But that doesn't quite line up with "Avatar: The Last Airbender," which never offers any real exposition about why Azula's flames are blue. Both Zuko and Azula's father, Fire Lord Ozai (Mark ...

Learn how living things make blue, and why this beautiful hue is so rare in nature. Among living things, the color blue is oddly rare. Blue rocks, blue sky, blue water, sure.

Why are Knoxville hydrants blue and yellow? Let's start with the mechanics. There are two parts of a fire hydrant: the "bonnet," which sits on top, and the "barrel," which is the body that comes ...