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Why is the sky blue using avogardo's number?

  1. Jul 8, 2003 #1
    [SOLVED] Why is the sky blue using avogardo's number?

    This question was brought up in a physics class, and was never answered for me.

    I was wondering if anyone here can tell me, given avogadro's number, why is the sky blue? (including all the messy equations if possible).

    I believe Einstein was the first person to figure this one out.

  2. jcsd
  3. Jul 8, 2003 #2


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    To reflect the color of your pretty eyes

    Nah, honestly, I have no clue.
  4. Jul 10, 2003 #3
    haha that's sweet, but then that'd make the sky brown
  5. Jul 17, 2003 #4
    Tyndall and Rayleigh thought that the blue colour of the sky must be due to small particles of dust and droplets of water vapour in the atmosphere. Even today, people sometimes incorrectly say that this is the case. Later scientists realised that if this were true, there would be more variation of sky colour with humidity or haze conditions than was actually observed, so they supposed correctly that the molecules of oxygen and nitrogen in the air are sufficient to account for the scattering. The case was finally settled by Einstein in 1911, who calculated the detailed formula for the scattering of light from molecules; and this was found to be in agreement with experiment. He was even able to use the calculation as a further verification of Avogadro's number when compared with observation. The molecules are able to scatter light because the electromagnetic field of the light waves induces electric dipole moments in the molecules.
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