We don't think about that as often as we think about light pollution.
我们不像思考光污染那样经常思考这个问题。
光是怎样的？
A good way to think about light is to pretend that it's water.
一个很好的方法是把光想成水。
Classic scientific ideas about light were changed by Einstein.
爱因斯坦改变了对于光的古典科学观念。
Today, I'm going to talk about light, and in particular about laser beams.
今天，我要谈一谈光，特别是镭射光。
Talking about light, light is essential.
光，是非常必要的。
Talking about light, light is essential.
光，是非常必要的。
应用推荐