【NO547 - 260319】
牛顿因为被苹果砸到头所以发现了重力这回事是虚构的。
但虚构的仅仅是“自己被苹果砸到头”的部分。
不仅是牛顿自己和好几个人说了“是因为看到苹果落地”，这个说法甚至还被记录了下来。根据其好友William Stukeley的说法，在1726年4月15日——
The weather being warm, we went into the garden and drank tea, under shade of some apple trees, only he and myself. Amidst other discourses, he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. It was occasion'd by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself. Why should it not go sideways or upwards, but constantly to the earth's center.
顺便一说，那颗苹果树就在牛顿的故乡Woolsthorpe，但在1820年因为风暴而被连根拔起。
