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Argument47 From 荧惑

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.


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In this argument, the author claims that the significantly cooling in the mid-sixth century was likely caused by a volcanic eruption. To support the argument, the arguer cited that the ancient record to disprove that a meteorite collision may result in the temperature.The argument appeals to be somehow appealing, but a close examination will reveal how groundless it is.

First, the historical records in Asian can not competely bolster that assumption that volcanic eruption may happen in mid-sixth century. A loud boom can be consistent with many natural disasters. For example, an earth quake, a landslide, even a large meteorite collision may cause a large noise as well. The author rudely ignores others alternative events. Besides, the place where unearth these records have no volcanic around it. In this case, the sound was highly possibly caused by a large meteorite, rather than a volcanic eruption. So the records take no effect on support the conclusion.

Second, there no evidence to prove that the cooling happened in mid-sixth century is due to the dimming of the sun at that time. There are many factors may result in extremely cold temperatures. For example, weather diasters as anti-ELNINO, which may also cause the gobel temperature lower than average, are alternative reasons to explain the extremely old temperatures. Obviously, the dimming of the sun was just a coincident phenomena happened with the cooling. Or, the dust in that time may be so tremendous as to dim the sunlight, and not effect on the temperature. In both of these cases, the dimming of sun is not a main factor to the extremely cold temperature.

Third, the argument turns on the assumption that the cooling was not caused by a meteorite collision because there no records of the time mention a light consistent with the collision. However, the collision may happen, but the eyewitness fails to record it or even all the eyewitness died by the collision. In another case, the record mentioned the collision may be damaged during a war in the past time. For all these reason, the fact, no extant historical records of that time mention the sudden bright flash of light, do not indicate there was no collision in this time. The author fails to consider such possibility.

Finally, even if both of two assumptions above can be proved, the author assumes that volcanic eruption and meteorite collision are mutually exclusive alternatives. However, the author is presenting a false dilemma by imposing an either-or choice between the two events. For example, the sun itself actived in a low level in these years and provided much less energy than usual, which lead to a dimming of the sun, and an extremely old temperature as well. But unfortunately, the author provides no evidence to conclude other alternative chooses.

In sum, the author fails to validate the conclusion that the cooling in mid-sixth century was caused by a volcanic eruption. To make the argument more convincing, the arguer should prove that there were no other alternative possibilities which may result in such disaster. Further, I would like to have a strong evidence to support a volcanic eruption real happened that time.


[ 本帖最后由 荧惑 于 2007-3-16 10:49 编辑 ]