The simple geocentric model cannot explain the retrograde motion of the planets . around 140 a . d . , 由于早期的地心说解释不了行星逆行的现象，所以在公元140年，
2.
2nd century ad ) proposed a geocentric system of astronomy that was undisputed until copernicus （公元2世纪）在哥白尼之前提出了无人怀疑的地心说的古希腊天文学家。
3.
Proposed his refined geocentric model . he proposed many refinements . we only talk about the simplest one 提出他的改良版地心说他提出了不少修订，但我们只会简述他的学说。
4.
This was generally accepted and the ptolemaic model dominated the western world for about 1500 years 当时的人对此已心满意足，结果托密勒地心说主宰了西方世界约一千五百年。
5.
However the prediction of this model is about as good as the ptolemaic , the copernican model was not commonly accepted at that time 可惜的是，日心说预测天体运动的准确性和地心说只是不相伯仲，并未为当时的人普遍接受。
