OG23讨论帖没有，奇怪啊？有3个小破问题

hhl3000

OG23讨论帖没有，奇怪啊？有3个小破问题，多了点，我把文章帖出来了

Passage 23

New observations about the age of some globular clusters in our Milky Way galaxy have cast doubt on a long-held theory about how the galaxy was formed. The Milky Way contains about 125 globular clusters (compact groups of anywhere from several tens of thousands to perhaps a million stars) distributed in a roughly spherical halo around the galactic nucleus. The stars in these clusters are believed to have been born during the formation of the galaxy, and so may be considered relics of the original galactic nebula, holding vital clues to the way of the formation took place.

The conventional theory of the formation of the galaxy contends that roughly 12 to 13 billion years ago the Milky Way formed over a relatively short time (about 200 million years) when a spherical cloud of gas collapsed under the pressure of its own gravity into a disc surrounded by a halo. Such a rapid formation of the galaxy would mean that all stars in the halo should be very nearly the same age.

However, the astronomer Michael Bolte has found considerable variation in the ages of globular clusters. One of the clusters studied by Bolte is 2 billions years older than most other clusters in the galaxy, while another is 2 billion years younger. A colleague of Bolte contends that the cluster called Palomar 12 is 5 billion years younger than most other globular clusters.

To explain the age differences among the globular clusters, astronomers are taking a second look at “renegade” theories. One such newly fashionable theory, first put forward by Richard Larson in the early 1970’s, argues that the halo of the Milky Way formed over a period of a billion or more years as hundreds of small gas clouds drifted about, collided, lost orbital energy, and finally collapsed into a centrally condensed elliptical system. Larson’s conception of a “lumpy and turbulent” protogalaxy is complemented by computer modeling done in the 1970’s by mathematician Alan Toomre, which suggests that closely interacting spiral galaxies could lose enough orbital energy to merge into a single galaxy.

139. Which of the following, if true, would be most useful in supporting the conclusions drawn from recent observations about globular clusters?

(A) There is firm evidence that the absolute age of the Milky Way galaxy is between 10 and 17 billion years.

(B) A survey reveals that a galaxy close to the Milky Way galaxy contains globular clusters of ages close to the age of Palomar 12.

(C) A mathematical model proves that small gas clouds move in regular patterns.

(D) Space probes indicate that the stars in the Milky Way galaxy are composed of several different types of gas.

(E) A study of over 1,500 individual stars in the halo of the Milky Way galaxy indicates wide discr 10 and 17 billion years.epancies in there ages.

The best answer is E. The recent observations have to do with the age of globular clusters in the

Milky Way galaxy. One conclusion that has been drawn from these observations is that the galaxy

may have formed over a long period of time (lines 27-32). The discovery that stars in the halo of

the galaxy vary greatly in age would support this conclusion and weaken the conventional theory,

which suggests that “all stars in the halo should be very nearly the same age” (lines 18-19). The

information contained in the other choices is of little or no relevance to any conclusions drawn

from the recent observations.

第1个观点不是说The conventional theory of the formation of the galaxy contends that roughly 12 to 13 billion years ago （2段首句）那A不是说是 10 and 17 billion years.么，那不是说明支持了第2个观点么（不是在同一时间形成）为什么不选A呢？

140. If Bolte and his colleague are both correct, it can be inferred that the globular cluster Paloma 12 is approximately

(A) 5 billion years younger than any other cluster in the galaxy

(B) the same age as most other clusters in the galaxy

(C) 7 billion years younger than another cluster in the galaxy

(D) 12 billion years younger than most other clusters in the galaxy

(E) 2 billion years younger than most other clusters in the galaxy

The best answer is C. Bolte claims that one cluster is 2 billion yeas older than most other clusters

in the galaxy (lines 22-23). The colleagues claims Palomar 12 is 5 billion years younger than most

other clusters (lines 24-26). If both clams are correct, Palomar 12 is 7 billion years younger than

another cluster in the galaxy. The statement made in A is not implied by the two clams made by

Bolte and his colleague, whereas the statements made in B, D, and E are false if the two clams are

correct.

这个数学题一敲不通啊！

141. The passage suggests that Toomre’s work complements Larson’s theory because it

(A) specifies more precisely the time frame proposed by Larson

(B) subtly alters Larson’s theory to make it more plausible

(C) supplements Larson’s hypothesis with direct astronomical observations

(D) provides theoretical support for the ideas suggested by Larson

(E) expands Larson’s theory to make it more widely applicable

The best answer is D. Larson’s theory holds that numbrous gas clouds “drifted about, collided, lost

orbital energy, and finally collapsed into a centrally condensed elliptical system” (lines 33-35).

Toomre’s computer modeling apparently indicates a way in which this process could have

occurred. The computer medeling thus provides theoretical support for Larson’s theory. Nothing in

the passage suggests that Toomre’s computer modeling does any of the things mentioned in the

other choices.

感觉计算机MODEL这是模拟了一下过程，并不是 theoretical support （理论支持啊）仅仅是演示了一下也叫理论支持么？

wangyu73cn

139 第1个观点不是说The conventional theory of the formation of the galaxy contends that roughly 12 to 13 billion years ago （2段首句）那A不是说是 10 and 17 billion years.么，那不是说明支持了第2个观点么（不是在同一时间形成）为什么不选A呢？

[关键是A的意思：银河系的绝对年龄在100亿至170亿年之间。没有表明是具体在多长时间内形成的，可能是从110亿年至160亿年形成，也可能在125亿年至125.6亿年之间形成。所以不能推断其对于论点二的支持程度。如果说是一组统计数据的话，这A选项只给出了样本的值域，而没有给出离散状况。]

140 这个数学题一敲不通啊！

[怎么不通啊！？某个星群与大部分星群相比老20亿年，P12与大部分星群相比年轻50亿年，当然能推出，P12与这个星群相比年轻70亿年了。]

141 感觉计算机MODEL这是模拟了一下过程，并不是 theoretical support （理论支持啊）仅仅是演示了一下也叫理论支持么？

[是的。The computer modeling thus provides theoretical support. 你就认可OG的正确性吧。如果有异议时，一般地，就需要修正我们自己的认识了。其实，建模过程就是一种理论研究。你或许还记得，物理中的很多理论就是建立一个模型而已，例如，爱因斯坦的相对论理论也可以说是一种模型吧。]

[此贴子已经被作者于2006-1-27 14:30:49编辑过]

rosmarine

以下是引用wangyu73cn在2006-1-27 14:29:00的发言：

139 第1个观点不是说The conventional theory of the formation of the galaxy contends that roughly 12 to 13 billion years ago （2段首句）那A不是说是 10 and 17 billion years.么，那不是说明支持了第2个观点么（不是在同一时间形成）为什么不选A呢？

[关键是A的意思：银河系的绝对年龄在100亿至170亿年之间。没有表明是具体在多长时间内形成的，可能是从110亿年至160亿年形成，也可能在125亿年至125.6亿年之间形成。所以不能推断其对于论点二的支持程度。如果说是一组统计数据的话，这A选项只给出了样本的值域，而没有给出离散状况。]

论点二是什么？是不是就是Bolte的观点？以我的理解，Bolte观测的结果可以conclude银河系并不是像老观点说的形成于短短200 million years，而是前后跨度至少可达4 billion years，若再加上另一个人的观测，更可达7 billion years。结合老观点说的“银河系在12~13billion years ago开始形成”，则说明了A所说的银河系的年龄是10~17 billion years old. 这个“12~13billion years ago”是个绝对的数字，所以推导出的10~17 billion years也是绝对的。所以我觉得A对新观点支持得很好呀。谁来给我洗洗脑？

另外，黄字部分我想指出的是，银河系开始形成的那一年（可能是爆炸发生啊什么的那年）就应该是绝对年龄开始的那一年，没错吧？怎么会可能是从110亿年至160亿年形成，也可能在125亿年至125.6亿年之间形成？只能是从100亿年前的那一年开始呀！

E说研究了1500颗星星也不足以证明什么，银河系有多少星星啊？况且wide discrepancies指的是几百年的不同、还是几十亿年的不同？真不明白E怎么能支持新观点呢？

[此贴子已经被作者于2006-3-10 21:23:35编辑过]

rosmarine

help~~~

xjlv128

这题有讨论，是17篇里的，你找一下吧

wangyu73cn

以下是引用rosmarine在2006-3-10 20:20:00的发言：

论点二是什么？是不是就是Bolte的观点？以我的理解，Bolte观测的结果可以conclude银河系并不是像老观点说的形成于短短200 million years，而是前后跨度至少可达4 billion years，若再加上另一个人的观测，更可达7 billion years。结合老观点说的“银河系在12~13billion years ago开始形成”，则说明了A所说的银河系的年龄是10~17 billion years old. 这个“12~13billion years ago”是个绝对的数字，所以推导出的10~17 billion years也是绝对的。所以我觉得A对新观点支持得很好呀。谁来给我洗洗脑？

另外，黄字部分我想指出的是，银河系开始形成的那一年（可能是爆炸发生啊什么的那年）就应该是绝对年龄开始的那一年，没错吧？怎么会可能是从110亿年至160亿年形成，也可能在125亿年至125.6亿年之间形成？只能是从100亿年前的那一年开始呀！

E说研究了1500颗星星也不足以证明什么，银河系有多少星星啊？况且wide discrepancies指的是几百年的不同、还是几十亿年的不同？真不明白E怎么能支持新观点呢？

The evidence that "the absolute age of the Milky Way galaxy is between 10 and 17 billion years" only indicates the range of the age of the Milky Way. This evidence doesn't indicate "the wide discrepancies of the ages" of any part of the Milky Way. And the latter is "the conculsion drawn from recent Observations'.

For example, "The age of people is between 0 and 500 years " is true, although in vague description. But this doesn't support the conclusion that the age of some people is 500 years.

For your reference.

imharper

文章里从头到尾都没提到"1500"这个数字,不明白E选项为什么会提到1500这个数字.