Why is the sky blue?

This is quite a cool question asked by my 8 year old daughter. Parties can't swing without it, we can't survive without it, and blue skies would be black and spotty without it: Atmosphere. In short, the blue sky is caused by particle diffraction. The air we breathe is made of molecules of common substances; nitrogen and oxygen being the main constituents. Light hits some of these molecules bouncing off in another direction and some is absorbed - both changing the colour slightly.

The rest of the explanation is pretty dull, so only carry on if you're made of stern stuff. First, here is some South African Blue sky for you. It's Pilgrims Rest in the Low Veld - A lovely place if you're visiting.