Online reading assignment: the Milky Way (SLO campus)

Astronomy 210, fall semester 2014
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.
"I'm super-interested in the Milky Way so I'm excited to learn more."

"That we were able to basically determine the shape of the Milky Way (flattened disk) based on the fact that we view the stars only as a stream across the sky rather than in all directions."

"How we're able to see distinguish how far we are away from the center of the Milky Way by looking at certain landmarks."

"The fact that scientist used roundabout ways to find the shape and size of our galaxy is interesting and amazing. They must have gotten very creative with their ideas."

"I liked the video about traffic jams."

"The proof that dark matter exists and the mystery behind what dark matter actually is is interesting because scientists know that something has to be generating the gravity that affects the rotation of a galaxy but can't yet see what that thing is because it is invisible as of now."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Dark matter--for something we don't know much about, we have a lot of information about it."

"I did not find anything confusing."

"I found spiral arm star formation theories to be a little hard to grasp. I understand what is happening but not how it is happening."

"I still don't fully understand the concept behind density waves. If the milky way absorbs other dwarf galaxies due to its gravity, why are the spiral arms an optical illusion and not the flow of stars and dust into the center?"

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.  **************** [16]
Not very much.  ********** [10]
Barely seen it.  ******* [8]
(Never been able to see it.)  *** [3]
(Unsure/guessing/lost/help!)  [0]

Using the most powerful light-gathering telescopes in the darkest skies, up to how much of the stars in our entire galaxy can be observed from Earth?
1%.  ****** [6]
5%.  ***** [5]
10%.  ***************** [17]
50%.  * [1]
100%.  * [1]
(Unsure/guessing/lost/help!)  ******* [7]

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?
"Ask one of my honest friends."

"I would put a hat on so I wouldn't have to worry about it."

"Nothing, my hair is always a mess."

"The camera on your phone, of course. Take a #selfie."

"Look into something that would show a reflection: spoon, sunglasses, phone screen, etc."

"The whole point of camping is getting as gross as possible and not caring what you look like."

"Typically I wake up with a lion's mane so I would know. Girls...just...know."

"Feel it with your hands to find out if you feel any hairs in odd places or hairs escaping from a ponytail, etc. Or even better you could inspect your shadow to see if there are any crazy stray hairs coming off your head."

Look at PimpStar Rims (*.html) for cars, or MonkeyLectric Rims (*.html) for bikes. Briefly explain how they work.
"There is only one string of lights on one part of the wheel, but as the wheel moves it gives the illusion of a full circle."

"The eye perceives the lights as a stream so the synchronized patterns create a consistent image."


"There are LED lights that are blinking on and off to make it visible and to make an illusion. This is similar to what spiral arms do."

"The Pimpstar Rims are dope and are flashy looking. The MonkeyLectric Rims make your mind explode as you're going down the road."

"Please don't ride bikes...we see bicyclists daily in the ER. :-("

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I'm confused as to why the Milky Way appears blue. Shouldn't it appear pink due to hydrogen and star formation?" (The blue-hot main-sequence stars outshine all other stars, but look carefully at a picture of a galaxy (computer-generated or an actual Hubble Space Telescope) and there should be quite a few faint pink clouds scattered throughout.)

"No questions...just need explanations."

"What does camping have to do with astronomy?"

"Where can I go to see the Milky Way?" (Sounds like you need to go camping. But beware of bad hair.)

"Whats the next big astronomical event?" (The European Space Agency just landed a probe on a comet today. As for stuff in the sky, there is the Leonid meteor shower late Sunday night/early Monday morning.)

"It would be great if we could get the answers to our in-class activities. I realize that we check with our neighbors, but what if we are all wrong?" (Then ask me. Don't be afraid to ask either in class, during break, or just after class. If you're not completely confident that you have the correct answers (which I assume is true for everyone else who leaves class right after turning their in-class activities?), then ask.)

"Can you provide details about the extra credit offered on the day before Thanksgiving?" (I understand if you need to leave town for break and can't come to the regularly-scheduled class next week, but if you're still in town and desperately need extra-credit points, it's pretty much an open session--stellar evolution board games, movies, telescope viewing at the Bowen Observatory, and/or training on the portable telescopes. Whatever is interesting to whoever shows up. Good times.)

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