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#25 - In Peru, ancient disturbances in the dark surface

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What does (B)'s constellation referring to? I'm having a hard time thinking why (B) is the right answer. Is is simply because (B) gives an explanation thus (B) is the right one?
David Boyle
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GLMDYP wrote:Hi!
What does (B)'s constellation referring to? I'm having a hard time thinking why (B) is the right answer. Is is simply because (B) gives an explanation thus (B) is the right one?


If this is the question starting "In Peru, ancient disturbances in the dark surface material of a desert show up as light-colored lines that are the width of a footpath and stretch for long distances", then in B, the constellation is probably some constellation of stars in the sky that looks like a big bird or something.

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Is it possible for you guys to explain this stimulus, as well as the answer choices with it? None of this makes sense to me. I believed the answer choice to be C because it demonstrates that the lines actually do have a related purpose, by saying that it's part of a large connected complex of patterns connecting certain points with one another.

Is B the correct answer because it refers to an "astronomical" event and the stimulus says "for someone who interprets the lines as referring to astronomical phenomena"??

I assumed that in the stimulus, the investigator who interprets the lines for spaceship traveling aliens, this is the astronomical phenomena they are referring to in the question stem, is this not the case?

Please help!!

Thanks in advance
Adam Tyson
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Your confusion is understandable, S2KMo, as this is a very confusing stimulus/stem combo, coupled with the fact that it is one of the old-school "double trouble" questions with one stimulus followed by two different questions. Let me see if I can break it down for you some.

First, the stimulus tells us that there are a bunch of lines in the ancient Peruvian desert. One group of lines are straight, branching out from a central point in rays. Another set of lines are curved and form a bird shape. The two sets of lines intersect, with the straight lines crossing over the bird shape. Those are the facts as we know them.

In the stimulus, one investigator gives evidence that these two sets of lines couldn't be roads, so they must of course be landing strips for aliens. That guy sounds a little crazy, but more importantly he is making a sort of false dilemma, assuming that there are only two possible explanations for the lines and, having supposedly eliminated one, claims that the other must be the true explanation.

The stem for question 25 comes along and proposes a third explanation, that these lines might be referring to astronomical phenomena. That means things like stars, galaxies, planets, asteroids, constellations, etc. Not roads and not, as the investigator concluded, alien landing strips (which landing strips would be earthly phenomena, not astronomical, even though they are used for folks coming here from outer space). It also proposes a possible objection to that third explanation - the two sets of lines must have had different, unrelated purposes because they cross over each other. Phew, complicated enough yet?

Finally, still in that question stem, we now are asked to strengthen the third explanation - astronomical phenomena - against the objection - that they must have had unrelated purposes. In other words, show that they could have had a related purpose and that that purpose had something to do with referring to astronomical phenomena. That's a lot of hoops to jump through for just this one question! They did that on purpose, by the way - you get a break by only having to read one stimulus to answer two questions, but then one of those questions is complex enough to erase the benefits of that break.

Answer C doesn't do anything to show that the straight lines and the curved lines have a related purpose. Instead, it only tells us that the straight lines are all related to other straight lines. What does that tell us about the related purpose of the curved lines in the bird shape? Nada! Answer B, though, ties them both together, suggesting that both sets of lines have a similar purpose in that they are both related to astronomical phenomena, one set telling you where to stand to see something and another telling you something about what you will be looking at.

That's a lot to digest! Chew on it a while and let us know if you need any more help with it!
Adam M. Tyson
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