中国古代天地结构理论的重大缺欠

中国古代关于天地结构的理论，在一定程度上反映了天地结构的客观状况，但在以下四个方面存在重大缺欠：（１）地半径与天半径（指太阳与地的距离）之比过大；（２）地依赖水的承托而不坠落；（３）地平的观念：（４）单层天壳论和不健全的多重天说。该文论述了在解释日食、月食、月受日光而发光等天文现象时，这些重大缺欠所造成的难以克服的理论困难，以及中国古代天文学家如何修订这些重大缺欠，不断缩小地半径与天半径之比，改地在水中为地在气中，从地平到地圆的转换与疑虑，多重天说的探索等等艰难的过程，以期表明科学的理论思维的重要性。

VITAL DEFECTS IN ANCIENT CHINESE THEORY ABOUTTHE STRUCTURE OF HEAVEN AND EARTH

Though reflecting to some extent the objective situation of the structure of heaven and earth , ancient China's theory about the structure of heaven and earth con- tains four vital defects as follows , 1. The ratio of radius of the earth to the heaven (i. e. the distance between the earth and the sun ) is too great ; 2. The reason for the earth's not sinking is ascribed to its being held by water , 3. The idea of a flat. earth ; 4. The theo- ry of one-spherical heaven and imperfect theory of multi-spherical heaven. This paper deals with the insurmountable theoretical difficulty caused by these vital defects in ex- plaining solar and lunar eclipses , and the moon's receiving light from the sun and giving out light , and also treats the difficult process of ancient Chinese astronomers, revising the vital defects , reducing the ratio of the radius of the earth to that of the heaven , changing the idea of the earth's floating above water to its being in the air , transforming from a flat earth to a global one and the suspicion about it , the researching on multi- spherical heaven , etc. , so as to show the importance of scientific theoretical thinking.