PrepTest 140, Section 3, Question 2
Klein: The fact that the amount of matter(50 more words not shown)
On the basis of their(18 more words not shown)
- AScientists have found(9 more words not shown)
- BEinstein's theory has(3 more words not shown)
- CIt is possible(14 more words not shown)
- DThe failure to(15 more words not shown)
- EScientists are able(14 more words not shown)
Reading the argument
Have we found all the matter, or have we only found all the matter we know how to find?
Klein sees a gap between Einstein's prediction and the amount discovered, then treats that gap as a reason to abandon the theory. But a disappointing search can have more than one explanation. Maybe the prediction is wrong. Maybe the missing matter is somewhere we haven't looked, or our methods aren't detecting it.
Brown takes that second possibility seriously. Because the theory has been successful elsewhere, Brown would keep it and conclude that much of the matter remains undiscovered. Both speakers can accept the amount found so far while disagreeing about what to do with that information.
What we’re looking for
For the disagreement question, I'd predict: should this shortfall lead us to abandon Einstein's theory? Klein says yes; Brown says no. We don't have to turn Brown's defense into proof that every part of the theory is correct. The dispute is over whether this finding gives us reason to give it up.
Working the answers
- A
This is their common starting point. Klein cites the one-tenth figure, and Brown explains the shortfall by suggesting that most of the matter hasn't been found. They disagree about what the figure means for the theory, not about whether scientists have found that amount.
- B
Brown explicitly appeals to the theory's successes. Klein doesn't deny them. A theory could have achieved many successes and still, in Klein's view, deserve to be abandoned because of this new problem. We don't have two opposing positions on B.
- C
Neither speaker tells us whether scientists can determine the total amount of matter without using Einstein's theory. Klein could object to a failed prediction without offering an independent way to measure the entire galaxy. Brown could defend the theory without ruling out such a method.
- DCorrect
This puts the disputed decision directly on the page. Klein thinks failing to find the predicted matter gives good reason to abandon the theory. Brown thinks the better response is to keep the theory and treat the search as incomplete. That gives us a clear yes from Klein and a no from Brown.
- E
Accurately measuring what has been found is different from having found everything. Brown can trust the measurements of discovered matter and still believe there is much more to discover. Nothing here establishes a disagreement about scientists' ability to judge the amount already found.
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