argument50 欢迎拍砖

freepoohUID: 2365587

TOPIC: ARGUMENT50 - 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."
提纲：1.地球达到它目前的形状时，会有彗星撞击。这一点没有证据能够解释，而且彗星中含有ice 的数量也不一定足够。
2．作者开始提到宇宙空间中的撞击会导致气体蒸发，而后又提到过，彗星撞击地球气体则会留在地球中，论据不充分。
3.不一定是由彗星中的水构成海洋，还可能有其他原因，诸如化学反应。

In this manuscript, the author recommends that the water in Earth's oceans must have originated from comets. The author explains that a comet striking the Earth would have vaporized due to the large amount of ice in the comets. And when the Earth reached to its current size, the gases and water vapor were kept inside the Earth. Moreover, the author also informs us the information of the earth origination that it was formed out of the collision of space rocks and produced heat. The argument might be convincing at the first glance. However, careful scrutiny of it would reveal how ridiculous it is.
The threshold problem with this argument is the author's false assumption that there surely would be a comet striking Earth when Earth reached its current size. However, the author provides no such evidence to demonstrate this point. It is possible that when the Earth reached its current size, unfortunately, no such a comet stroke the Earth. No scientists could explain precisely what really happened to the Earth thousands of years ago. What we all know is the description with both scientific researches and imagination.
Even if the comet stroke the Earth at the time the Earth reached its current size, the author's assertion that the comet would bring about gases and water vapor to the Earth is founded on unwarranted assumption. Admittedly, the technologies are developing at a high speed and we could search the space more than before. However, we could not get enough information about the substances in the comets which are probably different from each other. Even if we confirm the ice is an essential substance in the comets, could we be sure that the ice is sufficient enough to form the atmosphere and oceans?  The answer probably is no.
Secondly, a paradoxical flaw confuses me in this argument. On one hand, the author argues that any water present would have evaporated and gone off into the space during the collisions. On the other hand, when it comes to the collision between the Earth and comets, the author indicates that the gases and water vapor would form the atmosphere and the oceans due to the gravitation. However, the author does not provide more information to further explain this weak point.
Thirdly, the author assumes that the collision of the Earth and comets is the only cause other than other possibilities contributed to the origination of the Earth's oceans. It is possible that many chemical changes resulted in a larger amount water after the collision. However, without ruling this or other possible reasons, the author could not demonstrate the conclusion that the water in Earth's oceans was only from the collision between the Earth and comets.
To sum up, the author fails to convince me his conclusion that the water in Earth's oceans must have been originated from comets. To better evaluate the recommendation, the author should provide more information about the origination of the earth. I would also need to know the statistical information about the substances in comets. Moreover, the author is better to exclude the paradoxical point I have mentioned above.

lucialuckyUID: 2347401

如果是限时间写的就很牛哦