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新浪首页 > 教育天地 > 玻璃为什么是透明的

Why is Glass Transparent?
http://www.sina.com.cn 2002/01/18 18:25  空中美语

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  课文内容

  Marian and Michael are traveling in Thailand and decide to take a glass-bottomed boat tour.

  Michael: So, once we get on board, do we have to wear slippers so we don’t step through the bottom of the boat?

  Marian: That’s right. And jumping up and down is also strictly forbidden.1

  Michael: You know, I’ve never understood why glass, or any material for that matter, is transparent.

  Marian: Well, you know that light acts like a wave of electromagnetic energy, right? Any material that can conduct2 the wave is transparent.

  Michael: I see. It’s got something to do with the structure of a material.

  Marian: Right. It’s kind of complicated. If the electrons3 in a material cannot absorb4 any energy, then the wave will pass through undisturbed.

  Michael: So the material will be transparent.

  Marian: And if the electrons can absorb energy, then the material isn’t transparent.

  Michael: But what about coal and diamonds? One is black and the other is transparent, yet they’re both made up of the same carbon atoms with the same electrons.

  Marian: The electrons in coal aren’t tied up as tightly as they are in diamonds. So they’re free to grab the light and prevent it from passing through.

  Michael: Now it all makes sense. Ready to board, Ms. Einstein?

  Marian: Let’s go. My lab coat doubles as a life jacket.---by Brian Greene/Sonya Roy

玻璃为什么是透明的

  翻译:

  玛丽安和迈克尔正在泰国旅行,他们决定乘玻璃底的船观光。

  迈克尔:我们是不是一上船就要穿拖鞋,这样才不会把船底踩破?玛丽安:是啊,而且还严禁蹦蹦跳跳。迈克尔:你知道的,我从来都没搞懂,玻璃或者类似的物品为什么是透明的。玛丽安:嗯,你知道光像电磁波那样传播,是吧?任何能传导那种波的物质都是透明的。迈克尔:我知道了。这跟物质的结构有关。玛丽安:对。那是有些复杂。如果物质中的电子吸收不了任何能量,光波就会不受干扰地穿过。迈克尔:所以那种物质就是透明的。玛丽安:要是电子能吸收能量,物质就不是透明的了。迈克尔:那煤炭和钻石呢?一种是黑的,另一种是透明的,但是它们都是由同样的碳原子组成,具有同样的电子啊。玛丽安:煤炭的电子不象钻石的电子结合得那样紧密。所以它们就可以挡住光线,不让它穿过。迈克尔:现在问题都弄清楚了。可以上船了吗,爱因斯坦小姐?玛丽安:走吧。我的实验服还可以兼作救生衣呢。




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空中美语 专栏

Annotation

1. forbidden a.禁止的

2. conduct v.传导

3. electron n.电子

4. absorb v.吸收


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