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 Milky Way's shape, size and composition and spiral arm structure and formation.
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.
"Finding out what the Milky Way galaxy looks like and discovering where we are located in it."
"The perspective of our Milky Way was interesting to me. It's pretty wild that even though we have an incredible body of knowledge of our galaxy, we are still so limited and have only seen so far out/so many angles. Our milky way is cool enough as it is, knowing how much we have yet to learn is really cool."
"Just the Milky Way in general!"
"When I read about our location in the universe and try to wrap my head around it I start to get lost. It's interesting because it is explaining away some of the things I have trouble understanding."
"How giants pulsate and how this can be a way to measure distances to globular clusters."
"I really liked the comparison to when you're camping and can't tell if your hair is okay or not."
"That we know about dark matter because of the speed the inner and outer parts of a galaxy rotate at. This has been personally interesting because dark matter was one of those concepts I had a hard time wrapping my brain around but now I feel like I have a little bit more understanding of it."
"Dark matter has always been super-interesting to me, so it was nice to see it talked about."
"The fact that you can't see dark matter but it still exists."
"Dark matter. It's just so mysterious still, even when we know and have evidence of it's existence."
"The persistence of vision section was cool. I had seen things like that in the past, but it was cool to read how it works."
"That the most massive stars don't have the time to move from their place of birth. This makes sense, but I never realized it."
"The fact that the Milky Way impermanent and illusory and in a sense is also self-sustaining."
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Nothing was particularly confusing other than the apparent reliance of a hypothetical person on a mirror for fixing their hair."
"The question about how much of the stars in our galaxy can be observed from Earth, because I couldn't find it in the presentation or the book."
"I have a problem imagining where things are supposed to be in space."
"Figuring out our position in the Milky Way. It's something I'd really like to focus on in class."
"What the halo is confuses me. I really don't get what it is."
"Dark matter. Specifically the halo and what it is made of."
"I found gravity and orbits within the Milky Way slightly confusing, I am having trouble distinguishing the two different motions."
"I have a tough time understanding dark matter and where its from and where it is in the universe. I am not fully understanding its origin."
"I don't know if I'm fully grasping the concept of spiral arms in our Milky Way. I think I get the main idea but I'm not entirely sure how it relates to us on earth. Also, how many of these arms does our Milky Way have? It looks like four on one of the diagrams but I'm not sure if that's solely meant to illustrate the concept or not."
"I'm not sure why the spiral arms on our galaxy don't actually move...can you go over the PimpStar Rims thing?"
"I don't really understand the spiral arms presentation very well. I'm having trouble with all of it. I don't really know what questions to ask."
"That spiral arms and spurs have two separate causes that form them. Why do density waves not also account for spurs?"
"Density waves/spiral arms. I get the just of it, but am still a bit confused on how they form."
"Straightforward!"
"For once I actually think I am not completely confused."
"I didn't find this too confusing compare to the last reading assignment. Then again I understand the topic a bit better right after your explanations."
In your experience, how much of the "Milky Way" (the band of faint stars across the celestial sphere) have you been able to see in the night sky?
As much as can be seen with the naked eye. ************ [12] Not very much. ************* [13] Barely seen it. ***** [5] (Never been able to see it.) *** [3] (Unsure/guessing/lost/help!) * [1]
Using the most powerful light-gathering optical telescopes in the darkest skies, __________ of the stars in our entire galaxy can be observed from Earth.
1%. ******* [7] 5%. ****** [6] 10%. ********* [9] 50%. **** [4] 100%. [0] (Unsure/guessing/lost/help!) ******** [8]
If you did not have access to a mirror while camping, what could you do to find out whether or not you're having a bad hair day?"Look at your reflection in a stagnant pool of water or something shiny."
"Phone camera or app."
"You could use a metal spoon."
"Ask someone if you are camping together. (Or just don't worry about it.)"
"Well first of all, I would have a friend with me because camping alone sounds awful."
"You could ask a friend to draw you a picture."
"Hope for the best."
"I wouldn't care, I'm camping!"
"I have short hair, so this would not bother me."
"I would put on a beanie and worry no longer."
"It would not matter, I would throw it up in a ponytail and put a hat on. Because who cares! No need to impress anyone."
"You could look at your shadow on the ground to see if the outline of your hair looks messy."
"Feel it and try to feel the shape?"
Look at PimpStar Rims (*.html) for cars, or MonkeyLectric Rims (*.html) for bikes. Briefly explain how they work.
"They work by utilizing the persistence of vision illusion. This is done by coordinating the color of (or potentially turning on and off specific parts of the) lights on the wheels to make a pattern as they are spun at high speeds."
"The lights are hooked up to a computer that tells it when to light up and when not to, causing them to put off special images."
"The images are made with a strobe modulation technique."
"Rapidly blinking lights are coordinated to create patterns when swept across our field of vision."
"Using persistence of vision, coordinating the lights, when it is swept across our field of vision the picture appears. Just like when short-lived massive stars are born and die at certain intervals as they orbit around."
"Not sure."
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"What is making the whole galaxy rotate in the first place? What's stopping everything from going past the boundaries and beyond?" (The Milky Way formed from a gigantic cloud of hydrogen that contracted over time; any rotation in the original cloud, no matter how slow, would just get faster as it the cloud got smaller to form the Milky Way.)
"Maybe our galaxy just has billions of Nibblers floating around producing 'dark matter' in our galaxy that causes this spread of gravity."
"What is dark matter made of?" (Nobody knows for sure, but there is a short list of suspects.)
"Do you really have a bike with 'PDOG' lights on the wheels? If so, that's awesome. How much did that setup cost you?" (That Schwinn Tire Writer was about $30-$40 or so; but they've been discontinued.)
"Talking about galaxies makes me feel small, as if talking about stars didn't already." (Then my job here is finished.)
"Are you ever sleepy during class? You always seem alert and I don't know how you do it." (You would be pretty enthusiastic too, if you had the opportunity to talk about the universe to astronomy students. #stoke)
"Could you describe your life using any one law of physics?" (Newton's first law: objects that are in motion tend to stay in motion. #keepmoving)
"Is it true that the last quiz is pretty much freebie points?" (Well, yes, if you show up for the last week of class and take the exit survey on how much you've learned about how stars work.)
"Do you like to go camping or glamping? Do you enjoy camping, if so what is your favorite spot?"(Mrs. P-dog and I probably do equal amounts of camping and glamping together. It's hard to pick a favorite spot, but earlier this year we did snag a great campsite at the Valley of Fire.)
"Happy Hanukkah." (Chag Urim Sameach! #toosoon)
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