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Why does the sky is blue?

  1. Apr 30, 2009 #1
    Please, answer the question, Why does the sky is blue?
  2. jcsd
  3. Apr 30, 2009 #2
    Because: the wind is high. It blows my mind.
  4. Apr 30, 2009 #3
    Look up Rayleigh scattering on the web: http://en.wikipedia.org/wiki/Rayleigh_scattering
    I like the derivation and discussion in Slater and Frank "Electromagnetism" Chapter XII better than in Jackson "Classical Electrodynamics"
  5. Apr 30, 2009 #4


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    Because if it were green, we wouldn't know where to stop mowing.
  6. Apr 30, 2009 #5


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  7. Apr 30, 2009 #6


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    Cos raindrops keep falling from it's head.....
  8. Apr 30, 2009 #7
    In short: the color we see is scattered light from the sun. However, the scattering process of air with light depends inversely with a fourth power on the wavelength, meaning that blue light (short wavelength) is way more likely to scatter than red light (long wavelength).

    However, if a very long distance is travelled, longer wavelength photons will scatter as well, which you can see during a sunset. In case of a sunset, the sunlight "hoovers" over the surface of the earth for a long distance until it reaches your eyes; draw the earth as a circle and you will see why.
  9. Apr 30, 2009 #8
    Not sure what youre asking. Do you mean "Why is the sky Blue?" I dont think the sky does blue. either way its what lennox said. The scattering of light. Thats all it is.
  10. Apr 30, 2009 #9
    When does the grass is stopped mowing?
  11. May 1, 2009 #10
    Think: why does the grass is mowed? The grass does is mowed to know when to stop.
  12. May 1, 2009 #11
    why is the sky blue ? Because god made it that way. is as good a reason as any .
    the question should be how is the sky blue. basically what lennox said , it was explained to me this way its blue beacuse when the light hits the nitrogen molecules
    it absorbs some of the light and blue is a higher energy wavelenght therefore blue light is scattered. sunsets are red becsue the angle of refraction is different and the light is traveling further through the air there fore red light is scattered.
  13. May 1, 2009 #12


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    Oh, stop! Many of the posters on this board had to learn English as a second language. How would you like to have to phrase question in Holoholo?
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