# 第四册 Lesson 14 The butterfly effect 蝴蝶效应

## 一、课文原文

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, 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 60 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 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 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*

## 二、重点词汇详解

| 单词 | 音标 | 词性 | 释义 | 用法说明 |
|------|------|------|------|----------|
| speculative | /ˈspekjʊlətɪv/ | adj. | 推测性的，不确定的 | speculative forecasts 推测性预报 |
| worthless | /ˈwɜːθləs/ | adj. | 无价值的，没用的 | 反义词 valuable/worthwhile |
| deteriorate | /dɪˈtɪəriəreɪt/ | v. | 恶化，退化 | prediction deteriorates 预报变差 |
| cascade | /kæˈskeɪd/ | v./n. | 级联，瀑布般倾泻 | cascading upward 层级向上传递 |
| turbulent | /ˈtɜːbjʊlənt/ | adj. | 湍流的，动荡的 | turbulent features 湍流特征 |
| dust devil | /dʌst ˈdevl/ | n. | 尘卷风 | 小型旋风 |
| squall | /skwɔːl/ | n. | 飑，暴风 | 突然刮起的强风 |
| eddy | /ˈedi/ | n. | 涡流 | continent-size eddies 大陆尺度的涡流 |
| grid | /ɡrɪd/ | n. | 网格 | a grid of points 网格点 |
| sensor | /ˈsensə/ | n. | 传感器 | spaced one foot apart 间隔一英尺放置 |
| humidity | /hjuːˈmɪdɪti/ | n. | 湿度 | temperature, pressure, humidity 温度、气压、湿度 |
| meteorologist | /ˌmiːtiəˈrɒlədʒɪst/ | n. | 气象学家 | meteorology 气象学 |
| fluctuation | /ˌflʌktʃuˈeɪʃn/ | n. | 波动，起伏 | tiny fluctuations 微小波动 |
| deviation | /ˌdiːviˈeɪʃn/ | n. | 偏差，偏离 | deviations from the average 偏离平均值 |

## 三、语法知识点

### 1. beyond 引导的介词短语表条件

> **Beyond** two or three days, the world's best weather forecasts are speculative...

- beyond = 超过（时间/范围）
- = After more than...

### 2. 虚拟语气（suppose引导的假设）

> **Suppose** the earth **could be** covered with sensors spaced one foot apart...

- suppose = let us suppose，引导虚拟假设
- 用could be, would want等虚拟形式

### 3. 现在分词作结果状语

> Errors and uncertainties multiply, **cascading** upward through a chain of turbulent features...

- cascading = 向上级联传递，是multiply的自然结果
- 主动式现在分词表自然延续的结果

### 4. so on up to 如此递增直到

> Soon the errors will have multiplied to the ten-foot scale, and **so on up to** the size of the globe.

- so on = 等等，以此类推
- up to = 直到，达到

## 四、重点句型分析

### 1. of the order of 大约

> ...a grid of points **of the order of** 60 miles apart...

- = approximately, on the order of
- 表示数量级
- 仿写：The cost is of the order of 5 million dollars.

### 2. all the way to 一直到

> ...rising at one-foot intervals **all the way to** the top of the atmosphere.

- = right up to, as far as
- 强调连续性和距离

### 3. tiny deviations from the average 偏离平均值的微小偏差

> ...tiny **deviations from the average**.

- deviation from = 偏离，背离
- 仿写：There was a deviation from the original plan.

### 4. and so on 以此类推

> ...and so on up to the size of the globe.

- = etc., and so forth
- 与up to连用，表示递增过程

## 五、课文翻译

超过两三天，世界上最好的天气预报也只是推测性的，超过六七天就毫无价值了。蝴蝶效应就是原因。对于小范围的天气——对全球预报员来说，小范围也可以意味着雷暴和暴风雪——任何预测都会迅速恶化。误差和不确定性成倍增加，通过一系列湍流特征层层向上传递，从尘卷风和暴风一直到只有卫星才能看到的大陆尺度的涡流。

现代气象模型使用间隔约60英里的网格点进行计算，即使如此，一些初始数据也必须靠猜测，因为地面站和卫星不能观测到每个角落。但假设地球可以被间隔一英尺的传感器覆盖，以一英尺的间隔一直延伸到大气层顶部。假设每个传感器都能给出温度、气压、湿度以及气象学家所需的任何其他数据的完全准确的读数。正好在中午，一台无限强大的计算机处理所有数据，计算每个点在12:01、12:02、12:03...将发生什么。

计算机仍然无法预测一个月后的某一天新泽西州普林斯顿是晴天还是雨天。正午时分，传感器之间的空隙会隐藏计算机不知道的波动——偏离平均值的微小偏差。到12:01，这些波动已经在一英尺外造成了小误差。不久，误差就会成倍增大到十英尺的尺度，如此递增，直到全球尺度。

## 六、语言点精讲

### 1. 写作手法：极限假设法

- 先说明现实限制（60英里网格，数据靠猜测）
- 再做极限假设（一英尺间隔传感器，无限强大计算机）
- 结论：即使如此也无法准确预测——论证极为有力

### 2. 文化背景

- **蝴蝶效应（Butterfly Effect）**：混沌理论的核心概念，由气象学家爱德华·洛伦兹（Edward Lorenz）提出
- **命题来源**：一只蝴蝶在巴西扇动翅膀，可能在美国德克萨斯引起龙卷风
- **詹姆斯·格莱克（James Gleick）**：美国科学作家，《混沌》一书使混沌理论广为人知

### 3. 修辞分析

- **递进**：dust devils → squalls → continent-size eddies——从小到大
- **极限假设**：suppose... suppose...——通过极限假设反证不可预测性
- **精确数字**：12.01, 12.02, one foot, ten-foot——用精确数字增强说服力

## 七、课后练习要点

1. **理解题**：Why can't even a perfect weather-prediction system forecast accurately?（传感器间隔的微小波动导致误差级联放大）
2. **语法题**：suppose引导虚拟语气的用法
3. **词汇题**：区分 speculative/worthless/deteriorate 的搭配
4. **写作练习**：用极限假设法论证一个观点

## 八、本课小结

本课讲解**蝴蝶效应与天气预报的局限性**，核心论点：由于初始条件的微小偏差会被级联放大，即使理论上完美的观测系统也无法实现长期准确预报。语法重点包括beyond介词短语表条件、suppose虚拟假设、现在分词作结果状语、of the order of数量级表达。写作手法上运用极限假设法和递进论证，是科普说明文的杰作。