gravitation

Isaac Newton formulated the universal law of gravitation after watching an apple fall.

(Chinese) 艾萨克·牛顿在观察苹果落地后提出了万有引力定律。

The moon's gravitation is the primary force responsible for the Earth's ocean tides.

(Chinese) 月球的引力是造成地球海洋潮汐的主要力量。