Richard Brock, age 8, of Rochester, New York, for his question:

What is the real color of water?

A bucket of pure water is as clear as glass. You can see right through it. But if the bucket were as deep as a lake, the clear water would be tinged with blue. The blueish tinge of water is so faint that in a bucket or a drinking glass you don't see it all. But as you know, lakes and oceans are not always blue. This is because a lot of open water plays tricks with the sky and the sunbeams. Its shiny surface acts like an enormous mirror and reflects the colors in the sky above it.

Notice when the sky is strewn with murky grey clouds. A lake mirrors the same murky grey    and so does the ocean. Sometimes the water reflects the gorgeous colors of the sunset. When skies are blue, so are the lakes and oceans. They look even bluer than the sky. This is because deep water steals the red, orange and yellow rays from the sunbeams. Only the blue rays can reach down deep    and they add their blue color to the water.