translation.en: They didn't have sparklers. But, they --  -- you can make up rules, but they have to relate only to the things that you've been able to demonstrate.
translation.zh: 他们当时还没有所谓电火花。但是他们 —  他们可以推广这些原则，但是他们必须 局限在那些已经被实验科学证明的事情上。