These absences are called Fraunhofer lines, after the German physicist who discovered them two centuries ago.
这些缺失的频率被称为夫琅和费谱线,200年前,德国物理学家发现了它们。
PBS趣味科普
He didn't know exactly why this happened but concluded that Fraunhofer's black lines were caused by elements in the sun absorbing specific wavelengths.
In physics and optics, the Fraunhofer lines are a set of spectral lines named after the German physicist Joseph von Fraunhofer (1787–1826). The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun.