 17 students

Section 4138
(A) : 1 student
(B) : 1 student
(C) : 1 student
(D) : 3 students
(E) : 13 students

Section 4139
(A) : 1 student
(B) : 0 students
(C) : 0 students
(D) : 2 students
(E) : 14 students