In scientists’ endless quest for the secret of invisibility, we now have a cloak that makes SOUND invisible. Now they are studying a group of sharks that can sneak up on their prey by seeming to becoming one with the ocean around them. (on your next ocean voyage, be sure to stay inside!)
It turns out that Lantern sharks have the ability to create an optical illusion that makes them visually undetectable (so watch out if you’re swimming somewhere nearby!) They do it by emitting light which, along with natural shimmer, creates the illusion of matching their surroundings.
Discovery News quotes biologist Julien Claes as saying, "The photophores replace the down-welling light from the sun, which is absorbed by the shark’s body. The silhouette of the shark therefore disappears when seen from below."
Now we need to muffle sound and researchers are working on that too: A new acoustic invisibility cloak–that blocks out sound–is made of a unique plastic that makes objects invisible to sound waves. It could be used to shield ships from sonar, or build better soundproof walls for concert halls and other spaces. It could lead to silent helicopters and invisible submarines–a great boon for the military.
Invisibility cloaks work by bending light waves in ways that would not normally be possible. This cloak uses the same principles to bend sound waves.