Those who deal with underwater warfare will know that sonar is one of the primary methods of detecting your enemy, so what happens when you want to go dark? You might not command the seas at will like Moses or Namor, but good thing there is this tiny cylinder developed by researchers at the University of Illinois which will make you invisible to sound waves of a certain range – 40 to 80 KHz. The device itself consists of 16 concentric rings of acoustic circuits, where sound waves will find their way into the channels between the circuits, moving faster toward the innermost rings. Since this acceleration requires energy, the waves will instead gather on the outer rim of the cloak, which in layman’s terms, bend the sound waves around itself while remaining hidden. Of course, much more work needs to be done to cater for faster moving objects, and we are pretty sure the Navy is more than interested in such technology being made available to them (if not already).