It might not knock Coldplay or Kanye West off the top of charts, but physicists who say they have cracked the riddle of 'singing' sand dunes are compiling a CD of sand music. The team say their new theory allows them to predict the notes that different dunes will make.
Sand dunes in certain parts of the world are notorious for the noises they make as sand avalanches down their sides. Some emit low powerful booms, others sound like drum rolls or galloping horses, and some are even tuneful. These dune songs have been reported to last for up to 15 minutes and can sound as loud as a low-flying aeroplane. Physicists know it is the avalanches that set the grains humming, but the precise mechanism has remained controversial.
St�phane Douady of the French national research agency CNRS and his colleagues shipped sand from Moroccan singing dunes back to his lab to investigate. They found that they could play notes by pushing the sand by hand, or with a metal handle. That put to rest one theory that the noise was the result of the entire dune resonating.
You might think that orchestrating a sand dune is the height of musical eccentricity. You would be wrong...