时差N小时:哪一个先落地?(下)

Why not? You cry.Well,ask yourself this question:which one is easier to move in the first place? Thegolf ball. So it takes more force to move the bowlingball. And the bowling ball is also the one gravitypulls on more. See the connection? A more massiveobject has more stuff for gravity to act on. Butbecause it is more massive, it is also that muchharder to move! A smaller object is easier to move.But it also has less stuff for gravity to act on! Thecool thing is these two factors exactly balance eachother out. And that’s why any object, from dumptrucks to linguini, falls at exactly the same rate as any other object.

为什么不是重的物体先落地?你喊道。问下你自己这个问题：那一个首先比较容易移动?高尔夫球。所以要花更多的力量来移动保龄球，它也是引力作用更多的球。看见联系了吗?质量更重的物体引力作用更多但是因为质量更大，移动也比较难。一个较小的物体比较容易移动，但是引力作用也少。最有意思的是这两种因素互相抵消。那就是任何物体，从自动倾卸卡车到宽面条，都会以和其他物体相同的速度下落的原因。

gravity n.引力 factor n.因素 balance out 抵消 dump truck 自动倾卸卡车