## 20130203

Physics 205B, spring semester 2013
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 polarization.

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.
"I've never had polarization defined for me, so it is interesting to know what it is, and the concept is far less confusing than I thought it would be."

"That unpolarized light can be fully blocked by two perpendicular polarizers."

"Some electronic devices display diagonally polarized light, in order to not be blocked by polarized sunglasses. My BlackBerry and iPod are not viewable when I am wearing my vertically polarized sunglasses because they display horizontally polarized light. This was interesting because my polarized sunglasses were expensive."

"Reflected or scattered sunlight is partially polarized. It seems strange that if we filter some of this light out, we can see a more vivid and detailed world (for example getting rid of the reflection on a lake and being able to see more of what's underneath)!"

"A vertical antenna will only pick up vertically polarized radio waves."

"Visible light is something we all like. I like learning about the electromagnetic spectrum. I'm in art right now and were mixing colors."

"Liquid crystal displays were very interesting for the reason that we spend so much time in front of our computers, yet not too many people now how they really work."
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Distinguishing between transmitting light and polarized light at a horizontal or vertical axis. But reading through the material more carefully, I was able to understand it more."

"I'm not sure how polarization of radio waves works. It seems pretty complicated."

"Is the majority of glare seen during fishing and driving really horizontally polarized? Why is this ambient glare horizontally polarized?"

"Light passing through three polarizing filters."

"The questions at the end of the blog presentation."
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I do not have my text book yet. I will be getting it Monday, so I should start doing the reading by that day on. =("

White light was confusing because it appears 'white' but contains all the colors--when do we see white light, how is it different than the light that a light bulb puts out?" (A light bulb gives off all wavelengths (which we would perceive individually as colors) of visible light in nearly equal amounts. We also perceive a nearly equal mixture of red, green, and blue colors as 'white.' This is just how our perception of colors work.)

"Does light being polarized change the speed that it will travel versus being unpolarized?" (No.)

"Those 3D movie glasses are polarized lenses that are easy to acquire. Next time you go to the 3D movies wink at your fellow 3D moviegoers before the lights dim to see the polarization." (Note that many 3D glasses are circularly polarized (clockwise and counterclockwise), instead of linearly polarized, which is discussed in this class.)

"Polarization is interesting!" (Yay!)