那颗传说中的苹果，到底有没有砸到牛顿的脑袋上？
今天，告诉大家终极答案。
答案是这样的，英国的历史资料显示：牛顿声称自己看见了苹果直接从树上掉到地面上，并没有砸到牛顿的脑袋上。
历史考据出处之一：牛顿的朋友William Stukeley写过一本书，名叫《艾萨克·牛顿爵士生平回忆录》，在他这本书中，William Stukeley回忆了他和牛顿在花园里发生的一幕。
William Stukeley的原文是这样的：
“We went into the garden, & drank tea under the shade of some apple trees, only he, & myself. Amidst other discourse, he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. "why should that apple always descend perpendicularly to the ground," thought he to himself: occasionally by the fall of an apple, as he sat in a contemplative mood: "why should it not go sideways, or upwards? but constantly to the earths centre? assuredly, the reason is, that the earth draws it. There must be a drawing power in matter and the sum of the drawing power in the matter of the earth must be in the earth’s centre, not in any side of the earth. Therefore does this apple fall perpendicularly, or toward the centre. If matter thus draws matter; it must be in proportion of its quantity. Therefore the apple draws the earth, as well as the earth draws the apple.”
翻译成中文，牛顿的朋友William Stukeley是这个意思：
"我们走进那座花园，在苹果树下，喝茶聊天。当时，只有牛顿和我，就我们两个人。牛顿告诉我，他以前也有过类似的经历，那时候，牛顿也是坐在苹果树下，陷入沉思。此前，他就对重力问题有了模糊的概念、认识和思考，这时候，一个苹果碰巧从树上掉在地上，打断了他的沉思：为何苹果总是垂直落到地面？为何苹果不会斜着落下？或者冲向天空？很显然，地球对它有拉力，这拉力来自物质，而地球物质的拉力总和必然在地心，而不是在地球任何一侧，所以苹果垂直落下、朝向地心。如果物质间互相存在拉力，那么，拉力必然和质量成正比，也就是说，苹果对地球有拉力，同理，地球对苹果，同样也有拉力”
从牛顿的朋友William Stukeley这篇回忆文章看，所谓“苹果”的故事，其实是牛顿对William Stukeley说的，而且，牛顿说的是，一个苹果从树上掉到地面上，而并没有砸到牛顿的脑袋上。
换句话说，后世各国的文人，对牛顿的故事，进行了讹传、夸张和加工。
我们再来看第二个证据。
历史考据出处之二：牛顿的助手 John Conduitt，关于牛顿和苹果的故事，也写过这么一段回忆录，原文如下：
“In the year 1666, he retired again from Cambridge to his mother in Lincolnshire. Whilst he was pensively meandering in a garden, it came into his thought that the power of gravity (which brought an apple from a tree to the ground) was not limited to a certain distance from earth, but that this power must extend much further than was usually thought.
Why not as high as the Moon said he to himself & if so, that must influence her motion & perhaps retain her in her orbit, whereupon he fell a calculating what would be the effect of that supposition.”
翻译成中文，牛顿的助手 John Conduitt是这个意思：
“1666年那一年，牛顿再次离开剑桥大学，回到了当时住在林肯郡的他妈妈的身边。当牛顿在一座花园中沉思和散步时，他突然想到了重力（它的作用让苹果从树上掉到地面）不会仅局限于地球周围的有限距离里，而会延伸到一般人设想的更远处。他自言自语：为什么不能是和月亮一样高呢？如果这样，一定会对它的运动产生影响，也许可以让它保持在它的轨道上，于是他开始计算那样的假设会产生什么样的效果”
于是，我们从牛顿的助手 John Conduitt、牛顿的朋友William Stukeley的文字里，可以得知：牛顿确实多次谈到过那颗“苹果”，但是，牛顿自始至终没有说过“苹果砸中了他的脑袋”，而是说“苹果从树上掉到地面上”。
所谓“苹果砸中牛顿脑袋”的故事，是后人夸张、演绎、传讹的产物。
顺便提一下：牛顿在自己传世的文字中，并没有提到过“苹果”。所以，关于“苹果”的故事，John Conduitt和William Stukeley的文字和证言，是我们可以查到的最原始的出处。
