That's sometimes confusing for people, because it seems like okay, is it a photon or is it an electron.

有时候这对人们来说是令人迷惑的，因为它看起来好像是对的，它是一个光子还是一个电子？

麻省理工公开课 - 化学原理课程节选

So up to this point, before it was really established that yes, light is like a particle sometimes, there was this very strong distinction between what is light and what is matter.

所以关于这个观点，在它被真正确立之前，光有时候像粒子，在什么是光和什么是物质之间,有一个非常巨大的区别。

麻省理工公开课 - 化学原理课程节选