Chinese Work Sees Through Invisibility Quest
Researchers explain how theoretical 'anti-cloak' could bring objects out of hiding
FRIDAY, Sept. 5, 2008 (HealthDay News) -- Just in case someone develops a cloak of invisibility, a team of Chinese scientists say they know how to uncloak the objects it hides.
According to a paper published in Optics Express, certain materials underneath an invisibility cloak would allow invisible objects to be seen again.
Researchers at Shanghai Jiao Tong University in China said their theoretical "anti-cloak" would be made of material with exactly the same optical properties as those of an invisibility cloak. In this way, while an invisibility cloak would bend light around an object, any part touching the anti-cloak would reflect some light back making it visible.
Scientists have found some special types of "meta" materials that become effectively invisible because of how they interact with light. However, the invisibility achieved to date in the laboratory works only for a narrow band of light wavelengths. Making an object invisible to the broad range of wavelengths the eyes normally see has never been achieved.
The U.S. National Library of Medicine has more about eyes and vision.