Michele Krusa, age 10, of Gary, Indiana, for her question:

How can you possibly hear the sea in a seashell?

If you hold a large coiled seashell to your ear, you hear something that sounds like the sea. There is a soft surging "swoosh swoosh" that sounds just like the waves washing up and down on a faraway beach. This seems impossible, especially if you and the shell are 1,000 miles from the nearest beach. But then you remember that the world of nature is full of miracles. And perhaps by some miracle the shell carries a secret record of the sea sound inside it.

It would be nice if we could hear the sea in a shell    but this miracle does not happen. What we hear are soft echoes from our own bodies. The coils inside the shell are little echo chambers that catch and copy sounds. When you hold the shell to your ear, it catches and echoes the soft sound of the blood surging through your veins. And this sound swoosh swooshes somewhat like the sound of the surf on a beach.