Humanity also has been obsessed with trying to capture the meaning of time. Einstein used a definition of time for experimental purposes, as that which is measured by a clock. Thus time and time's relativity are measurable by any hour glass, alarm clock, or atomic clock that can measure a billionth of a second.
人類也已癡迷試圖捕捉時間的意義。愛因斯坦用壹個時間定義為實驗目的，因為這是衡量壹個時鐘。因此，時間和時間的相關性是衡量任何小時玻璃，鬧鐘，或原子鐘，可以測量十億分之壹秒。