時差N小時:山體滑坡后 花草安然無恙

You're hiking through the Rockies one day whenyou hear a low, ominous rumble. Landslide!Hundreds of tons of rock and soil are careeningtoward you at enormous speed.

一天，你徒步在巖石堆中穿行，這時你聽到一陣低低的隆隆聲，勢頭不妙。是山體滑坡!上百噸的巖石和泥土以極快的速度朝你傾瀉下來.

Fortunately, there's a helicopter nearby and youlift off just in time to escape unharmed. But nowyou notice something odd. After the landslide hasgone by, in its tracks little dainty flowers are still standing. Blades of grass are unbent. How isthis possible?

幸運的是，附近有架直升飛機，你及時乘飛機起飛，逃過了這一劫。但你卻注意到了一些奇怪的現(xiàn)象?；陆Y(jié)束后，美麗的花朵依舊挺立在石塊沖刷過的地方，小草也沒有被低下頭來，是什么讓這些植物還能生存下來呢?

Before we tell you the answer, here's another question. What happens when you drop abook flat onto a table?

在我告訴你答案之前，先問你另一個問題。如果你將一本書水平扔到桌面上，會發(fā)生什么呢?

If you try it, you'll see that the book doesn't hit the table unimpeded, but lands on a littlecushion of compressed air. If you don't believe us, try putting some little pieces of paper on thetable before dropping the book. The whoosh of compressed air escaping will blow them off.

試一下，你會發(fā)現(xiàn)書在撞擊桌子的時候遇到了阻礙，落在了壓縮空氣形成的緩沖墊上。如果你不相信,你可以先在桌上放一些小紙片，再將書拋下去。受壓的空氣向外逃出，呼嘯著將紙片吹走.

That's the same phenomenon that happens with landslides. When an enormous sheet ofrocks and dirt gets moving, it acts like a solid object. It traps the air underneath it and actuallyrides downhill on a cushion of air. Strange as it may seem, much of the landslide nevertouches the ground at all.

這與山體滑坡時發(fā)生的現(xiàn)象相同。當巨大的泥石移動的時候，它們的行動就像一個固體。它將空氣壓在下面。實際上，其實它是在一個氣墊上滾下去的。盡管看上去有點怪，但大多數(shù)山體滑坡從不會接觸到地面。

Because the cushion of air stays underneath it, the rocks and dirt aren't slowed down byfriction much and continue picking up speed as they fall. Large landslides have been clocked inexcess of 100 miles an hour.

由于空氣墊的作用，巖石和泥土并沒有受到很大摩擦力而減速下滑，相反它們會不停地加速。規(guī)模大的山體滑坡時速超過100英里每小時.

So—could you just lie down and let the landslide whoosh over you? No, unless you areabout the size of a blade of grass. People who are bigger than that should keep a helicopterhandy.

因此，你會躺下來，讓滑坡從你身上越過嗎?絕對不行。除非你只有草葉般大小。比草葉體積大的人類應(yīng)該保證身邊有一架直升飛機。