The dream of "invisibility cloaks" is at last becoming possible, and although the process will likely take another decade or two, steps have already been made in that direction. A group of graduate students at Duke University are already working on developing metamaterials-a special kind of material that causes light to bend in unusual ways, following the contours of the material's structure, and come back out the same way it went in. Provided that this technology is feasible, preliminary trials will be performed by the end of the decade, and the first economical cloak to be put into use (for hiding obstrusive structures from the riverfront areas) will be constructed before 2020.

Experience will show that the technique works best with flat surfaces. Curved surfaces lead to differences in the length of the light path, which are visible as artefacts. Accordingly the material will be first adopted in buildings as a replacement for windows, allowing people deep in a large building the illusion of having an office with a prime location in the building and with excellent views.