..."Now scientists from the University of Dundee, in Scotland, have created something with a bit more muscle. While most of the documented experiments with tractor-beam technology so far have involved light waves, the team from Dundee used sound waves to manipulate a half-inch triangular prism made of metal and rubber, successfully pulling the target toward the source of the acoustic beam. Half an inch may not sound like much, but it’s a vast improvement on fifty nanometres. The experiment was part "...