When is an invisibility cloak not an invisibility cloak?
August 20, 2007 When you’re reporting about new technologies, it’s easy to get carried away with excitement over a breakthrough, particularly when sensationalist press releases are involved. This appears to have happened with Duke University’s somewhat misleading 2006 release announcing “the first demonstration of a working invisibility cloak – and a competing press conference is being called to contest the press releases' claims and demonstrate a 13-year-old technology that’s much closer to delivering optical invisibility.
On Tuesday August 21, a press conference will be held that will contest the October 19, 2006 claim by the Duke University Department of News and Communications that researchers at the Duke Pratt School of Engineering had presented "the first demonstration of a working invisibility cloak.”
The press conference will discuss in detail why this announcement by the university was not only misleading but in fact, by its wording, a historical error. The controversy centers around the Department's use of the term "invisibility cloak" which invokes thoughts of the Invisible Man, Harry Potter's invisible cloak and even Star Trek spaceship cloaking. All three of these describe optical invisibility which the Pratt team have yet to achieve - the Duke technology has merely been shown to be effective in making objects invisible to specific frequencies of microwaves, and its prospects of ever being used to achieve true optical invisibility are very limited.
The press conference will include video tape and other documentation of a previous development in invisibility cloaking in the optical frequency range that dates back to 1994 when it was originally demonstrated and publicized through a variety of media channels and in a scientific colloquium sponsored by the Biological and Physical Sciences department of a local college.
Pratt's David R. Smith has been quoted as describing his team's work as "...really a scientific explanation. Whether it’s useful is always a question." Conversely, the 1994 optical invisibility development today has lethal, as well as nonlethal capabilities, suitable for military, paramilitary and law enforcement uses. Because of this, certain aspects of its operation will be withheld at the conference, but the organizers say it will be clear that the effect is real, and to what extent it appears operational.
Organizers claim there is already a permanent exhibit being planned around this 1994 optical invisibility development and a TV special is in the works, along with a DVD.