The blue sky above the Earth is so integral to the human experience we don't often question it, but there is a scientific explanation as to why the sky is blue.

Is the blue sky not actually blue?On a clear day, the sky is a deep, clear blue... But the sky isn't painted blue. The air ...

From blue lights to social media tributes, here's why the color blue has become synonymous with remembering 9/11 victims.

Look up on a clear sunny day and you will see a blue sky. But is this the true color of the sky? Or is it the only color of the sky? The answers are a little complicated, but they involve the nature ...