ambience: Seagulls / Ocean Waves
We’ve all had the experience of holding a conch shell up to our ear and hearing something that sounds remarkably like the ocean. But shells have even more to say, if you know how to listen. I’m Jim Metzner and this is the Pulse of the Planet, presented by DuPont. ambience: Shells clanging “By simply tapping the shells, or banging them together, you can deduce something about what they’re made of.” That’s one of the ways that Geerat Vermeij learns about a new shell when he first picks it up. And Vermeij handles quite a few of them, since he’s one of the world’s leading experts on shells. He finds listening to them especially useful, because he happens to be blind, but he recommends this technique to anyone. “You can listen to shells and deduce something about its mineralogy, the material from which the shells are built. So, for example, scallop shells — and I have here two examples of a scallop from Newfoundland. If you tap them together, (tapping sound) they sound rather metallic, in fact if you placed one on top of the other, (clanging sound) they sound like dishes, a very nice metallic sound. Whereas, if you take a cohog clam, another common Eastern thing, it has a very matte sound (clapping sound), no echo, it’s sort of dull. And that’s because the scallop shells are composed of what we call calcite, whereas the cohog clam is composed of something we call aragonite. And so, the mineralogy makes the shells sound different. It just goes to show how you can use one’s senses to deduce all kinds of things about shells.” Please visit our website at nationalgeographic.com. Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation.