Samples from the floor of a rock shelter in Pennsylvania were dated by analyzing the carbon they contained. The dates...
HannahNgMarch 10, 2020
More explanation pls
Hello. I chose the correct answer after ruling out B to E. I still wanna know exactly why A is correct so I read all the explanations. Unluckily, I found all of them confusing.
Answer A simply states that Contamination is likely affecting the uppermost sample before the deeper one. I still don't understand how could you figure out the sample in the passage was not contaminated. Maybe my vocab about this topic is weak.
Can sb pls re-explain in simple vocabulary, two arguments in the passage, and why A weakens the skeptics' argument.
Thank you so much!!!
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Thanks for the question! Let’s walk through the argument first. The stimulus is telling us about carbon dating of rock shelters that humans used. The test results show that the oldest sample was 19,650 years ago. But the skeptics think that that date is too early, and say that the samples could have been messed up because of “old carbon†from outside sources (percolating groundwater from nearby coal deposits).
Now we need something that will weaken the skeptics’ arguments. (A) tells us that the groundwater wouldn’t have messed up the deeper samples without messing up the earlier sample. If this were true, all of the samples would have been messed up, which they weren’t. So (A) weakens the skeptics’ arguments, and it is the correct answer.
Hope this helps! Feel free to ask any other questions that you might have.
ShirnelMay 10, 2020
Where does it state the samples weren't messed up?
AlejandroJune 9, 2024
I have a similar problem with this question. I ruled out A because the stimulus tells us the skeptics said the *samples* (plural) were contaminated. I don't know how to read the description of their skepticism without assuming they are skeptical of all of the samples rather than just the one deeper sample. This one only seemed difficult because it had "samples" plural.
Emil-KunkinJune 12, 2024
As to the point about samples, the nearest antecedent use of that word is specifically referring to the oldest and deepest samples- and since we are told that the skeptics are only questioning the oldest dates, I think we can safely assume that the samples they are talking about are those oldest and deepest ones mentioned in the previous sentence.
However as to the bigger point I mostly agree with you. We are never actually told the skeptics accept the other dating, only that they question the oldest dating. That said I think there is still a strong argument as to how it weakens: A would mean that the skeptics would have to commit themselves to a view that all the samples are likely questionable at best. However, this position is much more extreme than the one they actually took. It does cast some doubt on a position if you can show that it commits the author to an even more extreme position. It certainly doesn't kill the argument, but it does make me less likely to accept it, and that's what a weakener should be. Furthermore the fact that they only attacked the oldest date does give us some hint that they are not likely to actually contest the more recent date.
