argument47 微观状态小组第六次作业 诚恳排砖

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TOPIC: ARGUMENT47 - Scientists 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.


Before concluding that a volcanic eruption possibly gave rise to the cooling of the Earth, a complete examination to the evidence afforded by the author is needed. The author seem to have assumed that the dimming of the sun that is caused by a large meteorite colliding or a huge volcanic eruption is the only reason for the cooling without considering other some factors which may have impaired the credibility of the assertion.

First of all, the author rests on the assumption that the large dust cloud created by a large meteorite colliding or a huge volcanic eruption caused the dimming of the sun and in turn make the earth cool; however, no evidence was provided to substantiate the hypothesis. In fact, some other possibilities have been overlooked by the author. For instance, it is fully likely that the respectively recorded time about a dimming of the sun and the cooling is not at the same ages, that is, perhaps the occurrence of the former preceded the latter. Further, it is possible that there occurred a solar eclipse causing the dimming of the sun, whereas the cataclysm of climate caused by a huge earthquake led to the cooling after 50 years. Consequently, unless considering these cases, the fact that only a large meteorite colliding or a huge volcanic eruption can the cooling of the earth is not convincing.

Even assuming that a huge volcanic eruption and a large meteorite colliding is the mere reason for the cooling, to claim that a large meteorite collision did not occur only because there is no extant historical records of a flash produced by collision is open to doubt. As is known to all, no extant historical records does not mean that the ancient people did not see it. In fact, it is fully likely that the ancient people did not observe the sudden bright flash of light because it occurred in day, especially considering the inferior observing instrument of them. In addition, it is also quite possible that the records regarding the bright flash of light has been destructed or still bury deeply in a secret area that no one finds. Without taking these possibilities into consideration, it is too rashly to deny the occurrence of a large meteorite collision.

Finally, even if we concede that a large meteorite collision did not indeed occur, the author fails to assume that the loud boom mentioned by some surviving historical records of the time is attributable to an volcanic eruption. As a common sense, there are a myriad of variables that can lead to a loud boom, such as a huge hurricane, a big earthquake, and so forth. Further, perhaps a huge hurricane brought great amounts of dust into air and shaped the similar dust clouds as those caused by a huge volcanic eruption in that time; at the same time it created the collapse of hill which produced a loud boom. Thus, the author should further investigate the reason for the loud boom in that time; otherwise, it is hard to convince us his or her conclusion.

From what has been discussed above, we may safely arrive at the conclusion that unless the author can preclude other possibility that lead to the cooling of the earth, his or her conclusion will be futile.