July 15, 2009 -- A cloak of illusion, or a material that disguises one object as another, is being developed by scientists in Hong Kong. "The metamaterial can turn the appearance of one object into that of another," said CT Chan, a scientist at the Hong Kong University of Science and Technology and coauthor of a paper that recently appeared in the journal Physical Review Letters. "For example, it can make an apple look like an orange," said Chan. Unlike most materials, which derive their properties from their chemical makeup, a metamaterial gets its special properties from its physical composition. The tiny hills, valleys, and shapes imprinted onto a metamaterial, many times smaller than the wavelengths of light they intend to manipulate, can bend light waves around objects (invisibility cloaks), back towards their source (a universal mirror), or reflect a false image (cloak of illusion). The metamaterial the Hong Kong scientists propose, which exists solely as a mathematical model with no physical example yet, would have several layers. Some layers would face inwards, and cancel the light coming from the object through a process called destructive interference. Related Content:
Other layers would face outward, reflecting incoming light in very specific patterns to make the object inside look like something else. The surface on both inner and outer surfaces would be smooth, says Chan, made of an alloy copper or aluminum and a dielectric. "This is very intriguing because the theory points out a completely new approach of camouflage," said Nicholas Fang, a researcher in Illinois who recently developed an acoustic metamaterial. "Instead of making things completely transparent, the parts can be disguised under radars." "Imagine if you confused a F-22 for a Boeing 747 on the radar screen," sand Fang. "It [would be] hard to take quick action." The cloak of illusion won't be covering aircraft or anything else soon however. For relativity long microwaves, Chan says the material could be created in as little as two years. For shorter infrared or even visible wavelengths, it would take even longer to create. "This is really interesting in theory; 10 years ago nobody would have had any idea how to do this," said Steve Cummer, a scientist at Duke University who helped develop the original invisibility cloak in 2006. "But this would be tremendously difficult to make." Related Links: Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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