Online reading assignment: the Milky Way (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 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.
"The Milky Way is a beautiful galaxy, to understand how stars grow and die, and in the consuming of other smaller galaxies create more stars, is very fascinating."

"I liked the comparison of the lights at eye level in the mirrored room with the flat disk shape of the Milky Way."

"How so many of the stars in our galaxy aren't visible to us."

"William and Caroline Herschel mapping our galaxy in 1785--it gives us an idea of the progression of the astronomical science."

"I really liked how you said that even though we do not know what dark matter is made of it, it doesn't mean that it doesn't exist. and then compared it to the Zodiac killer. Very cool!"

"I liked the part on dark matter because there was something oddly comforting about it. It's like being surrounded by an invisible blanket; we're pretty sure it's there all around us but we can't prove that it's true."

"I found self-sustaining star formation cool; how the death of stars can lead to the birth of new stars and how this process repeats over and over again."

"I found it very interesting that the arms and spurs of galaxies are maintained by either fusing with a dwarf spiral galaxy or by the explosions of type II supernovae massive stars which adds to the growth and repair of a galaxies spiral arms. I thought this was interesting as I never thought of it as something that would be necessary for a galaxy to need to do."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I didn't understand how the Milky Way's flat disk shape works out to be seen as just a strip of stars."

"How Shapley could estimate the distances of globular clusters. Don't understand how he calculated true luminosities of Cepheid variable stars."

"I am still a little confused on how you can map the Milky Way and how we know what it looks like, when we can't see much of it from Earth."

"The positioning of the global clusters and how we receive the information that tells us the location of the Milky Way center."

"What the rotation curve is and what it means."

"Dark matter is confusing, 'cause liiiiiike... what is it?"

"Dark matter, because how exactly can you find the dark matter?"

"The dark matter was kind of confusing to me. I don't understand how there's just a weird thing on the outside that causes gravity to spread. Its also confusing about how we have learned so much about the galaxy but some of it is just assumptions because we cannot see much due to the gas and dust."

"Why are spurs a separate thing? They look like arms but they have a different category. Is it due to size, composition, etc? I'm interested to know why they have a name besides arms."

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.  *************** [15]
Not very much.  ********** [10]
Barely seen it.  ***** [5]
(Never been able to see it.)  * [1]
(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%.  ****** [6]
5%.  ** [2]
10%.  ********* [9]
50%.  *** [3]
100%.  ** [2]
(Unsure/guessing/lost/help!)  ********** [10]

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?
"Do I have my mobile phone? If so, I'd whip out that selfie cam. Even if it was dead I could use the reflection of the screen."

"Find a puddle of water and use that as your mirror. This works very well actually, trust me I know."

"Funny, I am going to Coachella this weekend, and I was laughing because I have never packed a mirror before while camping. But this weekend, YES, no bad hair at Coachella."

"Shave your head."

"Ask a squirrel or lizard what they think."

"Put on a ball cap and call it a day! No need to look in a mirror while you're camping."

"Run my fingers through my hair to see if my hair is different from normal."

Look at PimpStar Rims (*.html) for cars, or MonkeyLectric Rims (*.html) for bikes. Briefly explain how they work.
"Images are sent to the wheels using WiFi, and the wheel has a microprocessor and wireless adapter to interpret the signal and display it using the LED lights."

"Persistence of vision illusion from rapidly blinking lights coordinated to create patterns when swept across our field of vision."

"By spinning fast the display an image what would be un seen while standing still."

"Lights blink rapidly in a coordinated pattern."

"They use a strip of different colored lights in the wheel. So then, when the wheel is spinning, it looks like the entire wheel is one massive blob of color."

"The human brain can only process visual stimuli so quickly, so a sequence of lights blurs into a word."

"Okay, I have a bit of a hard time with this. But its something to do with the flashing patterns."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"The subject matter in this class just gets more interesting and more mind boggling every time."

"It's interesting and cool to see how all the different astronomers work together, even if they don't live at the same time. They appreciate each other's work and continue it when they die. If astronomers didn't work together like this, we wouldn't know half of what we know now about space and stars and galaxies." (Kind of like self-sustaining star formation?)

"The Milky Way is beautiful and fascinating. It's one of my favorite things to look up at while I'm stargazing." (Me, too.)

"The puddle thing works really well too if you want to do your makeup. You know, just in case Mrs. P-dog wants to do her makeup while in the wilderness. #protip" (Or Mrs. P-dog could find a mysterious time portal in the middle of the desert.)

"Every time you post a link on these assignments, I cannot help but to click on it, and then immediately hit the back button, but it's too late; I have to redo the assignment." (Ctrl-click or mouse-right-click on the link to open a new tab/window, without affecting the reading assignment window. #protip)

"Do you consider staying in an RV camping?" (No, but what about if you built your own "RV" yourself?)

"P-dog, is this camping question like the house party? Why are there reocurring events we aren't actually having?" (I think you need to get out more.)

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