The Myth of Liquid Glass

Answer choices

1. A

   Too Narrow1% picked this

   Zanotto's research has proven that the amount of time required for viscous flow to change the thickness of medieval cathedral glass would be greater

   This is a derivable claim from the end of the 2nd paragraph, but it doesn't have any of the big picture framing ideas. Where's the Challenge Position part? It doesn't address the popular belief that glass flows downward. Where's the Answer a Question part? It doesn't address the real reason that medieval cathedral glass bulges at the bottom (old glass-making techniques).

   1%
2. B

   Wrong Emphasis: technology3% picked this

   The technology of window-glass production has progressed substantially from medieval stained-glass techniques to today's production of very flat

   This answer's main clause is, "The technology of window-glass production has progressed substantially". Did the author write this passage to update the world on window-glass production technology? Heavens, no. She wrote it to go after the misconception that glass flows downward. The author was helping people let go of their misconception by telling them the real reason that old glass bulges at the bottom is because of the old school janky technology.

   3%
3. C

   Wrong Emphasis: calculating flow rates4% picked this

   After years of investigation motivated partly by a common misunderstanding about the structure of glass, scientists have developed ways of precisely calculating even extremely

   The main clause here is, "Scientists have developed ways of precisely calculating even slow rates of flow in solids such as glass". Did the author write this passage in order to alert the world that science has gotten better at calculating the flow rates of solids? Heck no. She wrote it to address the misconception that glass flows downward, to present a study debunking that idea, and to supply the real causal story behind the misconception. The phrase "such as glass" in this answer makes it seem like glass was just one of potentially many examples of solids we were considering. Meanwhile, we know that glass wasn't an aside or an example. It was the central topic of the whole passage.

   4%
4. D

   Opposite9% picked this

   Recent research provides evidence that although solid glass flows slightly under the influence of gravity, such flow is only one of several factors that

   This answer is conceding that solid glass does flow slightly downward. That flow is part of why there is a noticeable difference in thickness between the top and bottom of old windows. This answer choice makes the passage out to be saying, "People think that old glass is thicker at the bottom because glass flows downward, and while that's true, there are other factors that also contribute." The passage is actually saying, "People think old glass is thicker at the bottom because glass flows downward, but they're believing a myth. Scientists think it's weird how people insist on believing this. Luckily, a new study empirically debunks this myth. It would take trillions of years for the flow of glass to make any noticeable change in thickness, and these old windows are less than 1,000 years old." The last sentence begins, "The difference in thickness in antique windows probably results instead from glass manufacturing methods". This answer is acting like it said, "... probably results in addition from glass manufacturing methods".

   9%
5. E

   Correct83% picked this

   Contrary to a commonly held belief, noticeable differences in thickness between the top and the bottom of some old glass windows are not due

   Why this is right

   The main clause here is the Challenge Position part of the passage: differences in thickness are not due to the flowing of solid glass. The final clause captures the Answer a Question final paragraph: the real reason for old glass's weird thickness is glass manufacturing methods.

   Skill tested: Main Point · how this choice captures the passage's function is the move to repeat next time.

   83%