Because here’s another extremely interesting article on the use of an acoustic superlens to do kind of the same thing, only for ships and subs. Only this will be able to do the opposite as well – pinpointing ones that are trying to hide. Here’s a great explanation of what an acoustic superlens can do, found in the article:
“Acoustic lenses can be made to focus sound much as the lens in a microscope focuses light. But physicists’ ability to work with both types of waves is limited by scattering effects called diffraction. Using conventional lenses, it’s not possible to focus light waves or sound waves to a spot size smaller than half the wavelength of the light. To get around these limitations, a lens must refract, or literally bend light backward. No naturally occurring materials have a negative index of refraction, but some materials carefully designed in the lab, called metamaterials, do. The same tools used to make materials that can focus light or sound waves beyond the diffraction limit, enabling high-resolution imaging, can also be used to make materials that accomplish the opposite, cloaking an object by directing light or sound around it.”
Here’s what the resonant plate looks like:
Fascinating, isn’t it!