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#24 - The supernova event of 1987 is interesting in that the

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Complete Question Explanation

Strengthen. The correct answer choice is (B)

Current theory regarding supernovas states that when there is a supernova event the size of the one that occurred in 1987, a neutron star should have remained afterward. Yet there is still no evidence of any such neutron star or of the pulse of radiation normally associated with such an event, in spite of searches conducted using some of the most sensitive instruments ever developed. The writer then concludes that current theory is wrong with regard to the assertion that supernovas of a certain size always produce neutron stars.

This stimulus presents the following conditional relationships: If there is a supernova, there is a neutron star, and if there is a neutron star, there is generally a pulse of radiation:

    Supernova ..... :arrow: ..... neutron star ..... :arrow: ..... pulse of radiation

We are asked which of the answer choices most strengthens the argument, the conclusion of which is that current theory is wrong with regard to supernovas and neutron stars.

Answer choice (A): This answer choice lends support to current theory, which would actually weaken the author’s conclusion that current theory must be wrong.

Answer choice (B): This is the correct answer choice. If these instruments have detected neutron stars at a greater distance than the 1987 supernova, this would strengthen the case that these instruments would detect a neutron star that resulted from the 1987 supernova, if such a star existed. This lends support to the author’s assertion that current theory must be wrong.

Answer choice (C): This statement neither strengthens nor weakens the writer’s conclusion that the current theory is wrong.

Answer choice (D): Since this answer choice lends credibility to current theory, this weakens the writer’s conclusion that current theory must be wrong.

Answer choice (E): None of this explains the absence of the neutron star in this instance. This information is irrelevant to the writer’s argument regarding current theory. Because it certainly does not strengthen the author’s conclusion, this answer choice should be eliminated.
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Can you please explain why B is a better AC than D? Based on the passage, I was skeptical as to whether or not a supernova actually occurred. Given that doubt, D appeared to be the best choice because it can eliminate that doubt.


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Hi Angela,

Thanks for your question.

The general rule is that you accept the premises of an argument on the face as "facts", and what can be critiqued, strengthened or weakened, is the reasoning that links those premises to the conclusion. The first premise describes "The supernova event of 1987", with no modifiers that would indicate that there is a question about its existence. The conclusion is that the theory, which claims that all supernovas produce neutron stars, is wrong.

What's in question here is therefore not whether there was a supernova, but whether the evidence given is enough to conclude that the theory is wrong. The possible flaw in the argument is that we do not know for certain that the technologies used are adequate for detecting a neutron star. That is, maybe there is one that the scientists studying the supernova did not find. Answer choice B helps to at least partially fix that flaw (i.e. to strengthen the argument), by establishing that the equipment is sensitive enough to detect a neutron star within the range of the supernova event in question. D is not a helpful answer, because it does not address that flaw and therefore does not strengthen the conclusion that the theory is wrong in claiming that supernovas always generate neutron stars.

Hope this helps!

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I have a question with answer choice (A). If most supernova remnants that have been detected have a neutron star nearby, but astronomers have not yet detected a neutron star in the event of 1987, doesn't that strengthen the argument that the theory is indeed wrong to claim that supernovas always produce neutron stars?

Is this thought process faulty because a lack of evidence does not necessarily mean it is false? Thus, even if most supernova remnants that astronomers detected have a neutron star, this has no effect on whether or not the 1987 event produced a neutron star. Thanks.
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Hi rpark,

The prevailing theory is that supernovas :arrow: neutron stars.

The author is arguing against the prevailing theory by pointing out that the 1987 supernova did not produce a neutron star. We are then asked to support the author's argument that the prevailing theory is wrong.

Answer choice (A) actually supports the prevailing theory, since it states that most supernova traces detected by astronomers have been accompanied by neutron stars in the vicinity. Essentially, the more times that supernovas :arrow: neutron stars, the more likely the prevailing theory is to be true. This is an incorrect answer since we are trying to find support for the author's argument that the prevailing is wrong.

By contrast, answer choice (B) tells us that the instruments astronomers currently use have been able to detect neutron stars further away than the site of the 1987 supernova event. In other words, the technology we have is capable of detecting a neutron star in this particular area, but has failed to do so. This attacks the causal reasoning of the prevailing theory (that supernovas produce neutron stars) by showing the cause (supernova event of 1987) but no effect (neutron star).

Answer choice (B) also strengthens author's argument by eliminating a possible line of attack (that the neutron star exists, but that we haven't been able to detect it with current instruments).

Hope this helps!

Athena Dalton
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Hi. According to the Q.Stimulus, is Supernova, a Necessary cause for the Neutron Stars and Pulse of Radiation and
Is neutron stars a necessary Cause for Pulse of Radiation conditions?
Adam Tyson
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Let's not mix up our jargon, lathlee! Avoid thinking about "necessary causes", because that is mixing up conditional reasoning (sufficient and necessary conditions) with causal reasoning. This argument is causal, not conditional, so just focus on the cause and effect claims. Leave words like "necessary" out of your analysis completely, lest you end up confusing yourself.

More specifically in this case, this argument is anti-causal, in that the author is arguing that supernovas do NOT cause neutron stars. His evidence for this anti-causal argument is that we have looked for signs of the neutron star (the purported effect) at the site of a supernova (the alleged cause) and have not found one. In other words, he is saying "we haven't found the effect, even though the cause definitely happened, therefore it isn't always a cause."
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