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.