四季长短和地球轨道偏心率

The length of the four seasons and the eccentricity of the earth orbit

利用现代四季长度的数据计算了地球轨道偏心率的大小和方向.以偏心圆模型为基础,假设地球沿轨道匀速运动,计算出的偏心率大小为0.0334,远地点的经度为103.22°.改变假设,从开普勒面积定律出发,得到的偏心率大小为0.01668,和真值0.01671非常接近,方向仍为103.22°.对比两个模型可以清楚地看到开普勒定律的作用,并清晰地说明偏心率的概念.

The magnitude and direction of the eccentricity of the earth orbit are calculated from the real data of the modern lengths of the four seasons. Based on an eccentric circle model with the assumption that the earth travels at constant speed,the eccentricity is calculated to be 0. 033 4 and the longitude of the apogee is shown to be103. 22°. With modifying the model by Kepler＇s area law,the eccentricity is shown to be 0. 016 67,which is in excellent agreement with true value of 0. 01671. The direction is still 103. 22°. The comparison of the two models clearly illustrates the role of Kepler＇s law and the concept of eccentricity.