why is the sky blue?

Question

lots of people ask me why is the sky blue? I dont know maybe you can help me. Why IS the sky blue HMMMMMMMM?????

Answer 1

The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the 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. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.

Answer 2

This question has been asked over 5000 times, and I've prepared a simple answer, without too much science:

The correct answer is that the blue light is scattered by the air molecules in the atmosphere (referred to as Rayleigh scattering). The blue wavelength is scattered more, because the scatteing effect increases with the inverse of the fourth power of the incident wavelength.
OK, but I've known science graduates who don't understand what this means.
Here's my attempt at an answer without too much physics:

I think most people know that sunlight is made up of light of several different wavelengths, and can be split up into the colours of the rainbow. Blue light has the shorter wavelength, and red the longest wavelength.

When sunlight hits the molecules in the atmosphere, the light strikes the molecules and is absorbed. The molecules vibrate and and give off, or 're-emit' the light. Because the molecules vibrate in all directions, the light is emitted in all directions (called 'scattering'). The molecules in the air are much smaller than the wavelength of visible light, but because the blue wavelength is shorter and more energetic, it reacts much more with the air molecules than the red and yellow wavelengths; which tend to pass straight through.

Because the blue radiation is re-emitted from the air molecules in all directions, it seems to us looking from the ground that the blue light is coming from everywhere; hence the sky seems blue.

Near sunset, because of the low angle of the sunlight, we see more of the red and yellow wavelendth passing straight through, hence the colours of the setting sun.

BTW: The sky isn't blue because of a reflection of the sea; its the other way round, The blue colour of the sea is a little more complicated, because as well as the water molecules scattering the blue light, the water absorbs more of the red and yellow wavelengths, leaving the blue part of the spectrum, as well as part of the green (which is why deep water can appear bluish-green). This effect is even stronger with ice; which results in the intense blue colour we see if we look down a crevasse in a glacier, or down a hole in the snow made by a ski stock..
My thanks to varoius contributers for correcting me on some details.

For a complete, scientific explqanation, look up 'blue sky' in Wikipedia.

Answer 3

The sun's rays hit the
Earth's
atmosphere, where the light is scattered by nitrogen and oxygen molecules in the air. The blue wavelength of this light is affected more than the red and green wavelengths, causing the surrounding air to appear blue. At sunset, the sun's light passes farther through the atmosphere, deflecting and decreasing the blue in the air. Scattering by dust particles and pollution in the air causes the sunset to appear red.

Answer 4

when you were typing that question a little box appeared right below the title listing hundreds of other questions exactly like yours.

your question is the fifty second i have answered on that topic since joining Y!A

type in your title in the search box above.


OMG.

the apple is red because it absorbed the red colour and reflected all the others into our eyes. the brain looks through the colours it sees and concludes that the red is missing and therefore absorbed by the apple


blue light is scattered in the sky by gas molecules and never reaches our eyes, so our brain thinks that the "sky" must have absorbed blue and is therefore BLUE.

"kelleylu" is right except thaqt the blue light never reaches us. our brain thinks that whatever the sky is made of absorbed the blue and then labels the sky blue in our vision.

Answer 5

The repeated asking of this question will eventually cause me to go on a mad rampage through the streets.

http://answers.yahoo.com/search/search_result;_ylt=Aq8QV.mwdjS1tLBp2UxfV_UDxgt.;_ylv=3?p=why+is+the+sky+blue

Answer 6

The sky is blue because God made it that way. I am so glad that he made it with such a beautiful and peaceful color.

Answer 7

Reflection from the ocean. When the sun hits the water the light reflects into the atmoshpere

Answer 8

because Jesus wants it that way.

Answer 9

why is your poop brown?