论文部分内容阅读
对於研究地球——我们生活在其上面的行星——构造的学者们来说。能够直接研究到的仅仅是地球的极薄的表面层。这一层仅祇含有地球全部物质的百分之一还不到。关於地球的内部构造,只得根据间接的标志求判断——根据内部密度的估计,根据地震波的传播性质和传播速度等等。这时候对於研究家偿显示重大帮助的是关于别的和地球相近的太阳系里天体的知识——例如行星、陨星和彗星。
For scholars who study the Earth, the planet we live in. What can be directly studied is only the extremely thin surface layer of the earth. This layer contains only less than 1% of all the earth’s substances. Regarding the internal structure of the Earth, it is only necessary to make judgments based on indirect signs—according to the estimation of the internal density, the nature of the propagation of the seismic wave, the speed of propagation, and so on. At this time, the major help for the researcher’s compensation is the knowledge of other celestial bodies in the solar system that are similar to Earth—such as planets, comets, and comets.