20170228

Online reading assignment: quantum leaps, sun's outer layers (NC campus)

Astronomy 210, spring semester 2017
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 quantum leaps, and the sun's outer layers.


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.
"That sunspots are magnetic."

"The miso soup portion because I enjoy it and had it Friday before reading the presentation and thought it would be a good astronomy connection."

"Comparing the sun to the wings and fire-spitting cobras was cool. I never knew that was a thing. The Egyptians had amazing imaginations! However, I do see why they related the two! Too cool :)"

"The sun's corona; that it was named after the Greek word for 'crown.' It's neat that even though you can't see it during the daytime, you can see parts of it during a total solar eclipse."

"The chemistry is interesting to me. I am also taking chemistry this semester, so it's interesting to see the chemistry behind astronomy."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I sort of found the way they explained electrons, absorption, and other things they explained about atoms, as I have always heard it described somewhat differently."

"I found the two rules, photon and electron rules, somewhat confusing. Can't really explain why it was confusing, it just was."

"Understanding the different energy levels of an electron is a little bit confusing. How exactly do you move an electron from a low energy to a high energy level?"

"It is easy to mix up how electrons move between orbitals."I'm not really confused on anything yet. I do believe I may have a question once we are in class and talking about everything though. Other students usually help spark questions in my head ;)"

An electron in an atom must emit a photon when it jumps from a __________ energy orbital to a __________ energy orbital.
lower; higher.  ** [2]
higher; lower.  ****************** [18]
(Both of the above choices.)  [0]
(Unsure/guessing/lost/help!)  [0]

An electron in an atom must absorb a photon when it jumps from a __________ energy orbital to a __________ energy orbital.
lower; higher.  ******************* [19]
higher; lower.  * [1]
(Both of the above choices.)  [0]
(Unsure/guessing/lost/help!)  [0]

The exterior of the sun, from inner to outermost layers, are the:
(Only correct responses shown.)
inner: photosphere [85%]
middle: chromosphere [85%]
outer: corona [80%]

State your preference regarding miso soup.
Strongly dislike.  [0]
Dislike.  **** [4]
Neutral.  **** [4]
Like  *** [3]
Strongly like.  **** [4]
(I don't know what miso soup is.)  ***** [5]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"With regards to the blueshift and redshift Doppler effect for light, it is kind of like a car's lights. Blue-ish headlights coming at you (the distance between you and the car is growing shorter), vs the red taillights when it's driving away from you (distance is growing longer) :) That's an easy way to remember it for me!"

"Miso soup?"

"Please tell us what miso soup is ;)"

"I like the smell of miso soup, just haven't become a huge fan of the taste of it yet. Plus I am not a huge fan of tofu."

"Thanks for reminding us that the sun is not literally a bowl of miso soup, for a second there I started thinking it was."

"It feels like we are way ahead in class--can we slow down? It's a little weird taking a quiz on things we went over a few weeks ago, and then learning something completely different after the quiz." (We will definitely slow down after today to review for the upcoming midterm, and then review for the quiz after that. We just needed to go over stuff first before we can review it later.)

"When will we get a chance to see the telescopes?" (Next scheduled date is late March, if it stops raining long enough that the swampy path out to the telescope shelter will dry out.)

"So looking at all the eclipses on timeanddate.com, is that all the different eclipses we will ever see from Paso Robles in the next three years? Or could more be discovered?" (Since eclipses can be predicted accurately, then that's all the eclipses that will occur within the next three years.)

"Will this question be shown in class?" (Yes.)

"I love your teaching methods and patience with everyone as a whole, you're a great teacher, very interesting, relatable, and let us understand with light effort."

20170227

Physics quiz question: focal length of microscope objective lens

Physics 205B Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA

A Leitz Ortholux microscope[*] (–47× magnification) has an eyepiece lens with a focal length of +1.8 cm, and a 17.0 cm distance between the objective and eyepiece. The focal length of the objective lens is:
(A) +0.53 cm.
(B) +4.5 cm.
(C) +15.2 cm.
(D) +85 cm.

[*] microscopy-uk.org.uk/mag/artnov15/The%20Mechanical%20Tube%20Length%20Version%201.pdf.

Correct answer (highlight to unhide): (B)

The angular magnification M of a microscope is given by:

M = –(LfeN/(fo·fe),

where L is the distance between the objective and eyepiece, N = 25 cm is the nominal value for the near point, and fo and fe are the focal lengths of the objective and eyepiece, respectively. Thus with the given values given in the statement of the problem, the focal length of the objective can be solved for:

fo = –(LfeN/(M·fe),

fo = –(17.0 cm – 1.8 cm)·(25 cm)/((–47)·(1.8 cm)),

fo = +4.4917257683 cm,

or to two significant figures, the focal length of the objective is +4.5 cm.

(Response (A) is N/M; response (C) is Lfe; response (D) is M·fe.)

Sections 30882, 30883
Exam code: quiz02J4sZ
(A) : 1 student
(B) : 21 students
(C) : 5 students
(D) : 3 students

Success level: 70%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43

Physics quiz archive: lenses, optical instruments

Physics 205B Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA
Sections 30882, 30883, version 1
Exam code: quiz02J4sZ



Sections 30882, 30883 results
0- 6 :  
7-12 :   **** [low = 9]
13-18 :   ********
19-24 :   ********** [mean = 20.2 +/- 6.6]
25-30 :   ******** [high = 30]

Online reading assignment: diffraction, charges and materials

Physics 205B, spring semester 2017
Cuesta College, San Luis Obispo, CA

Students have a bi-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 diffraction and charges and materials.

Note the fainter fringes on either side of the central maximum 'spread.'

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.
"Diffraction is the spread of light from a single slit."

"Due to the diffraction minima equation, if there is a smaller slit opening, it would result in an increase of the spread of the diffracted waves and if you make the slit opening larger, it would result in decreasing the spread of the diffracted waves."

"Electrons in an insulator are constrained to their atoms, while a conductor has atoms that are more free to move around."

"When a neutral insulator (the electrons are pretty fixed in place) is placed near an object that has a charge there is a net attraction depending no matter what the charge is of the object. If a conductor (the electrons are way more free-moving) is placed near a charged object the electrons move away if it is negative or towards the object if it is positively charged."

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.
"I don't understand why it is that the smaller slit gets a larger spread or vise versa."

"The mobility of electrons part was a bit confusing for me."

"I am having trouble understanding how a neutral insulator or conductor has always has a net attraction towards a charged object, regardless if it is negatively or positively charged.

Match the single slit parameter with its symbol. (Only correct responses shown.)
Width of a single slit: W [96%]
Any positive or negative non-zero whole number: m [76%]
Distance from the slit to a projection screen: L [84%]
Wavelength of light passing through the slit: λ [96%]
Direction, as measured from the centerline: θ [60%]
Position along screen, as measured from the centerline: y [48%]

A gas pump fire is inadvertently caused by the sudden discharge of an electrical spark. Describe when and how the woman became electrically charged.
"She became electrically charged after she got in and out of her car. This likely occurred as she adjusted her sweater because her hands were rubbing the electrically neutral fabric."

"What kind of sorcery is this?!? But I think she was able to transfer a change in electrons from clothes to spark a fire."

"When she is getting out of the car and as she slides across the seat she becomes charged."

"The lady became statically charged when she sat in her car. She could have de-charged by touching something metal to ground herself."

"This is one of my biggest fears, so I always make sure to touch something metal before I begin pumping gas

Electrically neutral polystyrene "packing peanuts" would be attracted to a cat that has __________ charge.
a positive.  * [1]
a negative.  * [1]
either a positive or a negative.  ********************** [22]
zero (neutral).  [0]
(Unsure/lost/guessing/help!)  * [1]

An electrically neutral aluminum soda can would be attracted to a balloon that has __________ charge.
a positive.  [0]
a negative.  ** [2]
either a positive or a negative.  *********************** [23]
zero (neutral).  [0]
(Unsure/lost/guessing/help!)  [0]

Electrically neutral polar molecules in a water stream would be attracted to a comb that has __________ charge.
a positive.  * [1]
a negative.  ** [2]
either a positive or a negative.  ********************* [21]
zero (neutral).  * [1]
(Unsure/lost/guessing/help!)  [0]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Very cool to see different types of everyday things that people use or do and see physics out of it!"

"Practicing diffraction minima examples would be helpful."

"I did not feel as comfortable with the diffraction minima part of the blog. Why is the 'm' value equal to 1? Also, do minimas get categorized with a number like maximas do?" (Mathematically using m = 0 in the diffraction minima equation would give you a dark spot at θ = 0°, which is not what happens physically as the center is always bright, so we "disallow" using m = 0. Using m = 1 gives you the first minimas (dark spots) on either side of the central spot, which is effectively the "spread" of light on the screen. There are other dark (and faint light) spots farther out from the center, and so the locations of these (relatively unimportant) dark spots are given by higher values of m = 2, 3, 4, etc., until you get to θ = 90°.)

"I am slightly confused about using a hair in lab to diffract laser light--will it diffract light the same way as if it was going through a slit of the same size?" (Yes, due to Babinet's principle, light spreading out through a small opening will create the approximately same diffraction pattern as light wrapping around a small obstacle. If you think about light going through a small opening, it is curving around each side of the opening, causing light to spread out from the center. So when you look at light encountering a small obstacle, it will curve around each edge of the obstacle (and cross paths), effectively causing light to spread out from the center (ignoring most of the direct light that passes on either side of the obstacle that doesn't "wrap around" the edges of the obstacle).)

20170224

Astronomy current events question: comets falling into star HD 172555

Astronomy 210L, spring semester 2017
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!)
Donna Weaver, Ray Villard, and Carol Grady, "Hubble Detects 'Exocomets' Taking the Plunge into a Young Star" (January 6, 2017)
hubblesite.org/news_release/news/2017-02
The Hubble Space Telescope detected evidence of comets falling into star HD 172555, based on observations of:
(A) flickering star brightnesses.
(B) a young gas-giant planet.
(C) rapidly moving gaseous debris.
(D) ice crystal reflections.
(E) comet tail formation.

Correct answer: (C)

Student responses
Sections 30679, 30680
(A) : 7 students
(B) : 7 students
(C) : 13 students
(D) : 3 students
(E) : 3 students

Astronomy current events question: revised age of the moon

Astronomy 210L, spring semester 2017
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!)
Stuart Wolpert, "The Moon is Older than Scientists Thought, UCLA-led Research Team Reports" (January 11, 2017)
newsroom.ucla.edu/releases/the-moon-is-older-than-scientists-thought-ucla-led-research-team-reports
The age of the moon has been revised to be older than previously thought, based on analysis of moon samples brought to Earth by:
(A) Apollo mission astronauts in 1970.
(B) the Chinese moon rover Yutu.
(C) Google Project X.
(D) lunar impact meteorites.
(E) the aurora borealis.

Correct answer: (A)

Student responses
Sections 30679, 30680
(A) : 23 students
(B) : 3 students
(C) : 3 students
(D) : 4 students
(E) : 0 students

Astronomy current events question: extra-galactic origin of distant stars in Milky Way galaxy

Astronomy 210L, spring semester 2017
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!)
Christine Pulliam, "Farthest Stars in Milky Way Might Be Ripped from Another Galaxy" (January 11, 2017)
cfa.harvard.edu/news/2017-02
Our Milky Way galaxy's farthest known stars may have been ripped from the neighboring Sagittarius dwarf galaxy, based on matching the stars' __________ with computer simulations.
(A) positions and velocities.
(B) sizes and temperatures.
(C) ages.
(D) compositions.
(E) fusion rates.

Correct answer: (A)

Student responses
Sections 30679, 30680
(A) : 26 students
(B) : 4 students
(C) : 2 students
(D) : 1 student
(E) : 0 students

Online reading assignment: double-slit interference

Physics 205B, spring semester 2017
Cuesta College, San Luis Obispo, CA

Students have a bi-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 double-slit interference.


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.
"I know the difference between maxima and minima."

"That the path length difference relation tells us where the maxima or minima will be."

"With the double-slit interference, the source phase differences don't matter, but that just their path differences do, we are wanting to know how much longer the wave from one source travels than the wave from the other source. I also understood that in a double-slit interference condition the constructive is maxima, and a condition that is destructive is minima."

"Double slit interference is two side-by-side in-phase sources. Phase differences don't matter with this and only the path matters. When calculating this we locate where these two sources interfere constructive (maxima) or destructively (minima)."

"A really small difference in distances can put waves in interference with each other; it is interesting how much of a difference it can be."

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.
"I am not understanding the flow chart for the constructive and destructive conditions. How am I able to tell which pathway I am to choose for the condition I am given?"

"How to figure out the difference between the minima and maxima for double-slit interference."

"Path length differences. I'm just not fully understanding on how to find it."

"I don't really understand what double-slit interference is."

Explain the difference between "maxima" and "minima" in double-slit interference.
"Constructive interference is maxima and minima is destructive interference."

"The difference between the two is that the maxima is when there is a constructive interference or when the path difference is a multiple of the wavelength. A minima happens when there is a destructive interference or when the path difference is either an odd number of half wavelengths."

"No idea."

"I'm trying to understand it."

"Maxima and minima is the minimum and maximum of wavelength?"

Match the double-slit parameter with its symbol. (Only correct responses shown.)
Distance between slits: d [77%]
Any positive or negative whole number: m [77%]
Distance from slits to a projection screen: L [41%]
Wavelength of light passing through both slits: λ [100%]
Difference in paths for light passing through both slits: d·sinθ [50%]
Position along screen, as measured from the centerline: y [46%]

Identify the characteristics of the sources, path difference, and interference type. (Only correct responses shown.)
Sources: in phase [95%]
Path difference: integer number of wavelengths [91%]
Interference: constructive [91%]

Identify the characteristics of the sources, path difference, and interference type. (Only correct responses shown.)
Sources: in phase [59%]
Path difference: odd number of half wavelengths [86%]
Interference: destructive [77%]

Identify the characteristics of the sources, path difference, and interference type. (Only correct responses shown.)
Sources: in phase [73%]
Path difference: integer number of wavelengths [82%]
Interference: constructive [68%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Can we discuss the difference between maxima and minima in double-slit interference?

"Do we call it maxima/minima only when we're talking about interfering waves?" (Well, yes, but this works for both interfering sound waves (loud/quiet regions) or interfering light waves (bright/dark regions).)

"Petition for more long weekends!"

"Did you ride any emus over the long weekend?" (No, but Mrs. P-dog and I went snowshoeing up in the mountains.)

20170222

Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (SLO campus)

Astronomy 210, spring semester 2017
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 runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


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.
"I found the greenhouse factors unique to each planet was particularly interesting and I was able to read and see how each planet was affected by its conditions and atmosphere."

"The 'frustrated volcanos' on Venus were interesting because The Simpsons GIF animation really made it make a lot of sense."

"Venus may have had a lot of water but due to the greenhouse affect the water turned into vapor and now the planet's greenhouse effect gets worse with time, and I find that fascinating because it proves the possible extreme result of Earth's global warming and human activity in the worsening of our greenhouse effect."

"That Venus and Mars are considered 'runaway' planets because of the fact that they have lost their greenhouse gas cycles...which kinda worries me because what if earth also starts to do the same?"

"That how much mass a planet has contributes to the amount of greenhouse gases it lets out into the atmosphere. Also, how the distance from the sun to the planet determines how much warming there will be from the greenhouse effect."

"The dwarf planets!!!! I had no clue there were other dwarf planets than pluto! Wicked. Haumea is the most interesting to me by far, it's interesting that they classify it "round enough" to be a dwarf planet."

"It is good to finally know why Pluto is no longer considered a planet. Before, I just accepted that fact without giving it too much thought."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I am confused how both Venus and Mars can have volcanos without plate tectonics."

"Why is Venus so much hotter than Mars since their masses aren't vastly different, and orbits aren't that significantly different?"

"The whole greenhouse things and how they relate to different planets, if you could please go into detail that would be great."

"Greenhouse effect factors are still pretty confusing for me. I've been trying to read up on it more, but I think I just need a simpler way of understanding it! The more I read about it, the more confused I get."

"Uranus--is the axis really that drastically tilted, and could you explain again the impact this has on making it cooler than Neptune?"

"I found Kuiper belt a bit confusing. What exactly is the belt and why are the objects, such as Pluto, located on that belt not considered planets."

"More about Pluto and why it's no longer a planet."

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)
Interior core heat, today: about the same as Earth [51%]
Geologic activity, today: less than Earth [64%]
Volcanic outgassing, up until now: about the same as Earth [43%]
Heat from the sun: more than Earth [84%]
Amount of atmosphere, today: more than Earth [65%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)
Interior core heat, today: less than Earth [81%]
Geologic activity, today: less than Earth [83%]
Volcanic outgassing, up until now: less than Earth [62%]
Heat from the sun: less than Earth [81%]
Amount of atmosphere, today: less than Earth [92%]

Which jovian planet has the coolest interior temperatures?
Jupiter (most massive).   **** [4]
Saturn (most prominent rings).   [0]
Uranus (least active weather patterns).   ******************** [20]
Neptune (farthest from the sun).   ********** [10]
(Unsure/guessing/lost/help!)   *** [3]

I believe Pluto should be a planet.
Strongly disagree.   * [1]
Disagree.   ***** [5]
Neutral.   ******************** [20]
Agree.   ******* [7]
Strongly Agree.   **** [4]

Briefly explain your answer to the previous question (whether Pluto should be a planet).
"Pluto is considered a dwarf planet, along with four others along the Kuiper belt. Pluto was once considered a planet. For the sake of argument, if Pluto was a planet, then the other four should be as well, as they are all on the Kuiper belt. But just because they are all on there doesn't mean they should all be planets."

"If Pluto no longer fulfils the requirements of planethood, then I have no problem with it not being a planet."

"Because it is itsy-bitsy, and scientists say so."

"It's not up to me if it is a planet or not."

"I'm fairly neutral on the topic. I feel if they outline a criteria for what defines a planet then they need to hold consistent with that criteria and no exceptions should be made. If Pluto is granted an exceptions then what is stopping people from defining some of the other dwarf planets as actual planets?"

"I believe if something has moons, it should be considered a planet."

"I grew up with Pluto being a planet, plus I liked Pluto the Dog from Disney movies."

"You can't give a present and take it back without being rude. Can't give it planethood and take it back without being rude either."

"Pluto is like the main character in My Big Fat Greek Wedding that couldn't sit with the cool crowd because her lunch wasn't in a brown paper bag.

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"What exactly is 'outgassing?'" (Gases spewed out into the atmosphere from volcanoes and vents, released from bubbles in molten rock under the crust. So basically, Earth is burping.)

"Ok, from what I have heard and from what is on NASA's website, NASA wants to 'colonize"' Mars. It is to my understanding that Mars is unable to be inhabited by anything because of its low mass and it's practically non-existent volcanic activity to create an atmosphere suitable to sustain life like Earth. So my question is, is it possible? (Yes, if we send people who don't mind staying indoors most of their time, in underground shelters.)

"Do you think Pluto should be a planet? Do you think that we all feel a little bit like Pluto sometimes?" (No, because, reasons. And yes, but that's life.)

"Do you like to go out and get your groove on in downtown SLO? If yes, what is one of your favorite bars to go to?" (I'm one of the DJs for swing dancing at the Madonna Inn on Monday nights.)

"How was your break?" (Mrs. P-dog and I had a snow day up in the mountains. It was awesome. How was your break?)

20170221

Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (NC campus)

Astronomy 210, spring semester 2017
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 runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


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.
"That Venus's crust is so flexible it is unable to break into moving plates."

"The different weather on each of the planets is so unique and it would be interesting to see in person."

"The different atmospheres of the planets. It is really cool to hear how the atmospheres differ and why they are different."

"That low mass planets lose heat faster--I thought the small space would be able to retain heat easier."

"I think its interesting that Neptune is blue because the methane! I also think its cool that an astronaut could 'swim' through Saturn's rings. I also didn't know Mars was red because of rust!"

"Sunlight helps give the gas giants their bold colors. Well Jupiter, that's why it's so much brighter and colorful than Saturn."

"The categorization scheme on what defines a planet--I was wondering how you categorize a moon being a moon and a planet being a planet. And now there is a new classification called dwarf planets and that's what Pluto is now considered. I wondered about that since it is no longer considered a planet. That Pluto is no longer a planet and now I know why and I agree that it shouldn't be. As we gain new knowledge some old truths get ruled out with new data. That's what science is about."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I think all the information about the planets and comparing them to Earth. Like Venus and Mars compared to Earth. I'd like a little more of a basic breakdown of the comparisons."

"The planetary greenhouse effect factors: mass, distance, temperatures and all that--maybe a little more reading and practice will help; I'm just a little confused right now."

"The comparisons between Venus and Mars to Earth. I was mostly looking at the mass of the planets to gauge the differences."

"How Pluto isn't a planet."

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)
Interior core heat, today: about the same as Earth [20%]
Geologic activity, today: less than Earth [60%]
Volcanic outgassing, up until now: about the same as Earth [35%]
Heat from the sun: more than Earth [75%]
Amount of atmosphere, today: more than Earth [80%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)
Interior core heat, today: less than Earth [90%]
Geologic activity, today: less than Earth [80%]
Volcanic outgassing, up until now: less than Earth [75%]
Heat from the sun: less than Earth [85%]
Amount of atmosphere, today: less than Earth [95%]

Which jovian planet has the coolest interior temperatures?
Jupiter (most massive).   [0]
Saturn (most prominent rings).   [0]
Uranus (least active weather patterns).   *********** [11]
Neptune (farthest from the sun).   ******* [7]
(Unsure/guessing/lost/help!)   ** [2]

I believe Pluto should be a planet.
Strongly disagree.   * [1]
Disagree.   *** [3]
Neutral.   *********** [11]
Agree.   ** [2]
Strongly Agree.   *** [3]

Briefly explain your answer to the previous question (whether Pluto should be a planet).
"I believe that anything that consistently orbits around the sun should be considered a planet. Plus, it's my favorite planet. And I found that Earth is hit with asteroids and debris just as often as Pluto, therefor that is not enough of a reason to classify it as a non-planet (learningmind.com)."

"It used to be one so it should still be one."

"I don't really have an opinion. I mean, I kind of wish Pluto was still a planet. I mean, its kind of not fair to classify it as a planet and then take it away. But, I don't really have more of an opinion than that."

"Ohana means family! Family means no one gets left behind! jk :)"

"Pluto was a planet to me until it wasn't. It's awkward now that its not. I feel like he's lonely. I guess I feel neutral about it."

"Pluto shares orbital space with lots of other object out in the Kuiper belt, being very icy and super-small. Pluto does not dominate the neighborhood around its orbit."


Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"When will we get a chance to look at the telescopes the North County campus?" (When it stops raining long enough for the swamp around the telescope shelter to dry out.)

"I'm still a little confused as to why Uranus' interior would have been stirred more than Neptune's causing Uranus to cool off faster. The water bottle in the ice bath analogy didn't really make sense because, in one of the ice baths, the bottle wasn't rotating at all. Don't both Uranus and Neptune both rotate?" (Yes, they both rotate, so they should be both cool off at the same rate. However, Uranus' rotational axis is tilted over probably from a large impact event which would have dramatically shaken and stirred its interior for a brief time, so that would have cooled off its interior dramatically more than Neptune.)

"Do you think Pluto should be considered a planet?" (No, because, reasons.)

"The way you relate facts to things we can see in everyday life is so helpful! The gravy skin and tectonic plates... :D I will never forget that analogy!"

"Why are we funding space research versus researching more ways that we can help cut back on CO2 production and help preserve Earth?" (We use a lot of the same technology developed to observe and understand other planetary climates to observe and understand Earth's climate, which is a big first step to try to address global warming. Also, NASA's share of the U.S. budget is only 0.8% each year.)

"Since the jovian planets accumulated ice and helium/low density hydrogen to make them bigger, could they continue to grow through the present day?" (No, because all the dust and gas between planets has been cleared out, so barring pulling in any random asteroid or comet, the jovian planet sizes and masses are pretty much set.)
"I didn't quite understand why Pluto has a faster orbit around the sun than Neptune. It's confusing to me because Pluto's orbit is slightly larger than Neptune's, so that's where I'm stuck." (Pluto's period is slightly longer than Neptune's (248 years versus 165 years.))

20170220

Astronomy quiz question: August 2017 partial solar eclipse in San Luis Obispo, CA

Astronomy 210 Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA

A total solar eclipse will occur on August 21, 2017 for many observers in the United States[*]. During this event, observers San Luis Obispo, CA will only see a partial solar eclipse[**], because they will be located in:
(A) the moon's umbra.
(B) the moon's penumbra.
(C) the moon's negative shadow.
(D) Earth's umbra.
(E) Earth's penumbra.

[*] eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2017Aug21Tgoogle.html.
[**] timeanddate.com/eclipse/in/usa/san-luis-obispo?iso=20170821.

Correct answer: (B)

An observer in the moon's penumbra will see a partial solar eclipse, while an observer in the moon's umbra will see a total solar eclipse. (The "negative shadow" refers to the antumbra of the moon.)

Section 30674
Exam code: quiz02n1hT
(A) : 2 students
(B) : 17 students
(C) : 0 students
(D) : 2 students
(E) : 2 students

Success level: 76% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.38

Section 30676
Exam code: quiz02sNoO
(A) : 3 students
(B) : 28 students
(C) : 1 student
(D) : 3 students
(E) : 7 students

Success level: 69% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64

Astronomy quiz question: planet(s) visible at sunset?

Astronomy 210 Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA

Tthe locations of Venus, Earth and Mars are shown in the diagram below (not to scale, and orbits have been simplified as circles instead of ellipses).


Which planet(s) will be visible at sunrise?
(A) Venus.
(B) Mars.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (B)

If a line is drawn from Earth to the sun, the observer at sunset (6 PM) is located perpendicular to that line. Since Venus is below that horizon line, it would not be visible at that time; while Mars is above that horizon line, it would be visible high over the east horizon at that time.


Section 30676
Exam code: quiz02sNoO
(A) : 11 students
(B) : 24 students
(C) : 2 students
(D) : 5 students

Success level: 60% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.91

Astronomy quiz question: planet(s) visible at sunrise?

Astronomy 210 Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA

Tthe locations of Venus, Earth and Mars are shown in the diagram below (not to scale, and orbits have been simplified as circles instead of ellipses).


Which planet(s) will be visible at sunrise?
(A) Venus.
(B) Mars.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (A)

If a line is drawn from Earth to the sun, the observer at sunrise (6 AM) is located perpendicular to that line. Since Mars is below that horizon line, it would not be visible at that time; while Venus is above that horizon line, it would be visible low over the east horizon at that time.


Section 30674
Exam code: quiz02n1hT
(A) : 19 students
(B) : 0 students
(C) : 2 students
(D) : 2 students

Success level: 84% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.17

20170217

Astronomy quiz archive: eclipses/history of astronomy

Astronomy 210 Quiz 2, spring semester 2017
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz02n1hT

Section 30674
0- 8.0 :  
8.5-16.0 :  
16.5-24.0 :   ****** [low = 20.0]
24.5-32.0 :   ********* [mean = 29.1 +/- 5.6]
32.5-40.0 :   ******** [high = 40.0]


Section 30676, version 1
Exam code: quiz02sNoO

Section 30676
0- 8.0 :   * [low = 8.0]
8.5-16.0 :   *******
16.5-24.0 :   ***********
24.5-32.0 :   ********* [mean = 24.5 +/- 7.8]
32.5-40.0 :   ********* [high = 40.0]

20170215

Online reading assignment: atmosphere problems, Earth, the moon, Mercury (SLO campus)

Astronomy 210, spring semester 2017
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 problems caused by the atmosphere for telescope observing, Earth, and the impacted worlds: the moon, and Mercury.

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.
"The practice of 'sidereal tracking' to keep telescopes pointed towards whichever celestial object as the Earth turns on its axis. The calculations and equipment to constantly keep up with the tiny adjustments have to be very accurate and precise which is incredible."

"I found the enormous telescopes built on mountain tops to be the most interesting. I know how much energy goes into residential and commercial projects in cities. Projects of such scale, with totally custom materials and equipment, in locations so secluded are extraordinarily impressive."

"Our atmosphere blocks out most electromagnetic radiation, allowing the things below it, such as us humans, to not be harmed by gamma rays, x-rays, and some radio waves. This is personally interesting because I find it fascinating how much nature naturally helps us out."

"I found atmospheric turbulence to be very interesting. I never realized there was such a thing. I especially liked the comparison of looking at an image from under water and the distortion if there is movement in the water. Fascinating that clarity in our sky is effected much in the same manner through atmospherical turbulence."

"I found it interesting that volcanoes over time and still today have contributed a massive amount of our greenhouse gases present today."

"I loved your analogy of gravy for plate tectonics. It was pretty funny but the way you described it made a lot of sense and actually helped me out. And you're right, heating up gravy in the microwave is just wrong!"

"I think it's so cool that at one point long ago there might have been an ocean on Mars. I mean, it's crazy how over time a planet can lose so much of its internal heat that it changes so drastically! Imagine if at one point there was life on Mars and things were swimming in the ocean--the idea of life outside of Earth is so fascinating."

"Studying the planet Mercury, I honestly had no clue what this planet looked like and how similar it looks to the moon!"

"I found Mercury to be very interesting considering it being a 'one-plate' planet. Knowing how earth was formed with plate tectonics, you might assume that other terrestrial planets might be similar, but Mercury is considered the "one-plate" planet. I found it interesting how Mercury actually has a bigger core than Earth, but looks very similar to our moon, and yet our moon has a smaller core than Earth."

"I found the large-impact hypothesis to be very interesting and a unique way to look at how the Earth and the moon could have possibly formed together at the same time."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The concept of adaptive optics was kind of confusing. First off, why is the it necessary to have the technique of adaptive optics and what is the process that achieves that."

"Using two separate telescopes to get a more powerful resolution by them working together."

"I don't understand how airborne telescopes are practical. Wouldn't it be very expensive to merely stabilize it, as to not blur everything?"

"The histories of the moon and Mercury."

"This section was the most confusing for me so far. The plate tectonics, greenhouse gases and geological activity were tricky. The only background I have with learning about these things is what I learned in elementary school, so I feel a bit lost. After reading through it a few times, it seems to be clicking more--but I still feel a bit rusty."

A large modern optical telescope in outer space would have images with better __________ than a comparable ground-based telescope.
brightness.   ** [2]
resolution.   **************** [16]
magnification.   * [1]
(None of the above choices.)   [0]
(Two of the above choices.)   ****** [6]
(All of the above choices.)   *********** [11]
(Unsure/guessing/lost/help!)   * [1]

Stars to appear to "twinkle" in the night sky because of...
"With changes in movement and constant turbulence of the atmosphere, our view of the stars are distorted causing a 'twinkling' stars."

"I have no idea... This is what I am confused about."

"The force of gravity from other celestial objects?"

"Magnification?"

Identify how carbon dioxide enters and how it is taken out of Earth's atmosphere.
(Only correct responses shown.)
Enters atmosphere from: volcanoes [49%]
Taken out of atmosphere by: oceans [46%]

Identify the oldest (longest ago) to the youngest (most recent) features on the moon.
(Only correct responses shown.)
Craters partially filled in with flat lava plains: oldest (formed longest ago) [43%]
Flat lava plains: middle [25%]
Craters on top of flat lava plains: youngest (formed most recently) [41%]

Identify the oldest (longest ago) to the youngest (most recent) features on Mercury.
(Only correct responses shown.)
Large crater basins: oldest (formed longest ago) [41%]
Lava-filled lowlands: middle [38%]
Long curving ridges: youngest (formed most recently) [46%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Would an infrared telescope work well on the ground if you were somewhere higher up, or is it only for higher altitudes?" (Because Earth's atmosphere blocks a lot of that type of light, going higher (where the air is thinner) helps, an infrared telescope on a mountain would be better than at sea level, but would not be able to see as much infrared light going higher, as with an airborne or space-borne telescope, )

"Are there many other theories on the origin of the moon?" (Yes, but they've all been disproven, and the large-impact hypothesis is the theory that is best supported by analysis of rocks brought back from the moon by Apollo mission astronauts.)

"I am confused by the moon's smooth low-lands, formally knowns as its mare, being ancient lava flow, for me, I can't imagine the moon having lava flow. Is it different type of lava than on Earth or did the moon have active volcanoes?" (It's a slightly different type of lava, but yes, the moon had active volcanic eruptions (typically welling up from vents and cracks in the surface, rather than from mountainous volcanoes).)

"How can we identify older or younger features on a distant planet without visiting the planet?" (By counting the density of impact craters (old areas) with smooth plains (new areas). Since we've confirmed this method on the moon's surface, we can apply this to determine the ages of many areas on Mercury, Venus, and Mars.)

"Do you see the shape of a dinosaur on the moon like I do?" (Not really, but I see a rabbit, but some people see a man's face or a woman's profile in the moon.)

"Where have you seen the darkest sky with the brightest stars/planets/constellations?" (Lots of places.)

"The textbook says that the preferred direction of motion in the solar system is counterclockwise and all planets revolve around the sun in that direction, except for Venus and Uranus. What does that mean? Why not those planets?" (Their contrary behavior suggests that they experienced extraordinary impacts in their pasts that altered their rotational motion.)

"Your slides are really fun and interesting but this textbook is so hard to read, not because the information is confusing but because the chapters are so dense and the subject matter is dry. I guess I'm using this textbook to complain...sorry." (#sorrynotsorry)

"How long have you used the format of combining a textbook with online blog information?" (It's been a work in progress over the past five years or so.)

20170214

Online reading assignment: atmosphere problems, Earth, the moon, Mercury (NC campus)

Astronomy 210, spring semester 2017
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 problems caused by the atmosphere for telescope observing, Earth, and the impacted worlds: the moon, and Mercury.

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.
"Something interesting form the slide was the way the twinkled stars actually look. This seemed interesting because I've never actually looked up how a star looked like before this class."

Why stars twinkle. I found it interesting because of how all the air that it goes through, it distorts it and our eyes see the 'twinkle' effect."

"I really liked the analogy that compared turbulence distorting the astronomical views to being underwater and having the ripples disrupt your view of the surface. It's a really interesting concept, and the analogy made it easy to understand."

"The visible light spectrum is interesting to me, its crazy to think there are colors on the electromagnetic spectrum we as humans cannot see."

"The fact that the stars 'twinkle' because of the atmosphere, I always thought it was the stars actually twinkling. Like how our sun flares, I thought maybe other stars flared as well."

"I was interested to learn that the ocean plays a role in removing carbon dioxide from our atmosphere. I thought plants were the main filter."

"I found it interesting that the moon and mercury are similar with their craters and being mostly airless. I found it extremely interesting that neither of them have an atmosphere therefore unable to inhabit life."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The section about the different telescopes was confusing, I hope we won't be tested on them and what they do!"

"I could not find where in the textbook it talked about oldest and youngest features on the moon."

"For some reason, I can't seem to grasp the concepts of the features on the moon and Mercury. The terminology is different in the questions and the readings, and I am finding it difficult to establish a timeline for the formation of the features."

A large modern optical telescope in outer space would have images with better __________ than a comparable ground-based telescope.
brightness.   ** [2]
resolution.   ****** [6]
magnification.   [0]
(None of the above choices.)   [0]
(Two of the above choices.)   ***** [5]
(All of the above choices.)   **** [4]
(Unsure/guessing/lost/help!)   *** [3]

Stars to appear to "twinkle" in the night sky because of...
"the atmosphere is disrupted as we look up at the stars and we are at the bottom so is easier for things to get distorted. The twinkles are from our atmosphere not being calm."

"When the light from the stars comes through the atmosphere, different temperatures, densities and winds make it look like they twinkle."

"The turbulence of the atmosphere."

Identify how carbon dioxide enters and how it is taken out of Earth's atmosphere.
(Only correct responses shown.)
Enters atmosphere from: volcanoes [50%]
Taken out of atmosphere by: oceans [65%]

Identify the oldest (longest ago) to the youngest (most recent) features on the moon.
(Only correct responses shown.)
Craters partially filled in with flat lava plains: oldest (formed longest ago) [30%]
Flat lava plains: middle [20%]
Craters on top of flat lava plains: youngest (formed most recently) [55%]

Identify the oldest (longest ago) to the youngest (most recent) features on Mercury.
(Only correct responses shown.)
Large crater basins: oldest (formed longest ago) [40%]
Lava-filled lowlands: middle [45%]
Long curving ridges: youngest (formed most recently) [55%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"If the atmosphere is what makes stars appear to twinkle, then why don't planets also twinkle? Doesn't the atmosphere's turbulence also affect them?" (The planets do twinkle, but it's not as noticeable. The stars are basically points of light, and 'twinkling' a point of light will make it noticeably distorted. Planets are large enough to be a small disk of light, and 'twinkling' a disk would only distort its edges, so the effect on its brightness is not as noticeable.)

"Is it that we don't have the technology for telescopes to overcome the opacity of the atmosphere, or is that a problem that can't be resolved aside from using telescopes on high mountains, or up in space?" (Can't stop the atmosphere from stopping the types of light that it stops. #neverstopstopping)

"How does visible light pass through glass to heat up objects such as plants, but the infrared light that comes from the plant doesn't escape the glass? Is the plant producing the infrared?" (Everything that is warmed-up will have an infrared glow, (unless it's super-hot like a light bulb or the sun, then it will emit visible light, or smoking-hot like an emitting ultraviolet or x-ray light. It turns out that the atoms in glass don't absorb visible light (letting it pass through), but absorbs and re-emits infrared light (blocking it). Interestingly the atoms in a plastic garbage bag will absorb and re-emit visible light (blocking it), but doesn't absorb infrared light (letting it pass through!)).

"Do we have to do group work every class? Or could solo work at least be an option?"

"Could we maybe try groups of two instead of three during class? I feel that it would be easier for me to work with one other person versus working with two others." (I'll think about it. Initially I'm assigning you to work in groups of three, according to recent astronomy education research, but I'm willing to adapt and experiment. You're also encouraged to print out your own individual copies of the in-class activities from the course website.)

"Did we skip Chapter 5? Am I behind in the reading?" (Yes, and no. Chapter 5 covers the sun, which the textbook groups together with the planets (because that's our solar system); but we'll do the planets first, and then cover the sun later with the rest of the stars (because the sun is just a star).)

"I was curious to know why you are teaching astronomy, when physics is your passion? (You're a great teacher, I was just curious as to why.)" (Astronomy is physics. However, an astronomy textbook is what you get when you take out everything that is awesome from the field of physics. Everything that is left over--well, that's what physics is.)

"The large-impact hypothesis seems like a lot of guesswork. Is there actual evidence to prove that's what happened, or is it just a theory that makes sense?" (Yes, and yes. It is the only theory that is consistent with the lunar rock samples gathered by Apollo astronauts, and it is the only theory that is not refuted by those same rocks.)

"If the greenhouse effect is causing the atmosphere to warm up, then how could we prevent global warming besides reducing our carbon footprint?" (There are some elaborate schemes that involve taking the carbon dioxide from the air and making dry ice (solid carbon dioxide), and then injecting this as a slurry deep underground, speeding up what the oceans, sedimentation, and tectonic plate subduction does. Or we could just lay off producing as much carbon dioxide (and other greenhouse gases) as we do and letting Earth slowly catch up and take care of itself over a long time. Either choice is very expensive and costly.)

"I am confused about how to identify the oldest to youngest features on the moon. What do these features look like and how do I categorize them? The material in the book was slightly confusing. Also there was a lot of information in the slides and in Chapters 4 and 6! I will definitely need to catch up on some more reading..."