首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
"Weather and Chaotic Systems" Weather and climate are closely related, but they are not quite the same thing. In any particul
"Weather and Chaotic Systems" Weather and climate are closely related, but they are not quite the same thing. In any particul
admin
2018-07-24
39
问题
"Weather and Chaotic Systems"
Weather and climate are closely related, but they are not quite the same thing. In any particular location, some days may be hotter or cooler, clearer or cloudier, calmer or stormier than others. The ever-varying combination of winds, clouds, temperature, and pressure is what we call weather. Climate is the long-term average of weather, which means it can change only on much longer time scales. The complexity of weather makes it difficult to predict, and at best, the local weather can be predicted only a week or so in advance.
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? To understand why the weather is so unpredictable 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. But suppose you run the model again, making one minor change in the initial conditions—say, a small change in the wind speed somewhere over Brazil. A This slightly different initial condition will not change the weather prediction for tomorrow in 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.
Despite their name, chaotic systems are not necessarily 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—like the weather—are "predictably unpredictable." Our understanding of chaotic systems is increasing at a tremendous rate, but much remains to be learned about them.
The word features in the passage is closest in meaning to
选项
A、problems
B、exceptions
C、characteristics
D、benefits
答案
C
解析
In this passage, characteristics is a synonym for "features." Context comes from the contrast with "details" later in the sentence.
转载请注明原文地址:https://kaotiyun.com/show/VxfO777K
0
托福(TOEFL)
相关试题推荐
Completethenotesbelow.WriteONEWORDONLYforeachanswer.TheTawnyOwlMost【L31】______owlspeciesinUKStronglynocturna
Completethesentencesbelow.WriteNOMORETHANTHREEWORDSforeachanswer.Youcanfindmoreinformationina______onmydes
Choosethecorrectletter,A,BorC.WhatdoesJimthinkaboutthedifferenceamongspeciesinnaturalandartificiallight?
Completethenotesbelow.WriteONEWORDONLYforeachanswer.ChimpanzeeBehavioursSpeciesWecanfindPanorPanTroglody
Completethesentencesbelow.WriteNOMORETHANTWOWORDSforeachanswer.ProducingaweatherforecastRa
ChooseTWOletters,A-E.WhichTWOtopicsdopeoplemostfrequentlyaskabout?Atheidealtemperaturesettingonthethermostat
ChooseTWOletters,A-E.WhichTWOtopicsdopeoplemostfrequentlyaskabout?Atheidealtemperaturesettingonthethermostat
Scientistshavediscoveredthatforthelast160,000years,atleast,there hasbeenaconsistentrelationshipbetween
Whataspectofpaintinginthenineteenthcenturydoesthepassagemainlydiscuss?Theexhibitionofpaintingsorganizedin187
随机试题
1000kg对硝基氯苯(ClC6H4NO2)用含20%游离SO3的发烟硫酸磺化,规定反应终点时,废酸中含游离7%SO3(假定反应转化率为100%)。反应式如下:ClC6H4NO2+SO3→ClC6H3(SO3H)NO2试计算:对硝基氯苯磺酸生成量?
A.肺炎B.脑膜脑炎C.心肌炎D.急性肾炎E.关节炎流行性腮腺炎最常见的并发症是
A.肼屈嗪 B.呋塞米 C.卡托普利 D.普萘洛尔 E.硝普钠可抑制肾素分泌的药物是
A.皂角、白芥子B.地龙、丝瓜络C.石菖蒲、远志D.龙胆草、夏枯草E.僵蚕、全蝎颤证患者肢体颤动不止,应加用
某高级宾馆,地上建筑层数为22层,裙房部分为4层,裙房和建筑主体之间设有防火墙完全分隔,裙房部分的防火分区宜按()建筑的要求确定。
下列选项中,属于合同中免责条款无效的情形是()。
【2012广州NO.16】《曹全碑》是东汉邰阳县令曹全的纪功碑,明代万历时在陕西邰阳县莘里庄出土,今存西安碑林。《曹全碑》书法秀雅,是汉碑的典范;碑文涉及疏勒叛乱、黄巾起义、党锢之祸。尤其可补史志之缺。这些情况,明清以来的金石学家讨论已详,稍可补充的,是碑
人的需要按起源可分为()。
20世纪50年代中期,社会主义改造基本完成.标志着()(2009年多选)
HowtoapproachSpeakingTestPartOne•Inthispartofthetestyouanswerquestionsaboutyourselfandexpresspersonalopinio
最新回复
(
0
)