Online reading assignment: Milky Way history, big bang clues (NC campus)

Astronomy 210, fall semester 2016
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 raisin bread analogy--I never knew that the raisins would move relatively; now that I do know it, it makes sense."

"That the universe essentially began with only hydrogen, and over the course of time has fused it into heavier elements. It makes the history of the universe feel like it's working toward creating something larger."

"How we are in an expanding universe."

"That the universe is progressively getting dirtier, because it makes sense and from what we have learned so far I understand why and how it is happening."

"That we are made from 'star stuff' because we are extremely tiny and knowing we are made from stars makes us feel special."

"I really tripped out that when we look at Deneb we are seeing it 1,400 years ago."

"That we can see stars that took millions of years to reach us, which is sort of like time travel."

"How time interacts with light at great distances. Because it's something that you don't see much on Earth because the distances are too short."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Monolithic collapse model; I can't seem to grasp what happens or what it really does. Just one of those things I need explained in class."

"he 'gaps' and 'edges' in the universe--how do we know the universe has an end? What might the edge or end look like?"

"The edge of the universe. It makes sense that it should be there, but it's a hard concept to wrap your mind around."

"I didn't understand the difference between stars in the halo and stars in the disk. I'm not sure what those locations are referring to, in regards to the Milky Way."

"That younger stars have more metals than older stars."

"The edge of the universe and the gaps. How do we know it has an edge? What is there are galaxies further than Hubble can see? This confuses me."

"I want to do know more on the big bang theory. I don't really understand why we don't know if it happened when we have evidence/examples."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [58%]
Metals (elements heavier than hydrogen and helium): increased [71%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  ******* [7]
young stars that formed very recently.  **************** [16]
(There is a tie.)  * [1]
(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 [38%]
Carbon in your body: another star, in the past [54%]
Calcium in your bones: another star, in the past [54%]
Iron in your blood: another star, in the past [46%]
Gold and silver from mines: another star, in the past [54%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I liked watching the video about 'Why Is It Dark at Night?' because I thought I knew the answer to that, but I actually knew nothing."

"What's your opinion of studying astronomy and not believing in the big bang theory at the same time?" (Well, the "big bang" is actually a misrepresentation of the expanding space between galaxies; but I think people can believe in certain things while scientifically studying how nature works based on evidence. Beliefs have been wrong before, but so has evidence.)

"Will the universe ever stop expanding?" (Current evidence is that the expansion rate appears to now be accelerating.)

"Is the universe expanding at an increasing rate because we are still in the big bang and apart of the expanding explosion?" (We have evidence that the expansion of space between galaxies is speeding up, but we don't know what's causing it. So for now it's called "dark energy," whatever that is. Similar to the evidence of additional gravitational forces holding galaxies together--we don't know what's causing that, but it's called "dark energy," whatever that is.)

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