20110531

Astronomy quiz archive: solar system

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Section 30676, version 1
Exam code: quiz07Sq5h


Section 30674
Quiz 7 results (max score = 40):

0- 8.0 : * [low = 8.0]
8.5-16.0 : ***********
16.5-24.0 : ************** [mean = 21.4 +/- 7.7]
24.5-32.0 : *********
32.5-40.0 : **** [high = 40.0]

20110530

Astronomy quiz archive: solar system

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz07N3mi


Section 30674
Quiz 7 results (max score = 40):
0- 8.0 : ** [low = 6.5]
8.5-16.0 : **********
16.5-24.0 : ************ [mean = 20.5 +/- 8.4]
24.5-32.0 : ********
32.5-40.0 : **** [high = 40.0]

20110529

Astronomy quiz question: carbon dioxide sink

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Where does the carbon dioxide in Earth's atmosphere go before it is recycled back down into the mantle?
(A) Volcanoes.
(B) Plants.
(C) Oceans.
(D) Polar ice caps.

Correct answer: (C)

Oceans absorb vast amounts of carbon dioxide, which settle into sedimentary rocks on ocean floors, which are then subsequently subducted back into the mantle.

Section 30674
Exam code: quiz07N3mi
(A) : 4 students
(B) : 6 students
(C) : 26 students
(D) : 0 students

"Success level": 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

Section 30676
Exam code: quiz07Sq5h
(A) : 3 students
(B) : 12 students
(C) : 22 students
(D) : 3 students

"Success level": 59% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.82

Compare to a similar version of this question from Fall 2009.

20110528

Astronomy quiz question: radioactive decay age

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Consider two samples with differing amounts of radioactive elements, embedded gaseous daughter elements, and inert material (which is not involved in the decay process). Which sample is older, as determined by radioactive dating?
(A) Sample A.
(B) Sample B.
(C) (There is a tie.)
(D) (Cannot be determined, as they have different amounts of inert material.)

Correct answer: (C)

The solidification age of a sample (how long ago has it been since it was last molten) is determined by the ratio of decay products to its unstable isotopes. A larger ratio of decay products to unstable isotopes corresponds to a sample with a very old solidification age, but since both samples have the same ratio of decay products to unstable isotopes, they must have the same solidification age.

Section 30676
Exam code: quiz07Sq5h
(A) : 10 students
(B) : 13 students
(C) : 13 students
(D) : 2 students

"Success level": 39% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55

Compare to an older version of this question from Fall 2010.

20110527

Astronomy quiz question: condensation sequence hypothesis

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

The inner planets of the solar system are composed of metals/rocks, while the outer planets are composed of ices/gases because of the sun's:
(A) gravity.
(B) strong winds.
(C) heat.
(D) magnetic fields.

Correct answer: (C)

Heat generated by the sun means that volatiles cannot condense to start forming the cores of the inner terrestrial planets, while further out, where it is cooler, volatiles can condense to start forming the outer jovian planets.

Section 30676
Exam code: quiz07Sq5h
(A) : 7 students
(B) : 0 students
(C) : 23 students
(D) : 9 students
(No response: 1 student)

"Success level": 61% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64

Compare to an older version of this question from Spring 2010.

20110526

Astronomy quiz question: IAU classification scheme

Astronomy 210 Quiz 7, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Listed below are the minimal qualifications established by the International Astronomical Union for a planet:
I. Orbits the sun.
II. Shape "rounded-out" by gravity.
III. Cleared/dominates orbit around sun.
Of the following choices, which solar system object(s) only meets qualifications I and II?
(A) Mars.
(B) Io, a moon of Jupiter.
(C) Eris, a dwarf planet.
(D) Parnethope, an asteroid.
(E) (More than one of the above choices.)
(F) (None of the above choices.)

Correct answer: (C)

Eris directly orbits the sun (it is not a satellite of a planet), is round in shape, but does not dominate its orbit in the Kuiper belt around the sun.

Section 30674
Exam code: quiz07N3mi
(A) : 2 students
(B) : 2 students
(C) : 20 students
(D) : 1 student
(E) : 11 students
(F) : 0 students

"Success level": 60% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43

Section 30676
Exam code: quiz07Sq5h
(A) : 1 student
(B) : 2 students
(C) : 21 students
(D) : 4 students
(E) : 12 students
(F) : 0 students

"Success level": 58% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55

20110525

Education research: astronomy laboratory student learning outcomes

Student achievement of course learning outcomes are assessed by administering a Student Learning Outcomes survey, a five-point Likert scale questionnaire to Astronomy 210L students at Cuesta College, San Luis Obispo, CA. This course is a one-semester, introductory astronomy laboratory (separate from lecture), and is taken primarily by students to satisfy their general education science laboratory transfer requirement.

This survey is administered online during the second-to-last week of instruction, to be completed just before the final laboratory session.

The results from this semester are compiled below. Values for the mean and standard deviations are given next to the modal response category for each question. Also listed is the percentage of students who have self-assessed themselves as having successfully achieving a learning outcome (responding "fairly well" or "very well") as opposed to not achieving success with a learning outcome (responding "not at all," "slightly" or "somewhat").

Cuesta College
Student Learning Outcomes for Astronomy 210L (SLO-Astr210L)
Astronomy 210 Spring 2011 sections 30678, 30679, 30680, 30682

The questions below are designed to characterize your achievement of each of the
learning outcomes by filling in a bubble on the rating scale provided to the
right of each statement. Mark the level of achievement that best describes your
learning at the completion of the course.

1. Keeping abreast of present-day discoveries and developments in astronomy
(current events).
(Achieved: 66%, unachieved: 34%)
1. Not at all 1 : *
2. Slightly 1 : *
3. Somewhat 22 : **********************
4. Fairly well 27 : *************************** [3.9 +/- 0.9]
5. Very well 20 : ********************

2. Developing scientific evidence-based research questions.
(Achieved: 82%; unachieved: 12%)
1. Not at all 4 : ****
2. Slightly 9 : *********
3. Somewhat 37 : ************************************* [4.1 +/- 0.8]
4. Fairly well 21 : *********************
5. Very well 18 : ******************

3. Developing procedures to gather evidence in order to answer research
questions.
(Achieved: 87%, unachieved: 13%)
1. Not at all 0 :
2. Slightly 3 : ***
3. Somewhat 6 : ******
4. Fairly well 36 : ************************************ [4.2 +/- 0.8]
5. Very well 25 : *************************

4. Making appropriate evidence-supported conclusions.
(Achieved: 92%, unachieved: 8%)
1. Not at all 0 :
2. Slightly 1 : *
3. Somewhat 5 : *****
4. Fairly well 38 : ************************************** [4.3 +/- 0.7]
5. Very well 27 : ***************************

5. Explaining research findings in a report, poster, or presentation.
(Achieved: 90%, unachieved: 10%)
1. Not at all 0 :
2. Slightly 0 :
3. Somewhat 7 : *******
4. Fairly well 30 : ******************************
5. Very well 33 : ********************************* [4.4 +/- 0.7]

6. Evaluating evidence to determine whether or not it appropriately answers a
research question.
(Achieved: 94%, unachieved: 6%)
1. Not at all 0 :
2. Slightly 1 : *
3. Somewhat 3 : ***
4. Fairly well 38 : ************************************** [4.3 +/- 0.6]
5. Very well 29 : *****************************

Note that the overall class average for current events quizzes (where students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab) is 65% +/- 31%, which is comparable to the self-assessed success rate of 66%.

As per the ACCJC (Accrediting Commission for Community and Junior Colleges), results from this assessment tool will be used for course/program improvement by increasing emphasis on these lowest student learning outcomes in instruction in future semesters.

20110524

Astronomy current events question: Gravity Probe B

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Trent J. Perrotto "ASA's Gravity Probe B Confirms Two Einstein Space-Time Theories," May 4, 2011
http://www.nasa.gov/mission_pages/gpb/gpb_results.html
NASA's Gravity Probe B spacecraft confirmed general theory of relativity predictions by:
(A) monitoring bacterial aging in space relative to on Earth.
(B) comparing the timing of back-and-forth laser pulses.
(C) measuring minute temperature fluctuations in space.
(D) accelerating to near the speed of light.
(E) tracking changes in alignment with a reference star.

Correct answer: (E)

Student responses
Sections 30682
(A) : 2 students
(B) : 3 students
(C) : 1 student
(D) : 1 student
(E) : 14 students

20110523

Astronomy current events question: Dawn spacecraft to visit Vesta

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Jia-Rui C. Cook, Dwayne C. Brown, "Dawn Reaches Milestone Approaching Asteroid Vesta," May 3, 2011
http://www.nasa.gov/mission_pages/dawn/news/dawn20110503.html
This July, NASA's Dawn spacecraft will fly by:
(A) Vesta, an asteroid.
(B) Saturn's rings.
(C) Halley's comet.
(D) Jupiter's Great Red Spot.
(E) Space Shuttle Endeavour, on its final mission.

Correct answer: (A)

Student responses
Sections 30682
(A) : 14 students
(B) : 2 students
(C) : 0 students
(D) : 4 students
(E) : 0 students

20110522

Astronomy current events question: asteroid 2005 YU55

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Don Yeomans, Lance Benner and Jon Giorgini, "Asteroid 2005 YU55 to Approach Earth on November 8, 2011," March 10, 2011
http://neo.jpl.nasa.gov/news/news171.html
When asteroid 2005 YU55 makes it closest approach to Earth this November, it will:
(A) cause higher than normal tides.
(B) disrupt GPS and cell phone communications.
(C) be visible in the sky later that evening.
(D) transit across the face of the moon.
(E) have developed a long, bright tail.

Correct answer: (C)

Student responses
Sections 30682
(A) : 4 students
(B) : 4 students
(C) : 11 students
(D) : 0 students
(E) : 2 students

20110521

Astronomy certificate of achievement

20110505845
http://www.flickr.com/photos/waiferx/5704649689/
Originally uploaded by Waifer X

Astronomy 210 Certificate of Achievement, Cuesta College, San Luis Obispo, CA. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

20110520

Physics midterm problem: charge moving near two magnets

Physics 205B Midterm 2, spring semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 18.65

A positive charge moves near two identical bar magnets such that the magnetic force on it is to the right (in the +x direction). Determine (a) the direction of the magnetic field at the location of the charge, and (b) the direction of the velocity of the charge. Show your work and explain your reasoning.

Solution and grading rubric:
  • p:
    Correct. Determines (a) the magnetic field at the location of the positive charge knowing how magnetic field lines behave at the respective poles of the magnets, then (b) uses RHR1 to determine the direction of the charge's velocity, given the directions of the magnetic field and the force exerted on the charge.
  • r:
    Nearly correct, but includes minor math errors. Direction of one of the vectors in (a)-(b) is reversed.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Problems with reversing directions of both vectors in (a)-(b), but understands direction of magnetic field lines and RHR1.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. May involve currents and/or RHR2, RHR3, etc.
  • x:
    Implementation of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Section 30882
Exam code: midterm02H3nR
p: 6 students
r: 1 student
t: 0 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 3773):

20110519

Physics midterm problem: light bulb power dissipation in circuit

Physics 205B Midterm 2, spring semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 18.65

[20 points.] An ideal 12 V emf source is connected to ideal light bulbs and an ideal resistor, as shown at right. Find the amounts of power used by each of the two light bulbs. Show your work and explain your reasoning.

Solution and grading rubric:
  • p = 20/20:
    Correct. Finds equivalent resistance of circuit, and uses Ohm's law to find the current flowing through the emf and top light bulb. Can use P = (I2R to find power used by top light bulb, and then Kirchhoff's loop rule to find the voltage remaining after the top light bulb, then P = (∆V2)/R to find the power used by the lower light bulb.
  • r = 16/20:
    Nearly correct, but includes minor math errors. Has at least one light bulb power correct, but has minor misapplications of Kirchhoff's loop rules or junction rules in finding the other light bulb power.
  • t = 12/20:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. At least has systematic approach to finding equivalent resistance and current of circuit, and finding powers of each light bulb.
  • v = 8/20:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner.
  • x = 4/20:
    Implementation of ideas, but credit given for effort rather than merit.
  • y = 2/20:
    Irrelevant discussion/effectively blank.
  • z = 0/20:
    Blank.

Grading distribution:
Section 30882
Exam code: midterm02H3nR
p: 3 students
r: 3 students
t: 2 students
v: 0 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 7503):

20110518

Physics midterm question: LR circuit current

Physics 205B Midterm 2, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 20.55

[10 points.] An ideal emf source is connected to an ideal resistor and inductor. The switch is closed at t = 0. Determine whether the resistor or inductor has more current flowing through it just after the switch is closed, or if there is a tie. Explain your reasoning using the properties of currents and potential differences, and Kirchhoff's rules, Ohm's law, Faraday's law and/or Lenz's law.

Solution and grading rubric:
  • p = 10/10:
    Correct. Due to Kirchhoff's junction rule applied to this series circuit, both the resistor and the inductor must have the same current flowing through them at any given moment in time.
  • r = 8/10:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes.
  • t = 6/10:
    Nearly correct, but argument has conceptual errors, or is incomplete. Says different amounts of current, but at least demonstrates an understanding of Lenz's law.
  • v = 4/10:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  • x = 2/10:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y = 1/10:
    Irrelevant discussion/effectively blank.
  • z = 0/10:
    Blank.

Grading distribution:
Section 30882
Exam code: midterm02H3nR
p: 3 students
r: 0 students
t: 3 students
v: 2 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 7673):

20110517

Physics midterm question: direction of current

Physics 205B Midterm 2, spring semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 18.37

A two ideal batteries and two resistors are connected in series as shown at right, where ε1 = ε2, but R1 > R2. Determine which battery has more current flowing through it, or if there is a tie. Explain your reasoning using the properties of Kirchhoff's rules and/or Ohm's law.

Solution and grading rubric:
  • p:
    Correct. Due to Kirchhoff's junction rule applied to this series circuit, both emfs must have the same current flowing through them. May also remark that from Ohm's law, there is actually no current flowing through this circuit.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes.
  • t:
    Nearly correct, but argument has conceptual errors, or is incomplete.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Section 30882
Exam code: midterm02H3nR
p: 7 students
r: 0 students
t: 0 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 9904):

20110516

Astronomy current events question: Saturn-Enceladus electrical link

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Jia-Rui C. Cook, Dwayne Brown, "Cassini Sees Saturn Electric Link With Enceladus," April 19, 2011
http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20110420.html
NASA's Cassini spacecraft detected _________ near Saturn's north pole, related to an electric and magnetic connection between Saturn and one of its moons, Enceladus.
(A) a patch of ultraviolet light.
(B) radio transmission interference.
(C) faint arcs of lightning.
(D) water vapor and organic particles.
(E) radioactivity.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 6 students
(B) : 5 students
(C) : 2 students
(D) : 4 students
(E) : 2 students

20110515

Astronomy current events question: Mars' buried carbon dioxide

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Guy Webster, Maria Martinez, Dwayne Brown, "NASA Orbiter Reveals Big Changes in Mars' Atmosphere," April 21, 2011
http://www.nasa.gov/mission_pages/MRO/news/mro20110421.html
Ground-penetrating radar from NASA's Mars Reconnaissance Orbiter has detected:
(A) large buried deposits of frozen carbon dioxide.
(B) underground reservoirs of liquid water.
(C) warm magma pockets under Olympus Mons.
(D) a network of long, straight underground tubes.
(E) remnants of a large asteroid impact.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 14 students
(B) : 3 students
(C) : 0 students
(D) : 1 student
(E) : 3 students

20110514

Astronomy current events question: Allen Telescope Array mothballing

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Kelly Beatty, "Forced 'Hibernation' for SETI Telescope," April 26, 2011
http://www.skyandtelescope.com/news/home/120703884.html
Searching for alien radio transmissions at the Allen Telescope Array has been suspended due to:
(A) nearby wildfires.
(B) funding problems.
(C) migrations of deer.
(D) Air Force secrecy restrictions.
(E) sunspot interference.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 1 student
(B) : 22 students
(C) : 1 student
(D) : 5 students
(E) : 10 students

20110513

Astronomy current events question: STEREO discovers eclipsing binaries

Astronomy 210L, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, 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!)
Gemma Lavender, "Variable Stars Under the Gaze of STEREO," April 23, 2011
http://www.astronomynow.com/news/n1104/23stereo/
United Kingdom researchers discovered _________ using NASA's STEREO solar satellites.
(A) sources of sunquakes.
(B) Pluto's carbon monoxide atmosphere.
(C) new eclipsing binary systems.
(D) transiting extrasolar planets.
(E) sunspots near the sun's poles.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 3 students
(B) : 1 student
(C) : 15 students
(D) : 12 students
(E) : 7 students

20110512

Overheard: Ceres, Ceres-ously

Astronomy 210, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

(Overheard during a presentation on dwarf planets, and the 2006 International Astronomical Union classification of solar system bodies.)

Instructor: "Consider Ceres, which is now just the largest asteroid. But after it was first discovered in 1801, people called it a planet."

Student 1: "Where did that name come from?"

Instructor: "The Greek goddess of the grain harvest. You know, like where the word, 'cereal' comes from."

(Beat.)

Student 2: "Seriously?"

Instructor: "Ceres-ously."

20110511

Backwards-faded scaffolding laboratory/presentation: end-of-semester poster session

Is everyone ready for today's poster session?

(This is the fourteenth and last Astronomy 210L laboratory at Cuesta College, San Luis Obispo, CA. This course is a one-semester, optional adjunct laboratory to the Astronomy 210 introductory astronomy lecture, taken primarily by students to satisfy their general education science transfer requirement.)

We'll be dividing you and the time today in laboratory into two parts.

During the first session, half of you will be presenting your posters. Nothing formal, just be accessible to answer questions and address comments from the non-presenting students.

If you are not presenting during the first session, you should circulate and look at every poster presented.

You will then fill out a session report, which asks you to critique two posters, and then select and explain the most important and the most confusing aspect from any of these first session posters...

...as well as a question you asked (and got an answer to) from these presenters. Even if nothing in particular interested or confused you, there should have been something that you at least found somewhat interesting and somewhat confusing.

Then for the second session, presenters and non-presenters will switch roles, and the new non-presenters will circulate and fill out their session reports.

EQUIPMENT
     (none)

BIG IDEA
     Attending a research poster session is an opportunity to personally engage colleagues in person about their findings, and to enrich each others' professional knowledge, perspective, and insights.

GOAL
     Students will alternate between presenting their independent research posters, and circulating and assessing others' research posters.

TASKS
1. Sign-up Sheet
  1. If you have brought a completed research poster, sign up for your preference of first-half or second-half presentations. (Your instructor may move people near the bottom of either list to the other session in order to even out the number of presenters in each session.)
  2. Tape your poster up in the space(s) available.
2. First Session
  1. If you are presenting, stand by your poster, and answer questions and make clarifications for other attendees.
  2. If you are observing, circulate among every first-session poster. Be sure to ask questions and make constructive comments to the presenters. After looking at all the first-session posters, complete a session report.
3. Second Session
  1. If you are now observing, circulate among every second-session poster. Be sure to ask questions and make constructive comments to the presenters. After looking at all the second-session posters, complete a session report.
  2. If you are now presenting, stand by your poster, and answer questions and make clarifications for other attendees.
(If you did not bring a poster to present today, you may fill out a session report for the first session, and another report for the second session.)

Session report (adapted from "Improving Student Engagement at Public Lectures: Assigning a Writing Task," Tim Slater and Gina Brissenden, http://astronomy101.jpl.nasa.gov/teachingstrategies/teachingdetails/?StrategyID=15; and Tim Slater, Stephanie Slater, Daniel J. Lyons, Engaging in Astronomical Inquiry, W.H. Freeman & Company, New York, 2010, p. 152):


20110510

Backwards faded scaffolding laboratory/presentation: poster session preview

Have you ever participated in a science fair? Posed your own research question, done your own research (this student apparently has done quite a bit of "research"), and displayed your results for all the world to see?

Even though these events are called "poster sessions" in science conferences, it's pretty much the same idea as a science fair.

(This is the thirteenth Astronomy 210L laboratory at Cuesta College, San Luis Obispo, CA. This course is a one-semester, optional adjunct laboratory to the Astronomy 210 introductory astronomy lecture, taken primarily by students to satisfy their general education science transfer requirement.)

At a conference poster session, presenters and participants get to interact with each other and exchange constructive criticism...

...most importantly, face-to-face. In order to facilitate this valuable opportunity to mingle and network with colleagues, poster session organizers typically furnish refreshments and beverages.

Which is what we'll be doing next week--so before you leave today, submit an individual research question on some aspect of the concepts explored earlier this semester, get it approved, and complete your research report before you come to the next laboratory.

We'll have a poster session, so you'll be allowed nine letter-size sheets in a 3 x 3 format (or equivalent-sized poster board) to present your findings.

20110509

Backwards-faded scaffolding laboratory/presentation: heat transfer laws

Anybody know who these guys are?
(Mr. Heat Miser, Mr. Cold Miser.)

(This is the twelfth Astronomy 210L laboratory at Cuesta College, San Luis Obispo, CA. This course is a one-semester, optional adjunct laboratory to the Astronomy 210 introductory astronomy lecture, taken primarily by students to satisfy their general education science transfer requirement.)

Let's consider different examples, both edible, and non-edible, of heat transfer phenomena--later you'll determine which heat transfer law(s) apply in each of these cases (Newton's Law of Cooling, Bergman's/Allen's Rule, Convection Law).

Nothing cuter than baby penguins snuggling to stay warm. Especially when they tuck their heads in, and put their wings around their buddies. (Wait--edible, or non-edible?)

The infamous Cooper Cooler™, where a tray of ice, a cup of water are added, and by spinning a soda can, it renders it ice cold in just 60 seconds in this infomercial. Just three easy payments of $19.99, shipping and handling and applicable state and local taxes extra.

Read those directions, and watch the clock--that ginormous turkey is going to require more cooking time.

Too hot? Blow on it cool it off.

And why is Earth geologically active today, while the other terrestrial planets, such as Mars, currently geologically dead?

Which snowman will melt fastest?

So think about these examples, and determine which heat transfers apply to each of these cases.

The second part of this laboratory is actually demonstrating these heat transfer laws, and also coming up with an experiment to answer a heat transfer law research question.

You'll have various size beakers, thermometers, trays, tap water, scalding hot water from a coffee percolator (caution!), and ice available for your use...

...along with empty plastic water bottles, and of course, a few Cooper Coolers™.

EQUIPMENT
      thermometers
      plastic trays
      Cooper Cooler(TM) Rapid Beverage Chiller
      large/small beakers
      percolator (plug in to heat water 30 minutes prior to lab)
      ice, ice chest
      empty water bottles with caps (undented, uncrushed)

BIG IDEA
Heat loss over time of astronomical objects such as star and planet interiors depends on several laws of energy transfer:
  • Newton's Law of Cooling:
    Rate of heat loss of an object is proportional to the temperature difference between itself and its surroundings. (Greater temperature differences between an object and its surroundings mean faster heat transfers; smaller differences have slower transfers.)
  • Bergman's Rule (or Allen's Rule):
    Rate of heat transfer to/from an object is proportional to the ratio of its volume to its surface area. (Small objects have greater surface area per volume ratios and faster heat transfers, large objects have lower surface area per volume ratios and slower heat transfers.)
  • Convection Law:
    Rate of heat transfer to/from an object is dependent on the amount of convection within itself and in its surroundings. (More convection results in faster heat transfer, less/no convection results in slower heat transfer.)
GOAL
      Students will be guided through discussions and demonstrations of heat transfer laws, and later conduct inquiries about the relative dependence of heat transfer rates on various factors.

TASKS
(Record your lab partners' names on your worksheet.)
1. Exploration
  1. Fill a small and a large beaker with same temperature hot water from the coffee percolator. Prepare an ice water bath in a plastic tray (but with not so much water that small beaker would float when placed into the ice bath). Record the initial temperatures in each beaker, and place each beaker into the ice water bath for at least 10 minutes. Set this experiment aside.

  2. Several real-life observations of heat transfer phenomena are listed below. For each phenomenon, determine which heat transfer law(s) are demonstrated, and summarize your findings in a list(*). (You should come back to this list later in the laboratory for revisions/completion, if necessary.)

    1. Emperor penguin babies huddle together in order to stay warm.

      Heat transfer law(s), and explanation: _________.

    2. A room temperature bottle of wine will take 60 minutes to chill to a proper serving temperature when left in the freezer, while it chills "10 times faster" spinning in circulating ice water in a Cooper Cooler(TM) Rapid Beverage Chiller (*.html) appliance.

      Heat transfer law(s), and explanation: _________.

    3. The cooking time for a turkey depends on its weight (allrecipes.com):

      Weight of
      unstuffed bird (lbs):
      Roasting
      time, (hrs):
      10-18 lbs3 to 3-1/2 hours
      18-22 lbs3-1/2 to 4 hours
      22-24 lbs4 to 4-1/2 hours
      24-29 lbs4-1/2 to 5 hours

      Heat transfer law(s), and explanation: _________.

    4. Blowing on a hot spoonful of soup to make it cooler.

      Heat transfer law(s), and explanation: _________.

    5. Earth is still geologically active today, while Mars is no longer geologically active.

      Heat transfer law(s), and explanation: _________.

    6. Small snowmen melt faster than larger snowmen.

      Heat transfer law(s), and explanation: _________.

  3. After at least 10 minutes have elapsed, simultaneously record the final temperatures for the small beaker and the large beaker. Summarize your temperature data in a table(*).


    Beaker size:
    Initial
    temperature (° C):
    Final
    temperature (° C):
    Small
    Large

  4. Record the volumes of water in the small beaker and the large baker. Measure the diameters of the small beaker and large beaker, and also the heights of the water in the small and large beaker. Calculate the total surface area of the water in each beaker by approximating its size as a box: 2×(diameter × diameter) + 4×(diameter × height). Summarize your data in a table.


    Beaker size:
    Water
    volume (mL):
    Beaker
    diameter (cm):
    Water
    height (cm):
    Surface
    area (cm^2):
    Small
    Large

  5. Calculate the surface area per volume ratios for the small beaker and the large beaker.

    Small beaker surface area per volume ratio = __________ cm^2/mL.
    Large beaker surface area per volume ratio = __________ cm^2/mL.

2. Does Evidence Match a Given Conclusion?
      Discuss whether your data from the previous activity adequately demonstrates a heat transfer law or laws, and specify which law(s). Explain your reasoning and provide specific evidence from data, with sketches if necessary, to support your reasoning.

3. What Conclusions Can You Draw From This Evidence?
      A beaker of very warm water with a starting temperature of 46° C was placed into an ice-water bath, and the temperature of the water in the beaker was recorded at one-minute intervals.


Time (min):
Beaker water
temperature (° C)
0 min46° C
1 min34° C
2 min26° C
3 min(Forgot to record)
4 min21° C
5 min19° C
6 min16° C
7 min14° C
8 min11° C
9 min10° C
10 min9° C

      What conclusions and generalizations can you make from the information given above in terms of "How does the change in temperature of warm water in a beaker over time adequately demonstrate a heat transfer law or laws?" Explain your reasoning and provide specific evidence, with sketches if necessary, to support your reasoning.

4. What Evidence Do You Need to Pursue?
      Describe precisely what evidence you would need to collect in order to answer the research question of, "How much would a constant breeze across the surface of hot water (such as coffee or tea) cool it off faster than if there were no breeze?" You do not need to actually complete the steps in the procedure you are writing.
      Create a detailed, step-by-step description of evidence that needs to be collected and a complete explanation of how this could be done--not just "place a cup of hot water next to a fan," but exactly what would someone need to do, step-by-step, to accomplish this. You might include a table and sketches--the goal is to be precise and detailed enough that someone else could follow your procedure.

(At this point you should go back and revise/complete the explanations for the heat transfer laws in 1(b).)

5. Formulate a Question, Pursue Evidence, and Justify Your Conclusion
      Design an answerable research question, propose a plan to pursue evidence, collect data, and create an evidence-based conclusion about an aspect that you have not completed before, in order to demonstrate a heat transfer law. (Have your instructor approve your whiteboard research question before proceeding further.)
      Research report summary on whiteboards/poster paper, to be worked on and presented to the class as a group, should include:
  1. Specific research question.
  2. Step-by-step procedure to collect evidence.
  3. Data table and/or results.
  4. Evidence-based conclusion statement.

20110508

Backwards-faded scaffolding laboratory/presentation: impact craters

Breaking news--impact event in the not too distant future. But first, a word from our sponsor. And in our next hour, cooking tips for healthier eating in our studio kitchen.

(This is the eleventh Astronomy 210L laboratory at Cuesta College, San Luis Obispo, CA. This course is a one-semester, optional adjunct laboratory to the Astronomy 210 introductory astronomy lecture, taken primarily by students to satisfy their general education science transfer requirement.)

Let's first consider impact events from the distant, and also not-so-distant past.

Notably the "K-T" (Cretaceous-Tertiary) extinction event about 65 million years ago.

What would happen if you were a dinosaur living at that time? According to this artistic depiction, the ceratopsid on the left may have already perished from the blast wave, or maybe has just laid down due to the sheer despair of acknowledging its impending doom. Or maybe you would feel more like the plesiosaur on the right, either surfing its last killer wave, or asphyxiating from lack of oxygen.

This sort of stuff happens more often than you might like to think. Consider a much smaller event about a century ago in remote Siberia.

The air blast from this impact devastated the landscape below, fortunately far away from inhabited areas.

So why wait around for the next impact event to happen on Earth?

Why not get some payback for the dinosaurs, which NASA got by launching a washing machine-sized projectile into a comet nucleus?

Besides the obvious gratification, the science that can be done is in looking at the composition of the material flung out from the impact, in order to determine the ingredients of a comet. Also by making and freezing these ingredients, varying their compactness from fluffy to firmly packed, results from shooting projectiles into these lab samples can be compared with the size of the impact crater on the comet, in order to determine the type of cratering process in this material.

Which is what you get to do in laboratory today.

By dropping objects of different mass, or different height, you can create different energy impact events.

And you can measure the resulting diameters of these resulting impact craters.

By plotting the different impact energies versus impact crater diameters, you can determine the cohesion of a material, and the type of cratering process in this material.

Plotting different impact energies versus crater diameters should result in a linear data set, as graphed with "log-log" scales.

And by drawing a best fit line (not just "connecting the dots") for your data set...

You can slide a slope template to find the impact cratering process that best fits your data set.

EQUIPMENT
15 cm rulers (small, flexible)
meter sticks
material containers
medium-grain playground sand
coarse water softener salt
fine-grain table salt
baking soda
stainless steel balls
digital weight scales
hanging mass set (10 g, 20 g, 50 g, 100 g, 200 g, 500 g, 1000 g)

"Impact Energy vs. Crater Diameter Log-Log Graph"

"Impact Process Template"

BIG IDEA
Depending on the specific circumstances, an impactor will create a crater in a target material principally due to one of four processes:
  • Avalanche (splash): crater diameter set by how much material falls in around impactor.
  • Surface crack/pulverization (thud): crater diameter set by surface disturbed by impactor.
  • Compression (crunch): crater diameter set by material crushed beneath impactor.
  • Excavation (spray): crater diameter set by material thrown outwards by impactor.
GOAL
Students will conduct a series of inquiries about impact processes by varying different impactor and target parameters, and be able to quantitatively categorize different types of impact processes.

TASKS
(Record your lab partners' names on your worksheet.)
1. Exploration
  1. Carefully observe a stainless steel ball falling from 50 cm onto medium-grained sand, as measured from the top of the sand surface. Try this several times; note that you will need to cover your sand box and shake it vertically up-and-down a set number of times between each drop to consistently "reset" your sample surface between each drop.
    Discuss in your group the hypothesized process(es) of crater formation (i.e., "splash, thud, crunch, or spray," and briefly explain what you observed to support your choice(s). Do not worry about guessing the "correct" answer, this is just a preliminary hypothesis. You may note dissenting opinions, if any.

    Medium-grain sand crater process hypothesis: __________.
    Explanation of choice: __________.

  2. How the diameter of an impact crater is measured is a qualitative decision. Thus it is important to measure these diameters consistently. In order to do this, first make several trial impacts from different heights (do not record data yet), and discuss and agree in your group on a consistent description of a crater edge that can apply generally for impactors dropped from heights ranging from 10 cm to 100 cm, as measured from the top of the surface. Also record the mass of your stainless steel ball, in grams.

    Description/drawing of crater "edge" definition: __________.

    Mass of stainless steel ball: __________ g.

  3. Release (do not throw down) the impactor from 10 cm to 100 cm, in 10 cm increments, as measured from the top of the surface of medium-grain sand (in order to vary its energy), and measure its crater diameter. Make at least three drops for each height in order to test for consistent results. Then for each drop height, calculate the impact energy (in kiloergs) = (mass, in g)*(height, in cm), and the average crater diameter. (Example: a 50 g impactor released from 20 cm would have 50*20 = 1,000 kiloergs of impact energy.)

    Make a table compiling your drop heights (in cm), impact energies (in kiloergs), and crater diameters (in cm).

    Impactor
    height (cm):
    Impact
    energy (kiloergs):

    Crater diameters (cm):
    Average crater
    diameter (cm):
    10 cm
    _____, _____, _____.
    20 cm _____, _____, _____.
    30 cm
    _____, _____, _____.
    40 cm
    _____, _____, _____.
    50 cm
    _____, _____, _____.
    60 cm
    _____, _____, _____.
    70 cm
    _____, _____, _____.
    80 cm
    _____, _____, _____.
    90 cm
    _____, _____, _____.
    100 cm
    _____, _____, _____.

  4. Plot the data points from (c) on a group "Crater Diameter vs. Impact Energy Log-Log Graph," and use a ruler to draw a straight best-fit line across the entire graph.
2. Does Evidence Match a Previous Hypothesis?
The slope of your "Impact Energy vs. Crater Diameter Log-Log Graph" is related to the specific cratering process involved. Place the "Impact Process Template" over your graph, and slide it left or right while keeping the horizontal and vertical baselines aligned to determine which impact process slope is most parallel to your best-fit line.
Does your data support or refute your original cratering process hypothesis? Explain your reasoning and provide specific evidence from data to support your reasoning.

3. What Conclusions Can You Draw From This Evidence?
The table below summarizes the results of dropping different mass impactors, all from the same height (20 cm) into medium-grain sand.

Impactor
mass (g):
Impact
energy (kiloergs):

Crater diameters (cm):
Average crater
diameter (cm):
10 g
3.0, 3.0, 2.8, 3.0, 2.5 cm
20 g
3.0, 3.8, 3.3, 3.5, 3.5 cm
50 g
3.5, 4.2, 4.9, 5.0, 5.1 cm
100 g
5.0, 5.2, 5.5, 5.0, 5.4 cm
250 g
6.0, 7.0, 6.2, 5.8, 5.9 cm
500 g
7.0, 8.8, 8.2, 7.5, 8.0 cm

What conclusions and generalizations can you make from the information given above in terms of "Does varying impactor energy by varying mass (while keeping drop height constant), and by varying drop height (while keeping mass constant) give the same results for determining medium-grain sand cratering processes?" Explain your reasoning and provide specific evidence (a group "Crater Diameter vs. Impact Energy Log-Log Graph," with data points plotted, and best-fit line), to support your reasoning.

4. What Evidence Do You Need to Pursue?
Recall that you covered your sand box and shook it vertically up-and-down between each drop to consistently "reset" your sample. Consider the following claim:
"If the sand box is shaken side-to-side between each drop, the sand grains will sift and settle, becoming more tightly compacted for the next drop from the same height."
Describe precisely what evidence you would need to collect in order to answer the research question of, "How does a 'side-to-side reset' for medium-grain sand affect the results of each subsequent drop from the same height?" You do not need to actually complete the steps in the procedure you are writing.
Create a detailed, step-by-step description of evidence that needs to be collected and a complete explanation of how this could be done--not just "drop the ball multiple times," but exactly what would someone need to do, step-by-step, to accomplish this. You might include a (blank) table and sketches--the goal is to be precise and detailed enough that someone else could follow your procedure.

5. Formulate a Question, Pursue Evidence, and Justify Your Conclusion
Design an answerable research question), propose a plan to pursue evidence, collect data, and create an evidence-based conclusion about an aspect that you have not completed before. (Have your instructor approve your whiteboard research question before proceeding further.)
Research report summary on whiteboards/poster paper, to be worked on and presented to the class as a group, should include:
  1. Specific research question.
  2. Step-by-step procedure to collect evidence.
  3. Data table and/or results (including graph(s)).
  4. Evidence-based conclusion statement.


Procedure adapted from Gary Parker, "Low Velocity Impact Craters In The Lab," presented at Cosmos In The Classroom 2004 (*.html).