英语听力文摘 English Digest 497、像雾一样的固体物质（在线收听）

Frozen Smoke 

固体烟

Male: What's as light as smoke but strong as a brick?

Female: I'm gonna take a while guess and say... aerogel?

Male: Sorry,yaoyao,the answer is... Wait a second! Did you say aerogel? How did you know?

F:Yeap! Did you know that aerogel is the lightest solid on earth?

M: I was going to tell you that.

F: Another cool thing is that it starts out as a kind of chemical Jello. Then the gel is dried in a powerful pressure cooker and emerges as a very lightweight, dry, sponge- like material that looks like frozen smoke.

M: OK! Did you know that aerogel is ninety-nine-point-eight percent air?

F: Sure.That was in your notes.And it’s incredibly light–one thousand times less dense than glass. But it's also really strong and an excellent insulator.

M: Is there anything you don't know about aerogel? For instance,scientists are using it to try to capture dust particles from the tail of a comet. When the particlesslam into an aerogelpanel aboard a space probe, they'll bury themselves inside and leave visible trails. Since aerogel is mostly air, it won't damage the particles.

F: Actually, I know that too.

男：什么东西既可以跟烟一样轻，又可以跟砖块一样重？

女：让我想会儿... 气凝胶？

男：瑶瑶，不好意思，答案是... 等等！你说的是气凝胶吗？你是怎么知道的？

女：是的！你知道气凝胶是地球上最轻的固体吗？

男：我刚刚正要告诉你呢！

女：了不起的是，气凝胶开始是作为一种化学凝胶物的。然后胶体在压力很强的锅里变干，成为了一种重量很轻、很干燥、类似海绵状，看起来像固体烟雾的物体。

男：是的！那你知道气凝胶中99.8%都是空气吗？

女：知道啊！你的笔记中有的！气凝胶相当的轻，轻到密度只有玻璃的千分之一。但它也很结实，是几号的绝缘体。

男：关于气凝胶，你还有什么不知道的吗？比如说，科学家正在试图用它捕捉彗星经过的微尘。当（微尘）颗粒猛烈撞击到航空探测器上的气凝胶板时，它们将会自然，从而留下可见的痕迹。因为气凝胶差不多等同于空气，并不会破坏（微尘）颗粒。

女：其实这个我也知道！

【Words & Expressions】

aerogel：气凝胶，又称为干凝胶。是一种固体物质形态，世界上密度最小的固体。当凝胶脱去大部分溶剂，使凝胶中液体含量比固体含量少得多，或凝胶的空间网状结构中充满的介质是气体，外表呈固体状，这即为干凝胶，也称为气凝胶。

slam into：猛烈撞击

space probe：航空探测器