A physics professor and his 14-year-old son have built and demonstrated three different invisibility devices. They were constructed from off-the shelf materials and could hide people, vehicles or even satellites.

John Howell, a quantum physics professor, and his 14-year-old son, J. Benjamin Howell, created three devices using mirrors, tanks of water and lenses. Although based on the way a magician might use mirrors, the research behind the new designs has been submitted to the American Journal of Physics. Despite the fact that the effect depends on the angle from which the object to be hidden is viewed, the methods developed by the father-son pair might be put to practical use by police and the military.

One of the methods demonstrated at the University of Rochester involves a set of L-shaped mirrors. Another uses four Fresnel lenses, purchased for three dollars each, to bend light around the subject. Although the object shows up in this device, the image passes at a different time than the person or object being cloaked. A third design from the Howells depends on L-shaped plexiglass tanks of water.

"Overall, I believe that this is interesting engineering work, as a smart composition of mirrors or materials may realize an optical trick that hides an object for certain observers. I don't necessarily find the concept scientifically too exciting. It is more of an optical engineering challenge," Andrea Alu, a researcher at the University of Texas at Austin working on cloaking technology, said.

Current devices for producing a degree of invisibility, like those in Alu's lab use exotic materials and are expensive to produce. They often only block certain wavelengths of light and only work on small objects.

The devices constructed by the Howells have no moving pieces and were constructed for a total of $150. The concepts behind the three devices are scalable to large dimensions, the Howells wrote in the paper announcing the results.

"This volume is sufficient to cloak a human, albeit with not as much convenience as Harry Potter's cloak," the Howells said.

These could include cloaking satellites, which would not be hindered by the uni-direction nature of the effect. The devices even work if the object to be hidden is giving off light of its own.

One possible development that could come from these devices could include police cars being able to hide in plain sight in order to catch people speeding.