German physicist Gustav Kirchhoff was a pioneering scientist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects. He formulated several eponymous laws related to electrical circuits and thermodynamic reactions. Kirchhoff and Robert Bunsen—of Bunsen burner fame—began a new era in astronomy when they applied spectrum analysis to the Sun. Which two chemical elements did they discover in the 1860s? Discuss