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美英科學(xué)家成功研制“隱形斗篷”
[ 2006-10-20 09:01 ]

哈里·波特的“隱形斗篷”曾讓人類羨慕不已。最近,美英科學(xué)家研制成功的“隱形斗篷”,讓現(xiàn)實世界看到了科幻世界中魔法變成現(xiàn)實的希望。美國和英國科學(xué)家最近合作研發(fā)出一種“隱形斗篷”,可以避開微波探測,成功將一個銅質(zhì)圓柱體“隱藏”起來。在首次嘗試中,研究人員設(shè)計的“外衣”能夠阻止探測到物體的微波。這種隱形原理與軍事稱謂中的“隱形戰(zhàn)斗機”不同,“隱形戰(zhàn)斗機”并不能讓物體真正隱形,只是通過減少雷達(dá)可以探測到的戰(zhàn)機橫截面而降低暴露的風(fēng)險。不過,研究人員對這次研究成果并不十分滿意,認(rèn)為目前的“斗篷”隱形效果仍處于二維階段,在實驗中還可能留下微弱陰影。

 

 

A photo of the "metamaterial" cloak, released to Reuters on October 19, 2006, which deflects microwave beams so they flow around a "hidden" object inside with little distortion, making it appear almost as if nothing were there at all. U.S. and British scientists said on Thursday they had found a way to hide an object from microwave radiation in a first step toward making a what they hope will be an invisibility cloak. [Reuters]

Scientists are boldly going where only fiction has gone before - to develop a Cloak of Invisibility. It isn't quite ready to hide a Romulan space ship from Capt. James T. Kirk or to disguise Harry Potter, but it is a significant start and could show the way to more sophisticated designs. 

In this first successful experiment, researchers from the United States and England were able to cloak a copper cylinder.

It's like a mirage , where heat causes the bending of light rays and cloaks the road ahead behind an image of the sky.

"We have built an artificial mirage that can hide something from would-be observers in any direction," said cloak designer David Schurig, a research associate in Duke University's electrical and computer engineering department.

For their first attempt, the researchers designed a cloak that prevents microwaves from detecting objects. Like light and radar waves, microwaves usually bounce off objects, making them visible to instruments and creating a shadow that can be detected.

Cloaking used special materials to deflect radar or light or other waves around an object, like water flowing around a smooth rock in a stream. It differs from stealth technology, which does not make an aircraft invisible but reduces the cross-section available to radar, making it hard to track.

The new work points the way for an improved version that could hide people and objects from visible light.

Conceptually, the chance of adapting the concept to visible light is good, Schurig said in a telephone interview. But, he added, "From an engineering point of view it is very challenging."

The cloaking of a cylinder from microwaves comes just five months after Schurig and colleagues published their theory that it should be possible. Their work is reported in a paper in Friday's issue of the journal Science.

"We did this work very quickly ... and that led to a cloak that is not optimal ," said co-author David R. Smith, also of Duke. "We know how to make a much better one."

The cloak is made of metamaterials, which are mixtures of metal and circuit board materials such as ceramic, Teflon or fiber composite.

In an ideal situation, the cloak and the item it is hiding would be invisible. An observer would see whatever is beyond them, with no evidence the cloaked item exists.

(Agencies)

Vocabulary:
 

Cloak of Invisibility: 隱形斗篷

copper cylinder: 銅柱

mirage: 海市蜃樓

microwaves: 微波

optimal: 最佳的、最理想的

(英語點津陳蓓編輯)

 
 

 

 

 
 

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