Nevernevergiveup wrote:
When astronomers observed the comet Steinman-Arnet 3 becoming 1,000 times brighter in September 1995, they correctly hypothesized that its increased brightness was a result of the comet’s breaking up. When comets break up, they emit large amounts of gas and dust, becoming visibly brighter as a result. However, their observations did not reveal comet Steinman-Arnet 3 actually breaking into pieces until November 1995, even though telescopes were trained on it throughout the entire period.
Which of the following, if true, most helps to resolve the apparent conflict in the situation above?
(A) Comets often do not emit gas and dust until several weeks after they have begun to break up.
(B) The reason comets become brighter when they break up is that the gas and dust that they emit refract light.
(C) Gas and dust can be released by fissures in a comet, even if the comet is not broken all the way through.
(D) The amount of gas and dust emitted steadily increased during the period from September through November.
(E) The comet passed close to the sun during this period and the gravitational strain caused it to break up.
OFFICIAL EXPLANATION
Solution: C
As evidenced by the phrase, “most helps to resolve the apparent conflict”, this is an “Explain the Paradox” question, a subtype of the Strengthen category. Our mission is strategically similar to traditional Strengthen questions, but instead of minding the logical gap between a conclusion and its supporting premises, we must focus on the logical gap separating two contradictory statements. With this particular problem, we understand that gas and dust caused increased brightness, and when comets break up they emit gas and dust. The paradox lies in the fact that the scientists observed the increased brightness – caused by gas and dust – but didn’t observe the comet’s breakup until later. The paradox hinges on the timing of the observations. (Notice that the problem explicitly states the scientists “correctly hypothesized that its increased brightness was a result of the comet’s breaking up” – we can rule out any answers which imply the brightness was caused by something else.)
Answer choice “A” actually intensifies the paradox, not fixes it. (Be careful of Weaken answers in Strengthen question types!) If the comet broke up first, then emitted gasses later, the increase in brightness caused by the gas and dust would actually come after the breakup, not before. The problem clearly states that the increased brightness preceded the observed breakup.
Answer choice “B” provides new information, but does nothing to bridge the gap between the two contradictory observations. While it explains the scientific mechanism behind why a disintegrating comet is brighter, it doesn’t explain why the Steinman-Arnett 3 comet was brighter before it was visibly breaking up.
Answer choice “C” bridges the gap and explains how gas and dust – which cause increased brightness – can be emitted before a comet completely disintegrates. This explains the timing of the contradictory observations and shows how scientists could note increased brightness before observing the comet’s complete dissolution. “C” is the correct answer.
Answer choice “D” seems to imply that more and more gas and dust were emitted by the comet throughout the timeframe in question, but it fails to resolve why the scientists observed a 1,000 times increase in brightness in September, but didn’t observe the breakup until November. The gap in timing is not explained.
Answer choice “E” is another answer that provides new background information without bridging the gap between the two contradictory observations. Explaining why the comet broke up is not the same as explaining why the scientists observed the brightness before the actual disintegration. With questions like these, we must focus on connecting both paradoxical pieces.
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28 Sep 2015, 11:45
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