Every foot of distance you look away, or every foot of distance an object is away, you're looking back about a billionth of a second in time, and this idea or this notion of looking back in time has revolutionized our ideas about the universe, not once but multiple times.
我们望出去的每一尺距离， 或者一个物体离去的每一尺距离， 你看到的都是十亿分之一秒之前的画面。 而这一概念，或者说时间回溯的概念， 彻底地改变了我们对宇宙的认知。 不是一次，而是好多次。