新概念第四冊課文精講 Lesson14:蝴蝶效應(yīng)
課文14 蝴蝶效應(yīng)
200. Beyond two or three days, the world's best weather forecasts are speculative, and beyond six or seven they are worthless.
世界上最好的兩三天以上的天氣預(yù)報(bào)具有很強(qiáng)的猜測性，如果超過六七天，天氣預(yù)報(bào)就沒有了任何價(jià)值。
201. The Butterfly Effect is the reason.
原因是蝴蝶效應(yīng)。
202. For small pieces of weather -- and to a global forecaster, small can mean thunderstorms and blizzards -- any prediction deteriorates rapidly.
對于小片的惡劣天氣 -- 對一個(gè)全球性的氣象預(yù)報(bào)員來說，“小”可以意味著雷暴雨和暴風(fēng)雪 -- 任何預(yù)測的質(zhì)量會(huì)很快下降。
203. 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.
錯(cuò)誤和不可靠性上升，接踵而來的是一系列湍流的徵狀，從小塵暴和暴風(fēng)發(fā)展到只有衛(wèi)星上可以看到的席卷整塊大陸的旋渦。
204. The modern weather models work with a grid of points of the order of sixty miles apart,
現(xiàn)代氣象模型以一個(gè)坐標(biāo)圖來顯示，圖中每個(gè)點(diǎn)大約是間隔60英里。
205. and even so, some starting data has to guessed, since ground stations and satellites cannot see everywhere.
既使是這樣，有些開始時(shí)的資料也不得不依靠推測，因?yàn)榈孛婀ぷ髡竞托l(wèi)星不可能看到地球上的每一個(gè)地方。
206. 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.
假設(shè)地球上可以布滿傳感器，每個(gè)相隔1英尺，并按1英尺的間隔從地面一直排列到大氣層的頂端。
207. Suppose every sensor gives perfectly accurate readings of temperature, pressure, humidity, and any other quantity a meteorologist would want.
再假定每個(gè)傳感器都極極端準(zhǔn)確地讀出了溫度、氣壓、溫度和氣象學(xué)家需要的任何其他數(shù)據(jù)。
208. Precisely at noon an infinitely powerful computer takes all the data and calculates what will happen at each point at 12.01, then 1202, then 12.03...
在正午時(shí)分，一個(gè)功能巨大的計(jì)算機(jī)搜集了所有的資料，并算出在每一個(gè)點(diǎn)上12：01、12：02、12：03時(shí)可能出現(xiàn)的情況。
209. The computer will still be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away.
計(jì)算機(jī)無法推斷出1個(gè)月以后的某一天，新澤西州的普林斯頓究竟是晴天還是雨天。
210. At noon the spaces between the sensors will hide fluctuations that the computer will not know about, tiny deviations from the average.
正午時(shí)分，傳感器之間的距離會(huì)掩蓋計(jì)算機(jī)無法知道的波動(dòng)、任何偏平均值的變化。
211. By 12.01, those fluctuations will already have created small errors one foot away.
到12：01時(shí)，那些波動(dòng)就已經(jīng)會(huì)在1英尺遠(yuǎn)的地方造成偏差。
212. Soon the errors will have multiplied to the ten-foot scale, and so on up to the size of the globe.
很快這種偏差會(huì)增加到尺10英的范圍，如此等等，一直到全球的范圍。
