Sky Polarization: Understanding & Experiments

[jangheej]

hi all

im studying polarization, and i want to check if i have the right idea about sky polarization.
basically i want to find the position of the sun when i know the angle theta (refer to the attachment) of the sun but doesn't know the exact position.
so i look at the portion of the sky that is at the right angle from the plane of the sun and rotate the polaroid and find the axis of the polaroid when it's the brightests.
so from this, i assume that the polarization direction by scattering is in the same direction as the axis of the polaroid and therefore determine the position of the sun as shown in the picture.

do i have the right idea?


and also, i actually tried to find the sun's position myself with a normal polaroid.
but when i looked throgh the polaroid and rotated it, there wasnt any difference in the brightness of the polaroid. what is wrong with my approach in this experiment??
is the linear polarization by scattering usually not strong enough to detect by a normal polaroid? if so, how can i design the experiment?

 

[M.KALEM]

I am wondering did you decided to the experiment? How will you explain polarization? And what is the relationship between polarization and navigation?

 

[Andy Resnick]

do i have the right idea?

Yep.

but when i looked throgh the polaroid and rotated it, there wasnt any difference in the brightness of the polaroid. what is wrong with my approach in this experiment??
is the linear polarization by scattering usually not strong enough to detect by a normal polaroid? if so, how can i design the experiment?

The sky polarization is very sensitive to aerosols (water vapor, for example) and pollutants: without knowing more, I can't guess why you did not notice any change. On a clear day, it's a very pronounced effect:

http://farm1.static.flickr.com/6/86864348_ed115c64fb.jpg

 

[cosmik debris]

It should be possible, many insects use this technique for navigation.

 

[M.KALEM]

Yes, it is possible but Vikings using tourmaline cyristals for decided to describe sun position. And due to sun positions they can find their directions. But how? And How can ı explain this topic? Which experiment should I do?