If you're a Harry Potter fan, you're probably familiar with the concept of an invisibility cloak. Slip this magical garment over your head and to the eyes of of the beholder, you vanish. Well Muggles, science has some good news for you -invisibility is quickly becoming a reality.
One method is the optical camouflage technology developed by scientists at the University of Tokyo. This approach works on the same principles of the green screen used by TV weather forecasters and Hollywood filmmakers. If you want people to see through you, all you have to do is redirect the green screen onto your body? Granted, it hardly matches up to the personal cloaking of the master fictional wizard, but it's a start.
And while you won't find The Invisible Man hiding out in Europe, made famous by in the 1930's by Claude Rains, a group of German scientists at the Karlsruhe Institute of Technology have made gold 'disappear' by bending light waves to suppress light. If a cloak was made from metamaterials, it could actually guide rays of visible light around an object - much like a rock diverting water in a stream.
Anyone who attended SWSWi this March in Austin, Texas and participated in Junaio's ScavengAR Hunt is probably familiar with the next technique. Optical camouflage can take advantage of something called augmented-reality technology -- a type of technology first pioneered in the 1960s by Ivan Sutherland and his students at Harvard University and the University of Utah.
Most augmented-reality systems require a user to look through a special viewing apparatus to see a real-world scene enhanced with synthesized graphics. In optical camouflage, the use of retro-reflective material is critical because it can be seen from far away and in bright sunlight -- two requirements for the illusion of invisibility.
While drawing another reference to Harry Potter, see how the Daily Prophet newspaper is also becoming a reality by use of Augmented Reality (see "Augmented Reality Could Transform Legacy Newspapers
Into Video Media").
This video will provide you with a quick snapshot as to how augmented reality system can make walls transparent.
So while the source of invisibility was thought to only be derived by magic or mad scientists, it appears (or doesn't appear, as the case may be) that making yourself invisible might be something we'll all be able to do, with or without an invisibility cloak, in the very near future.