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47Scientists studying historical weather patterns have discovered that in the mid-sixth century, Earth suddenly became significantly cooler. Although few
historical records survive from that time, some accounts found both in Asia and Europe mention a dimming of the sun and extremely cold temperatures. Either a
huge volcanic eruption or a large meteorite colliding with Earth could have created a large dust cloud throughout Earth's atmosphere that would have been
capable of blocking enough sunlight to lower global temperatures significantly. A large meteorite collision, however, would probably create a sudden bright
flash of light, and no extant historical records of the time mention such a flash. Some surviving Asian historical records of the time, however, mention a
loud boom that would be consistent with a volcanic eruption. Therefore, the cooling was probably caused by a volcanic eruption.
提纲:
1. 仅欧亚两洲的少量记录难以说明全球突然变冷:有可能那些地区气温本来就很低;这些记录有可能只是局部地区的个别现象,而欧亚两洲其它大部分地区,以及其它各洲气温正
常。
2. 没发现闪光纪录不等于没有发生闪光:有可能发生在人迹罕至的郊外而未被观测到;有可能有记录但遗失或未被发现。
3. 巨大的隆隆声并非一定由火山爆发引起:有可能是其它自然现象引起,比如雷电,洪水。
This article concludes that Earth suddenly became significantly cooler in the mid-sixth century which was probably caused by a volcanic eruption. To
justify this conclusion the article's author cites that some accounts found both in Asia and Europe mention a dimming of the sun and cold temperatures. The
author also notes either a huge volcanic eruption or a large meteorite colliding with Earth would be responsible for such low temperatures. Moreover, no
extant historical records of the time mention a sudden bright flash of light which was created by a large meteorite collision, but a loud boom that would be
consistent with a volcanic eruption was mentioned in some surviving Asian records of the time. Careful examination of this supporting evidence, however,
reveals that it lends little credible support to the applicant's claim.
To begin with, only some accounts from both Asia and Europe are not enough to reach such a conclusion that Earth suddenly became significantly cooler.
Perhaps the areas related with such accounts always had extremely cold temperatures in the past. Perhaps the majority of land in Asia and Europe which were
not mentioned by those accounts had normal temperatures in the mid-sixth century. For that matter, perhaps all other continents hold comparatively stable
temperatures so that the average temperature in Earth changed little in that time. In short, without providing sufficient proofs for the sudden fall in
temperature the article's author cannot make any sound conclusions on the basis of that drop.
What's more, no extant historical records mentioning a sudden bright flash of light created by a large meteorite collision do not necessarily indicate that
such collision did not exist in that time. Perhaps the flash happened in a field far from city and village and was not observed by any one. Or perhaps there
were surely some records about such flash but they have not been discovered or have already been lost. If so, the fact would further undermine the author's
assumption that no large meteorite occurred in those cold days.
Finally, the recorded loud boom consistent with a volcanic eruption in Asian cannot prove a real volcanic eruption. It is entirely possible that such loud
boom arose from a great storm with thunder and lighting, or a large flood, or other nature disasters. At a word, without ruling out other possible reasons
for the loud boom, the volcanic eruption is unacceptable.
In sum, the conclusion relies on certain doubtful assumptions that render it unconvincing as it stands. To bolster the conclusion, the author must provide
more historical records to make sure that cold temperatures spread all over the world in mid-sixth century, and to attest that the volcanic eruption did
happen and created a large dust throughout Earth's atmosphere which blocked enough sunlight to lower global temperatures significantly. |
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