Q11

[cyruswhittaker]

Can you explain question 11? And also, as it relates to choice D, could you explain the context of the last sentence of paragraph one?

[ManhattanPrepLSAT2]

The major theoretical approaches discussed are --

1. Disintegration of large body -- peppered inner solar system until 4 billion years ago

2. declining stream of hits to moon over billions of years

3. Sharply defined cratering period that did not extend through solar system

All three ideas are consistent with the fact that cratering decreased significantly after LHG.

(D) is very attractive, but we're not told that the period destroyed life -- rather that life couldn't survive during the period. The reason (D) is not correct is that life could have started after the period (and thus there would be no life to destroy).

[geverett]

I landed on C during this by process of elimination, but I can't seem to find any direct support for it. Is this one of those answer choice that just make common logical sense since if the LHB ended then you would expect a decrease in cratering?

[LSAT-Chang]

I had the same question. I was down to B and C, and ended up choosing B because I couldn't find support for C. But I guess there is also no evidence for "origin" of the debris, so I can see why B is wrong, but not where we get evidence for C..

[irene122]

what about E? when I was confronting E I remembered "debris" was mentioned in the article but somehow vague, compared to E, I was not aware of whether cratering decreased after LHB--it's not like one could locate the answer directly from the article but one need to read between the line?

Any thought would be appreciated!

[ohthatpatrick]

(E) would be incorrect because the 2nd theoretical approach does not believe there was any "debris" during the LHB. These theorists think that the LHB wasn't a specific event, but just the leftover fingerprints of a multi-billion year process of regular bombardment.

By contrast, the 1st and 3rd groups believe that there was specifically a noteworthy large body that was deteriorating, creating debris, thereby causing the LHB. However, they disagree about whether the debris would "pepper the inner solar system" (1st group) or whether the debris would be kept "within the Earth-Moon system" (3rd group). So even those two theories would probably disagree about the amount of debris.

In terms of finding support for (C), it's a bit of "read between the lines", as previous posters indicated.

However, group 1 thinks "the LHB was linked to the disintegration of an asteroid or comet orbiting the sun". If they believe the LHB is caused by something disintegrating, then it is logical to infer that the more that thing disintegrates, the more the bombardment will taper off.

Group 2 explains the LHB as the end of billions of years of "continuous, declining heavy bombardment". So they must believe that bombardment dropped following the LHB.

Group 3 calls the LHB "a sharply defined cataclysmic cratering period", implying it has a noticeable beginning and and a noticeable ending. Hence, they must believe there was a drop off following the LHB.

It's definitely easier to get this right by eliminating the other four. The "proof" for (C) is basically there, but definitely implictly, not explicitly.

[zainrizvi]

I looked at answer choice (C), thought to myself there is no mention of what happens "after the LHB" -- therefore, out of scope. How can I avoid such thinking?

I managed to choose (D) because after eliminating all the other choices, I came up with some crappy justification for (D). Doesn't seem like my approach is very efficient right now - I am trying to be as "open" as possible in terms of not eliminating answer choices.. but it doesn't work.. Should I just try to be very conservative in eliminating answers -- if that doesn't work, then be liberal for each one? Or should I just try to refine how "open" I am initially and work on improving that skill?

[matthew.mainen]

There is in fact such mention. Life on Earth began (paragraph 1). We can reasonably infer that the scientists don't disagree over this fact. In order for life to have began, the LHB would have had to subside.

[ttunden]

Here is my full explanation

Okay so for this we are going to have to refer to paragraph 1 and 2. 1 for background just to remind ourselves of the "debate" and 2 for the 3 theories.

So theory 1 is saying it was basically one large comet or asteroid that was orbiting the sun, part of it broke off and bombarded the moon

Theory 2 is saying it was not one large comet/asteroid but a prolong period of a billion years of comets hitting the moon.

Theory 3 says it was a brief duration and was only between earth and moon system and not the rest of the galaxy.

Now that we have a summary of paragraph 2. lets hit the answer choices.
A- well all three theories are disagreeing on the duration. Eliminate
B- theory 1 and two disagree. eliminate
D- well this is clearly out of scope since the theories never mentioned this and paragraph 1 never mentioned explicitly that LHB destroyed human life, the author just put it in a IF Then statement(lines 9-11)
E- Theory 1 and 2 disagree. Eliminate

So we are left with C and we will choose that. It does not explicitly mention this but the question stem does say "implies" so C is allowed. This question is best attempted by working wrong to right and referring to paragraphs 1 and 2.