translation.en: Each mirror, there are four of them, is made of a single piece of glass, a monolithic piece of high-tech ceramic, that has been ground down and polished to such accuracy that the only way to understand what that is is [to] imagine a city like Paris, with all its buildings and the Eiffel Tower, if you grind down Paris to that kind of accuracy, you would be left with bumps that are one millimeter high.
translation.zh: 一共有四个镜面， 每一个镜面都是有一块单独的玻璃制成， 材料是巨大的高科技陶制品， 已经被抛光、打磨到非常精确的地步 唯一可以理解这种精确的方式 就是想象一个像巴黎一样的城市， 拥有巴黎所有的建筑包括埃菲尔铁塔， 如果按照这种精度去研磨巴黎， 会得到一毫米厚的沉淀物，