Online reading assignment: Milky Way history, big bang clues (NC 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 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 fact that older stars born a long time ago will be metal-poor, it doesn't confuse but rather makes sense as the older stars will not have hardly any metal to speak of other than the little amount they have themselves while newer stars are born into a rich metal landscape."

"That the atoms in our bodies come from stars."

"That space is dark because of the redshift of stars moving far away."

"The fact that we live in the remains of the big bang is awesome. I used to picture the big bang as occurring in a particular place, but reading the textbook helped me understand how wrong that notion is."

"'The universe is inside us.' I thought that my high school teachers were just saying we were made of stars to keep our interest. But I guess its actually true, in a way."

"How we are technically looking at super-super-old light through telescopes. It's a little confusing though."

"I'm super-interested in the expansion of space without the actual movement of the galaxies because I previously didn't understand how all galaxies could be moving away from each other. This made me science-happy."

"Olbers' Paradox is really cool it really solidifies the beginning of the universe since some light hasn't reached us yet. It's crazy."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Bottom-up model versus the monolithic collapse model because I can't conceptualize the idea of it all."

"The whole idea of metals being the way we found out how old the universe really is was kind of confusing because what started this process of metal fusion and supernovas in the first place?"

"Lookback time."

"The Hubble law--I just don't get it."

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [42%]
Metals (elements heavier than hydrogen and helium): increased [81%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  ********* [9]
young stars that formed very recently.  ************** [14]
(There is a tie.)  [0]
(Neither, as stars cannot have metals.)  ** [2]
(Unsure/guessing/lost/help!)  * [1]

Indicate what produced these elements.
(Only correct responses shown.)
Helium in the sun's core: the sun [7%]
Carbon in your body: another star, in the past [46%]
Calcium in your bones: another star, in the past [38%]
Iron in your blood: another star, in the past [54%]
Gold and silver from mines: another star, in the past [31%]

People breaking up a relationship are most likely to update their Facebook status to "single":
on Valentine's Day.  ******* [7]
during spring break.  *********** [11]
just after Thanksgiving.  * [1]
on Christmas Day.  [0]
(Unsure/guessing/lost/help!)  ******* [7]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"How can we possibly map out our Milky Way galaxy with all the dust we would have to look through?" (We just need to look at infrared and radio waves, which easily pass through interstellar gas and dust.)

"You're most likely to see 'single' FB status updates a few days before the Mid-State Fair starts during the summer."

"So, if we see a star 25 light-years away dying...it technically died 25 years ago?" (Yes. Like if you received a postcard from your significant other breaking up with you, then your significant other actually broke up with you a few days ago.)

"When we die, will the some of the atoms from our body ever go back into space and be part of stars again or will they all remain on Earth?" (They will all remain on Earth. Unless you launch your body into space, or wait long enough for the sun to swallow Earth up as a red giant, and what remains of Earth dissipates outwards as the sun goes through its planetary nebula phase.)

"Do most of your students believe in the big bang?" (Well, I would much rather you all understand how the evidence for the big bang is interpreted, which is something I can test you on; rather than whether you believe in the big bang, which is something I can't test you on.)

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