argument47 victors小组第五次作业

ghost33UID: 2267869

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: 636          TIME: 49min          DATE: 2007-5-16

In this argument, the arguer concludes that the cooling in the mid-sixth century was caused by a volcanic eruption. The arguer cites some accounts found in Asia and Europe which mention a dimming of the sun and extremely cold temperatures, but not historical records of that time, to get that either a huge volcanic eruption or a large meteorite colliding with Earth created a large dust cloud throughout Earth's atmosphere which blocked enough sunlight to lower global temperatures significantly. Then he rules out the possibility of a large meteorite collision by stating that there was no records of a sudden bright flash of light which might happen during a collision. This argument seems quite reasonable at first sight; however, closer examination reveals several flaws which makes it not as convincing as it stands.

To begin with, the arguer bases his analysis on some accounts without evidence of their reliability. As the arguer points out that no historical records of that time survive, those accounts found in Asia and Europe only mention some phenomenon which seems have some relation to the mid-sixth century’s global cooling. However, without solid confirmation that the phenomenon described is of the studied weather pattern, there is a good chance that it talks about another thing. And as common sense tells us that not all historical materials are telling the truth because of the recorders’ self-interests and the rulers’ taste, it is quite possible that these accounts are found in some interpretations of a King’s death, the recorder described scenes such as a dim sun and cold days to state that the whole nation grieved on the King’s death which is common in Chinese history. What’s more, the arguer fails to show the quantity of the accounts. Given that there is only one or less account, we’d better leave it alone.

Even if these accounts are reliable, the arguer’s hasty conclusion that the dim sun is due to a large dust cloud blocking the sunlight is not convincing. Admittedly, a huge dust cloud can prevent a lot of sunlight reaching the earth, however, there are some other factors which can cause a dimming of the sun, for example, another planet orbits between the sun and the earth. Without further information, such result is not acceptable.

Given that it was a large dust cloud that weakened the sunlight, the arguer creates a false dilemma by assuming that either a terrible volcanic eruption or a disastrous meteorite collision produced the dust cloud. While this is fairly possible, we cannot exclude other possibilities: a wild cyclone blowing sands in the sky or something like that. If the arguer cannot clarify that no more reasonable factors, his conclusion would better remain dubious.

When trying to get the final conclusion, the arguer uses some dubious evidences which undermine his argument. First, the fact that a sudden bright flash of light would possibly happen during a large meteorite collision does not lend much support to rule out the possibility of a collision. Since the fact leaves some place for a large meteorite collision without a light, no extant historical records of that time mentioning such a flash does not bolster that the dust cloud cannot be the result of a collision. What’s more, no extant surviving records simply imply that the study is not complete, thus it is too early to draw any conclusion. Also, while it is possible that the mentioned loud boom was consistent with a volcanic eruption, it is equally possible that they were independent happening or even didn’t happen at the same time period. Without further analysis and more clues, the arguer’s conclusion seems too rough and hasty.

In conclude, this argument isn’t well studied. The evidences showed are too vague to rely on. To further develop his argument, the arguer needs to find out more reliable materials.