Online reading assignment: Milky Way history, big bang clues (NC 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 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.
"The observable universe being finite due to light speed in an infinite universe."

"Why when we look up at the night sky it is dark to be very interesting. Considering many of the stars are as bright as the sun."

"How older stars are metal-poor and new stars are medal-rich. Which somewhat makes sense why space is pretty dirty."

"I found all of the evidence for the big bang very interesting. It is cool to be able to look at all of the proof for how our universe began, and to have the knowledge of how we came to be."

"That there is no edge of space. I found this interesting because I thought there had to be an end to space."

"Being able to tell which galaxies are moving toward us and away from us is pretty cool"

"The age of the universe has always been interesting to me."

"That atoms in our body were part of a cloud of gas and dust that formed 5 billion years ago."

"That the early universe started with basically only hydrogen."

"Look back time. That we are seeing this distance galaxies as they were a long time ago rather than right now is fascinating."

"How all elements beyond a certain point are created by supernovas."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The distance and look back time of a star or galaxy is super confusing. The whole seeing a specific object light years away is really hard to wrap my head around."

"What type of star has more metal--is it the older or younger?"

"Hubble law."

"The expansion of space has me a little confused--how long would it take before all of everything in space would take up all of the open area in space? Could we overcrowd space? Glad that wouldn't happen any lifetime soon!"

"I understand how light can be a sort of 'time machine' but how exactly does it work?"

"Why is the universe expanding? If it was from the big bang, wouldn't it be slowing it down (since it's the edge of an explosion)? Why is it speeding up?"

"Monolithic collapse."

"How the universe gets progressively dirtier as each new generation of stars converts hydrogen into metals"

"Where all the different elements came from, whether it was all supernovas or from some other source."

"Nothing was too confusing."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [65%]
Metals (elements heavier than hydrogen and helium): increased [94%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  *** [3]
young stars that formed very recently.  ************** [14]
(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 [29%]
Carbon in your body: another star, in the past [47%]
Calcium in your bones: another star, in the past [41%]
Iron in your blood: another star, in the past [47%]
Gold and silver from mines: another star, in the past [47%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"If near the very edge of our perspective we see a sea of hydrogen, is it a giant pink wall?" (Well, hydrogen appears pink if its electrons are excited by a nearby star, so before the first stars were born, all the hydrogen was there, but would have been dark.)

"I feel like I can't wait to go over all this information in class. It seems all really confusing. Just reading this information made me feel like I was watching Back to the Future."

"Did the telescope night get rescheduled? I completely forgot to call two hours before the meet up to get details. :( hopefully I didn't miss it!" (You missed it. Don't worry, everyone else missed it. Wait for the partial solar eclipse event on the SLO campus on the first day of class this fall semester.)

"Are there gonna be more extra-credit opportunities?" (Yes, at the end of the semester.)

"While in class, are we safe from the werewolves?"

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