Trekkies rejoice: An invention used on the old TV series to hide the USS Enterprise from hostile craft appears to have become a reality. This as various entities have already worked on replicating the show's legendary Tricorder device used to diagnose a person's medical condition by waving it in the body's general direction.
A team of researchers led by Amanda D. Hanford of the Pennsylvania State University have undertaken the first steps to manufacture "acoustic ground cloaks" -- devices that could redirect oncoming sound waves around an object without disrupting the wave energy, resulting in hiding the object from being detected by, say, sonar.
Phys.org reports that Hanford and her associates embarked on creating a "metamaterial" that could permit sound waves to bend around an object as though it weren't present.
Metamaterials typically display unusual qualities that are not present in nature. To work, though, the tiniest cell in a metamaterial has to be smaller than the acoustical wavelength being deployed.
"These materials sound like a totally abstract concept, but the math is showing us that these properties are possible," said Hanford. "So, we are working to open the floodgates to see what we can create with these materials."
Rather than try to use acoustic metamaterials to deflect sound waves in the atmosphere, which has already been attempted, Hanford decided to try the same thing underwater.
She and her team built a 3-foot-high pyramid and produced waves that approached it. The results, says Phys.org, "demonstrate that this material could make an object appear invisible to underwater instruments like sonar."
The discovery has the potential to be applied to acoustic materials that muffle sound and seem invisible underwater.