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How does the air polarise the light?

  1. Jun 16, 2008 #1
    I'm not sure if this is right but, when the light is absorbed by an air molecule, the air moleclue emits light (photons) in the at right angles to the direction of the light beam therefore in the direction of the electric field. This will cause the light to be either vertically or hoziontally polarised, dependant on the direction of the scatter? correct?

    Therefore if you look through the a polarised material ie sunstone, you can find the direction of the sun yes?

    I got a picture from a site

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  2. jcsd
  3. Jun 17, 2008 #2

    Andy Resnick

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    Rayleigh scattering describes how light is scattered by the atmosphere, and Mie scattering is used to include scattering by particulate matter. Both indicate that polarization effects occur, based on the differences between the reflection coefficients of s- and p- polarization incident on a surface. Some clouds (noctilucent) will preferentially polarize sunlight via scattering.

    As you look into the sky, the light entering your eyes will have a small amount of polarization, and the region of highest polarization is in quadrature ('90 degrees') to the location of the sun. The effect is very slight and easily obscured by particulate matter in the sky. Some people can see "Haidinger's brushes", and it is rumored that the Vikings used crystals of Iolite to navigate via polarization.
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