He's covering his head in a traditional religious fashion, so in order to enter this holy place he covers his head.

他以一种传统的宗教方式包裹他的头，为了进入那个神圣的地方而包裹头。

耶鲁公开课 - 1945年后的美国小说课程节选

So, we'll take a little bit of a step back after we introduce quantum mechanics, and talk about light as a wave, and the characteristic of waves, and then light as a particle. And one example of this is in the photoelectric effect.

等我们介绍完量子力学后,我们要回过头来讨论下光,作为一种波和它的波动性特征,以及光作为一种粒子,其中的一个粒子就是光电效应。

麻省理工公开课 - 化学原理课程节选