## 20171018

### Online reading assignment: Kirchhoff's laws (SLO campus)

Astronomy 210, fall 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 Kirchhoff's laws.

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.
"That temperature is just the average speed of particle motion. I find this interesting because I have never really thought anything of temperature besides it just being a number."

"What I found interesting was the spectrums and how there were different kinds. I didn't know that there were different ones, I just thought it was really interesting!"

"The dark lines in the absorption spectrum of a star are like bar codes, each star's is unique."

"How much different a star can look if from when its coming towards us and when its moving away from us. It's interesting to see how much of a shift there is between the two cases."

"The Doppler effect for sounds was cool, like how wavelengths are squished from a source moving towards you, but as the source moves away from you, the wavelengths stretches out."

"It totally makes sense now why the sounds of a car horn change when they pass by you. I've heard of the Doppler effect but never knew what it meant until now. Pretty funny about Sheldon's costume."

"I found it interesting that you aren't a fan of Big Bang Theory. It made me like you more."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The difference between continuous, emmision, and absorption spectra."

"How can solids emit light--I thought they just absorbed light?"

"It's going to be hard remembering the difference between all of the spectrums and what they look like."

"The spectra types was also confusing for me because I don't know how to tell what spectra everyday things give off."

"Can you please go over the three types of spectra and to tell them apart from one another?"

"I was confused on how somebody on Earth, with a telescope, could predict what type of gas the sun is made out of. The sun is so far away, and is deep in space, I don't see how we can tell exactly what it is made of."

"I was confused with the moving car Doppler effect demo. Why are waves off the front more squished than the waves off of the back, and why are the waves the same in either direction when the car is stationary?"

"The most confusing part of the slides was why people think The Big Bang Theory is a funny show."

I believe Pluto should be a planet.
 Strongly disagree. ** [2] Disagree. *********** [11] Neutral. *************** [15] Agree. ***** [5] Strongly Agree. *** [3]

Briefly explain your answer to the previous question (whether Pluto should be a planet).
"Because it doesn't fit all the classifications to be a planet anymore and I now know that."

"I still disagree because Pluto doesn't meet the updated requirements for what constitutes a planet."

"Pluto is circular, and follows the suns orbit, but it does not have dominance over its own orbit making it a dwarf planet."

"I don't really care. If we keep finding things in space, we will have to continue to narrow down the definition of planets and other heavenly bodies."

"No need to change."

"It doesn't follow all the rules required to be a planet. It doesn't dominate its orbit and if every object that revolved around the sun and was round shaped was a planet, there would be way too many planets to keep track of."

"I think there has to be a cut off and if Pluto doesn't qualify then that's a non issue. It's nothing personal, there are qualifications for all kinds of things in science. I don't think it makes sense to keep going back and forth on the matter."

"I honestly still don't really have an opinion on this. I'm perfectly okay either way."

"I only agree because it doesn't fit what is now 'what makes a planet' but I tend to want to agree because I grew up believing it was a planet."

"Honestly it;s technically registered as a dwarf planet and that is enough for me."

"I don't know why the size of the planet maters but science decided that Pluto wasn't a planet. it might be like the egg thing and they will change their minds."

"It needs to stop trying and just accept the fact that it is small, far away, and kinda of a loser."

"It fits most IAU specifications, but it's just too small to dominate its orbit, and doesn't a normal elliptical path like the other planets. (Sorry, Pluto.)"

"Pluto does not meet all of the criteria to be considered a planet however, we've considered it a planet before and it seems harsh to rescind its status. As I mentioned before Pluto should be considered an 'honorary planet.'"

"I always grew up with Pluto being a planet, and think it should stay that way."

"Pluto doesn't meet the requirements for a planet anymore. Although the qualifications of a planet use to be different, there are new updates which suggest to us that Pluto is no longer a planet. Pluto is not the boss of its own realm, so no."

"I believe it should be a planet because it passes two of the categories that would make it quality as for planet."

"Pluto being a planet doesn't concern me all that much."

"This is because of the International Astronomical Union's rule of what is and isn't a planet. It makes a lot of sense and it's very simple to use!"

"Because it doesn't meet any of the IAU standards of being a planet--neither terrestrial or jovian."

"K-12 education."

"Pluto doesn't have enough mass to generate a gravitational field strong enough to bring nearby objects into its orbit. That makes it a dwarf planet."

"It is too small to be a planet, but I think it should be one because it may feel left out and discriminated against."

"The Plutonians need to conserve their planet's resources and it will only happen with reform."

"Doesn't matter to me, it's still in space somewhere."

"It meets 2/3 of the criteria, but it does not make a huge difference if it was considered a planet, could go either way. "

"Considering how often the rules and regulations for classification of planets change I think Pluto is cute and should be let back in the cool kids club."

"Technically it should not be considered a planet because it does not pass the 3 test thing, it does not dominate its orbit."

"Definitions do change as does uses of language, that why bloody means two different things depending on whether you live in America or England. I point this out to illustrate that it is OK for a definition to shift, and that is just what happened with the term planet. So, the current definition of a planet should be used. If the questions to differentiate bodies in space are applied to Pluto we see that it is not a planet."

"I feel like unless there is something special about Pluto, then it doesn't need to be classified as an actual planet."

"Pluto is only .07 times the size of all the Kuiper belt objects in its orbit and it doesn't follow the third rule of 'clearing the neighborhood' around its orbit. "

Match the spectrum type with their appearance.
(Only correct responses shown.)
Rainbow containing all colors: continuous [86%]
Rainbow with thin black lines: absorption [89%]
Colored lines on a black background: emission [86%]
Given off by hot, dense object: continuous [69%]
Given off by hot, diffuse gas atoms: emission [78%]
Passing through cool, diffuse gas atoms: [67%]

Hot, molten metal produces a __________ spectrum, which appears as a:
 continuous; rainbow. **************** [16] emission; series of bright lines on a dark background. ******** [8] absorption; series of dark lines on a rainbow background. *** [3] (Unsure/guessing/lost/help!) ********* [9]

The sun produces a __________ spectrum, which appears as a:
 continuous; rainbow. ******** [8] emission; series of bright lines on a dark background. ********** [10] absorption; series of dark lines on a rainbow background. ************** [14] (Unsure/guessing/lost/help!) **** [4]

The lights atop the Fremont Theater in San Luis Obispo, CA, produces a __________ spectrum, which appears as a:
 continuous; rainbow. ************ [12] emission; series of bright lines on a dark background. ***************** [17] absorption; series of dark lines on a rainbow background. ***** [5] (Unsure/guessing/lost/help!) ** [2]

Your instructor produces a __________ spectrum, which appears as a:
 continuous; rainbow. ********** [10] emission; series of bright lines on a dark background. ********** [10] absorption; series of dark lines on a rainbow background. *********** [11] (Unsure/guessing/lost/help!) ***** [5]

The balrog from The Lord Of The Rings: The Fellowship Of The Ring produces a __________ spectrum, which appears as a:
 continuous; rainbow. ********* [9] emission; series of bright lines on a dark background. ******** [8] absorption; series of dark lines on a rainbow background. ********** [10] (Unsure/guessing/lost/help!) ********* [9]

Suppose you are standing on the sidewalk as a car, with its horn continuously on, passes by (video link). The loudness of the car horn:
 starts loud, then gets quieter. ****** [6] starts quiet, then gets louder. * [1] starts quiet, gets louder, then goes back down to quiet. ************************** [26] starts loud, gets quieter, then goes back up to loud. ** [2] (Unsure/guessing/lost/help!) * [1]

Suppose you are standing on the sidewalk as a car, with its horn continuously on, passes by (video link, same as above). The pitch (high note/low note) of the car horn:
 starts high, then drops lower. *************** [15] starts low, then goes higher. * [1] starts low, goes higher, then drops back down to low. *************** [15] starts high, goes lower, then goes back up to high. **** [4] (Unsure/guessing/lost/help!) * [1]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Further review of the three different spectra will be appreciated."

"The different spectra are a little confusing. How to tell them apart from one another? Especially for the picto-quiz."

"Liv Tyler ('Arwen') was the hottest person in The Lord of the Rings."

"Temperature aside, you have to admit Gollum is the hottest Lord of the Rings character by far."

"I am a little confused on the Kelvin temperature scale relating to absolute zero, and how you find that. Is absolute zero literally zero?" (Yes, when you define temperature as the energy of thermal motion, if you remove all the energy from the atoms in a substance such that they don't move at all, then you've reached absolute zero.)

"I thought I saw a red dot in the sky over the east horizon this week--was it Mars?" (Yes, in the early morning just before sunrise.)

"Will we have class the night before Thanksgiving?" (Yes, but it's just a review and extra-credit night.)

"What does the sun orbit? Does the sun and our solar system orbit the center of the Milky Way galaxy? Or does it orbit something that orbits the Milky Way galaxy?" (The sun goes around the center of the Milky Way, in a flat orbit within its disk.)

"Why aren't you a great fan of The Big Bang Theory?" (The Big Bang Theory makes fun of nerds and geeks. Shows like Community has fun with nerds and geeks.)

"Every seven years your body is completely replaced with entirely new cells so just because you look the same doesn't mean you are." (Well, some cells are replaced in less time or more time than that, but some of your cells are basically with you for the rest of your life--like the corneal lens in your eyes.)

"No questions, hope you had a nice weekend!" (Well, other than grading all your midterms, yes, thank you.)