ARGUMENT 50

错失湛蓝UID: 2585937

50From 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."


The arguer asserts that water in Earth’s oceans must have come from comet. To maintain this viewpoint the author proposes that comets are ice made up of frozen water; after the striking Earth,
the retained water is left and finally falls as rain.I concede that the theory seems resonable to some extent, but further consideration reveals that the argument rests on a serious of unsubstantiated assumptions and is unbelivable as it stands.


First and foremost, no exact evidences were presentated to verify that after the collision the gravitation of the planet is strong enough to hold the gases and water vapor and the following activities would happen in the sentences. Since the origination of the Earth and the collision are always the screte that people in search for many years. So far, the assorted theories like this viewpoint exist in school realm, however many of them like this theroy could not supply enough lab staff and the details of the experiments. Even the information was acquired ,which could not assure us of the similar phenomena have ever took place in our planets for the authentic condition is hard to imitate and numerous aspects are could not to think about.

Futhermore, even some part of the water in ocean originate from the commet are logical and convincing, however, it is well know that the quantity of the water in the ocean is titanic and hard to evaluate, so large amount of water is just form commet? Are there any other possibilities lie in? What if any other measurements that we don’t know nowadys produce so large water on the Earth,or the two ways produce water in common.In short, we could not ruling out these possibilities.
In addition, the text do not talk about the profund influences that the plants,animals, climate bring to the earth,because our earth is a combination of all lives, the chains between the circunstance and the lifes have always existed,which lead to the drastic changeS to the earth.
To sum up, since some possibilities and problems lie in the text, thus the argument is unreasonble and logically weak. To strengthen the point, the author should provide details of the relevant experiments ,and the basement of the theory.

ZeaLoTddjUID: 2717909

请问In addition那一段是在说什么啊？没看懂