I said the distance of the apple from the Earth is that.

我说苹果到地球的距离是它
But maybe it should be just the two meters from which I release it.

但那可能就是苹果离地面的那两米
Somehow he knew you have to measure

他知道得测量
the distance from the center of the Earth.

到地心的距离
So, it is not clear for the purposes of gravitation.

引力的作用并不明了
In other words, originally Newton had a law of gravitation

换句话说起初牛顿的万有引力
between two point objects, namely point-like.

是关于两个点物体的或者说视作点的物体
The distance between them

两物体之间的距离
is unambiguously the distance between the points,

就是两点间的距离
and he got this law.

他得到这个定律
But in the end,

但最后
he wants to apply it to the Earth and the apple;

他想把定律应用到地球和苹果