When the sun is straight up at noon, you see blue sky because all the other colors in the spectrum up until blue and purple are scattered away. This is known as the Rayleigh effect. We usually don't ...

Out of the impossibly blue sky, the unthinkable came. A generation has grown up since the events of Sept. 11, 2001 — 22 Septembers ago — but those who can cast their mind back to that day remember one ...

A monumental change has been made in Colorado's history after years of deliberation and review. Mount Evans is now officially named Mount Blue Sky. Those who helped make this change possible ...

The new photo contest from c't Fotografie is looking for motifs in blue. We are excited to see creative submissions featuring ...