SSS 2008-06-17（在线收听）

This is Scientific American's 60-Second Science, I'm Cynthia Graber. This'll just take a minute.

When Harry Potter slips underneath his invisibility cloak, he can wander freely undetected, but what about a cloak of silence, one that completely deadens sound. That's just what scientists from Spain's University of Valencia have designed on a tiny scale. They wrote about their research in the New Journal of Physics. A paper published last year showed how such cloak could be made in theory. Researchers proposed using materials made up of what are called sonic-crystals. These are solid cylinders that can scatter sound waves. The Spanish scientists wanted to figure out the specs to make a real acoustic cloak that could totally reroute sound around a given object. According to their models it will take about 200 layers of the sound-silencing materials to make it completely impervious to sound waves. They also think that they will eventually be able to get the same effect with a thinner cover. Among the first applications could be a silent coating for naval ships so that they are rendered invisible to sonar. But even more important could be wallcoverings that would finally protect your ears from those annoyingly noisy neighbors.

Thanks for the minute for Scientific American's 60-Second Science, I'm Cynthia Graber.