A cloaking device that makes you appear completely invisible is still trapped in the realm of science fiction. But researchers at Duke University, North Carolina, have successfully created a cloaking device that works with sound, making an object completely invisible to SONAR and other acoustic imaging techniques.
So how do perforated plastic sheets stacked in a pyramid stop an object from interfering with sound waves so that it's seemingly not there? It doesn't. What the cloaking device does do, however, is make the sound waves seem as if they were reflected off an empty flat surface by altering their trajectory and slowing them down ever so slightly to compensate for the plastic pyramid.
The science behind how it works and how the researchers designed this structure is complicated. But in essence it can fool a SONAR system by making it think its microphones are detecting a perfect reflection of the sound wave it just blasted out.
The downside to this creation is that hardly anyone relies on sound to detect anything on land. If you were thinking of robbing a bank by creeping through the entrance at night wearing one of these pyramids, you'll be even more noticeable by security cameras. But given light can also act like a wave, the techniques and insights learned here might eventually lead to breakthroughs with the ultimate cloaking device. [Duke Pratt School of Engineering via Dvice]