Week 7 Feedback

I just wanted to say that posting the lecture notes online have defintately helped me with the homework over the past two weeks.      

Glad to hear

I am just curious about something on the homework.  On the last question of HW6 you discuss the aurora borealis.  Is it the different atoms (nitrogen, oxygen, ect.) that make the different colors? 

yes these come from different spectral signatures of the molecules (the different energy levels)

Also, is it harmful to the health of an individual to be bombarded by this amount of electrons if you were at the earths poles?

  well I'm no doctor... wait a sec... I AM a doctor! Anyhow, the electrons do not reach the earth because of the atmosphere. (note the aurora does not reach the earth ; )

I was thinking about TV's the other day and was wondering what happens when the gets static on it? Does that have to do with the signals from the station or the actual TV? 

it's the actual TV -- that's wwhere the charges end up and stick... before they are 'grounded' or run off to th earth....note you are shooting electrons at the screen from the back of the TV.. they have to go somewhere.

I think class is going great.  The homeworks are a bit tedious at times because they are mostly written response.  ...but rather I am going to say that they really help me to understand the concepts.  The only thing that is in writing them we could go for ever to make sure that we get full credit.  I think that it needs to be explained better what we have to write to .5 credit point answers vs. 1 point credit answers.  I hope this makes sense.  

Sure thing.. thanks for the feedback...yes I'll have James announce his devious grading scheme.

(1) In terms of the reading quizzes, I prefer them at the end of class.  I mean I think you agree that the book doesn't do that good of a job teaching unless it's tiny details which we never cover in class, so it's kind of silly to test us on a nearly use-less material.  Or the 2 out of 3 questions correct idea is nice too.

well these are important ideas ... I just want you to know that you can learn them (and should learn them) on your own.. however I know the book is difficult .

(2)I really like how you include the learning goals in the lecture. :) It gives us a good sense of where we're going.

good to hear.

I really enjoy the help sessions.  I attend on Friday afternoons and Akiko always explains the concepts very well.  Thank you for the help sessions and I would like to thank her for all of her work!

we aiim to please... thanks for the feedback.      

The class lectures and homework seemed to go together really well last week.  There were no homework problems with concepts that we hadn't covered in class, so I felt really prepared when I was doing it.  I liked how we went into detail on how televisions work.  It was cool to find out how an entire device works instead of just parts of it.  One thing that I was really suprised about was that there's no such thing as a photon that's not a pure light color. 

thanks... it is worth being a little careful with you language --- all E/M radiation (including ) light is made up of photons. each photon has a particular frequency or 'color' associated with it.

I would have guessed that photons could be any color as long as their wavelength was different.

this is also true.. they can be any color... though sometimes the emission source is only allowed to produce certain colors. (though maybe you're referring to 'pink' which is a construction of our brain when the two cones (red and blue) are hit at the same time).

  Overall, I thought last week was really interesting, and that the concepts were presented really well.      

      glad to hear.. thanks.  

What color is the sun if I looked at it with my eyes from space? Would it be "whitish", "yellowish" or a different "yellowish" than we see from earth?I heard that the "yellowish" of our sun -- the way it looks to us from earth -- is primarily due to the scattering of blue light in our atmosphere.

both of these are true.. but our sun, I believe, is still not so hot as to be pure white... it is whiter than it appears to us at earth, but emits unequal amounts of light --- the simulation on the website should help out with this question.

For instance, assuming our sun is "whitish", that would mean a mixture of red, green, and blue light would be coming toward the earth. However, we lose some blue light in the atmosphere so that tips the scale more in the favor of red and green. Red and green minus some blue makes a "yellowish" sun.I guess I'm wondering how much of a difference is between the color of the sun we see from earth vs. the color we would see from space.     

great analysis...

I was wondering if energy is conserved. Thanks.          

always providing you look at the an entire system

   I think that what we learned last week about how our eyes interpret color was really interesting.  The questions on the homework regarding the simulation were a good way for me to see how the eye views two or three wavelengths of color together.  I did have a few concerns about the homework though.  First, there were a lot of essay questions and many were in-depth.  In our previous homeworks, the last question has been more in-depth, but in this homework it was many questions. 

glad to hear things are working well... I'll see what I can do, but obviously I value the essay writing / justification.

[comment on getting help from me and the LA's / TA's]

--- I'm around as often as I can be. Before and after class, during one or more help sessions and office hours... if you're looking for more help than is offered in the (voluntary) help sessions, please find me]   

           The image of our older TV appeared to be more reddish than that of the new TV.Is that something to do with physics?         

if it has to do with color it has to do with physics... I'm willing to bet that either your electron beams are not as strong as they use to be, or that they are not aligned (remember with a color TV there is a mask for different colors). I could also possibly be the phosphors on the front of the screen getting old..