The origin of the dark bands found in the Solar Spectra and its consequences
This paper discusses the history of Fraunhofer's puzzling discovery of the fixed lines in various spectra (most notably of the sun) and the implications of these spectral "imperfections". Moreover, the developments in spectroscopy by Kirchhoff, Bunsen, et al. in the 19th century and its effects on our understanding of the atomic structure are discussed.
physics.pop-ph↗