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
79
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 the economy in paragraph 6?
选项
A、To contrast a simple system with a chaotic system
B、To provide an example of another chaotic system
C、To compare nonlinear equations with linear equations
D、To prove that all nonlinear systems are not chaotic
答案
B
解析
The author mentions the economy to provide an example of another chaotic system. "For example, the economy is nonlinear because a rise in interest rates does not automatically produce a corresponding change in consumer spending."
转载请注明原文地址:https://tihaiku.com/zcyy/3333628.html
相关试题推荐
FIELDTRIPPLAN;WEATHER:everyoneneedswarmclothinganda【L6】________ACTIVI
FIELDTRIPPLAN;WEATHER:everyoneneedswarmclothinganda【L6】________ACTIVI
FIELDTRIPPLAN;WEATHER:everyoneneedswarmclothinganda【L6】________ACTIVI
FIELDTRIPPLAN;WEATHER:everyoneneedswarmclothinganda【L6】________ACTIVI
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
HistoryofweatherforecastingEarlymethodsAlmanacsconnectedthewe
Manyscientistsbelieve______asaresultofacollisionbetweenthenewlyform
随机试题
Certainpesticidescanbecomeineffectiveifusedrepeatedlyinthesameplace;
从……而得名getone’snamefrom…
被誉为“楷书四大家”的是( )。A.欧阳询 B.颜真卿 C.柳公权 D.褚
患儿,女,7岁,咳嗽、咳痰5天,医嘱给予氧气雾化吸入治疗。下列措施哪项是错误的
证券公司、证券投资咨询机构提供证券投资顾问服务,应当与客户签订证券投资顾问服务协
患者男,67岁,腹大胀满,按之如囊裹水,下肢浮肿,脘腹痞胀,得热稍舒,怯寒神倦,
属于外用液体药剂的是A.合剂 B.散剂 C.滴耳剂 D.颗粒剂 E.栓剂
肝素作为抗凝剂最常用于A.血细胞计数 B.红细胞渗透脆性试验 C.凝血功能检
根据《基础地理信息标准数据基本规定》,下列数据中,应当由国务院测绘行政主管部门委
如果2011年从业人员人数年增长率与2010年相同,则2011年从业人员
最新回复
(
0
)