SoundCloak
Latest
Duke University physicists test first air-based acoustic invisibility cloak
Firmly departing from the Stuff Of Dreams category, Duke University physicists have successfully tested an acoustic cloaking device that fools sound waves while looking nowhere near as scifi as you'd think. Layering nothing more than a bunch of hole-punched plastic sheets -- known as meta-materials, for those curious -- atop a ten centimeter long block of wood, highly-directed sound in the 1 - 4kHz range bounced right off the concealed object none the wiser. The cloaking tech owes some of its origin to the math behind transformation optics -- and maybe to the Duke team, too. Besides allowing defense department bunkers to erupt into silent applause, the research should prove useful in the construction of future concert halls. DIY hobbyists, let us know what you can rig up with some trash bags. [Thanks, Drew]
Scientists create "cloak of silence" -- serial killing will never be the same
Someday in the near future, the act of banging on your neighbor's door at 3 am because he won't stop playing I Can't Go For That at obnoxious volumes will be unheard of. Literally. Scientists have demonstrated a "cloak of silence" in the New Journal of Physics which might be used to build homes, concert halls, or aircraft which are impervious to sound waves. The process works by utilizing "sonic crystals," a meta-material made up of arrays of small cylinders which would channel sound around an object like water flowing around a rock. Says creator Dr. Sanchez-Dehesa, "It's not an unrealistic blueprint - it doesn't demand that we do extraordinary things... this is something that can easily be manufactured." Make it soon, please, we can't stand Hall & Oates.
Researchers say three-dimensional sound cloak is possible, in theory
Apparently not content with simply building an invisibility cloak, of sorts, those mad scientists at Duke University's Pratt School of Engineering now say that they've found that a three-dimensional "sound cloak" is also possible, in theory. According to Duke's Steven Cummer, the researchers have come up with a "recipe" for an acoustic material that would "essentially open up a hole in space and make something inside that hole disappear from sound waves." Needless to say, they haven't tested that possibility just yet, but they say it could one day be used to hide submarines from detection by sonar or even be used to improve the acoustics of a concert hall by making inconvenient structural beams effectively disappear. What's more, they say that the basic principles at play here could also suggest that cloaks could be created for other wave systems, like seismic waves, or even waves at the surface of the ocean, although the practical applications for those would seem to be a bit more limited.[Image courtesy of Royal Navy/BAE Systems]
