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第十三篇Invisibility Ring
Scientists can’t yet make an invisibility cloak1 like the one that Harry Potter2 ,for the first time,they’ve constructed a simple cloaking device that makes itself and somethingplaced inside it invisible to microwaves.
When a person “sees” an object,his or her eye senses many different waves of visiblelight as they bounce off the eye and brain then work together anize thesesensations and reconstruct the object’s original shape. So,to make an object invisible,scientists have to keep waves from bouncing off they have to make sure the objectcasts no ,the absence of reflected light on one side would give the obiectaway.
Invisibility isn’t possible yet with waves of light that the human eye can it is nowpossible with visible light,microwaves are a form of radiant part of the ic spectrum,which also includes radio waves,infrared light,ultraviolet rays,X rays,and gamma wavelengths of microwaves are shorter thanthose of radio waves but longer than those of visible light.
The scientists’ new “invisibility device” is the size of a drink coaster and shaped like ring is made of a special material with unusual microwaves strike thering,very few bounce off ,they pass through the ring,which bends the waves allthe way around until they reach the opposite waves then return to their originalpaths.
To a detector set up to receive microwaves on the other side of the ring,it looks as if thewaves never changed their paths as if there were no object in the way! So,the ring is effectively invisible.
When the researchers put a small cdpper loop inside the ring,it,too,is nearly invisible. However,the cloaking device and anything inside it do cast a pale the deviceworks only for microwaves,not for visible light or any kind of ic ,Harry Potter’s invisibility cloak doesn’t have any petition yet.
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