According to an on-line only publication in the highly reputable scientific journal Science (the premier scientific publication in the US), it would appear that the physics of invisibility, at least at the theoretical and technical levels, has been established. More below the jump, or check out snippets here yourself
There are two articles that discuss the findings, and so far I can only excerpt the first few sentences of each.
Controlling Electromagnetic Fields
J. B. Pendry 1*, D. Schurig 2, D. R. Smith 2
1 Department of Physics, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK.
2 Department of Electrical and Computer Engineering, Duke University, Box 90291, Durham, NC 27708, USA.
* To whom correspondence should be addressed.
J. B. Pendry , E-mail: firstname.lastname@example.org
Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields--electric displacement field D, magnetic induction field B, and Poynting vector S--are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
Optical Conformal Mapping
Ulf Leonhardt 1*
1 School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, Scotland.
* To whom correspondence should be addressed.
Ulf Leonhardt , E-mail: email@example.com
An invisibility device should guide light around an object as if nothing were there, regardless of where the light comes from. Ideal invisibility devices are impossible due to the wave nature of light. This paper develops a general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics. The imperfections of invisibility can be made arbitrarily small to hide objects that are much larger than the wavelength. Using modern metamaterials, practical demonstrations of such devices may be possible. The method developed here can be also applied to escape detection by other electromagnetic waves or sound.
As for a lay summary, here's all I feel comfortable quoting while still respecting the copyright:
News of the Week
High-Tech Materials Could Render Objects Invisible
No, this isn't the 1 April issue of Science, and yes, you read the headline correctly. Materials already being developed could funnel light and electromagnetic radiation around any object and render it invisible, theoretical physicists predict online in Science this week (www.sciencemag.org/cgi/content/abstract/1125907 and www.sciencemag.org/cgi/content/abstract/1126493). In the near future, such cloaking devices might shield sensitive equipment from disruptive radio waves or electric and magnetic fields. Cloaks that hide objects from prying eyes might not be much further off, researchers say.
The papers are "visionary," says George Eleftheriades, an electrical engineer at the University of Toronto in Canada. "It's pioneering work that sets the stage for future research." Greg Gbur, a theoretical physicist at the University of North Carolina, Charlotte, notes that others have studied invisibility but says the new papers describe more precisely how to achieve it. "Each gives specific examples of how you might design an invisibility device," he says.
The authors map out the necessary speed variations and leave it to others to design the materials that will produce them. But researchers already know how to design metamaterials to achieve such bizarre properties, at least for radio waves, says Nader Engheta, an electrical engineer at the University of Pennsylvania. "It's not necessarily easy, but the recipes are there," says Engheta, who last year proposed using a metamaterial coating to counteract an object's ability to redirect light, making combination nearly transparent.
Alas, even if invisibility proves possible, it may not work the way it does in the movies. For example, a cloaking device would be useless for spying, Pendry says. "Nobody can see you in there, but of course you can't see them, either." Keeping track of your always-invisible device might be a pain, too.
So, there you have it, the first description of how to build your own invisible material. From what I've read, it'll actually be difficult to build an invisible cloak per se, but rather, the application would be for a "shield." As this is the US military funding this technology, I can imagine we'll be seeing (or rather, not "seeing") invisible tanks through Tehran sometime late next year (they say that it'll take them 18 months or so to actually make the material).
Got any ideas for how to put this new technology to good use?