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
28
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 particular in the passage is closest in meaning to
选项
A、basic
B、specific
C、unusual
D、new
答案
B
解析
In this passage, specific is a synonym for "particular."
转载请注明原文地址:https://kaotiyun.com/show/uxfO777K
0
托福(TOEFL)
相关试题推荐
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.Researchingtheoriginofmedievalmanus
ChooseTWOletters,A-E.InwhichTWOareasdidtheseresearchfindingsdifferfromthoseoftheoriginalstudy?AStudents’int
Completethenotesbelow.WriteONEWORDONLYforeachanswer.TheTawnyOwlMost【L31】______owlspeciesinUKStronglynocturna
Completetheformbelow.WriteNOMORETHANTHREEWORDSAND/ORANUMBERforeachanswer.BOOKINGINFORMATIONRoomtype【L4】_____
Completetheformbelow.WriteNOMORETHANTHREEWORDSAND/ORANUMBERforeachanswer.CUSTOMER’SINFORMATIONDETAILSName:【L
Completethesentencesbelow.WriteNOMORETHANTHREEWORDSforeachanswer.Youcanfindmoreinformationina______onmydes
Completetheformbelow.WriteONEWORDONLYforeachanswer.HOUSESERVICEINFORMATIONExampleAnswerNameBarbaraHill
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.CLIMATEANDARCHITECTURECasesandexamplesarefrom
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.CLIMATEANDARCHITECTURECasesandexamplesarefrom
"PaleolithicArt"→Theseveralmillenniafollowing30,000B.C.sawapowerfuloutburstofartisticcreativity.Theartworks
随机试题
血瘀型不孕症的主方是痰湿型不孕症的主方是
下列各项中,属于合伙人协议退伙的情形是()。
关于自动化工程的控制阀和执行机构试验的说法,正确的有()。
根据《建设工程安全生产管理条例》,施工单位应当在()等危险部位设置明显的安全警示标志。
下列关于公司制期货交易所董事长职权的表述,正确的有()。
注册会计师进行总体合理性测试的目的在于,帮助审计人员评价账户余额中是否有重要错报。()
判断下列句子使用的修辞手法,正确的一项是()。①月下观景,雾中看花,不是别有一番情趣在心头吗?②读好文章如饮醇酒,其味无穷。③头顶上盘着大辫子,顶得学生制帽的顶上高高耸起,形成一座富士山。④许多马克思主义的学者也是言必称希腊,对于自己的祖宗,则
在教学过程中实施的,使教师能够了解学生学习进展情况的评定是()。
下列关于数字签名说法正确的是(34)________。
Whatkindofpeoplewereearlycolonialnewspapersdesignedfor?
最新回复
(
0
)