why sky is blue?

The blue color of sky is dues to Rayleigh scattering.As light moves through the atmosphere, most of the longer wavelengths pass straight through.Little of the red,orange,yellow light is affected by air. However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. it gets scattered all around the sky. Which ever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.

Well,as far as i remember that question was discussed by our teacher in physics. Sad to say during that time i am always sleeping coz i already know the style of teaching she does.She is just reading the information in the book. By the way, here are some key points that you must know.First of all we know that sun emits white light and white light contains different colors which are the"ROYGBIV" the rainbow colors. Isaac newton presented it using the spectrum. As the white light passess through our atmosphere, the blue light is absorb while the others bent. Since blue is the only color that was absorb,we see it clearly that the sky is blue with our naked eye.Its hard to remember all those things,i hope that i answer your question.

Yes rayleigh scattering is inversely proportional to the fourth power of the wavelenght, so the shortest wavelenght of the blue radiation is scattered more than the longer wavelenght of the reds. Being blue frequency more scattered in the atmosphere the diffuse radiation has a different spectrum than the direct sunlight. So basically photons with blue frequencies are scattered more than red ones, so most of the scattered photons are blue. And so our eyes sees it as blue!

It has to do with the light spectrum and the way it..uh.. bends.... I don't feel like looking it up to explain it and I don't remember it too well. Hehe.