February 13th, 2008
Scientists have figured out a way to bend sound waves around an object and, can even prevent the escape of all sounds created inside a given area…. Recently, Steve Cummer, Associate Professor of Electrical and Computer Engineering at Duke University announced that it is theoretically possible to create … a sound shield. Building on research demonstrating how light waves can be bent around an object to make it appear invisible, Cummer and his collaborators used mathematical analysis to show how to do the same thing with sound. They established that it is possible to create a material that bends sound waves around walls, pillars, or any enclosed area, where the sound waves emerge as if nothing had been in their way. It would be like someone in the bedroom being able to hear what someone in the living room said, but as if there were no wall between them. A side effect of this discovery is that sound waves generated inside the enclosed area would never escape.Source: LiveScience
This was sort of hidden in the article about Fairy Tales, but I thought this was the most interesting part. Large silent maneuverable craft have been seen in the skies for many years. Perhaps those alien ships do make a lot of noise, but they stop all the sound with a sound shield! I hope we have that same technology some day for our cars, jets, etc. Where does all the sound energy trapped in a sound shield go? Does it just bounce around in there until it runs out of steam? Perhaps it could be recaptured to increase the energy of the system.