Daniel Cressey for Nature.com

Acoustic method could quickly catch counterfeit coins.
You might assume that counterfeiters only bother with high-value bank notes, but there is a chance that some of the coins jangling around in your pocket right now are fake. If Mototsugu Suzuki gets his way, it may be that jangling that gives them away.

Suzuki, a researcher at the Tokyo Metropolitan Police Department’s Criminal Investigation Laboratory in Japan, has developed a way of examining coins based on the sound they make.

The traditional method of spotting a fake coin is to look at it — very closely. While this requires equipment no more specialist than a reasonable microscope, says Suzuki, it is time consuming and can cause “a lot of trouble” if the coins are heavily worn or when a large number of counterfeit coins are in the system. Read Full Story