0510G同主题写作第四期－－Argument50 彗星撞地球
【50】 From a draft textbook manuscript submitted to a publisher.
"As Earth was being formed out of the collision of space rocks, the heat from those collisions and from the increasing gravitational energy of the planet made the entire planet molten, even the surface. Any water present would have evaporated and gone off into space. As the planet approached its current size, however, its gravitation became strong enough to hold gases and water vapor around it as an atmosphere. Because comets are largely ice made up of frozen water and gases, a comet striking Earth then would have vaporized. The resulting water vapor would have been retained in the atmosphere, eventually falling as rain on the cooled and solidified surface of Earth. Therefore, the water in Earth's oceans must have originated from comets."
当地球在太空岩石的撞击作用下形成的时候，撞击产生的热量和行星越来越大的重力能量使整个行星融化，甚至包括表面。当时存在的任何水分都会蒸发并消失在太空。然而，当行星接近现在的大小的时候，它的重力强到了足以保持其周围的气体和水蒸气来形成大气层。由于彗星主要是由冻结的水和气体组成的冰，撞击地球的彗星将会蒸发。产生的水蒸气将被留在大气层，最终以降雨的形式落在地球已冷却而且坚硬的表面。因此，地球海洋的水分一定是来自彗星。
可攻击点:
(1) 彗星的组成: 没有提供证据说明它与海洋里的水的组成一致
(2) 文章”Because comets are largely ice made up of frozen water and gases, a comet striking Earth then would have vaporized.” 没有因果关系。仅仅因为由冰组成的就说它能蒸发吗？不对，忽视了一些其他条件：比如需要温度（光照） 以及撞击时产生的热量足够大使它融化。
(3) 水蒸气一定会留在大气层吗？文章没有排除其他可能比如大气层已饱和（不太实际） 或者撞击产生的气流力量远远超过地球的引力而把水蒸气卷走了。
(4) 最终以降雨形式一定落在地球表面时，地球的表面一定是已冷却而且坚硬的吗？ 水蒸气变成雨滴既凝结的时候要放热，因此温度降得可能比地表更快，因此当它变成雨滴落下来的时候，地表可能还没有完全冷却。
(5) 最后，地球海洋的水分不一定是全来自于彗星。其他情况比如：许多矿石含有结晶水或高温分解会产生水，既发生在地球物质的化学作用所制造出来。作者: tangjihede 时间: 2005-7-15 21:09:43
The argument seems to come from a science magazine, the author demonstrates that at the beginning of earth formed , the collisions and the increasing gravitational energy made many heat thus leading to the molting of the entire planet. Then the arguer conclude that as the reason of heat the water will not present at the some form we saw today , rather , they evaporated and went into space. Another process the author describe is that component of comets are largely ice forming as water and gases, when the comets collide with the earth, the water from it retained in the atmosphere ,eventually becomes the oceans .consequently , the author then try to convince us that the originating of water on the earth might be the comets.
At first glance , the assumptions sound reasonable , but when profound thinking , we may find the argument suffers from many mistakes.
At first , the conclusion that the Earth's water at the stage of collision has all become evaporation opens to doubt. firstly , the evidence built on at the beginning stage the earth formed, its heat leads to the water all become evaporation and went off into space is groundless , imaging the situation the author said , there will be a definite conclusion , for the size of the earth from the beginning to the current size spans a period of time , in this time the water of the earth may all become evaporation ,and without the gravitation to haul it around the earth , it will gone off into space , never come back . In this case ,there will not be an atmosphere around the earth. Conversely, at this period the evaporation cools, falling down to the earth . A more convincing assumption may be built on the research on if all the water become the evaporation , or there are some left , how many would it be.
Another fallacy the author built is to oversimplify the conclusion that the water in Earth's oceans must have been originated form comets. From the first fallacy , we may conclude there may be some water left on the earth after the collision ,moreover , the formation of earth have experience a large number of time, during this period , the water from the cosmos may come back to the earth at any chance , in addition , even the after the collision between the earth and the comets, the ice and water from the comets become the evaporation around the earth , at last , falling as rains .No one can definitely confirms that the evaporation falling on the earth is really from the cosmos or from the earth former atmosphere.
In conclusion , the argument suffer from two distinguish fallacy to eventually conclude the origination of the rain if from the cosmos and the false assumption that the originate water on the earth all become evaporation , to strength the idea of the author , there need more convincing researches and evidences.作者: clayman 时间: 2005-7-16 23:28:04
又是最后一个交作业的： https://bbs.gter.net/viewthre ... type%26typeid%3D103
提纲：
1.撞击的时候不一定能vaporize.
2.即使能vaporize也不一定能restrain.
3.即使能restrain也不一定能fall as rain.
4.不排除有地球内部起源的可能性，如chemical reaction.作者: peacock 时间: 2005-7-20 07:53:15 标题: perhaps, I am the last one......