PrepTest 143
[lcid:3669] Prep Test 143 LSAT — Reading Comp — S2
Reading comp
Passage
Questions 21-27 . To glass researchers it seems somewhat strange . that many people throughout the world share the
Remaining source text redacted.
Passage walkthrough
Passage SummaryTopic: Science
Paragraph 1
Zanotto has shown that the persistent belief that glass flows like water and this explains the thicker bottoms of medieval glass is wrong, as it would take longer than the universe has existed for that to happen, and it's probably the result of manufacturing methods.
Key Lines:
Lines 1-5 - A common belief and the fact that scientists think it's weird are introduced
Lines 8-10 - A partial reason for it is stated
Lines 20-21 - A phenomenon is noted, and the Author says that she believes an explanation related to the common belief has been debunked
Lines 44-46 - An alternative explanation is presented
Meta-Structure:
Common Belief/New Belief - This passage introduces a persistent belief shared by many (Line 3) before showing it's wrong. This metastructure is very common on the LSAT, and especially so in science passages.
Phenomenon/Explanation - Here, the Author presents a phenomenon—medieval glass is thicker at the bottom (Lines 20-23). After ruling out one explanation (Lines 20-23), she presents another (Lines 44-46).
Last Thoughts:
Remember - You don't need to know science! We don't care if you know what an amorphous atomic structure is, or if you know the atomic weight of geranium is (it doesn't have one, it's a flower! It's germanium, but it still doesn't matter). What we do want is you to tag these phrases so you can find them in case it asks about them in context.
Second, the main point. This passage has a lot going on, and we want to make sure that our anticipation of the main point is comprehensive. As such, we need to make sure that it includes the phenomenon being explained, the incorrect explanation (in some way), and the explanation put forward by the Author, along with how certain she is about each element (mainly the debunking and the new explanation).
Finally, this passage brings up a really important thing to note—and it's especially common in science passages. That's the certainty of the verb that the Author uses to describe proof (in this case, studies). There's a world of difference between a study that argues a common belief is wrong, one that provides evidence it's wrong, and one that proves it's wrong. If the Author says "argues," then we don't know her opinion on it. If she says "provides evidence," then she thinks there's a good case, but she's not sold. And if she says the study "proves" the belief is wrong, then the Author is on board. "Debunks" here is in the third camp—you can't use that verb if you don't think that the study has disproved the belief with certainty. Start to analyze these words when the Author introduces evidence!
Paragraph 1
- Paragraph note
- A myth is presented, what partly led to it is proposed, and background info on glass
- Views, minor Meta-Structures, and the author's attitude
- Myth (weird to glass experts) - Glass flows down like a liquid
- Origin - Unknown, but probably in part because of mistake on atomic structure
- Science/Structure - Liquid and glass similar, but cooling it makes it an amorphous solid
- Paragraph note
- A related phenomenon is introduced, and an explanation is debunked in a study
- Views, minor Meta-Structures, and the author's attitude
- Phenomenon - Medieval cathedrals have glass thicker at the bottom
- Explanation - Glass flows down
- Author - Zanotto study debunks this
- Zanotto - Gravity can cause solids to flow, but it'd take longer than the universe
- Paragraph note
- Zanotto's conclusions are explained
- Views, minor Meta-Structures, and the author's attitude
- GO glass - flows best - would take trillions of years
- Impurities would lessen that, but not by that much
- Flow requires 350+C (temp)
- Author - Study shows what scientists had known
- Paragraph note
- A true explanation for the earlier phenomenon is noted
- Views, minor Meta-Structures, and the author's attitude
- Explanation for thicker bottoms of medieval cathedral glass - Manufacturing processes
- Early (until 19th C) - Glass blown, which thickened some edges, and those were placed down for stability
- Later - Pulled from rod, making it more uniform
- Now - Molten tin floating, making it extremely flat
Zanotto has shown that the persistent belief that glass flows like water and this explains the thicker bottoms of medieval glass is wrong, as it would take longer than the universe has existed for that to happen, and it's probably the result of manufacturing methods.
Key Lines:
Lines 1-5 - A common belief and the fact that scientists think it's weird are introduced
Lines 8-10 - A partial reason for it is stated
Lines 20-21 - A phenomenon is noted, and the Author says that she believes an explanation related to the common belief has been debunked
Lines 44-46 - An alternative explanation is presented
Meta-Structure:
Common Belief/New Belief - This passage introduces a persistent belief shared by many (Line 3) before showing it's wrong. This metastructure is very common on the LSAT, and especially so in science passages.
Phenomenon/Explanation - Here, the Author presents a phenomenon—medieval glass is thicker at the bottom (Lines 20-23). After ruling out one explanation (Lines 20-23), she presents another (Lines 44-46).
Last Thoughts:
Remember - You don't need to know science! We don't care if you know what an amorphous atomic structure is, or if you know the atomic weight of geranium is (it doesn't have one, it's a flower! It's germanium, but it still doesn't matter). What we do want is you to tag these phrases so you can find them in case it asks about them in context.
Second, the main point. This passage has a lot going on, and we want to make sure that our anticipation of the main point is comprehensive. As such, we need to make sure that it includes the phenomenon being explained, the incorrect explanation (in some way), and the explanation put forward by the Author, along with how certain she is about each element (mainly the debunking and the new explanation).
Finally, this passage brings up a really important thing to note—and it's especially common in science passages. That's the certainty of the verb that the Author uses to describe proof (in this case, studies). There's a world of difference between a study that argues a common belief is wrong, one that provides evidence it's wrong, and one that proves it's wrong. If the Author says "argues," then we don't know her opinion on it. If she says "provides evidence," then she thinks there's a good case, but she's not sold. And if she says the study "proves" the belief is wrong, then the Author is on board. "Debunks" here is in the third camp—you can't use that verb if you don't think that the study has disproved the belief with certainty. Start to analyze these words when the Author introduces evidence!
Question prompt
The passage suggests that
Remaining source text redacted.
Why the credited answer is right
Credited answer: C
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
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AIt is higher for Remaining source text redacted.
Why choice A is not credited
Incorrect. (Lines 35-36) The passage notes that Medieval glass had impurities that could speed the flow to some degree—meaning that these impurities made it more like a liquid. That suggests that the transition temperature might be lower since it was already closer to a liquid. While we can't say that for sure, we can rule out this answer based on that. -
BIt has only recently Remaining source text redacted.
Why choice B is not credited
Incorrect. (Lines 25-30) Zanotto recently calculated how long it would take for viscous flow to change the thickness of glass. That's not the same as calculating its transition temperature which. After all, we know that early glass was made by blowing molten glass, flattening it, and cooling it. They had thermometers back then, so they very well could have known the transition temperature. -
CIts upper extreme is Remaining source text redacted.
Why choice C matches the stem
Correct. Question Type:
Must Be True
Strategy Overview:
Review what is said about the transition temperature of glass, then find an answer built off of those details
Answer Anticipation/Relevant Lines:
The transition temperature of glass was discussed in the "science" section of Paragraph 1. There, it's noted that it's a range of a few hundred degrees (Lines 15-16). Below it, glass has an amorphous atomic structure but the physical properties of a solid (Lines 17-19). This implies that above it, it still has that amorphous atomic structure ("retains"), but it has the physical properties of a liquid.
We could stop there, but that would neglect the other mention of temperature in the passage. At the end of Paragraph 3, we noted that it said glass would need to be heated to at least 350C before it would have the ability to flow, like a liquid. So that 350C must be the minimum temperature at which any glass would start to transition.
Let's find an answer that is based on any of these observations.
Answer Explanation:
(Lines 42-43; Lines 15-16) The passage notes that, for glass to flow at more than a negligible rate—for it to act more like a liquid—it would need to be heated to "at least" 350C. So the passage sets out a bare minimum for that transition temperature to start at 350C. The transition temperature spans several hundred degrees according to Paragraph 1, so the upper limit must be well above a few hundred degrees over 350C, making this the correct answer.
Key Takeaway:
Some tricky Must Be True questions will connect parts of the passage that aren't directly connected. Here, we ended up relying on a definition from Paragraph 1 and a data point from Paragraph 3. What connected them? They both talked about temperature. If you note one of these indirect connections in a passage, there's a good chance you'll end up answering a question based on it, so always be looking for them! -
DIt does not affect Remaining source text redacted.
Why choice D is not credited
Incorrect. (Lines 41-43) The passage notes that raising the temperature would potentially result in glass flowing at a more-than-negligible rate, and this answer runs counter to that. -
EFor some types of Remaining source text redacted.
Why choice E is not credited
Incorrect. (Line 43) The passage notes that glass would need to be heated to "at least" 350C for it to start flowing at a greater-than-negligible rate, so the transition temperature can't be lower than that established lower bound.
What this tests
Discussion
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Started by Ryan-Mahabir