Q23 - Eight large craters run

[janelso3]

I think that the argument sets up only two possible explanations, meteors or volcanoes, and concludes that it was volcanoes. So we should be looking for something that rules out meteors or gives support to volcanoes. Could someone please explain this one? Thanks.

[ManhattanPrepLSAT2]

One subtle distinction you want to pay attention to has to do with whether there are actually two possibilities, or if the author mistakenly assumes only two possibilities. It all has to do with the wording. Consider the following two examples:

"Every day, Jack either goes to the park or to the gym. Since he did not go to the park, he went to the gym."

vs.

"Jack likes to the go the gym and the park. Since he did not go to the park, he must have gone to the gym."

Notice the change in wording makes it so that a) we are required to consider exactly two possibilities or b) our job is to notice that the author has arbitrarily limited his thinking.

In this particular problem, the author presents two possible ways that craters can be formed, and mistakenly assumes, without justification, that these are the only possible ways. His argument can be strengthened, therefore, if we can show that there isn't another potential cause.

Hope that helps. Let me know if you have further questions about any of the particular answer choices.

[chlqusghtk]

Would you please explain why A or D cannot be the right one?

Also, I'm confused about B's wording because it seems like volcanic events are under the category of "natural causes". Aren't they?


Thank you.

[giladedelman]

Thanks for posting! This is a tricky problem.

Because of the linearity of the craters, the argument goes, it's unlikely that some were formed by volcanoes and some by meteors. And because they are all different ages, it concludes, they were more likely caused by volcanoes than by meteors.

Well, the gap here is pretty glaring: how do we get from the fact that the craters are of different ages to the conclusion that they were more likely caused by volcanoes than by meteors?

(B) strengthens the argument by making explicit the assumption that fills this gap. If no known natural causes would likely account for eight meteorite craters of different ages in a straight line, then these must not be meteorite craters -- so we can conclude that meteors were probably not the cause! It's that little word "meteorite" that sneakily makes this answer choice work.

(A) is out of scope, because we want to know why linear craters of different ages can't be formed by meteors.

(C) seems to weaken both explanations without addressing which one is more likely.

(D) is tempting, but be careful: the premise tells us that an extreme volcanic event could have caused these shocks. We've got to accept this as fact. This answer is a premise-attacker.

(E) is actually out of scope; the argument isn't about any single meteor shower.


#officialexplanation

[cyruswhittaker]

One subtle distinction you want to pay attention to has to do with whether there are actually two possibilities, or if the author mistakenly assumes only two possibilities. It all has to do with the wording. Consider the following two examples:

"Every day, Jack either goes to the park or to the gym. Since he did not go to the park, he went to the gym."

vs.

"Jack likes to the go the gym and the park. Since he did not go to the park, he must have gone to the gym."

Notice the change in wording makes it so that a) we are required to consider exactly two possibilities or b) our job is to notice that the author has arbitrarily limited his thinking.

In this particular problem, the author presents two possible ways that craters can be formed, and mistakenly assumes, without justification, that these are the only possible ways. His argument can be strengthened, therefore, if we can show that there isn't another potential cause.

Hope that helps. Let me know if you have further questions about any of the particular answer choices.

I'm still confused by this question and the above explanation.

I understand that essentially the author is arguing from a false dilemna by assuming that there are only two causes for the craters: volcanoes or meteorites.

In the sentence "Because of the..." the author presents evidence to suggest that the craters couldn't be caused by BOTH volcanoes and meteorites.

But then the author goes off and says that they were probably caused by volcanoes instead of meteorites because the craters were all of different ages.

So (B) only seems to provide the missing assumption from the statement immediately above by saying that no meteorites could form the craters of different ages.

But even though this strengthens the argument, it is still relying on the false dilemna that is presented initially.

I guess what I'm saying is that B doesn't seem to cross out other potential causes and help to rectify the primary flaw, but rather just helps to fill in a secondary assumption made by the author in the last sentence.

Please help to clarify this for me. Thank you!!

[haeaznboiyoung]

I also need some help seeing why B is correct, but for different reasons.

No known natural cause...

Aren't volcanic events and meteorites natural causes? I saw this more or less weakening the argument by saying that they no natural causes (volcanic and meteorites) would likely account for eight meteorite craters of different ages forming a straight line. As such, other things could have caused them, construction for example.

I would've chosen this if it said "No OTHER known natural causes..."

[cyruswhittaker]

I also need some help seeing why B is correct, but for different reasons.

No known natural cause...

Aren't volcanic events and meteorites natural causes? I saw this more or less weakening the argument by saying that they no natural causes (volcanic and meteorites) would likely account for eight meteorite craters of different ages forming a straight line. As such, other things could have caused them, construction for example.

I would've chosen this if it said "No OTHER known natural causes..."

I was confused by this too at first, so I'm definately interested in hearing other viewpoints on this question as well.

The reason I believed that the "No natural cause" part is not an issue with (B) is that it specifically references "for eight meteorite craters of different ages."

So, it's not saying that there can't be any natural causes in general, but only that there can't be any natural causes from the meteorites.

This seems like an odd way of phrasing this (of course the whole LSAT has weird phrases!! ), so please let me know if I've misinterpreted it.

[bbirdwell]

Yep. (B) doesn't say that no natural cause could account for the craters. It's sneaky in that way.

It says no natural cause could account for METEORITE craters forming a straight line, thus aiding the volcanic conclusion by ruling out meteors.

[didi0504]

why is e wrong?

[bbirdwell]

The argument states that the craters are all different ages, so we can already infer that they weren't caused by a single meteor shower. Thus, (E) doesn't add anything new.

[skapur777]

My biggest LSAT issue is wording of the answer choices. Does B say:

It is not very likely that nature could cause eight meteorite craters of different ages to form a straight line.

[timmydoeslsat]

I can understand the terminology issue.

This stimulus tells us that we have 8 large craters that are lined up.

Some of these craters are consistent with the idea of a meteorite causing this.

However, volcanoes could have caused it too.

But due to the fact that they are lined up, its unlikely that we would have a combination of the two causing this.

So, since the craters are all of different ages, it is likely the cause of volcanoes doing this.

Our job is to strengthen this idea of volcanoes being the cause.

My prephrase was as follows:

I need something that states how meteors are unlikely to account for the different ages.

Or perhaps help me ensure that volcanoes is really the cause. Maybe show me that this thing has happened before or is possible.

Answer choices:

A) All of the same age - doesnt help me.

B) This looks great. This would strengthen the idea of meteors not being the cause.

C) Weakens

D) Weakens as well. This is telling me that there is not evidence available of a volcano being able to cause some of these craters found.

E) This helps rule out that it was not a single meteor shower that caused this. But what about meteor showers over the years? It does not go far enough. We want to weaken the idea of meteors causing these craters, not a single meteor shower.

Of course, we would also have to assume that a single meteor shower can give rise to these types of craters of different ages. I suppose it is possible. I mean maybe it was a gigantic meteor shower that lasted 1,000 years.

[jamiejames]

Thanks for posting! This is a tricky problem.

Because of the linearity of the craters, the argument goes, it's unlikely that some were formed by volcanoes and some by meteors. And because they are all different ages, it concludes, they were more likely caused by volcanoes than by meteors.

Well, the gap here is pretty glaring: how do we get from the fact that the craters are of different ages to the conclusion that they were more likely caused by volcanoes than by meteors?

(B) strengthens the argument by making explicit the assumption that fills this gap. If no known natural causes would likely account for eight meteorite craters of different ages in a straight line, then these must not be meteorite craters -- so we can conclude that meteors were probably not the cause! It's that little word "meteorite" that sneakily makes this answer choice work.

(A) is out of scope, because we want to know why linear craters of different ages can't be formed by meteors.

(C) seems to weaken both explanations without addressing which one is more likely.

(D) is tempting, but be careful: the premise tells us that an extreme volcanic event could have caused these shocks. We've got to accept this as fact. This answer is a premise-attacker.

(E) is actually out of scope; the argument isn't about any single meteor shower.

Does that answer your question?

Is volcanic activity also not natural? That's why I got rid of B

[melmoththewanderer88]

I appreciate the long discussion by previous posters.

I have a purely semantic question concerning letter "B," and that is that it is limited only to "known natural causes." My first thought in reading that is what about "unknown natural causes?" That is throughout science we've had theories proven wrong on the basis of things we didn't know yet.

So my question here is why is that line of thought not valid here?

[sumukh09]

I had it down to E and B and went with E because I thought volcanoes can be categorized as "natural causes." B says "no known natural cause..." so doesn't that weaken the notion that a volcano may have been the culprit? For E, I didn't account for the relationship between the ages of the craters and the answer choice saying "single meteor shower," my astronomy skills are not the best so I assumed there was no issue there.

[sumukh09]

So I think getting this question correct depends on the assumption that you KNOW that meteorite craters are caused by meteorites. I know this sounds silly, but I interpreted "meteorite craters" as just craters that could have been caused by volcanoes, comets, asteroids, etc. but had the special designation of "meteorite crater" because the rocks in these craters had undergone shocks that were *characteristic* of meteorites slamming into Earth. What do you all think?

This is what I thought as well.

[samantha.b233]

So, I got the part that since B is about meteorite craters instead of craters in general. But I still have the following questions:

1. Is meteor shower a natural cause?

2. I understand B as saying, if there are 8 meteorite crators forming a straight line of different ages, any natural cause can't account for that. Correct me if I am wrong. But if that's the case, I don't see how B strengthens the prompt since it really has nothing to so with the prompt, which is about crators instead of meteorite crators.

It would seem a bit circular logic to me because, the author presents no evidence that these craters are not meteorite craters (that the craters are caused by volcanic activity instead of meteorite). Then B goes on saying, if craters are meteorite crators, then volcanic activity did not cause them.

[cwolfington]

Wow, ok, I get it now. (B) is saying "No known natural cause [eg. volcanoes or meteorites] would likely account for eight meteorite craters of different ages forming a straight line" So meteorites cannot cause meteorite lines such as the one described in the stimulus.

This strengthens the argument by reducing the chances that the line was caused by meteorites.

[ganbayou]

Hi,
I have similar question...Isn't volcanic events also "natural cause"?
If so, B would weaken the argument instead of strengthen, isn't it?

Thank you

[rinagoldfield]

Hi melmoththewanderer88,

The “natural” in choice (B) is a great detail to notice. I do think it’s a relevant detail. However, (B) strengthens even if we focus on it. Strengtheners often knock out a specific counterpoint – even very specific counterpoints.

Analogy:

Bob is happy --> Bob ate chocolate

Assumption: nothing other than chocolate makes Bob happy.
Possible right answer: Bob’s happiness isn’t due to a great first date.

^^ Here the strengthener knocks out a very specific counterpoint.

Let’s apply that to this argument:

Craters different ages --> volcanoes rather than meteors

Assumption: there’s no way the meteors could cause different aged craters.
Possible right answer: Meteors can’t cause different aged craters in X specific way.

That’s what (B) gives us.