the study of the way matter absorbs or sends out light and other radiation (= energy from light or heat that you cannot see)

Scientists have determined the proportions of the chemical elements present in the Sun using spectroscopy. 科学家们利用光谱学测定了太阳中存在的化学元素的比例。

His work in spectroscopy led to an understanding of the origin of the remarkable colours of gem stones. 他在光谱学方面的工作使人们了解了宝石的璀璨色彩的来源。