Why is the Sky Blue?

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                    Why is the Sky Blue?



       This is the one of those questions which four year old's ask all the time that what makes the sky blue.To understand that we have to look one thing which makes blue to sky is atmosphere.The atmosphere is mixture of gas molecules,water and dust that surrounding the earth.The light from the sun is scattered by the atmosphere in all direction.The white light that coming from the sun is really made up of all colors of the rainbow.Between all these seven colors blue light scattered more than the red light because of it's shorter wavelength.
       Light travel from the sun in the form of wave that similar to the wave of ocean. Some are close together and others are further far. Distance of each same peak of wave is called wavelength. When all the wavelength travel together light looks white to our eyes. If we break the light of sunlight we can see individual colors. Every individual color has equal wavelength. Blue color has shorter wavelength compare to the wavelength of red color. The shorter wavelength of light like blue and violet interact to the particles of atmosphere more than other color like red and orange. This causes the blue and violet waves to be separated from the rest of the light and become scattered in every direction for all to see. 
      The other wavelengths stick together as a group and therefore the sunlight in earth is slightly yellowish. The scattered violet and blue light dominates the sky, making it appear blue . But what happens to the violet? Some of the violet light is absorbed by the upper atmosphere. Also our eyes are not as sensitive to violet as they are to blue. The blueness of the sky is result of Rayleigh scattering which refers to the selective scattering of light off of particles that are no bigger than one-tenth the wavelength of the light.
       During sunrise or sunset,the sun's light has to pass through more of the atmosphere to reach our eyes. Even more of the blue and violet light gets scattered allowing the reds and yellowish to shine through .
(sky in the evening)





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