第十三次作业： Argument 47

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第13次作业： Argument 47

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 n 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：
A．
There are no extant historical records of the time mentioned flash does not mean that meteorite collision never happed at that time.
B．
Although there are some surviving Asian historical records of the time mention a loud boom, we can not deduce that it must be consistent with volcanic eruption.
C．
Suppose that there were volcanic eruption, the arguer still doesn’t give enough evidence to prove these eruptions are huge enough to produce much dust which can blocking enough sunlight to lower global temperatures.

正文字数：433

正文：
In the above argument, the arguer makes a conclusion that in mid-six century the earth became cooler because of volcanic eruption. But it is nothing to do with meteoric collision. To suppose his/her conclusion, the arguer quote that there are no extant records about meteorite collision at that time. Moreover, there are some recorders surviving Asian historical about a loud boom which would be consistent with a volcanic eruption. However, if we carefully examine this argument, we can find that the reasons of the arguer are too weak to convince others.

In the first place, the arguer says that there is few historical records survive from mid-six century. And if the large dust cloud throughout Earth’s atmosphere dues to meteoric collision, it probably create a sudden a flash. However, the arguer says that there is no extent records mention about this kind of flash. The question is the surviving records is few, if the records about this flash disappeared, how can the arguer say that there is no meteoric collision at that time? As we know, in mid-six century, the way of human being recording is limited. Most of the records may at that time be written down on paper, bamboo slip or even silk in Asian. These materials are hard to keep for long time. So the arguer fails to convince us that there is no large meteorite collision ever occurred in the mid-six century.

Furthermore, the arguer can not prove that the records about a loud boom equals to huge volcanic eruption for sure. As we know, loud boom can occurred in many situations such as earthquake, volcanic eruption or even meteorite collision. If the loud boom dues to earthquake, it is no possibility to create a huge dust cold which can block the sunlight and cook the temperature. So the hypothesis about a volcanic eruption cause the cooling in mid-six century is still needed to prove.

Suppose that the loud boom is consistent with a volcanic eruption indeed. How does the arguer know, the volcanic eruption is huge enough to create a large dust cloud? According to the statistic survey, the times of volcanic eruptions which happen on the earth are about on average 50. It means that the volcanic eruption on the earth is common. The arguer can not provide enough evidence to prove that the volcanic eruption whether is serious enough to bring such huge influence.

In sum, the reason supporting the conclusion is too weak to convince others. If the arguer wants to prove that the cooling events caused by volcanic eruption, he/she should collect more evidences.