So if we imagine a section of our infinite universe -- and so I've put down four spiral galaxies, OK -- and imagine that you put down a set of tape measures, so every line on here corresponds to a tape measure, horizontal or vertical, for measuring where things are.
所以如果我们想象无限宇宙中一小部分， 然后我放4个漩涡星系， 假设你放一套卷尺， 这里的每一条线对以一个卷尺--- 水平的或垂直的---用来测量东西的位置。