Question 165·Hard·Central Ideas and Details
In a recent white paper, astronomer Priya Deshmukh critiques the proposal to build a 100-meter ground-based optical telescope. She notes that beyond a mirror diameter of about 40 meters, the cost of each additional meter rises sharply while the increase in effective resolution is blunted by atmospheric turbulence that even state-of-the-art adaptive optics cannot fully correct. Deshmukh argues that allocating a fraction of the projected budget to a smaller, 30-meter telescope—supplemented by a new generation of space-based observatories—would produce a higher net return in image clarity and scientific output.
Which statement about the proposed 100-meter telescope is most strongly supported by Deshmukh’s assessment?
For “most strongly supported” questions, paraphrase the passage’s key claim (here: atmospheric turbulence limits practical resolution gains for very large ground-based telescopes) and then choose the option that restates that claim without adding new causal explanations. Treat extra specifics (what ‘mainly’ drives costs, what technology can ‘fully’ do, or what is ‘essential’) as red flags unless the passage explicitly states them.
Hints
Find the main criticism
Reread the bolded sentence. What two things does Deshmukh say happen when the mirror gets larger than about 40 meters?
Focus on what limits the telescope’s benefits
Why doesn’t the increase in resolution keep up as the mirror gets bigger? What environmental factor is named?
Eliminate choices that add new claims
Cross out any answer that introduces a cause or detail the passage never mentions (for example, what specifically drives the budget, beyond “each additional meter”).
Step-by-step Explanation
Clarify what the question is asking
The question asks which statement about the proposed 100‑meter telescope is most strongly supported by Deshmukh’s assessment.
That means:
- Choose what follows directly from what Deshmukh says.
- Avoid choices that add new causes or claims not in the text.
- Focus on her critique of the 100‑meter design.
Locate Deshmukh’s key criticism
In the bolded portion, Deshmukh makes two linked points about going beyond about 40 meters:
- Cost: the cost of each additional meter rises sharply.
- Benefit: the increase in effective resolution is blunted by atmospheric turbulence that even state‑of‑the‑art adaptive optics cannot fully correct.
So she’s arguing the 100‑meter telescope has diminishing practical resolution returns because the atmosphere limits performance.
Translate the criticism into a testable claim
Restate her idea:
- A much larger ground-based mirror in theory could resolve finer detail.
- But in practice, Earth’s atmosphere prevents the telescope from fully realizing those gains, even with advanced correction.
So the supported claim should emphasize that atmospheric conditions significantly reduce the payoff of going to 100 meters.
Match to the choices
Compare each option to the passage:
- Its potential gains in resolving power are largely undermined by Earth’s atmosphere. This directly matches the statement that resolution gains are blunted by atmospheric turbulence that adaptive optics cannot fully correct.
- Beyond about 40 meters, the telescope becomes expensive mainly because adaptive optics can fully correct atmospheric turbulence only at great cost. The passage does not say adaptive optics can fully correct turbulence, and it does not say the main cost driver is adaptive optics.
- Although expensive, its larger mirror would yield proportionally sharper images than a 30-meter telescope once adaptive optics are applied. This contradicts the idea that resolution gains are blunted even with adaptive optics.
- Most of its projected budget increase would be driven by the need to invent new adaptive-optics systems rather than by enlarging the mirror itself. The passage attributes rising cost to each added meter of mirror; it does not claim the budget is mainly driven by inventing new adaptive optics.
Thus, the best supported statement is: Its potential gains in resolving power are largely undermined by Earth’s atmosphere.