The notion of "cloaking": canceling out magnetic field lines, electromagnetic waves, sound waves

 

 

http://www.livescience.com/51925-magnetic-wormhole-created.html

 

One of the properties of "superconductors, which can carry high levels of current, or charged particles", is that they "expel magnetic field lines from their interiors, essentially bending or distorting these lines".

 

Excerpts:
"So the team designed a three-layer object, consisting of two concentric spheres with an interior spiral-cylinder. The interior layer essentially transmitted a magnetic field from one end to the other, while the other two layers acted to conceal the field's existence."

 

For shielding use mu-metals
"The inner cylinder was made of a ferromagnetic mu-metal. 
Ferromagnetic materials exhibit the strongest form of magnetism, while mu-metals are highly permeable and are often used for shielding electronic devices."

 

Structure
1. Ferromagnetic mu-metal inner cylinder.
2. Superconducting shell lining inner cylinder bends magnetic field.
3. Mu metal on outside cancels the bending of the magnetic field by the superconducting shell.

Link by Suja Vijayan

 

 

Acoustical cloaking: direct sound waves around an object so that they re-form on the other side with no distortion

https://www.technologyreview.com/s/410279/acoustic-cloak-designed/