時(shí)差N小時(shí):山體滑坡后 花草安然無(wú)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(shí)你聽(tīng)到一陣低低的隆隆聲，勢(shì)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(lái).

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(yùn)的是，附近有架直升飛機(jī)，你及時(shí)乘飛機(jī)起飛，逃過(guò)了這一劫。但你卻注意到了一些奇怪的現(xiàn)象。滑坡結(jié)束后，美麗的花朵依舊挺立在石塊沖刷過(guò)的地方，小草也沒(méi)有被低下頭來(lái)，是什么讓這些植物還能生存下來(lái)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(wèn)你另一個(gè)問(wèn)題。如果你將一本書(shū)水平扔到桌面上，會(huì)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(huì)發(fā)現(xiàn)書(shū)在撞擊桌子的時(shí)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(shū)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(shí)發(fā)生的現(xiàn)象相同。當(dāng)巨大的泥石移動(dòng)的時(shí)候，它們的行動(dòng)就像一個(gè)固體。它將空氣壓在下面。實(shí)際上，其實(shí)它是在一個(gè)氣墊上滾下去的。盡管看上去有點(diǎn)怪，但大多數(shù)山體滑坡從不會(huì)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(méi)有受到很大摩擦力而減速下滑，相反它們會(huì)不停地加速。規(guī)模大的山體滑坡時(shí)速超過(guò)100英里每小時(shí).

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(huì)躺下來(lái)，讓滑坡從你身上越過(guò)嗎?絕對(duì)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(jī)。