The Arctic Home in the Vedas c5.11

c5.11

Let *PQ'AQ* represent the orbit of the earth round the sun. This orbit is an ellipse, and the sun, instead of being in the centre *C*, is in one of the focii *S* or *s*. Let the sun be at *S*. Then the distance of the sun from the earth when the latter is at *P* would be the shortest, while when the earth is at *A* it will be the longest. These points *P* and *A* are respectively called perihelion and aphelion. The seasons are caused, as stated above, by the axis of the earth being inclined to the plane of its orbit. Thus when the earth is at *P* and the axis turned away from the sun, it will produce winter in the northern hemisphere; while when the earth is at *A*, the axis, retaining its direction, will be now turned towards the sun, and there will be summer in the northern hemisphere. If the axis of the earth had no motion of its own, the seasons will always occur at the same points in the orbit of the earth, as, for instance, the winter in the northern hemisphere at *P* and the summer at *A*.