Why is the sky blue?  

To understand this, it is important to understand that color doesn't exist as some separate thing in the world.  What we call blue paint just means paint that reflects light in certain wavelengths we have learned to call "blue".  Color-blind people have eyes that work perfectly well but are different from most other eyes in just his area - how they register light wavelengths.  Take a moment and think about this. Color does not exist - only reflected light exists.  In a red light, blue paint will look black. 

Now, the sky is blue because blue light comes in on a short wavelength and wallops into oxygen atoms of roughly the same size.  When we look up and see a blue sky, we are seeing that interatction.

At sunset, we see more red because the sunlight is passing through many more miles of atmosphere at that low angle near the horizon.  The blue light interacts with the oxygen and is scattered as before - but cannot reach the eye throught the extra miles this time.  Instead, we see the other end of the spectrum, the red light.

I just thought this was a cool answer to the age old question.  Its from the Dangerous Book For Boys by Hal Iggulden.

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Feb. 1, 2008 at 10:27 PM Wow i learn something new today ..

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Feb. 27, 2008 at 10:51 AM now that is really interesting !!! i still think its because its my favorite color , lol

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