Featured Research

from universities, journals, and other organizations

Invisibility Undone: Chinese Scientists Demonstrate How To Uncloak An Invisible Object

Date:
September 4, 2008
Source:
American Institute of Physics
Summary:
Harry Potter beware! A team of Chinese scientists has developed a way to unmask your invisibility cloak. According to a new paper in Optics Express certain materials underneath an invisibility cloak would allow invisible objects be seen again.

Harry Potter beware! A team of Chinese scientists has developed a way to unmask your invisibility cloak. According to new research, certain materials underneath an invisibility cloak would allow invisible objects be seen again.

Related Articles


"Cloaking is an important problem since invisibility can help survival in hostile environment," says Huanyang Chen of Shanghai Jiao Tong University in China. He and his colleagues have proposed a theoretical "anti-cloak" that would partially cancel the effect of the invisibility cloak, which is another important problem as it turns out.

If this sounds like more movie magic, it's no accident. From the 1933 classic The Invisible Man to the more recent installment in the Harry Potter series, devices that achieve invisibility have long been the stuff of film fantasy. In recent years, however, scientists using special types of "meta" materials have shown that these Hollywood fantasies could one day become reality after all.

These materials are effectively invisible because of the way they interact with light. All materials scatter, bounce, absorb, reflect and otherwise alter light rays that strike them. We perceive color, for instance, because different materials and coatings interact with light differently. Transformation media cloaks are special materials that can bend light so much that it actually passes around the object completely. In 2006, scientists at Duke University demonstrated in the laboratory that an object made of metamaterial is partially invisible when viewed using microwaves.

Sounds cool? Not so fast. Invisibility as it has been achieved so far in the laboratory is very limited. It works, but only for a narrow band of light wavelengths. Nobody has found a way yet to make an object invisible to the broad range of wavelengths our eyes are attuned to seeing, says Chen, and doing so would be a challenge.

An even greater problem for anyone who has aspirations to be concealed in public one day is that invisibility achieved through transformation media is a two-way street. With no light penetrating a perfect invisibility cloak, there would be no way for an invisible person to see outside. In other words, invisible people would also be blind—not exactly what Harry Potter had in mind.

But now, Chen and his colleagues have developed way to partially cancel the invisibility cloak's cloaking effect. Their "anti-cloak" would be a material with optical properties perfectly matched to those of an invisibility cloak. (In technical jargon, an anti-cloak would be anisotropic negative refractive index material that is impedance matched to the positive refractive index of the invisibility cloak).

While an invisibility cloak would bend light around an object, any region that came into contact with the anti-cloak would guide some light back so that it became visible. This would allow an invisible observer to see the outside by pressing a layer of anti-cloak material in contact with an invisibility cloak.

"With the anti-cloak, Potter can see outside if he wants to," says Chen, who conducted the research together with his colleagues at Shanghai Jiao Tong University and The Hong Kong University of Science and Technology.

This work was funded by the National Natural Science Foundation of China, the National Minister of Education Program for Changjiang Scholars and Innovative Research Team in University, and the Hong Kong Central Allocation Fund.


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Journal Reference:

  1. Huanyang Chen et al. The Anti-Cloak. Optics Express, Vol. 16, Issue 19, September 15, 2008, pp. 14577 %u2013 14582

Cite This Page:

American Institute of Physics. "Invisibility Undone: Chinese Scientists Demonstrate How To Uncloak An Invisible Object." ScienceDaily. ScienceDaily, 4 September 2008. <www.sciencedaily.com/releases/2008/09/080903073016.htm>.
American Institute of Physics. (2008, September 4). Invisibility Undone: Chinese Scientists Demonstrate How To Uncloak An Invisible Object. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2008/09/080903073016.htm
American Institute of Physics. "Invisibility Undone: Chinese Scientists Demonstrate How To Uncloak An Invisible Object." ScienceDaily. www.sciencedaily.com/releases/2008/09/080903073016.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
3D Printed Cookies Just in Time for Christmas

3D Printed Cookies Just in Time for Christmas

Reuters - Innovations Video Online (Dec. 18, 2014) A tech company in Spain have combined technology with cuisine to develop the 'Foodini', a 3D printer designed to print the perfect cookie for Santa. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
First Etihad Superjumbo Flight in December

First Etihad Superjumbo Flight in December

AFP (Dec. 18, 2014) The first flight of Etihad Airways' long-awaited Airbus A380 superjumbo will take place later in December, the Abu Dhabi carrier said Thursday, also announcing its first Boeing 787 Dreamliner route. Duration: 01:09 Video provided by AFP
Powered by NewsLook.com
Ford Expands Air Bag Recall Nationwide

Ford Expands Air Bag Recall Nationwide

Newsy (Dec. 18, 2014) The automaker added 447,000 vehicles to its recall list, bringing the total to more than 502,000. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins