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Scientists Work up a Disappearing Act

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Scientists Work up a Disappearing Act ENGLISH LANGUAGE SUPPORT | DEPARTMENT OF STUDENT SERVICES | RYERSON UNIVERSITY 1 Summary Writing How well can you write a summary (sometimes called an “abstract”)? Practise your summary writing skills by completing each of the following steps. Do not look at the suggested answer for each step until you have completed the step. Your answers may not be exactly the same as the suggested answer. This does not mean that your work is wrong. Different summaries may be made of the same article. However, each summary should contain the main points of the article. Step 1: Read the article carefully and underline or highlight all the important points. Ignore examples, statistics, details, quotations that do not contain important points, personal information, etc. Scientists work up a disappearing act The invisibility cloak that allowed Harry Potter to wander unseen through the halls of Hogwarts is no longer confined to the realm of fiction. Researchers in Britain and the United States have published a theoretical blueprint for constructing an invisibility cloak using revolutionary new materials engineered to bend light and other electromagnetic waves in ways not seen in nature. Sir John Pendry, a theoretical physicist at Imperial College London, says he may be able to make himself disappear in five years. "Maybe I'm being optimistic," he says, "but I think it could happen." It sounds like magic, but involves what are known as metamaterials, invented by Muggles (as non- wizarding folk are called in J.K. Rowling's books). Metamaterials are engineered to include tiny physical structures -- metal coils, or rods shaped like aerials. Scientists have been able to "tune" these materials to bend electromagnetic waves in strange ways. The plan, according to Sir John and his colleagues, is to channel light or other electromagnetic waves around an object, then restore them to their original trajectory on the other side. "The cloak would act like you've opened up a hole in space," says David Smith, a professor of electrical and computer engineering at Duke University in North Carolina. He and Sir John co-authored a paper on cloaking devices published in this week's on-line edition of the journal Science. Hide an object in a metamaterial cloak, Dr. Smith says, and electromagnetic waves would flow around it as water flows virtually undisturbed around a smooth rock. The work is most advanced in channelling the radio waves used in radar, and researchers say they may be able to hide planes or ships from enemy radar systems. The military applications are important, and in the United States the work is funded in part by the Defence Advanced Research Projects Agency, which is responsible for developing new technology for the Department of Defence. Dr. Smith is probably about 18 months away from developing a radar cloaking device using metamaterials, Sir John says. But even more astounding -- at least for the average person -- is the idea of wrapping yourself in an invisibility cloak and disappearing. Bending visible light is more difficult, the researchers say, because it has a much shorter wavelength than radio waves. This means the rods and coils would have to be extremely small, and perhaps built atom by atom with nanotechnology. Is it doable? University of Toronto researcher George Eleftheriades thinks so. He designs metamaterials. "Something will come eventually, in a couple of years. It is not easy, but it is not impossible. And people are pretty smart when the stakes are high." ENGLISH LANGUAGE SUPPORT | DEPARTMENT OF STUDENT SERVICES | RYERSON UNIVERSITY 2 He described the blueprint published by Sir John and his colleagues as "very exciting, very ingenious work." But it is not quite a match for the imagination of Ms. Rowling. In her books, Harry Potter's cloak is so thin, it fits in the inside pocket of his jacket. The real-life version would probably be quite a bit bulkier, Sir John says. "We can't do gossamer thin," he says. In the novels, Harry can see his silvery cloak, which he inherited from his father. But you wouldn't be able to see one made out of a metamaterial, Sir John says. The young wizard can also see where he is going while wearing the cloak; that wouldn't be possible in the real-life version, Dr. Eleftheriades says. Sir John and Dr. Smith first demonstrated metamaterials in 2000, and as many as three other teams are now researching how they could be used to make someone or something invisible. Another researcher, Ulf Leonhardt of the University of St. Andrews in Scotland, independently put forward a similar plan for an invisibility cloak, which was also published yesterday by the journal Science. (McIlroy, A. (1996 May 26). Scientists work up a disappearing act. Toronto Globe and Mail. Available: http://www.theglobeandmail.com/servlet/story/RTGAM.20060526.gtcloak26/BNStory/Technology/home Retrieved: 06/05/26.) Suggested answer: The main points in this article are: Sir John Pendry (Brit. Physicist) and associates plan to develop an invisibility cloak within five years Uses “metamaterials” Use small physical structures to bend electromagnetic waves Waves such as radar or light would bend around the object contained in the metamaterial A radar cloaking device may be possible within 18 months Bending light is more difficult than bending radar because the wavelengths are much shorter. So the physical structures that bend the waves would have to be atomic size Anything within the “cloak” would be invisible to the outside, and vice versa. Ulf Leonhardt has simultaneously advanced a similar plan. Step 2: Arrange the main points into an outline. Combine related facts. Use point form. Do not write whole sentences. Do not copy from the original text. Suggested answer: Sir John Pendry and associates plan: develop an “invisibility cloak” within five years: uses “metamaterials” made of small physical light-bending structures: bend electromagnetic waves around object. Object: invisible. Possibly: a radar cloaking device in 18 months Bending light more difficult than radar wavelengths much shorter. atomic size physical structures needed Anything within “cloak” invisible to the outside, and vice versa. Similar plan simultaneously advanced by Ulf Leonhardt in Scotland ENGLISH LANGUAGE SUPPORT | DEPARTMENT OF STUDENT SERVICES | RYERSON UNIVERSITY 3 Step 3: Use the outline to write a summary of the main points of the original text. Do not refer back to the text. Use your own words only. Suggested answer: British physicist Sir John Pendry, and his associates plan to develop a kind of invisibility cloak within five years. It would consist of “metamaterials” made of small physical structures that would be able to bend electromagnetic waves, such as radar or light, around an object, thus making the object invisible from the outside. It is possible that a radar-cloaking device based on this principle could be in operation within 18 months. Cloaking light waves is more difficult, however, since they have much shorter wavelengths than radar. Light-cloaking metamaterials would have to contain atomic size light-bending structures. Anything within the metamaterial would not only be invisible to the outside; the outside would be invisible to it as well. A plan similar to that of Pendry and his associates was revealed simultaneously by another physicist, Ulf Leonhardt in Scotland. .
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