这些反应是不发光的。

These reactions are not luminous.

youdao

但是其中差不多20%也可能是不发光的传统物质，如黑洞和不可能形成恒星的气体。

But as much as 20% could also be in more traditional things that don't emit light, such as black holes and clouds of gas that never became stars.

youdao

这是一个重要的成就，因为相对来说，行星很小，而且也不发光。

This is a major achievement because, in relative terms, planets are very small and do not emit light.

youdao

So, you would expect that when you rip open the skull and look at the brain; you'd see something glorious, you'd see, I don't know a big, shiny thing with glass tubes and blinding lights and sparks and wonderful colors.

所以你会期待,当你打开头盖骨时,当你看到大脑的时候,你会看到些非常辉煌的东西,你会看见,我不知道,附有玻璃管的大块发光的东西,发出耀眼的光芒,不停地冒着火花,拥有美妙的颜色

耶鲁公开课 - 心理学导论课程节选