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US-BRITAIN-PHYSICS-CLOAK
This handout photo received 20 October 2006 courtesy of Duke University in Durham, North Carolina shows an "invisibilty cloak". For fans of the fictional Harry Potter, US and British scientists have demonstrated a working "invisibility cloak" that could, in time, make wearers disappear. Initial tests focused on making objects invisible to microwaves, but the scientists said the same principles could theoretically apply to visible frequencies, making a true invisibility cloak like storybook hero Potter's possible. Scientists at Duke University in North Carolina sought to put into practice the design theory revealed earlier this year by Sir John Pendry of Imperial College London.They made a five-inch cloak (12.7 centimeters) from a complex artificial composite, or metamaterial, of copper rings and wires patterned onto fiberglass composite sheets.The material is designed to distort space so that microwaves are not reflected back, but are instead bent around the cloaked object, whatever its shape, and allowed to flow on as if it didn't exist. The result is that the beams are deflected like water flowing around a rock in a river, without noticeably interrupting the main current. "By incorporating complex material properties, our cloak allows a concealed volume, plus the cloak, to appear to have properties similar to free space when viewed externally," said Duke scientist David Smith. "The cloak reduces both an object's reflection and its shadow, either of which would enable its detection." The effect is different from, for instance, stealth technology which protects US Air Force bombers from radar. That technology simply deflects the radar in ways to disguise the jets, while not making them invisible. AFP PHOTO/DUKE UNIVERSITY/HO/ RESTRICTED TO EDITORIAL USE = GETTY OUT=
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Detalii fotografie |
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Durham, North Carolina, UNITED STATES |
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AFP / Mediafax Foto |
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HO |
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| Data: |
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20 Octombrie 2006 |
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| Dimensiuni: |
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2816 x 2112 (1.97 MB) |
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