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Scientists are boldly going where only fiction has gone before — to develop a Cloak(1) of Invisibility(2). 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(3) designs.
In this first successful experiment, researchers from the United States and England were able to cloak a copper cylinder(4).
It's like a mirage(5), 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(6) objects. Like light and radar waves, microwaves usually bounce(7) off objects, making them visible to instruments and creating a shadow that can be detected.
Cloaking(8) used special materials to deflect(9) radar or light or other waves around an object, like water flowing around a smooth rock in a stream. It differs from stealth(10) technology, which does not make an aircraft invisible but reduces the cross-section(11) 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.
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.
The cloak is made of metamaterials(12), 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.
However, their device works only with microwave radiation and only in two dimensions. And it does not yet provide complete invisibility, producing a small shadow that can be detected.
1. cloak n. 斗篷 v. 用外衣遮蔽
2. invisibility 看不见的东西
3. sophisticated 精致复杂的
4. cylinder 圆柱体
5. mirage 海市蜃楼
6. detect 探测
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