時差N小時:哪一個先落地?(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.

為什么不是重的物體先落地?你喊道。問下你自己這個問題：那一個首先比較容易移動?高爾夫球。所以要花更多的力量來移動保齡球，它也是引力作用更多的球。看見聯系了嗎?質量更重的物體引力作用更多但是因為質量更大，移動也比較難。一個較小的物體比較容易移動，但是引力作用也少。最有意思的是這兩種因素互相抵消。那就是任何物體，從自動傾卸卡車到寬面條，都會以和其他物體相同的速度下落的原因。

gravity n.引力 factor n.因素 balance out 抵消 dump truck 自動傾卸卡車