Acoustic chatter

FROM Bluetooth and Wi-Fi to FM and AM, wireless communication depends on electromagnetic waves--usually, radio waves. But as any motorist driving through a tunnel or under power lines can attest, such waves cannot always propagate properly past every obstruction. Sometimes, a system that used a different medium of transmission would make communication that bit easier. As they report in the Proceedings of the National Academy of Sciences, Alex Zettl and his colleagues at the University of Califor...