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 discussion of the big bang theory was interesting because I enjoy listening to different ideas of how things came to be in the universe. It is the biggest mystery after all."
"How elements that make up life are elements of the universe and how it all just connects. I find it interesting because I never really thought about it that way."
"I didn't know that we are made out of star stuff. I found this interesting because it shows that the universe extends to all things not just planets and galaxies and such."
"I just think it's really interesting that the galaxy started off as just a ton of hydrogen gas and then all it took was something to set it off to start making heavier elements."
"How light from Deneb takes 1,400 years to travel to us. We are seeing Deneb in the past 1,400 years ago."
"I thought the big bang was interesting to read about seems kind of crazy to think about."
"That what we are looking at millions of light years away from us is technically in the past. I never thought of the universe like that and it's amazing and confusing at the same time."
"I never really gave it much thought on how we are all made from 'star stuff.' It makes a lot of sense since everything comes from supernova explosions."
"How to explain that the universe is finite is through the gaps that you see in between stars where there are no stars."
"I really like the video about why the night sky is dark. I just assumed it was pitch black because space just seems like empty nothingness other than the stars and galaxies out there but when you break it down and realize that since we are viewing stars in the past when we look to the farthest stars which are redshifted stars it makes sense that even further than that would be infrared stars which we obviously cannot see and also that there is still light left over from the big bang."
"I thought the look back time part of the reading was super cool. The idea that we are looking at something so far in the past because of the time it takes for light to travel."
"The idea of the expansion of the universe not being from a central point. It's interesting because it's hard to understand."
"'Lookback time.' For example you can see the Andromeda galaxy, the farthest object seen with naked eye, but the nearest galaxy to ours. This galaxy is 25.4 million light years away, which means it is 25.4 million years back into time that we are seeing, not how it currently looks. It takes 25.4 million years for the light to reach Earth."
"Globular clusters are so interesting to me. They contain 105 to 106 stars in a region only 10-30 parsecs in diamters. That is extremely crazy to think about. One star alone is already crazy in mass--imagine that many of them!"
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Which elements were created by what, and how stars got the elements they have in the first place, because how does heat create everything when we don't know what few elements the universe started with?"
"I don't quite understand how the universe has an edge. I need more explanations on that."
"I personally found that metal-rich and metal-poor concepts to be confusing. Is it really just as simple as old stars are metal-poor whereas new ones are metal-rich?"
"Where does the carbon and calcium come from in our bodies?"
"how did the universe start out as mainly hydrogen."
"I didn't fully get the redshift with the expansion of space."
"I found the video confusing about how it explained how the night sky is both dark and light, I didn't fully understand the explanation."
"I kind of found the whole metal rich thing a bit confusing just because it says stars in the halo are apparently metal poor but stars in the disk are metal rich and some are even more metal rich than others."
"I am still unclear on the telling the difference between population I and II stars."
"How exactly are telescopes time machines?"
"Although I understand the concept of look back time and how the light we see is from the past. I don't understand how the images from a telescope are from the past. It makes sense, but it doesn't."
Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [43%]
Metals (elements heavier than hydrogen and helium): increased [78%]
The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago. ***** [5] young stars that formed very recently. ***************** [17] (There is a tie.) [0] (Neither, as stars cannot have metals.) [0] (Unsure/guessing/lost/help!) * [1]
Indicate what produced these elements.
(Only correct responses shown.)
Hydrogen in the sun's core: the very early universe [56%]
Helium in the sun's core: the sun [39%]
Carbon in your body: another star, in the past [35%]
Calcium in your bones: another star, in the past [35%]
Iron in your blood: another star, in the past [35%]
Gold and silver from mines: another star, in the past [26%]
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"How did our performance on the second midterm compare to previous years?" (You did pretty awesome. Keep it up!)
"Can we talk about how 'time travel' is related to things being millions of light years away?"
"Please go over the big bang more and elements in space."
"Since space is always expanding, would that make it impossible for it to get dirty from metals and dust?" (Even if space keeps expanding, on the local scale gravity keeps things together, so the galaxies (and everything else inside of it) stay more or less the same size.)
"Have you ever questioned what our existence is in the universe?" (I often do.)
"I don't believe in the 'big bang theory;' but I'm sure when God created the entire universe and everything in it in one week there was quite a big bang. It's interesting how the heavens declare the glory of God, and the firmament tells of his handiwork."
"Do you believe in the big bang and evolution?" (I think it's fair to say that I understand the evidence for both--and I think it's fair in this class to teach you and test your understanding of the evidence for both.)
No comments:
Post a Comment