評論
打印
Narrator:Listen to part of a lecture in a geology class.
獨白:請聽一段地質學上的演講。
Professor:Now we've got a few minutes before we leave for today.
教授:離下課還有幾分鐘，我想談一下某個有趣的話題，
So I'll just touch on an interesting subject that I think makes an important point.
我想這是有重要意義的一點。
We've been covering rocks and different types of rocks for the last several weeks.
過去幾周我們一直在討論各種不同的巖石。
But next week we are going to do something a bit different.
但是下周我們將說到一些不同的內容。
And to get started I thought I'd mention something that shows how uh…as a geologist,
而首先我想我要提到某些顯示呃, 作為一位地理學家，
you need to know about more than just rocks and the structure of solid matter, moving rocks, you may have heard about them.
你需要知道的不僅僅是巖石極其固體結構，移動巖石，你們可能聽過。
It's quite a mystery.
挺神奇的。
Death valley is this desert plane, a dry lake bed in California surrounded by mountains and on the desert floor these huge rocks,
死亡山谷就是這種沙漠平面，這是加利福尼亞的一個干涸的湖泊沉積礦，四面環山，而在沙漠地面上，
some of them hundreds of pounds.
這些巨大的巖石有的重達幾千鎊。
And they move.
而這些巖石會移動，
They leave long trails behind them, tracks you might say as they move from one point to another.
留下長長的尾痕，隨著他們從一地移到另一地，他們留下各種痕跡。
But nobody has been able to figure out how they are moving because no one has ever seen it happen.
然而沒人知道他們是怎么移動的，因為沒人目睹過。
Now there are a lot of theories, but all we know for sure is that people aren't' moving the rocks.
如今人們提出很多理論，但我們所能知道的就是這不是人為的。
There are no footprints,
沒有人的足跡，
no tyre tracks and no heavy machinery like a bulldozer.
沒有輪胎痕跡，也沒有重機械像推土機的痕跡。
uh, nothing was ever brought in to move these heavy rocks.
呃，沒有人帶來任何機器移動這些巖石，
So what's going on?
那么到底是怎么回事呢？
Theory NO.1-Wind?
理論一:風力移動？
Some researchers think powerful uh…windstorms might move the rocks.
某些研究人員認為強勁的風暴可能移動了巖石。
Most of the rocks move in the same direction as the dominant wind pattern from southwest to northeast.
盛行風移動模式是自西南向東北，巖石移動方向一致。
But some, and this is interesting, move straight west while some zigzag or even move in large circles.
但是有趣的是，某些巖石直線移動，其他一些曲折或甚至繞著大圈子移動。
Um…How can that be?
嗯，這怎么可能呢？
How about wind combined with rain?
是不是風雨交加造成的？
The ground of this desert is made of clay.
該片沙漠地面是黏土，
It's a desert, so it's dry.
這是一個沙漠，所以非常干燥。
But when there is the occasional rain, the clay ground becomes extremely slippery.
但有時也會下雨，黏土地面便會變得特別滑。
It's hard for anyone to stand on, walk on.
人很難在上面站立行走。
Some scientists theorized that perhaps when the ground is slippery the high winds can then move the rocks.
某些科學家提出理論，說可能當地面大話，強風便可以移動巖石。
There's a problem with this theory.
但是該理論存在一個問題。
One team of scientists flooded an area of the desert with water, then try to establish how much wind force would be necessary to move the rocks.
一組科學家在這片沙漠注水，然后試著測量多大的風力可以將巖石移動。
And guess this,
你們猜猜多少，
you need winds of at least five hundred miles an hour to move just the smallest rocks.
要至少 5 千米每小時的風速才可以移動最小的石頭。
And winds that strong have never been recorded.Ever!
而他們也記錄了強風時的情況。別想了，
Not on this planet.
地球上是不可能的。
So I think it's safe to say that that issues has been settled.
所以我想，保守的說，這個理論已經站不住腳了。
Here is another possibility-ice.
另一種說法即是冰。
It's possible that rain on the desert floor could turn to thin sheets of ice when temperatures drop at night.
當夜晚溫度降低時，沙漠地面上的雨水轉變成一層薄薄的冰是有可能的。
So if rocks…uh becoming better than ice, uh …OK, could a piece of ice with rocks in it be pushed around by the wind?
所以，當巖石，呃，被冰包裹，呃，ok，可能變成一塊被冰包裹的巖石，風一吹就滑動。
But there's a problem with this theory, too.
但這個理論也有一個問題。
Rocks trapped in ice together would have moved together when the ice moved.
巖石被包裹在冰里的話，冰一移動，巖石也跟著移動。
But that doesn't always happen.
但不是什么時候都有冰的。
The rocks seem to take separate routes.
巖石的移動路線似乎是分開的。
There are a few other theories.
還有其他幾個理論。
Maybe the ground vibrates, or maybe the ground itself is shifting, tilting.
也許地面震動，抑或也許地面移動，傾斜。
Maybe the rocks are moved by a magnetic force.
也許巖石是由于地磁力才移動的。
But sadly all these ideas have been eliminated as possibilities.
但是遺憾的是，這些看法都已經被推翻。
There's just no evidence.
就是沒有證據證明是對的。
I bet you are saying to yourself well, why don't scientists just set up video cameras to record what actually happens?
我想你們也會這樣說，為什么科學家不架起一臺攝像機記錄整個過程？
Thing is this is a protective wilderness area.
問題是，這是一塊受保護的原始地帶。
So by law that type of research isn't allowed.
所以法律上講，這種研究方式是不允許的。
Besides, in powerful windstorms, sensitive camera equipment would be destroyed.
此外，強勁的風暴可以摧毀搖搖欲墜的錄像設備。
So why can't researchers just live there for a while until they observe the rocks' moving?
那么為什么研究人員不能再那兒住一段時間，直到他們觀察到巖石的移動情況呢？
Same reason.
理由也是一樣的。
So where are we now?
好的，我們剛剛講到哪了？
Well, right now we still don't have any answers.
嗯，現在我們還沒有找到答案。
So all this leads back to my main point-you need to know about more than just rocks as geologists.
那么這些都回到主要觀點了。要成為地理學家，你們要知道不僅僅是巖石而已。
The researchers studying moving rocks, well, they combine their knowledge of rocks with knowledge of wind, ice and such…um not successfully, not yet.
研究人員研究移動的巖石，嗯，他們把巖石的知識和風，冰等的知識結合起來，但還沒有取得成功。
But you know, they would even have been able to get started without uh… earth science understanding-knowledge about wind, storms, you know, meteorology.
但你們知道，他們如果連地球科學的知識都不知道的話，那他們都不知道從哪開始好。這些知識是關于風，風暴等氣象的知識。
You need to understand physics.
你們要懂得物理。
So for several weeks like I said we'll be addressing geology from a wider prospective.
所以接下來幾周，就像我說的，我們將會從一個更為廣泛的角度解決地理問題。
I guess that's all for today.
那么今天就到這吧，
See you next time.
下次課見。
