You're by the water's edge, observing a turquoise lagoon, then a little further away, you see an almost black sea at the foot of a cliff. Why does the ocean take on such different hues, from deep dark ...

We may receive a commission on purchases made from links. The vacation to the Mediterranean you've been waiting for all year has finally arrived. You've made all the reservations, planned your ...

Add Yahoo as a preferred source to see more of our stories on Google. Crater Lake in Oregon looks brilliant blue because its water comes from melting snow and is extremely pure. CST Tami Beduhn, NOAA ...

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Curious Kids is a series for children of all ages. If you have a question you’d like ...