Lesson 14 The Butterfly Effect 蝴蝶效应

First listen and then answer the following question.

听录音,然后回答以下问题。

Why do small errors make it impossible to predict the weather system with a high degree of accuracy?

Beyond two or three days, the world's best weather forecasts are speculative, and beyond six or seven they are worthless.

The Butterfly Effect is the reason. For small pieces of weather - and to a global forecaster, small can mean thunderstorms and blizzards - any prediction deteriorates rapidly. Errors and uncertainties multiply, 5 cascading upward through a chain of turbulent features, from dust devils and squalls up to continent-size eddies that only satellites can see.

The modern weather models work with a grid of points of the order of sixty miles apart, and even so, some starting data has to be guessed, since ground stations and satellites cannot see everywhere. But suppose - the earth could be covered with sensors spaced one foot apart, rising at one-foot intervals all the way to the

10 top of the atmosphere. Suppose every sensor gives perfectly accurate readings of temperature, pressure, humidity, and any other quantity a meteorologist would want. Precisely at noon an infinitely powerful computer takes all the data and calculates what will happen at each point at 12.01, then 12.02, then 12.03 ...

The computer will still be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away. At noon the spaces between the sensors will hide fluctuations that the computer will 5 not know about, tiny deviations from the average. By 12.01, those fluctuations will already have created small errors one foot away. Soon the errors will have multiplied to the ten-foot scale, and so on up to the size of the globe.

JAMES GLEICK, Chaos

New words and expressions 生词和短语

grid (1.7) /grɪd/ $n$ . 坐标方格

sensor (1.9) $/$ sens $\ni /n$ . 传感器

humidity (1.11) /hju:'mɪdɪti/ n. 湿度

meteorologist (1.11) ${/}_{1}$ mi:tiә'rɒlədʒɪst/ $n$ . 气象学家

Princeton (1.13) /’prinstan/ $n$ . 普林斯顿(美国城市名)

New Jersey (1.13)/njuː-'dʒ3ːzɪ/n. 新泽西(美国州名)

fluctuation (1.14) $/$ , flʌktʃu'eɪʃən $/n$ . 起伏,波动

deviation (1.15) ${/}_{1}$ di:vi'er $\int \partial n/n$ . 偏差

forecast (I.1) /’ fo:kaːst/ n. 预报

speculative (1.1) / 'spekjʊlətɪv/ adj. 推测的

blizzard (l.4) $/$ 'blɪzəd/ n. 暴风雪

deteriorate (1.4) $/\mathrm{d}{\mathbf{I}}^{\prime }$ tiøriəreɪt/ $v$ . 变坏,恶化

multiply (1.4) $/\prime \mathrm{m} \land \operatorname{ltr}{\mathrm{p}\mathrm}/v$ . 增加

cascade (1.5) / kæ'skeɪd/ v. 瀑布似地落下

turbulent (1.5) /'tɜːbjʊlənt/adj. 狂暴的

dust devil (1.5) /'dʌst-ˌdeval/ 小尘暴, 尘旋风

squall (1.5)/skwɔːl/n. 暴风

eddy (1.6) $/$ edi/ $n$ . 旋涡

Unit 2 Lesson 14

View of the 76 metre diameter Mark 1 A radio telescope at Jodrell Bank near Manchester, England

Notes on the text 课文注释

1 beyond two or three days, 超过两一三天。

2 of the order of, 大约。

参考译文

世界上最好的两三天以上的天气预报具有很强的猜测性, 如果超过六七天, 天气预报就没有了任何价值。

原因是蝴蝶效应。对于小片的恶劣天气——对一个全球性的气象预报员来说,“小”可以意味着雷暴雨和暴风雪——任何预测的质量会很快下降。错误和不可靠性上升,接踵而来的是一系列湍流的微状,从小尘暴和暴风发展到只有卫星上可以看到的席卷整块大陆的旋涡。

现代气象模型以一个坐标图来显示, 图中每个点大约是间隔 60 英里。既使是这样, 有些开始时的资料也不得不依靠推测, 因为地面工作站和卫星不可能看到地球上的每一个地方。假设地球上可以布满传感器, 每个相隔 1 英尺, 并按 1 英尺的间隔从地面一直排列到大气层的顶端。再假定每个传感器都极端准确地读出了温度、气压、湿度和气象学家需要的任何其他数据。在正午时分,一个功能巨大的计算机搜集了所有的资料,并算出在每一个点上 12:01、12:02、12:03 时可能出现的情况。

计算机无法推断出 1 个月以后的某一天, 新泽西州的普林斯顿究竟是晴天还是雨天。正午时分, 传感器之间的距离会掩盖计算机无法知道的波动、任何偏离平均值的变化。到 12:01 时, 那些波动就已经会在 1 英尺远的地方造成偏差。很快这种偏差会增加到 10 英尺的范围, 如此等等, 一直到全球的范围。

Comprehension 理解

Give short answers to these questions in your own words as far as possible. Use one complete sentence for each answer.

1 What does the author mean by 'small pieces of weather'?

2 How do modern weather models work?

3 What do you think 'the butterfly effect' means in this passage?

Unit 2 Lesson 14

Vocabulary 词汇

Refer to the text to see how the following words have been used, then write sentences of your own using these words: speculative (1.1); global (1.3); deteriorates (1.4); rapidly (1.4); multiply (1.4); turbulent (1.5); suppose (1.10); accurate (1.10); precisely (1.11); data (1.12); fluctuations (1.14); average (1.15); errors (1.16).

The paragraph 段落

A Which one of these statements do you think the author would agree with?

1 Accurate readings by computers enable us to predict the weather.

2 It will never be possible to predict the weather accurately.

3 The only way to predict the weather accurately is to have sensors one foot apart, rising at one-foot intervals all the way to the top of the atmosphere.

Key structures 关键句型

A Note how these two sentences have been connected:

Errors and uncertainties multiply. They cascade upward through a chain of turbulent features.

Errors and uncertainties multiply, cascading upward through a chain of turbulent features. (II.4-5)

Join these sentences in the same way:

1 There's a fault in the earth's crust. It runs along the west coast of the USA.

2 The hurricane hit Florida. It swept away everything in its path.

3 I noticed the lights were on. I assumed they were at home.

4 He emerged from the airport. The president waved to the reporters.

B We can introduce conditional sentences with conjunctions other than if, for example:

Suppose the earth could be covered with sensors spaced one foot apart. (II.8-9)

Complete these sentences in any way you like:

1 You can go home early, providing (that) _____

2 We can offer you a job on condition (that) _____

3 You can come in any time you like tomorrow morning so long as _____.

4 I won't phone you unless _____.

5 He'll definitely win even if _____.

C Study these two sentences:

We will probably have some rain by noon.

By 12.01 those fluctuations will already have created small errors one foot away. (II.15-16)

Explain the differences in meaning between these pairs of sentences:

1 He won't receive this fax tomorrow morning.

He will have received this fax by tomorrow morning.

2 He won't leave Beijing until this message arrives.

By the time this message arrives, he will have left Beijing.

3 They will complete the new motorway by next June.

They won't have completed the new motorway until next June.

Unit 2 Lesson 14

Special difficulties 难点

A Explain the meaning of since in these sentences:

1 Some starting data has to be guessed, since ground stations and satellites cannot see everywhere.

2 John feels much happier since he changed his job.

3 Susan left in July and we haven't seen her since.

4 It hasn't stopped raining since eight o'clock this morning.

5 Since you're so clever, see if you can solve the problem!

B The computer will be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away. (ll.13-14)

Supply if or whether; note the sentences where we can use both if and whether.

1 _____ he has signed the contract (or not) doesn't matter.

2 The question is _____ he has signed the contract.

3 I want to know _____ he has signed the contract.

4 I'm concerned about _____ he has signed the contract.

5 Do you know _____ she's arriving by bus or by car?

Multiple choice questions 多项选择题

Choose the correct answers to the following questions.

Comprehension 理解

1 The reason it's hard to forecast the weather is that _____.

(a) conditions rapidly deteriorate

(b) there is always turbulence

(c) only satellites have a panoramic view of conditions

(d) the effect of tiny changes cannot be detected or calculated

2 Even with grid points which are sixty miles apart, forecasters _____

(a) have to depend on satellites for information

(b) have to make assumptions about some of the data

(c) work on modern weather models

(d) prevent errors from multiplying

3 Which of these statements is true?

(a) The only way to solve the problem is to have sensors spaced at one-foot intervals.

(b) The only way to solve the problem is to have infinitely powerful computers.

(c) The only way to solve the problem is to have perfectly accurate readings.

(d) At present, there is no way of making absolutely accurate predictions.

4 Tiny variations in temperature, pressure and humidity _____

(a) will be picked up by sensors at one-minute intervals

(b) are used to predict the weather one month ahead

(c) can lead to completely unexpected weather conditions

(d) produce expected results Unit 2 Lesson 14

Structure 句型

5 Generally speaking, any prediction _____ rapidly. (1.2)

(a) is deteriorating (b) has deteriorated (c) will deteriorate (d) had deteriorated

6 Only satellites _____ see continent-size features. (II.5-6)

(a) are able to (b) could (c) are possible (d) are capable

7 _____ the earth could be covered with sensors. (ll.9-10)

(a) Providing that (b) On condition that (c) Say (d) Allowing that

8 The computer will be incapable _____ whether Princeton will have sun or rain one month away. (11.13)

(a) predict (b) to predict (c) of predicting (d) predicting

Vocabulary 词汇

9 The world's best weather forecasts are based on _____ . (1.1)

(a) certain knowledge (b) guess work

(c) scientific facts (d) accurate calculation

10 The modern weather models work with a _____ of points. (1.7)

(a) scale (b) balance (c) line (d) network

11 'Humidity' refers to _____ . (1.11)

(a) light (b) water vapour (c) pressure (d) heat

12 An infinitely powerful computer takes in all the data and _____ what will happen. (II.11-12)

(a) predicts (b) foretells (c) estimates (d) works out