ARGUMENT47 米国有米第六次作业 欢迎修改

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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.
WORDS: 449          TIME: 0:43:00          DATE: 2006-12-22

According to this argument, a volcanic eruption is conjectured to take place in the mid-six century bases on the following evidence: (1) the earth suddenly became cooler at that time; (2) there were records about a dimming of the sun and extremely cold temperatures; (3) a loud boom that would be consistent with a volcanic eruption was mentioned in Asian historical material. Along with these evidence, the arguer provides a deduction to lead to the volcanic eruption. However, links between these evidence are associated with logical flaws and hence invalid.

To begin with, no sound evidence suggests that the dimming of the sun and the extremely cold temperatures are causally associative. The subsequent argument relies on the assumed causal effect of a large dust cloud throughout Earth's atmosphere that would have been capable block enough sunlight to lower global temperatures. However, no scientific evidence and theories are provided to illustrate that these two incidence are internal linked. It is still possible that these two incidences, dimming sun and cooler temperatures, are merely concurrent occasionally. Or, in contrast to what suggested by the arguer, dimming sun may have been caused by the cooler temperatures by some propagation mechanism.

In addition, even if we accept that the dimming of the sun induced the global cooler temperatures, it is still insufficient to the state that the source of the dimming sun was either huge volcanic eruption or a large meteorite. Firstly, dimming sun must not be the consequence of the huge blocking cloud. It is contingent that the dimming sun is due to the activity of the sun itself. No solid evidence show that the sun or factors influencing how sunlight traveled to the Earth rather than dust cloud had been constant. Moreover, one can not rule out the possibility that incidence rather than huge volcanic eruption or large meteorite collision caused that dimming sun. For example, maybe it is the multiple significant volcanic eruptions happen concurrently in that period make the air contain more dust so that less sunlight were absorbed to keep the globe warm.

Finally, even if we concede all argument except the last point about the loud boom, we still are not able to accept the source as volcanic eruption. It was stated that a loud boom probably consistent with a volcanic eruption was recorded in Asian account. However, anything between the loud boom and a volcanic eruption was missed. Such a loud boom can be resulted from the meteorite collision. Or such a loud boom can a result of volcanic eruption, however, it was no more than a regular one that impotent to have a global impact.

In sum, the evidence and deduction are far from conclusive. To have a better theory of such temperature fluctuation, the defects mentioned above are, at least, fixed and more reliable evidence are required to consolidate the conjectured source.

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不好意思~~居然忘记改这一篇了~~~实在不好意思
粗略的看了下,整个条例还不错~写的很好,,,,,看来大家阿狗都修炼得不错了哦