20160518

Online reading assignment question: advice to future students

Astronomy 210, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. The following question was asked after the last lecture, but prior to the final exam.

Tell a student who is about to take this course next semester what he/she needs to know or to do in order to succeed in this course. (Graded for completion.)
"Always be sure to go to class--even if you miss a day you end up missing so much information. As much as it may not seam like it the weekly reading assignment points really do add up. Don't be afraid to ask questions. Be sure to preview slide shows before class. And again...go to class."

"For the love of God read the textbook!"

"Read the book! Study for the quizzes!"

"Make sure to study and do the online reading assignments, they will benefit you a ton."

"I would DEFINITELY recommend when studying the test study right of the past quizzes and off of the book. FORGET WIKIPEDIA!"

"That P-dog does an excellent job in bringing high level science and math down to a level that a person like myself can comprehend."

"Come to class!!! Do your reading assignments!"

"Do the flashcard packets and get them checked. Read. Go to class."

"I would definitely keep up with the readings and take notes weekly! Always do your flashcard questions because those help so much! As long as you figure out how to study for this class it isn't as hard as it seems initially. "

"Do the reading and just keep up with the content because it can get difficult to make a recovery."

"Do all of the online reading assignments, do the flashcards, and come to class!"

"Always do the online reading assignments. ALWAYS!"

"Keep up with the online assignments and don't skip class."

"If you go to office hours and show you're putting forth an effort and actually care then you will do well."

"Read the online presentations and textbook! They'll be your friends, like when you need help/advice on something you don't understand lol"

"To be patient with the course. You may feel like you are not doing good at first and that the class is really hard, but with time you get used to the layout and the points add up quickly. "

"Do all the reading assignments and study the quizzes for the midterms, it really helped me!"

"Study for those damn quizzes "

"Make sure to do the homework and study for quizzes."

"You should not take the lab and class back to back, just go to class and you should be fine."

"Read the book before class!"

"Do all of the previous semesters' archived quizzes and midterms."

"To succeed in the course, you should probably read the textbook a lot and pay attention in class even though the class is long."

"Always go to the study sessions of class before you take your exam."

"Do all the homework and don't forget about it."

Education research: SPCI statistics (spring semester 2016)

Students at Cuesta College (San Luis Obispo, CA) were administered the Star Properties Concept Inventory (SPCI version 3.0, developed by Janelle Bailey, University of Nevada-Las Vegas) during the first and the last week of instruction. Astronomy 210 is a one-semester introductory general science course, with a separate optional adjunct laboratory (Astronomy 210L).

The pre- to post-test gain for this semester at Cuesta College (excluding students with negative informed consent forms (*.pdf), and missing pre- or post-tests) is:

Astronomy 210 spring semester 2016 sections 30674, 30676
N = 59 (matched-pairs)
<initial%>= 32% ± 15%
<final%>= 54% ± 14%
<g>= 0.32 ± 0.14 (matched-pairs); 0.33 (class-wise)

This semester's SPCI pre- and post-instruction scores are comparable to results from previous semesters at Cuesta College.

20160513

Physics quiz archive: radioactive decay, Feynman diagrams

Physics 205B Quiz 7, spring semester 2016
Cuesta College, San Luis Obispo, CA
Sections 30882, 30883, version 1
Exam code: quiz07eYE5



Sections 30882, 30883 results
0- 6 :   * [low = 6]
7-12 :   ***
13-18 :   **************
19-24 :   **************** [mean = 20.2 +/– 5.5]
25-30 :   ****** [high = 30]

Astronomy current events question: "Manx" comet C/2014 S3

Astronomy 210L, spring semester 2016
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!)
Karen Meech and Roy Gal, "Back from the Deep Freeze: A Piece of the Early Solar System Returns" (April 29, 2016)
ifa.hawaii.edu/info/press-releases/manx_comets/
Based on analysis of its spectrum and its lack of tail, comet C/2014 S3 may be a long-frozen remnant of material from:
(A) a nearby supernova remnant.
(B) the sun's red dwarf companion.
(C) Saturn's rings.
(D) the early inner solar system.
(E) solar wind filaments.

Correct answer: (D)

Student responses
Section 30680
(A) : 2 students
(B) : 0 students
(C) : 3 students
(D) : 7 students
(E) : 1 student

Astronomy current events question: multiple galaxies hidden within hot glowing dust

Astronomy 210L, spring semester 2016
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!)
Jacqui Bealing, "Bright Dusty Galaxies are Hiding Secret Companions" (May 6, 2016)
sussex.ac.uk/broadcast/read/35494
Based on __________, several hidden galaxies may be responsible for the glowing dust surrounding a bright galaxy.
(A) statistical methods.
(B) x-ray beams.
(C) ultraviolet observations.
(D) radar reflections.
(E) gravitational waves.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 3 students
(B) : 0 students
(C) : 4 students
(D) : 3 students
(E) : 3 students

Astronomy current events question: TRAPPIST discovery of three habitable zone exoplanets

Astronomy 210L, spring semester 2016
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!)
Michaël Gillon, "Life Elsewhere in the Universe? A New Nearby Planetary System Could Bring Soon the Answer..." (May 2, 2016)
ulg.ac.be/cms/c_7453882/en/life-elsewhere-in-the-universe-a-new-nearby-planetary-system-could-bring-soon-the-answer
The TRAPPIST robotic telescope discovered three habitable zone exoplanets as they __________ their ultra-cool dwarf star.
(A) gravitationally pulled.
(B) broke away from.
(C) collided with.
(D) passed in front of.
(E) reflected light from.

Correct answer: (D)

Student responses
Section 30680
(A) : 0 students
(B) : 5 students
(C) : 0 students
(D) : 4 students
(E) : 4 students

20160512

Astronomy quiz archive: Milky Way, cosmology

Astronomy 210 Quiz 7, spring semester 2016
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz07N4rK


Section 30674
0- 8.0 :   * [low = 8.0]
8.5-16.0 :   *****
16.5-24.0 :   ******** [mean = 19.1 +/- 6.1]
24.5-32.0 :  
32.5-40.0 :   ** [high = 33.0]


Section 30676, version 1
Exam code: quiz07SrRy


Section 30676
0- 8.0 :   ***** [low = 0.0]
8.5-16.0 :   ************
16.5-24.0 :   *************** [mean = 20.7 +/- 9.0]
24.5-32.0 :   ***********
32.5-40.0 :   ******* [high = 36.5]

20160511

Online reading assignment: origin of life, are we alone? (SLO campus)

Astronomy 210, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"Seeing Julia Child in the presentation, this was interesting to me because I never knew she used that kind of technology to cook."

"That shocking representation of how little time we as humans have actually been on Earth. I also found the idea of goldilocks planets interesting because it means potential for finding other life sources out there."

"That 'Here is Today' timeline kind of blew my mind."

"The LEGO® bricks, I never thought something like that could be possible. The more you know I guess."

"The Drake equation was particularly interesting to me. Although we don't have the measurements of all the factors it still reveals a lot about our place in the universe."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I'm still a little confused on the Drake equation. What's the point of making an equation where you can't possibly know so many of the factors?"

"Something I found confusing was what is defined as living on a different plant, should bacteria count as an alien?"

"I was really confused by the LEGO® article. Is it about washing LEGO® bricks in socks and they will form structures?"

"I don't see why the government doesn't provide funding if it costs so little. It doesn't seem too controversial. The most they can say is that it's insignificant but it also requires insignificant funding."

"I guess how is it that atheists only reply on science to explain how simple chemicals become complex chemicals. I'm not religious but it's interesting to watch atheists try and answer all of these questions."

Briefly describe a difference between life and non-living things.
"Something that is living often requires some sort of resource(s) to maintain itself."

"Living things take in energy and non-living things don't"

"Non-living things do not exhibit any characteristics of life. They do not grow, respire, need energy, move, reproduce, evolve, or maintain homeostasis."

"Something that is living will reproduce in some way and start another generation and non-living things do not."

"The transmission of information from one molecule to another!"

"Life has living cells and they can reproduce. Non-living things can have chemical reactions."

"Non-living things are dead and living things are alive."

How important is it to you to know whether or not there may be life elsewhere other than on Earth?
Unimportant.  [0]
Of little importance.  **** [4]
Somewhat important.  ***** [10]
Important.  ********* [9]
Very important.  ** [2]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"Even if there is other life out there, I doubt it will have much of an effect on us. Unless they figured out how to travel space faster than we ever though possible."

"It's important because the more we know about other planets, the more we know about how we became a part of this world."

"I'm extremely curious to know whether or not there is life on other planets, but I don't believe that knowing would have a huge impact on my life; or rather, that I would benefit from knowing."

"I feel like the universe is so huge and that if life was able to develop on earth there could be a chance that life is elsewhere. I feel like its ignorant to think that we are the only living beings out there."

"Searching for life in other parts of the universe is also a way of answering questions about ourselves. Where did we come from? Why are we here?"

"Because humans suck and I want to marry a Kryptonian."

Which type of star would be least likely to have a planet that could support life?
Massive.  *********** [11]
Medium-mass.  *** [3]
Low-mass (red dwarf).  ********* [9]
(Unsure/guessing/lost/help!)  ** [2]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).
"A massive star would die young and have harsh conditions, and be less likely to have time to be able to support life."

"I think it would be the low-mass stars because they take so long to burn out and they're hotter? But I could be wrong."

"A low-mass star is very cold and would be hard to heat a planet enough for life to form."

"Massive stars have a short lifespan."

"Low-mass star, because it would be cold and wouldn't support life."

"I think a low mass star is the least likely to host life-harboring planets because they are very small and cool relative to other stars. In order for a planet to be in the habitable zone of a low mass star, it would have to be incredibly close to the star, to the point of dangerously close, something that seems rather unlikely."

Describe what the Drake equation is used for.
"The Drake equation is used for calculating how likely it is for a civilization to arise in a galaxy."

"To find out how many planets in the Milky Way could sustain life."

"Used to arrive at an estimate of the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy."

"It is used to find the number of advanced technological civilization in the Milky Way."

"Other life."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible. ***  [3]
Not very plausible. **************  [14]
Somewhat plausible. ******  [6]
Very plausible.  [0]
(Unsure/guessing/lost/help!) **  [2]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Do you believe we are the only life in the universe?"

"What is your opinion on the Chilbolton message?"

"If we sent the Chilbolton message 30 years ago to a system thousands of light years away, why do people expect the reply to have arrived so quickly?"

"What are you and Mrs. P-Dog doing over summer break?" (This. #heretodaygonetomaui #thelifeofthelandisperpetuatedinrighteousness)

20160510

Online reading assignment: origin of life, are we alone? (NC campus)

Astronomy 210, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"Wondering if life may exist somewhere else."

"Here Is Today."

"Primordial soup. I just want to know how it all started and the soup is a start."

"How little time we've existed...but have managed to do so much harm."

"The possibility of extra-terrestrial life, I've always wondered if aliens existed."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The Drake equation was a little confusing to me."

"How do we find life on other planets?"

"Nothing was really all that confusing."

Briefly describe a difference between life and non-living things.
"Life is the process that a living thing goes through. Non-living things don't go through that process."

"Life is something that drinks water and non-living things don't drink water"

"Non-living things don't require oxygen to live."

"Living things grow and reproduce."

How important is it to you to know whether or not there may be life elsewhere other than on Earth?
Unimportant.  ** [2]
Of little importance.  *** [3]
Somewhat important.  ** [2]
Important.  ** [2]
Very important.  ** [2]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"If there is life on other planets it would be a huge discovery and allow us to further understand our universe."

"If there is life on other planets it would be cool to know but nothing we could do about it."

"It'd be interesting to know, but I highly doubt there's anything "living" out there, and just "life" out there doesn't really affect me."

"Unfortunately, my answer will label me as a closed-minded individual. Because I am a Christian, and have spent many years studying the Bible to answers for life, I just don't see this as viable... I do believe the big bang is plausible, because I have read Genesis... Due to my biblical research, I don't believe there is life on other planets; therefore, it is of no importance to me... Finally, in a time where conventional wisdom and knowledge seems to be transitioning, the Bible (the true source of knowledge and wisdom) remains the same. According to our textbook and it's definition of life and the scientific research the probability of life on other planets, the evidence points to little possibility of life on other planets."

"I just think it'd be nice not to wonder anymore, and just know if there is other forms of life out there or not."

"I just really want to see an 'alien.'"

Which type of star would be least likely to have a planet that could support life?
Massive.  ***** [5]
Medium-mass.  [0]
Low-mass (red dwarf).  ** [2]
(Unsure/guessing/lost/help!)  **** [4]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).
"The massive star wouldn't be around long enough for life to begin."

"Low-mass because it would be cold and wouldn't support life."

"Confused."

"I think it would be a massive star, because its short lifespan would create harsh conditions."

"I want to say low-mass but I'm really not too sure. In fact, I'm probably wrong. But that is what I am going with."

Describe what the Drake equation is used for.
"It helps us consider the possibility of life other than Earth."

"For estimating the number of advanced technological civilizations in the Milky Way."

"It's used to make new Drake songs so we can enjoy them."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible.  ** [2]
Not very plausible.  ***** [5]
Somewhat plausible.  **** [4]
Very plausible.  [0]
(Unsure/guessing/lost/help!)  [0]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"What is your opinion on the Chilbolton message?"

"Do YOU believe there are "living" beings out there? What's your favorite alien movie? Independence Day, Men In Black, Signs, Star Wars, Guardians of the Galaxy? Any of the many others?" (Meh, meh, no, yes, yes.)

"Do you believe there are other forms of life somewhere out there?"

20160509

Online reading assignment: QED, strong, weak interactions

Physics 205B, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading presentations Feynman diagrams (Phillip "Flip" Tanedo, Cornell University/USLHC Collaboration) and quantum electrodynamics (QED) (Christopher "Bot" Skilbeck, cronodon.com).

"The Feynman family poses by the famous camper"
Ralph Leighton
symmetrymagazine.org/article/may-2014/saving-the-feynman-van

Selected/edited responses are given below.

Describe what you understand from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically demonstrate your level of understanding.
"Well I understand now from the reading that when electrons come closer together, they will repel (knew this already), the virtual photon that is exchanged is the physical result of the repelling of forces (what I did not know) between electrons. This is what Yukawa discovered which developed into his quantum field theory after he determined that the neutron-proton interaction within an atomic nucleus diminishes rapidly for distances greater than about 2 fm (femtometer, 1 fm = 10−15 m). This actually helps paint the picture as to the decrease in energy of a particle within a nucleus as it travels through subsequent orbitals away from the nucleus (If I remember my chemistry correctly). Thanks, physics!"

"A system creates a highly energetic virtual particle, then that particle is shorter-lived, and since no such particle is assumed to travel faster than light, this means that the particle can not travel as far before it disappears and so the force has a shorter range."

"From what I understand of this section (which is not much) I understand the different types of elementary particles. I also understand the logic of the Feynman diagrams, I'm just not too sure I understand them at the moment."

"Quantum Electrodynamics is the theory of the electromagnetic interaction; the interaction between electrically charged particles "mediated by photons.'"

"Basically these diagrams require an in and an out. They aren't valid if the arrows are both pointing in or both out. You read them from left to right and that determines whether or not they're absorbing energy or releasing it."

"I understand that time traveling from left to right, it’s just that the photon-exchange occurs in the middle and can proceed in either direction. I also understand that the first-order processes dominate and the higher-order processes can usually be ignored, though some of them produce important physical effects and they may become more important at very high energies."

"I understand about as much as I did after the last lesson. I follow the lines and the squiggles, and that is what I understand so far."

Describe what you found confusing from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically identify the concept(s) that you do not understand.
"Feynman diagrams are just too much!!"

"For some reason it is hard for me sometimes to determine the charge of the interaction particle."

"I was confused as to why I did better on the midterm than I thought I was going to do."

"I do not understand how a positron mathematically can represent a electron particle going back in time, like I understand as how one can just say that but they don't 'really' mean it. However, I am having trouble as to determining what would make someone say that? My head is certainly not wrapping itself around this whole nuclear physics thing, first time reading this I was thinking, "Can subatomic particles actually move back in time?'"

"I have a hard time figuring out what the whole picture means--when the symbols are put together from the individual squiggles."

"I probably find everything to be confusing. I'm catching up though and from what I've heard, this stuff isn't that bad. I'll okay."

The above (valid) Feynman diagram depicts an electron exerting a (repulsive) electric force on another electron. The charge of the "virtual" photon (γ) exchanged between them is:
negative.  ******* [7]
zero.  ******* [17]
positive.  ******** [8]
(Unsure/guessing/lost/help!)  ***** [5]

The above (valid) Feynman diagram depicts two nucleons exerting (attractive) forces on each other. The charge of the pion (π) exchanged between them is:
negative.  ******* [7]
zero.  **** [4]
positive.  ************* [18]
(Unsure/guessing/lost/help!)  ******** [8]

The above (valid) Feynman diagram depicts weak force interaction between a proton and a electron. The charge of the "intermediate vector boson" (W) exchanged between them is:
negative.  ***** [5]
zero.  ************ [12]
positive.  ********** [10]
(Unsure/guessing/lost/help!)  ********** [10]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I met the coolest Golden Retriever today. His name was Tully, and I have been granted permission to hangout with him one-on-one this Friday. P-dog, you're invited too, come if you want! Also, I am taking pride in this comment, so...MY NAME IS __________ AND I'M HANGING OUT WITH A GOLDEN RETRIEVER THIS FRIDAY AND YOU AREN'T."

"LAST WEEK OF CLASSES!!!!! WE ARE ALMOST THERE!!!! JUST KEEP PUSHNG GUYS!!!"

"REVIEW!!!"

"I'm going to miss coming to physics."

"Will this stuff be on the final?" (Yes--refer to the study guide. But survive Quiz 7, first.)

"I AM SO LOST. How do you know if a Feynman diagram shows annihilation, pair production, photon emission or absorption? And now we are throwing negative, positive, and neutral charges in the mix! :O I need clarification. :O" (Feynman diagram emoji: >~~~~<)

20160508

Astronomy current events question: supernovae remnants on Earth's ocean bottoms

Astronomy 210L, spring semester 2016
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!)
Phil Dooley, "Supernovae Showered Earth with Radioactive Debris" (April 7, 2016)
anu.edu.au/news/all-news/supernovae-showered-earth-with-radioactive-debris
Material found on Earth's ocean bottoms may be remnants of two nearby recent supernova explosions, as determined from its:
(A) speed and trajectory.
(B) radioactivity.
(C) neutrino emissions.
(D) lack of organic compounds.
(E) electrostatic charge.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 1 students
(B) : 12 students
(C) : 5 students
(D) : 10 students
(E) : 3 students

Astronomy current events question: Cassini sampling interstellar dust

Astronomy 210L, spring semester 2016
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!)
Emily Baldwin, "Saturn Spacecraft Samples Interstellar Dust" (April 14, 2016)
nasa.gov/feature/jpl/saturn-spacecraft-samples-interstellar-dust
NASA's Cassini spacecraft collected dust grains that originated from outside the solar system, as determined from their:
(A) speed and trajectory.
(B) radioactivity.
(C) neutrino emissions.
(D) lack of organic compounds.
(E) electrostatic charge.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 9 students
(B) : 3 students
(C) : 6 students
(D) : 6 students
(E) : 3 students

Astronomy current events question: Venus Express' ultimate experiment

Astronomy 210L, spring semester 2016
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!)
Ingo Müller-Wodarg, Sean Bruinsma, Jean-Charles Marty, and Håkan Svedhem, "Venus Express' Swansong Experiment Sheds Light on Venus' Polar Atmosphere" (April 19, 2016)
sci.esa.int/venus-express/57735-venus-express-swansong-experiment-sheds-light-on-venus-polar-atmosphere/
The European Space Agency's Venus Express spacecraft collected data on Venus' atmospheric density and temperature by measuring:
(A) absorption spectra.
(B) bouncing radar signals.
(C) launching remote probes.
(D) aerobraking drag forces.
(E) reflected sunlight.

Correct answer: (D)

Student responses
Sections 30678, 30679, 30680
(A) : 6 students
(B) : 8 students
(C) : 4 students
(D) : 8 students
(E) : 1 student

Physics midterm question: inserting new dielectric into capacitor

Physics 205B Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

The insulating material between the plates of a capacitor that is connected to an ideal emf source is replaced with a different material of the same thickness. This is done to increase the electric potential energy of the capacitor. Discuss why the capacitance also increases. Explain your reasoning by using the properties of capacitors, charge, electric potential, and energy.

Solution and grading rubric:
  • p:
    Correct. Recognizes that the potential difference ΔV applied to the capacitor does not change (as it still connected to its emf source), uses at least one of two similar arguments:
    1. because the electric potential energy is stated as increasing, then from EPE = (1/2)⋅Q⋅ΔV, then the charge Q in the capacitor must increase, and then from C = QV an increasing Q (with ΔV constant) means that the capacitance C must increase; or
    2. from using EPE = (1/2)⋅C⋅(ΔV)2, increasing EPE with ΔV constant means that the capacitance C must increase.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. May not explicitly recognize that the potential difference ΔV applied to the capacitor is constant.
  • 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. Some attempt at applying properties of capacitors, charge, electric potential, and energy.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than that of applying properties of capacitors, charge, electric potential, and energy.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: midterm02Mc4s
p: 20 students
r: 7 students
t: 5 students
v: 10 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1104):

Another sample "p" response (from student 3214):

Physics midterm question: equally bright, different resistance light bulbs

Physics 205B Midterm 2, spring 2016
Cuesta College, San Luis Obispo, CA

An 6.0 V emf source is connected to a resistor r, and two light bulbs with different resistances R1 and R2. Both light bulbs have the same brightness. Discuss why R1 > R2. Explain your reasoning using Kirchhoff's rules, Ohm's law, and electric power.

Solution and grading rubric:
  • p:
    Correct. Discusses/demonstrates how R1 > R2 using at least one of two similar arguments:
    1. the current that flows through the R2 light bulb and emf splits in parallel through both the resistor and the R1 light bulb, such that I2 is greater than I1, and given P1 = P2, then (I1)2R1 = (I2)2R2, and since I2 is greater than I1, then R2 must be less than R1; or
    2. the current that flows through the R2 light bulb and emf splits in parallel through both the resistor and the R1 light bulb, such that I2 is greater than I1, and given P1 = P2, then I1⋅ΔV1 = I2⋅ΔV2, and since I2 is greater than I1, then ΔV2 is less than ΔV1, such that I2R2 is less than I1R1, and again from I2 is greater than I1, thus R2 must be less than R1.
  • 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. May use the statement to be proved (R1 > R2) and given information (P1 = P2) to instead demonstrate how I2 is greater than I1 and/or ΔV2 is less than ΔV1; or does not sufficiently show how either I2 is greater than I1 and/or ΔV2 is less than ΔV1 in order to prove that R1 > R2.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some attempt at applying properties of Kirchhoff's rules, Ohm's law, and electric power.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than that of applying Kirchhoff's rules, Ohm's law, and electric power.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Sections 30882, 30883
Exam code: midterm02Mc4s
p: 8 students
r: 4 students
t: 11 students
v: 15 students
x: 4 students
y: 0 students
z: 0 students

A sample "p" response (from student 1157):

Physics midterm question: total magnetic field of two perpendicular wires

Physics 205B Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

Two straight wires carry equal amounts of current, crossing perpendicular to each other in the plane of the page. Discuss why the direction of the total magnetic field at the location shown points out of the page. Show your work and explain your reasoning using the properties of magnetic fields, and superposition.

Solution and grading rubric:
  • p:
    Correct. Clearly discusses or draws diagrams showing how from RHR2 the magnetic field from each wire points out of the xy plane in the lower right quadrant, resulting in a total magnetic field that points in that direction.
  • 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. Some attempt at applying properties of magnetic fields, and superposition.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than that of applying properties of magnetic fields, and superposition.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: midterm02Mc4s
p: 26 students
r: 2 students
t: 1 student
v: 13 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1157):

Physics midterm question: loop descending into uniform magnetic field

Physics 205B Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

A square metal loop of resistance R (seen edge-on) is dragged down into a region with an external magnetic field that points into the plane of this page. Discuss why there will be no induced current in the loop while it enters into this region. Explain your reasoning using the properties of magnetic fields, forces, motional emf, Faraday's law and Lenz's law.

Solution and grading rubric:
  • p:
    Correct. Explains how there is no induced current in the loop using at least one of two similar arguments:
    1. plane of square metal loop is parallel to the magnetic field, such that there is zero magnetic flux through the loop, and since the magnetic flux is constantly zero, then there is no induced emf, and thus no induced current in the loop; or
    2. from using RHR1, the force on the fictitious positive charges in the square metal loop is to the right (in the +x direction), such that for the section of the loop closest to the viewer, this would induce a counterclockwise current (as viewed down into the magnetic field, along the −y direction), but in the section of the loop farthest from the view, a clockwise current is induced, such that there will be no (net) induced current in the loop.
  • 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. Some attempt at applying properties of magnetic fields, forces, motional emf, Faraday's law and Lenz's law.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. Approach other than that of applying properties of magnetic fields, forces, motional emf, Faraday's law and Lenz's law.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: midterm02Mc4s
p: 17 students
r: 7 student
t: 5 students
v: 10 students
x: 3 students
y: 0 students
z: 0 students

A sample "p" response (from student 1614), discussing the Lorentz force exerted on fictitious positive charges in the top and bottom segments of the wire loop:

A sample "p" response (from student 3214), using both the Lorentz force, and also applying Lenz's law to the changing flux through the wire loop:

Physics midterm problem: change in voltmeter reading

Physics 205B Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

A "AA" alkaline battery with an emf of 1.5 V and an internal resistance of r = 0.90 Ω is attached to an ideal voltmeter, with a R = 2.0 Ω light bulb that is wired in parallel with an open switch. Discuss why the voltmeter will have a lower reading after the switch is closed. Show your work and explain your reasoning using Kirchhoff's rules, Ohm's law, and properties of voltmeters.

Solution and grading rubric:
  • p:
    Correct. Recognizes that when the switch is open, the voltmeter will have a non-zero reading, and have a lower (zero) reading when the switch is closed, using one of two similar arguments:
    1. when the switch is open, there is a non-zero ΔV = +1.5 V − Ir reading, and when the switch is closed, from Kirchhoff's loop rule the voltage rise of +1.5 V from the emf must now exactly equal the −Ir voltage drop of the internal resistance of the battery, such that the voltmeter reading is now zero; or
    2. when the switch is open, there is a non-zero ΔV = − IR reading, and when the switch is closed, since the light bulb R is bypassed by a zero resistance switch, making ΔV = 0.
  • r:
    Nearly correct, but includes minor math errors. Does not sufficiently show numerically or qualitatively how voltmeter reading when switch is open is higher versus when the switch is closed.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. At least has a conceptual understanding of how a voltmeter measures a potential difference, and how the switch changes the current flow when it is open versus when it is closed.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Some attempt at applying Kirchhoff's rules, Ohm's law, and equivalent resistance.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. Approach other than that of applying Kirchhoff's rules, Ohm's law, and properties of voltmeters.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 30882, 30883
Exam code: midterm02Mc4s
p: 7 students
r: 17 students
t: 4 students
v: 12 students
x: 2 students
y: 0 students
z: 0 students

A sample "p" response (from student 3158):

Another sample "p" response (from student 5433):

20160504

Astronomy in-class activity: monolithic collapse hypothesis, stellar populations

Astronomy 210 In-class activity 22 v.16.05.04, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet to discuss different metallicities and ages of stars in the monolithic collapse hypothesis of the Milky Way.


Astronomy in-class activity: speed of light and look-back time

Astronomy 210 In-class activity 23 v.16.05.04, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet on the effect of the finite speed of light on look-back time.


Online reading assignment: Milky Way history, big bang clues (SLO campus)

Astronomy 210, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on the history of the Milky Way and big bang clues, a comic strip adaptation of of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"How our bodies' composition came directly from star deaths. The formation of who we are intrigues me."

"That when we look at Deneb, we are seeing it how it was 1,400 years ago."

"The big bang because it's crazy to me how people still don't believe it to be true"

"The big bang theory, because I like the TV show The Big Bang Theory, it's funny."

"I thought that the look-back time part was really interesting. The fact that we are viewing stars as they were years and years ago is another part of astronomy that blows my mind!"

"I liked learning about the big bang theory because its something you hear about as far back as elementary school so it was interesting to hear actual scientific explanations about it."

"That the Milky Way galaxy became what it is today by accumulating other galaxies and how our galaxy has so many different types of stars."

"To learn that the universe is getting dirtier and dirtier as more hydrogen is being formed into metals, and that we are made up of the dirt resulting from the formation of the planet, because I'd never thought of it this way before."

"That we are able to tell distinguish between older and younger stars by looking at absorption lines from atoms in their outer layers. This is interesting to me because the elements in the outer layers of stars are giving us insight to their age."

"That older stars are metal-poor while newer stars are metal-rich. I would think it would have been the other way around."

"The 'edge of the universe' is incredibly interesting to me. The fact that it isn't the non-objects that we're seeing but non-time makes so much sense that it just generates question after question."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"how looking at distance stars represents how they looked back in the day, not how they are now."

"I found light speed look back times to be the most confusing because I don't understand how we can somewhat look into the past."

"That stars were around for so long before us, where did we REALLY come from?"

"Why people find The Big Bang Theory TV show funny."

"Metal-rich versus metal-poor was super confusing, and it's confusing because I don't understand."

"The Hubble law was confusing to me. The nature of the expansion was unclear."

"The difference in metals between younger and older stars."

"What was there before the universe? How are scientists able to talk about what happened before the universe when it wasn't even born yet?"

"Metallicity. Not exactly sure what that is."

"I didn't really get the whole 'we are made of stars' things."

"Not sure about the edge of the universe. How do we know it isn't infinite? Is it possible we have not developed technology good enough to see 'farther into the forest?'"

"I thought all the elements came from Earth."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [78%]
Metals (elements heavier than hydrogen and helium): increased [81%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  ****** [6]
young stars that formed very recently.  **************************** [28]
(There is a tie.)  [0]
(Neither, as stars cannot have metals.)  * [1]
(Unsure/guessing/lost/help!)  ** [2]

Indicate what produced these elements.
(Only correct responses shown.)
Helium in the sun's core: the sun [65%]
Carbon in your body: another star, in the past [57%]
Calcium in your bones: another star, in the past [57%]
Iron in your blood: another star, in the past [57%]
Gold and silver from mines: another star, in the past [57%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Please don't make the final too hard." (Sure, just "hard enough" will do.)

"How big of a bang was the big bang?" (Well, it wasn't a "bang" so much as a gradual expansion of the space between galaxies, but it is/was "big," as the expansion is everywhere in this infinite universe.)

"Do you believe in the big bang theory?" (Well, I understand that it is the most consistently explanation for the factual observations we see out in the universe around us--that the night sky is dark, and that galaxies are all receding away from each other.)

"If we kept going in space through the dark would it eventually become bright or will it always be dark no matter how far you see/go?" (It would be dark, with no stars, as you would be looking out into the past, before there were any stars. However, looking further out, you would be looking so far back out into the past that you would see the faint energy remnants of the early big bang. But you can't look out further than that.)

"Is the starting point of the universe, where the big bang occurred, in the center?" (Since the universe started with zero space between everything, everything was "in the center," but this is a somewhat misleading concept, as there is no unique "center" in an infinite, expanding universe.)

20160503

Astronomy midterm question: IAU classification of centaurs

Astronomy 210 Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

In our solar system, "centaurs" are objects that:
...circulate [around the sun] between Jupiter and Neptune on unstable orbits that cross the paths of one of the jovian planets. That means they're probably doomed, within ten million years or so, to be flung into the inner solar system or out into interstellar space... There's a lot that's not known about centaurs, including how many have enough gravity to pull themselves into a round shape, which would earn them the title of "dwarf planet."[*]
Discuss how centaurs that are not dwarf planets should be classified. Explain using the International Astronomical Union classification scheme.

[*] Marcus Woo, "First Asteroid With Rings Discovered" (March 26, 2014), on.natgeo.com/1h3G1oI.

Solution and grading rubric:
  • p:
    Correct. Of the three IAU requirements (orbits the sun directly, has a rounded shape, cleared/dominates its orbit), a dwarf planet satisfies the first two. A centaur that is not able to be a dwarf planet would then not be rounded in shape, but still share an orbit around the sun with the jovian planets, classifying it as solar system debris.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Understands how IAU requirements apply in correctly categorizing centaurs that aren't dwarf planets must be solar system debris, but discussion of requirements is not explicit, or only implied.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Explicitly lists IAU requirements, but does not apply them correctly/consistently.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Discussion only tangentially related to the IAU classification scheme.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion unrelated to the IAU classification scheme.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30674
Exam code: midterm02n4s5
p: 10 students
r: 3 students
t: 7 students
v: 2 students
x: 0 students
y: 0 students
z: 0 students

Section 30676
Exam code: midterm02sLoX
p: 28 students
r: 6 students
t: 18 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1597) using the IAU classification flowchart:

Astronomy midterm question: same luminosity, but different temperature and size stars

Astronomy 210 Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
??: If two stars have the same luminosity, is it always true that the star with the lower temperature must be bigger?
qcp: Yes, that's true. A cooler star means that it must be bigger to be of equal 
luminosity.
Discuss why this answer is correct, and how you know this. Explain using Wien's law, the Stefan-Boltzmann law and/or an H-R diagram.

[*] answers.yahoo.com/question/index?qid=20160402221522AAZkrDm.

Solution and grading rubric:
  • p:
    Correct. Uses Wien's law, the Stefan-Boltzmann law and/or interprets H-R diagram to demonstrate how a cooler star must be bigger than a hotter star to have the same luminosity.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. At least discussion demonstrates understanding of Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not based on Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30674
Exam code: midterm02n4s5
p: 12 students
r: 3 students
t: 3 students
v: 1 student
x: 2 students
y: 1 student
z: 0 students

A sample "p" response (from student 1503), using both the "box method" to fill in relative Stefan-Boltzmann law parameters, along with using the diagonal lines on an H-R diagram to compare size:

A sample "x" response (from student 1096), appealing to recent tragic events in pop culture:

Astronomy midterm question: red dwarf same size as white dwarf?

Astronomy 210 Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
??: Can a red dwarf have the same size as a white dwarf?
Bpt: They can have the same size if the red dwarf was dimmer than the white dwarf.
Discuss why this answer is correct, and how you know this. Explain using Wien's law, the Stefan-Boltzmann law and/or an H-R diagram.

[*] answers.yahoo.com/question/index?qid=20160402083607AA27vRN.

Solution and grading rubric:
  • p:
    Correct. Uses Wien's law, the Stefan-Boltzmann law and/or interprets H-R diagram to demonstrate how a red dwarf can be the same size as a white dwarf by recognizing that:
    1. from Wien's law, the red dwarf is cooler than the white dwarf;
    2. from the Stefan-Boltzmann law (or interpreting an H-R diagram), the lower temperature red dwarf must have a lower luminosity than a white dwarf of the same size.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. At least discussion demonstrates understanding of Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not based on Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30676
Exam code: midterm02sLoX
p: 37 students
r: 8 students
t: 4 students
v: 3 students
x: 2 students
y: 0 students
z: 0 students

A sample "p" response (from student 0796), using the "box method" to fill in relative Stefan-Boltzmann law parameters:

A sample "p" response (from student 5713), using the diagonal lines on an H-R diagram to compare size:

A sample "p" response (from student 8041):

Astronomy midterm question: star cluster with white dwarfs?

Astronomy 210 Midterm 2, spring semester 2016
Cuesta College, San Luis Obispo, CA

Discuss which H-R diagram is more likely to be a star cluster with type II supernovae (which are deliberately not shown). Explain using the properties of mass and stellar lifetimes, evolution of stars, and star cluster ages.

Solution and grading rubric:
  • p:
    Correct. Understands that:
    1. stars in the same cluster are all born at the same time, but massive stars evolve faster than medium-mass stars, which evolve faster than low-mass stars (the "house party" analogy);
    2. medium-mass stars end their main-sequence lifetimes by becoming giants, planetary nebulae, and then white dwarfs;
    3. such that for medium-mass stars to have reached their end stage, massive stars have already gone through all their stages and have exploded as type II supernovae (and no longer appear on an H-R diagram), while low-mass stars have just begun their main-sequence life as red dwarfs.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Typically at least understands correlation between mass and main-sequence lifetimes.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion other than that of the properties and evolution of stars.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30676
Exam code: midterm02n4s5
p: 3 students
r: 6 students
t: 10 students
v: 3 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1503) discussing the "house party model":

Another sample "p" response (from student 1758):