OG RC passage23 116 and 117 求翻译，求解答

liangyun_105 · 发表于 2013-6-9 13:37:04

这个第23篇RC真心没看懂

Line After evidence was obtained in the 1920s that

the universe is expanding, it became reasonable

to ask: Will the universe continue to expand

indefinitely, or is there enough mass in it for the

(5) mutual attraction of its constituents to bring this

expansion to a halt? It can be calculated that

the critical density of matter needed to brake the

expansion and "close" the universe is equivalent

to three hydrogen atoms per cubic meter. But the

(10) density of the observable universe—luminous matter

in the form of galaxies—comes to only a fraction

of this. If the expansion of the universe is to stop,

there must be enough invisible matter in the

universe to exceed the luminous matter in density

(15) by a factor of roughly 70.

Our contribution to the search for this "missing

matter" has been to study the rotational velocity

of galaxies at various distances from their center

of rotation. It has been known for some time that

(20) outside the bright nucleus of a typical spiral galaxy

luminosity falls off rapidly with distance from the

center. If luminosity were a true indicator of mass,

most of the mass would be concentrated toward

the center. Outside the nucleus the rotational

(25) velocitywould decrease geometricallywith distance

from the center, in conformity with Kepler's law.

Instead we have found that the rotational velocity

in spiral galaxies either remains constant with

increasing distance from the center or increases

(30) slightly. This unexpected result indicates that the

falloff in luminous mass with distance from the

center is balanced by an increase in nonluminous

mass.

Ourfindings suggest that as much as 90

(35) percent of the mass of the universe is not radiating

at any wavelength with enough intensity to be

detected on the Earth. Such dark matter could be

in the form of extremely dim stars of low mass,

of large planets like Jupiter, or of black holes,

(40) either small or massive. While it has not yet been

determined whether this mass is sufficient to

close the universe, some physicists consider it

significant that estimates are converging on the

critical value.

116 The authors' study indicates that, in comparison with

the outermost regions of a typical spiral galaxy, the

region just outside the nucleus can be characterized

as having

(A) higher rotational velocity and higher luminosity

(B) lower rotational velocity and higher luminosity

(C) lower rotational velocity and lower luminosity

(D) similar rotational velocity and higher luminosity

(E) similar rotational velocity and similar luminosity

Answer D 没想通，因为文中没有提到similar

117

The authors' suggestion that "as much as 90 percent

of the mass of the universe is not radiating at any

wavelength with enough intensity to be detected on

the Earth" (lines 34-37) would be most weakened if

which of the following were discovered to be true?

(A) Spiral galaxies are less common than types of

galaxies that contain little nonluminous matter.

(B) Luminous and nonluminous matter are

composed of the same basic elements.

(C) The bright nucleus of a typical spiral galaxy also

contains some nonluminous matter.

(D) The density of the observable universe is

greater than most previous estimates have

suggested.

(E) Some galaxies do not rotate or rotate too slowly

for their rotational velocity to be measured.

Answer A, 逻辑没想通，题目也不是很明白。

求整理一下这个文章的逻辑链。。。文章几个变量的关系没看懂，谢谢！

liangyun_105 · 发表于 2013-6-10 21:55:59

没有人对这篇文章有疑问吗？自己顶一下，请XDJM赐教，谢谢啦～

kidsu1991 · 发表于 2013-6-11 11:42:59

刚想上来发帖子问题就看到同胞了～我也是这篇的117题困住了。。。
116题中的选D项similar rotational velocity 是由于27行中"the rotational velocity in spiral galaxies either remains constant with increasing distance from the center or increases slightly", constant是恒定的意思，其意思同similar一样。

wuersanmo · 发表于 2013-9-5 11:55:52

我也正准备发帖问这道题，跪求牛人来指点一下。
116那题根据OG解释是因为第27行那句话中的constant，所以simialar rotational velocity。可是前面那句Outside the nucleus the rotational velocitywould decrease geometricallywith distance from the center是什么意思，不是在说由中心几何减少吗？
同样困惑地是，This unexpected result indicates that the falloff in luminous mass with distance from the center is balanced by an increase in nonluminous mass.意思不是由中心光亮度开始减少吗？为什么outside的还会是higher luminosity呢？

117题虽然那句话意思看懂了，可为什么正确答案是A选项？？

同求高人指点一下这两道题，顺便说一下文章逻辑，读得云里雾里。

wuersanmo · 发表于 2013-9-5 11:58:09

LZ，117的题目我的理解是，有90%的宇宙物质在任何波长即使有足够的强度都不发光，所以很难在地球上被发现。
不知道理解得对不对，但是为什么选A，想不通。这两道题看不懂。。。。。。

tigerzheng · 发表于 2013-9-5 12:36:54

117说90%的宇宙物质都不发可见光，但注意这是研究spiral galaxies所得出的结果。但答案A说spiral galaxies只是很小的一部分，而其他大部分都没有暗物质。所以，是对问题的削弱。

坏小子哈哈 · 发表于 2013-9-23 10:20:15

wuersanmo 发表于 2013-9-5 11:55
我也正准备发帖问这道题，跪求牛人来指点一下。
116那题根据OG解释是因为第27行那句话中的constant，所以si ...

说说小弟的一点理解，这题我也错了

116说的是中心几何减少，不过是“in conformity with Kepler's law”，也就是说是根据开普勒定律，是中心几何减少。后面紧接着“Instead we have found”，所以后面说的才应该是正解。
翻成中文，就好像是说，如果跟开普勒定律，那就是是这么这么样；但其实我们观测到是怎么怎么样。
然后116问的是“The authors' study indicates that,”
所以，就……

fish0906yu · 发表于 2013-10-18 10:45:56

116 后面那higher……falloff in L mass with distance from center is balanced by an increase in nonluminous 的意思大概是说 L减少至平衡是在中心mass 部分而问题的是outside the nucleus 是远离center。。。。

CharlesDoit · 发表于 2016-9-17 01:04:28

117这题这题一开始根本没看懂，翻了og答案才明白。这里所有的发现和结论都是基于现有观察到的宇宙而言的。然而也许银河系外边还有其他的星系和我们的银河系有这不一样的物理规律导致了这一结论失效。因此选A

CharlesDoit · 发表于 2016-9-17 01:11:12

116哪一要注意看题干，题干说的是最外层的区域与刚好属于外层的临界区域相比较。首先定位instead we found that the rotational velocity in spiral galaxies either remains constant with increasing distant from center or increases slightly这句话确定了是DE 之间一个。再定位outside the bright nucleus of atypical spiral galaxy luminosity falls off rapidly with distance from the center，可以确定靠近outside临界点区域的luminosity比最外层区域要多

OG RC passage23 116 and 117 求翻译，求解答

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