首页
登录
职称英语
"Weather and Chaotic Systems" Scientists today have a ve
"Weather and Chaotic Systems" Scientists today have a ve
游客
2024-01-04
43
管理
问题
"Weather and Chaotic Systems"
Scientists today have a very good understanding of the physical laws and mathematical equations that govern the behavior and motion of atoms in the air, oceans, and land. Why, then, do we have so much trouble predicting the weather? For a long time, most scientists
assumed
that the difficulty of weather prediction would go away once we had enough weather stations to collect data from around the world and sufficiently powerful computers to deal with all the data. However, we now know that weather is
fundamentally
unpredictable on time scales longer than a few weeks. To understand why, we must look at the nature of scientific prediction.
→ Suppose you want to predict the location of a car on a road 1 minute from now. You need two basic pieces of information: where the car is now, and how fast it is moving. If the car is now passing Smith Road and heading north at 1 mile per minute, it will be 1 mile north of Smith Road in 1 minute.
Now, suppose you want to predict the weather. Again, you need two basic types of information: (1) the current weather and (2) how weather changes from one moment to the next. You could attempt to predict the weather by creating a "model world." For example, you could overlay a globe of the Earth with graph paper and then specify the current temperature, pressure, cloud cover, and wind within each square. These are your starting points, or initial conditions. Next, you could input all the initial conditions into a computer, along with a set of equations (physical laws) that describe the processes that can change weather from one moment to the next.
→ Suppose the initial conditions represent the weather around the Earth at this very moment and you run your computer model to predict the weather for the next month in New York City. The model might tell you that tomorrow will be warm and sunny, with cooling during the next week and a major storm passing through a month from now. Now suppose you run the model again but make one minor change in the initial conditions—say, a small change in the wind speed somewhere over Brazil.A For tomorrow’s weather, this slightly different initial condition will not change the weather prediction for New York City.B But for next month’s weather, the two predictions may not agree at all! C
The disagreement between the two predictions arises because the laws governing weather can cause very tiny changes in initial conditions to be greatly magnified over time.D This extreme sensitivity to initial conditions is sometimes called the butterfly effect: If initial conditions change by as much as the flap of a butterfly’s wings, the resulting prediction may be very different.
→ The butterfly effect is a hallmark of chaotic systems. Simple systems are described by linear equations
in which
, for example, increasing a cause produces a proportional increase in an effect. In contrast, chaotic systems are described by nonlinear equations, which allow for subtler and more intricate interactions. For example, the economy is nonlinear because a rise in interest rates does not automatically produce a corresponding change in consumer spending. Weather is nonlinear because a change in the wind speed in one location does not automatically produce a corresponding change in another location. Many (but not all) nonlinear systems exhibit chaotic behavior.
→ Despite their name, chaotic systems are not completely random. In fact, many chaotic systems have a kind of underlying order that explains the general
features
of their behavior even while details at any particular moment remain unpredictable. In a sense, many chaotic systems are "predictably unpredictable." Our understanding of chaotic systems is increasing at a tremendous rate, but much remains to be learned about them. [br] Why does the author mention a car in paragraph 2?
选项
A、The car is an example of how conditions are used to make predictions.
B、The author digresses in order to tell a story about a car.
C、The car introduces the concept of computer models.
D、The mathematical equations for the car are very simple to understand.
答案
A
解析
The author uses the example of the car to explain how conditions are used to make predictions. The prediction of the location of the car is compared with the prediction of the weather.
转载请注明原文地址:https://tihaiku.com/zcyy/3333623.html
相关试题推荐
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
Scientistshavetraditionally(classified)plantsby(groupingthem)accordingt
Thebankingsystemsoftheworldhavemanysimilarities,______theyalspdiffer
[audioFiles]audio_etoefz_025(20051)[/audioFiles]A、Callforthelatestweatherr
Whatdoesthepassagemainlydiscuss?[br]Scientistsconcludedfromtheexper
"WeatherandChaoticSystems"Scientiststodayhaveave
"WeatherandChaoticSystems"Scientiststodayhaveave
随机试题
Manyrapecrisisandbatteredwomen’sprogramsalsohaveeducationalcomponents
In1915EinsteinmadeatriptoGottingentogivesomelecturesattheinvit
下列各项中,属于我国《物权法》规定的担保物权的是( )。A.典权 B.地役权
2岁小儿,咳嗽、咳痰、咽部红肿,查体:T38.5℃。心肺听诊无异常。 下列
直疝三角的三边是A.腹壁下动脉、联合腱和腹股沟韧带 B.联合腱、腹直肌外缘和耻
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
中国证券监督管理委员会及其派出机构依法对期货公司及其分支机构实行监督管理。()
颞深间隙感染临床表现为A.张口受限,咀嚼时痛,口内上颌结节后方有压痛B.张口受限
根据《水污染防治行动计划》,全力保障水生态环境安全主要包括( )。A.保障饮用
男,60岁。2年来出现间歇性无痛性全程肉眼血尿,终末加重,近半年来出现尿频、尿痛
最新回复
(
0
)