ABSTRACT
Light, electromagnetic radiation, pervades the universe. Originating with the fusion of stars, blackbody radiation, the oscillation of electrons, and particle annihilation, electromagnetic radiation is both a useful byproduct of matter's change and a means of interrogating the structure of matter itself. In this chapter, the nature of electromagnetic radiation – as oscillating electric and magnetic fields – is discussed along with the division of the electromagnetic spectrum into distinct regions: γ rays, X-rays, ultraviolet (UV), visible light, infrared (IR), microwave (µW), and radio waves. The study of electromagnetic radiation, in the context of blackbody radiation, the photoelectric effect, and atomic emission spectra, also provides a useful framework for understanding the evolution of our understanding of light and the development and evolution of quantum mechanics. The chapter concludes with a brief discussion of the Bohr model as an imperfect culmination of early 20th-century physics.
