The dark regions in the starry night sky are not pockets in the univer

All correct in 3 mins 45 seconds, including 1 min 45 seconds to read.

1. According to the passage, which of the following is a direct perceptual consequence of interstellar dust?

(A) Some stars are rendered invisible to observers on Earth. - Correct
The dark regions in the starry night sky are not pockets in the universe that are devoid of stars as had long been thought. Rather, they are dark because of interstellar dust that hides the stars behind it.

2. It can be inferred from the passage that the density of interstellar material is
(E) not homogeneous throughout interstellar space - Correct
The average density of interstellar material in the vicinity of our Sun is 1,000 to 10,000 times less than the best terrestrial laboratory vacuum. --> since the passage talks about average density, we can infer that the density is not homogeneous

3. It can be inferred from the passage that it is because space is so vast that
(C) stars can be far enough from Earth to be obscured even by very sparsely distributed matter - Correct
It is only because of the enormous interstellar distances that so little material per unit of volume becomes so significant. Optical astronomy is most directly affected, for although interstellar gas is perfectly transparent, the dust is not.
_________________

Could someone tell me what is wrong in option A?

I chose A as it resembled the 2nd last sentence in the passage.

It is only because of the enormous interstellar distances that so little material per unit of volume becomes so significant.

(C) stars can be far enough from Earth to be obscured even by very sparsely distributed matter

What is sparsely, which means NOT so dense, to a long-distance the become significant in obscuring the stars

(A) little of the interstellar material in it seems substantial

It is not the same paraphrasing. Moreover, in C we talk about the matter + other material = Interstellar Material.

In A , on the other hand, we care about ONLY of matter

Hope is now more clear to you. The passage is short but nasty

Regards
_________________

Bumping up for more discussion.

Supporting details for Option C:

1. The dark regions in the starry night sky are not pockets in the universe that are devoid of stars as had long been thought. Rather, they are dark because of interstellar dust that hides the stars behind it.
2. Dust accounts for about one percent of the total mass of interstellar matter.

Option A is incorrect because despite the avg. low density of interstellar material, interstellar material has a substantial effect as it can hide the stars behind it.

Can someone explain the second question? Why is C wrong and how do I interpret that density is not homogenous throughout interstellar space. (From which part of the passage I should be deriving this inference)

2. It can be inferred from the passage that the density of interstellar material is

(A) higher where distances between the stars are shorter
(B) equal to that of interstellar dust
(C) unusually low in the vicinity of our Sun
(D) independent of the incidence of gaseous components
(E) not homogeneous throughout interstellar space

Hi Spunk17,

E can be inferred from the lines: "The average density of interstellar material in the vicinity of our Sun is 1,000 to 10,000 times less than the best terrestrial laboratory vacuum. Average density implies that density is not homogeneous.
Same lines tell us that C is incorrect, as the option talks about the density, and what's mentioned in the passage is average density. Also, the average density in the of interstellar material in the vicinity of the Sun is less when compared to the best terrestrial laboratory vacuum. But what is option C based on? We cannot infer with certainty that the density would be "unusually low" in the vicinity of our Sun.


Hope This Helps.
Thanks.

2. It can be inferred from the passage that the density of interstellar material is

(A) higher where distances between the stars are shorter
(B) equal to that of interstellar dust
(C) unusually low in the vicinity of our Sun
(D) independent of the incidence of gaseous components
(E) not homogeneous throughout interstellar space

Given, interstellar material has low avg. density because of enormous distance. So, density will be higher when distance are shorter. So I selected Option A. Someone pls explain?