Argument47

47Scientists 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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The article cites some surviving Asian historical records that a loud boom appeared in the middle six century, From these records, the author concludes that it was a volcanic eruption that caused the sudden cooling of the earth. In addition, just because on extant historical records of the time mention a flash, the author ruled out another important explanation for the cooling, that is, the meterorite colliding. This argument is flawed in several critical respects.The argument unfairly claims that the cooling of the earth is the result of a dimming of the sun, rather than some other phenomenon, such as the changes of the speed of the ocean circulation, the transformation of the distant between the sun and the earth. Together with the plain fact that only in Asia and Europe some accounts mention a dimming of the sun, the above two reasons were more likely to happen. In short, without exclude all other possible explanations for the cooling of the earth, the author can't convince me that it was by a dimming of the sun, earth suddenly became significantly cooler.Even if the cooling the earth did be led to by a dimming of the sun, the author made a mistake by setting up a cause-and-effect relationship between no record of the flash and no collision. It's highly possible that there was a flash by meterorite at that time, yet no one noticed such a phenomenon, because this meterorite hit the earth at a place where is far away from any urban or rural area at that time. Or maybe there were many people noticed the collision, but no one tried to record it, or there was such a record, yet it disappeared, or there was some records about this collision, another phenomenon accompanied by the collision rather than flash was recorded.Finally, even there wasn't any meteorite colliding with earth at all, and a loud boom actually happened in antient Asia at the time, there still existed a possibity that the boom is caused by other reason, such as earthquake, hillside creep, rather than volcanic eruption. The author's failure to investigate or even take into account other possible reasons for the boom renders the conclusion based upon it highly suspect.In sum, the conclution reached in this argument is invalid and misleading. To make it logically acceptable, the arguer would have to substantiate that a dimming of the sun was sure to be the only reason that caused the cooling of the earth, and that no meterorite happened anywhere in the earth at that time. Moreover, I would suspend my judgement about the credibility of this argument until the author can provide more informatian about that boom, and use more scientific results and archeologichal data to make the appearance of the volcanic eruption firmer.