"行星视运动"的教法初探

以哥白尼的日心说为理论基础把太阳置于宇宙中心，地内行星、地球和地外行星以椭圆轨道自西向东绕日运转，把天球套合在其外围，按行星和地球运动速度差异确定行星和地球绕转过程中在轨道上的相关位置，根据行星运动方向和太阳周年视运动的方向，清楚定义了东西大距和东西方照。根据行星和太阳在天球上的投影及运动的连续性解释行星的顺逆行和留。按照行星和太阳的角距离解释行星的出没规律。

Talking about Planets Apparent Motions

It bases on Copernicus' heliocentric theory , setting the sun on the center of the unive rse and the heaven on the periphery, the earth and the planets inside and outsid e the orbits of the earth circling the sun from the west to the east along the ellipse orbits. The relative positions of the planets and the earth from their d ifferent speeds. According to the planets' moving directions and the sun's annua l apparent direction, the biggest included angle between the west and the east i s clearly defined . The planet's direct motion, indirect motion and staying are explained by the projections of the planets and the sun on the celestia sphere a nd the continuity of the motions. The regular of the planets apparence and disap parence is explained by the angular distance between the planets and sun.