Online reading assignment: the Milky Way (SLO campus)

Astronomy 210, fall semester 2015
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.
"How long it takes the sun to orbit the Milky Way, because we don't usually think about the sun orbiting something else, rather we think about the sun as something that is orbitted."

"I think it's cool that the galaxy rotates as a whole, with the mass spread out over the disk. It's interesting to think that dark matter is spread out everywhere."

"That we can only see a portion of the Milky Way disk, but can still figure out where we are located."

"The Milky Way is a disk--I never really thought of why it took the form of a stream of stars. I look at it all the time and wow, just changed my outlook."

"Spiral density waves--I don't understand them in detail yet, but it's easy to understand the basics when the book compares them to traffic jams on the freeway."

"How scientists were able to infer the shape of our galaxy and it was interesting learning how they do this."

"PimpStar Rims. Because who wouldn't want to have rims like that on their car"

"How astronomers use the position of globular clusters to find 'downtown."

"The explanation of spiral arms was _______ brilliant! I was really impressed with both of the online presentations."

"Learning about the Milky Way, specifically our location within it. I found this to be most interesting because I had wondered about this before."

"How spiral arms maintain continuously"

"I thought the PimpStar 'P-dog rims' were really interesting because it made me LOL."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"dark matter. Wikipedia refers to it as 'hypothetical matter?' It's just so mysterious."

"I don't get how the spirals arms form from one galaxy absorbing another."

"I still don't quite get where we lie in the galaxy"

"I found the spiral density wave theory a bit confusing and odd. The 'traffic jam' example made it a little easier to understand."

"MACHOs (Massive Compact Halo Objects) and WIMPs (Weakly Interacting Massive Particles)--the difference between them was confusing. I had to re-read to somewhat understand."

"How scientists still don't know what dark matter is made of, we know details about it, but still do not understand the actual composition."

"I never knew there were such things as the PimpStar Rims. Confused as to why anybody would buy them."

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.  ********** [10]
Not very much.  *********** [11]
Barely seen it.  ****** [6]
(Never been able to see it.)  ****** [6]
(Unsure/guessing/lost/help!)  [0]

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%.  ******** [8]
5%.  ****** [6]
10%.  *********** [11]
50%.  ** [2]
100%.  ** [2]
(Unsure/guessing/lost/help!)  **** [4]

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?
"I ask the person I'm camping with to spot me. I better not be camping alone!"

"Ask a fellow camper whether or not you're on fleek."

"I wouldn't care. I'd rock the bad hair!"

"I know what my hair feels like, so I can determine whether or not it looks good simply by touching it."

"Use the mirror from your telescope."

"Am I camping by myself? My hair likes to stand straight up so always assume I'm having a bad hair day. Hence the constant wearing of hats. But I cannot complain, at least I'm not bald."

"Use Snapchat and take a selfie."

"Look at reflection in water"

"From the humidity of the air."

"I would use my shadow to see how out of place my hair is."

"Take my iPhone out and use my front camera."

"Wear a hat to avoid finding out."

"Look at the mirror in your car."

"What makes you think I'd be caught dead camping without my selfie stick?"

Look at PimpStar Rims (*.html) for cars, or MonkeyLectric Rims (*.html) for bikes. Briefly explain how they work.
"I understand that car rims are being used to explain how galaxies spin, but I don't share a similar interest in cars or how they work and the metaphor leaves me even more confused."

"The blinking lights appear to make a pattern because of persistence of vision."

"Strobe modulation"

"Lights on the rims spin at an equal speed to the wheel, creating an image visible to a stationary observer."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Do you have PimpStar Rims on your car? What image would you use for the PimpStar Rims?" (I have PimpStar rims on my bike.)

"I find it odd that anyone would hate on you for having SUCH AN AWESOME BIKE LIGHT." (#hatersgonnahate #donthatetheplayer #hatethegame)

"Reality is an illusion. The universe is a hologram."

"Only 5 more weeks! #iwillsurvive"

"Comparing the Zodiac Killer to dark matter was perfect! Best analogy ever. But what if dark matter isn't actually real?" (Dark matter is real, because there is too much gravity spread throughout the Milky Way, affecting how everything moves around. Just like the Zodiac Killer was real, because, people killed.)

"Is there going to be a way we can review Quiz 6 during the week before the midterm?" (You will be able to download this semester's version of the quiz from the course website later this week.)

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