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.

Alexandria Johnson does hard science on the most nebulous of subjects: clouds. As an atmospheric scientist and assistant professor of practice in Purdue University’s College of Science, she studies ...

The color of the leaves isn't the only thing that changes in autumn. Have you ever looked up on a crisp fall day and noticed how brilliant and clear the blue sky is? That's not just your imagination — ...