What appears to the naked eye to be just glowing is actually superposition of different lines of distinct frequency. So, you see, this is quantized.

出现在肉眼面前的光亮,事实上是波段不同的光线的叠加,所以，它是量子化的。

麻省理工公开课 - 固态化学导论课程节选

Mercury is a liquid metal, and mercury, the planet, is the fastest moving naked eye heavenly body. Mars, iron, why is Mars red?

水银是液态金属，水银，行星，是肉眼能看到的运动最快的天体,火星，铁，为什么火星是红色的？

麻省理工公开课 - 固态化学导论课程节选