20151201

Online reading assignment: Milky Way history, big bang clues (NC 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 history of the Milky Way and big bang clues, a comic strip adaptation of of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


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.
"It was pretty sick reading about how the elements of the universe have changed over the course of many years."

"When you look at a start or galaxy from lightyears away you are looking at how it was not how it is now."

"The big bang theory because I have always been curious on what it means/what it was."

"I think that metallification is a cool way to find out which stars are older than others."

"For every light year, it is equivalent to an entire year of look-back time. I've always wondered how far back we were seeing but never knew how it worked."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"What I found confusing was in the Milky Way, there is a broad distinction between stars in the halo, and stars in the disk. I can't wrap my head around how scientists know that they must be the Milky Way's first generation stars."

"Something I found confusing is how we can tell how the Milky Way was formed by looking at the metals?"

"How astronomers know that the universe if finite and not infinte. How are they able to figure that out?"

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [28%]
Metals (elements heavier than hydrogen and helium): increased [67%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  ****** [6]
young stars that formed very recently.  ************ [12]
(There is a tie.)  [0]
(Neither, as stars cannot have metals.)  [0]
(Unsure/guessing/lost/help!)  [0]

Indicate what produced these elements.
(Only correct responses shown.)
Helium in the sun's core: the sun [28%]
Carbon in your body: another star, in the past [33%]
Calcium in your bones: another star, in the past [39%]
Iron in your blood: another star, in the past [39%]
Gold and silver from mines: another star, in the past [22%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Help us."

"Is this material also on the final?" (Yes. Also on the next quiz.)

"Is there still any extra credit available?" (Yes.)

"The universe is getting dirtier as the new generations of stars burst--does this affect Earth?" (Yes, it already has--our sun is a third-generation star, and it and our solar system formed from the leftover hydrogen and the metals produced by two previous generations of supernovae. It's quite ironic that the name of our planet is literally, "Dirt.")

"Why do stars fall into a black hole instead of being sucked in?" (Think of it this way: Earth doesn't suck. When you jump up off the ground, its gravity pulls on you such that you fall back down towards Earth. Similarly with black holes--they also don't suck--because of their gravity, they pull on you such that you fall in towards them. #everythingsucks)

"I AM SO HAPPY AT HOW WELL I DID ON MIDTERM 2!!!!!!" (I KNOW--I'M SO HAPPY FOR YOU TOO!!!!! #bringiton #itsalreadybeenbroughten)

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