Hey gang,
I’ve been working through the Sufficient Assumption question bank, trying to turn my Level 3 and 2 questions into Level 1 questions (for terminology check this out this webinar:
https://7sage.com/webinar/timing-and-levels-of-certainty -- props to
@c.janson35 and his brilliant Timing Webinar).
This question bothers the you-know-what out of me because the answer doesn’t seem to justify the conclusion. It just seems like it’s like it’s blocking other potential explanations, which would make it a good necessary assumption or strengthening answer. I’d love people’s input on this.
Comments
That would make it a fairly binary argument - either they started out evenly spread and in some regions more of them were lost, or they weren't evenly spread to begin with (and the correct answer takes care of the second possibility by telling us that they were).
Now, this is not quite as nice and tight as I would like it, but "geophysical processes" is a broad enough term that it could potentially encompass pretty much anything that could make the holes disappear - earthquakes, mountains sprouting, volcanoes erupting, erosion, etc. I'm assuming that a large meteorite impact hole won't disappear from minor things like sheep grazing on the site, so it would have to be some sort of shift of the land itself - a geophysical process.
Good thing the other answers are pretty far off, so POE would work OK for this one.
I'm not entirely sure that answer D is sufficient, though. Geophysics is the study of physical geological phenomena, so what happens if answer choice D is true, but humans just built buildings and stuff on top of or around the impact craters? Then, D is true, but the conclusion doesn't necessarily follow: the reason why we have "securely identified" craters isn't solely due to natural/geophysical processes; it's partly because artificial processes (like slapping a building on the crater or building buildings around the crater, protected it from storms and stuff) got in the way.
Part of me wants to attribute the difficulty of this question to the fact that it's an old question, but that seems like a cop out. I agree with @runiggyrun that POE is probably the best way to arrive at answer D.
I suppose you could look at it like this:
-They're trying to convince us that there's only 1 reason as to why these stable regions have a greater density of craters. Due to their stability (no big @#$ earthquakes, volcanoes, etc. to destroy the craters).
Well, it could just be that there are more meteorite strikes in that area. After all, more meteorites striking = more craters.
There really aren't that many explanations as to what could cause a crater. I think the writer of that question expects us to assume that nothing, other than a meteorite, can cause a crater. If that's the case, and there is a similar number of meteor strikes all around the world, then it makes sense that these stable regions have more craters (in terms of density).
If the number of meteor strikes is similar from one region to another, you would expect a similar number of craters (I'm using "number" instead of "density"). But there aren't. Why not? Well, even though there are an equal number of meteor strikes, the unstable regions have natural disasters that keep us from identifying the craters. Hence why we can positively identify more in these stable regions.
I agree, Corey's pyramid strategy is amazing!!!
Before reading any further about your query, I pulled up the question. Got it - SA qstem and prephrased an assumption I found in the argument. Quickly marked off A, B, C, got to D and said NA/Str and marked it off. With pencil ready to circle E as correct, I read it and went "what the heck" - it couldn't be the correct AC. POE leaves "D" as the best of the worst.
Kudos for seriously attacking each question and sharing. I think this Question fell out of Corey's pyramid and hopefully met its demise under a meteor crater:)