20160907

Online reading assignment: history of astronomy, telescope powers (SLO 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 reviewing the history of astronomy, Kepler's and Newton's laws, and telescope powers.

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 when a planet orbits the sun it spends an equal amount of time in each 'section' even though it orbits in an elliptical pattern. Looking at it without the animation playing, you'd assume that it wouldn't spend equal time but it does and this is a bit of a mind blowing truth."

"Okay so you had told us to go back and re-read the text looking at classifying 'movers' and 'disprovers.' I like how reading about these philosophers and scientists and how they think. It really made sense to me that someone like Kepler had a background in mathematics."

"I found it interesting that there are two elements to explain planetary motion: 'how' and 'why.' Newton's laws I have heard before, but I have never heard of Kelper's laws before, therefore it is interesting."

"The concept of Newton's cannon is very intriguing. I never really thought of gravity working in that way."

"How Kepler was able to figure out exactly how the planets would move their orbits without knowing why."

"That Kepler was able to discover that the path of the planets around the sun is elliptical in shape, with the center of the sun being located at one focus."

"That Galileo invented a telescope that could magnify objects to the degree that he did. It's interesting because in that era you wouldn't think that it was possible to invent such a futuristic device."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Why was a donut sacrificed for science in Dr. Filippenko's experiment? A donut is an item of food that is to be consumed for its deliciousness and yet it was used very incorrectly."

"I still don't fully understand the path of the planets."

"Telescopes and how they reflect and capture light was somewhat confusing, but I'm sure it will be better understood with some demonstration."

"Why exactly do telescopes have mirrors?"

"A lot of it was confusing to me. I re-read every paragraph about twice just so I could imagine and understand it. Kepler's laws were more confusing to me than Newton's laws."

When a planet is undergoing retrograde motion, over several nights it moves __________ with respect to the background stars.
 east to west. ****************** [18] west to east. ************* [13] (Either of the above choices is possible.) *** [3] (Unsure/lost/guessing/help!) ***** [5]

When a planet is undergoing prograde motion, over several nights it moves __________ with respect to the background stars.
 east to west. ********** [10] west to east. ********************* [21] (Either of the above choices is possible.) *** [3] (Unsure/lost/guessing/help!) ***** [5]

Categorize each of Kepler's laws.
(Only correct responses shown.)
Kepler's first law: describes the shape of a planet's orbit. [85%]
Kepler's second law: describes the motion of a planet along its orbit. [82%]
Kepler's third law: describes the motion of a planet along its orbit. [59%]

Categorize each of Newton's laws.
(Only correct responses shown.)
Newton's first law: relates forces with changes in motion. [56%]
Newton's second law: relates forces with changes in motion. [72%]
Newton's third law: describes a property of forces. [64%]

The __________ power of a telescope depends on the: (Only correct responses shown.)
light-gathering: diameter of the primary lens/mirror [61%]
resolving: diameter of the primary lens/mirror [56%]
magnifying: both the focal lengths of the primary lens/mirror and eyepiece: [33%]

The least important feature to consider when purchasing an optical telescope is the __________ of its images.
 brightness. *** [3] resolution. ** [2] magnification. *************************** [27] (Two of the above choices.) * [1] (Unsure/lost/guessing/help!) ****** [6]

"Although it may seem intuitive that the magnifying power of a telescope would be the most important, it is actually the least valuable characteristic to consider when purchasing a telescope because this trait only enlarges what the telescope has already imaged. It doesn't improve a telescopes ability to acquire celestial images whatsoever."

"Higher magnifying power does not mean you'll get more detail. Main importance is resolving power, optical quality and seeing conditions."

"I'm having a hard time finding exactly what the book says, possibly the resolution is the least important."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Could we possibly go over 'retrograde' and 'prograde' a bit more? I found that I wasn't one hundred percent clear on how they work."

"While I was reading the slides I thought that I understood LGP, RP, and MP but once it came to the homework questions I realized I wasn't as well versed as I thought...can we go over this please? Also retrograde motion and prograde motion are still a little confusing to me."