PrepTest 147, Section 1, Question 4
If a civilization as technologically advanced as human(55 more words not shown)
Which one of the following(7 more words not shown)
- AScientists who are(18 more words not shown)
- BThere is no(20 more words not shown)
- CIf scientists received(18 more words not shown)
- DA technologically advanced(16 more words not shown)
- EIntelligent life forms(15 more words not shown)
Reading the argument
They could contact us. That doesn't mean they'd want to. Suppose an advanced civilization is nearby and has noticed us. We can grant the argument's claim that it could easily make contact. It might still have no interest in doing so. Maybe its members think there's nothing worth talking to us about. Their silence wouldn't show that they don't exist.
What we’re looking for
The argument nevertheless rules out finding such a civilization within fifty light years. It seems to rely on our not having heard from one, but that only helps if these civilizations would actually want to communicate. Since we're looking for a required assumption, I'd look for an answer that closes off the possibility that they're out there and simply don't care to talk to us.
Working the answers
- A
Where scientists generally focus their searches doesn't determine whether an advanced civilization exists nearby. They could focus on technologically simple life and still make this particular argument about advanced life. The missing step concerns what a nearby civilization would do, not what scientists usually look for.
- B
The conclusion is limited to civilizations within fifty light years. Whether scientists have reasons to doubt the existence of civilizations farther away doesn't help rule out the nearby ones. The argument could be right or wrong about its fifty-light-year limit regardless of what exists beyond it.
- C
Fully understanding a message is more than the argument needs. We could recognize that a message came from intelligent life without being able to translate every part of it. In any case, our ability to interpret a message doesn't address why an advanced civilization would choose to send one.
- DCorrect
This addresses the willingness to communicate. If these civilizations didn't want to contact the intelligent life they detected here, their ability to contact us would not be a reason to rule out their existence. They could be nearby, know we're here, and stay silent. The argument needs to exclude that possibility before using the lack of contact against their existence.
- E
They don't have to recognize every sign of intelligent life. Recognizing some evidence could be enough to notice us, even if other signs went undetected. The first sentence already grants that a sufficiently advanced nearby civilization would find evidence of life here. Requiring it to recognize all such signs adds a much stronger condition without addressing whether it wants to communicate.
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