時(shí)差N小時(shí):滑坡 Landslide

You're hiking through the Rockies one day when youhear a low, ominous rumble.

有一天你正試圖徒步穿越落基山脈，這時(shí)你聽到一種低沉的、不祥的隆隆聲。

Landslide! Hundreds of tons of rock and soil arecareening toward you at enormous speed.

是滑坡!數(shù)百噸的巖石和泥土眨眼間向你傾瀉過來。

Fortunately, there's a helicopter nearby and you liftoff just in time to escape unharmed.

幸運(yùn)的是附近的一架直升飛機(jī)助你逃出生天，多虧及時(shí)及時(shí)起飛，才免受這一劫難。

But now you notice something odd.

但你卻注意到了一些匪夷所思的怪現(xiàn)象。

After the landslide has gone by, in its tracks little dainty flowers are still standing.

滑坡過后的地方，小小惹人愛的花朵依然挺拔，

Blades of grass are unbent.

小草的葉子也沒有因此折腰，

How is this possible?

其中究竟有何奧秘?

Before we tell you the answer, here'sanother question.

揭曉答案之前，先想想另一個(gè)問題。

What happens when you drop a book flat onto a table?

如果你將一本書水平扔到桌面上會(huì)發(fā)生什么?

If you try it, you'll see that the book doesn't hit the table unimpeded, but lands on a littlecushion of compressed air.

你會(huì)發(fā)現(xiàn)書在撞擊桌子的時(shí)候并非順利，而是有壓縮空氣形成的緩沖墊阻礙。

If you don't believe us, try putting some little pieces of paper on the table before dropping thebook.

如果還持懷疑態(tài)度,你大可先在桌上放一些小紙張，然后再將書扔過去。

The whoosh of compressed air escaping will blow them off.

四散奔逃的受壓空氣會(huì)嗖的將小紙吹走.

That's the same phenomenon that happens with landslides.

這就如同滑坡現(xiàn)象的原理。

When an enormous sheet of rocks and dirt gets moving, it acts like a solid object.

當(dāng)巨大巖石和泥土塊移動(dòng)的時(shí)候，它們就像一個(gè)固體。

It traps the air underneath it and actually rides downhill on a cushion of air.

將空氣壓在下面的它實(shí)際上滾動(dòng)的時(shí)候下面就有了空氣墊。

Strange as it may seem, much of the landslide never touches the ground at all.

盡管聽上去有點(diǎn)怪，但大多數(shù)山體滑坡從不會(huì)和地面接觸。

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.

由于空氣墊，巖石和泥土并沒有受到摩擦力影響而減速，相反會(huì)不停地加速。

Large landslides have been clocked in excess of 100 miles an hour.

規(guī)模大的山體滑坡時(shí)速超過每小時(shí)100英里。

So-could you just lie down and let the landslide whoosh over you?

那么你能躺下來讓滑坡從你身上呼嘯著越過嗎?

No, unless you are about the size of a blade of grass.

這可不行。除非你只有草葉般大小。

People who are bigger than that should keep a helicopter handy.

因此比草葉體積大的人應(yīng)該隨時(shí)讓一架直升飛機(jī)在身旁待命。