Reading ComprehensionDifficulty: Medium

PT140 S4 P4 Q25 Explanation

Explaining Mirror Images

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsAuthor OpinionScience

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Passage

Physicists are often asked why the image of an object, such as a chair, appears reversed left-to-right rather than, say, top-to-bottom when viewed in a mirror. Their answer is simply that an image viewed in a mirror appears reversed about the axis around which the viewer rotates his or her field of sight about a vertical axis, mirror images usually appear reversed left-to-right. This is the field-of-sight explanation.

However, some physicists offer a completely different explanation of what mirrors “do,” suggesting that mirrors actually reverse things front-to-back. If we place a chair in front of a mirror we can envision how its reflected image will appear by imagining another chair in the space “inside” the mirror. The resulting reflection is explanation treats it as though it were as real and three dimensional as the original chair.

This explanation appeals strongly to many people, however, because it is quite successful at explaining what a mirror does—to a point. It seems natural because we are accustomed to dealing with our mental constructs of objects rather than with the primary sense perceptions on which those constructs are based. In general, we our eyes; rather, we look into them, with our focal lengths adjusted into the imagined space.

In addition to its intuitive appeal, the front-to-back explanation is motivated in part by the traditional desire in science to separate the observer from the phenomenon. Scientists like to think that what mirrors do should be explainable without reference to what the observer does (e.g., rotating a field of sight). However, questions longer addressing images and appearances, because an image entails an observer and a point of view.

What this question is testing

Author Opinion

Your task

Pin down exactly what the question asks about the passage — a detail, the author's view, the structure, or the main point — before looking at the choices.

Common trap

Answers that restate a true detail from the passage but don't answer the specific question being asked.

Winning move

Anticipate the answer in your own words from the passage, then find the choice that matches that prediction.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
25.

With which one of the following statements would the author of the passage be most

Answer choices

  1. Too Strong2% picked this

    The failure of one recent explanation of what mirrors do illustrates the need for better optical equipment in

    Too Strong: the need Out of Scope: better optical equipment The author never indicates having any issue with the field-of-sight explanation, so the fact that the author thinks the front-to-back explanation fails doesn't mean we need to do anything. We could just believe the explanation that doesn't leave out the observer. We certainly have no grounds for saying the author is agitating for better optical equipment.

  2. Too Strong: generally fail6% picked this

    Explanations of what mirrors do generally fail because physicists overlook the differences between objects and

    We only have one instance (front-to-back) of an explanation of what mirrors do failing. We can't inflate that into, "Yup ... this thing usually happens".

  3. Correct69% picked this

    One explanation of what mirrors do reveals the traditional tendency of physicists to separate a phenomenon to be explained from

    Why this is right

    Yes, this is supported by the first sentence of the final paragraph. (Beginning of 4th paragraph) in addition to intuitive appeal, the front-to-back explanation is motivated in part by the traditional desire in science to separate the observer from the phenomenon.

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

  4. Too Strong: depends on5% picked this

    The degree to which human beings tend to deal directly with mental constructs rather than with primary sense perceptions depends on

    In the 3rd paragraph, the author says "we (all humans) are accustomed to dealing with our mental constructs of objects rather than with the primary sense perceptions". She never qualifies that and say, "That is, unless you've had a lot of training in the sciences, in which case you deal more with primary sense perceptions". She doesn't make any connection between how much science training we've had and how much we deal with mental construct rather than primary sense perception.

  5. Word Salad18% picked this

    Considering objects reflected in mirrors to be mental constructs interferes with an accurate understanding of

    This answer is just taking lots of different words and phrases from the passage and tossing them together. It's hard to find an offending word (other than "interferes"). It's just the overall meaning of the sentence isn't close to anything the author ever said. The passage is never talking about whether or not we have an accurate understanding of how primary perceptions function. That's way too broad, when we are only talking about mirrors. The author is just shooting down an explanation for why the images in mirrors appear reversed. She's never complaining that how we think about mirrors disrupts our ability to have an accurate understanding about how our primary perceptions (sight / sound / taste / smell / touch) function.

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