1. The document discusses the history of theories about the nature of light, from Newton's corpuscular theory to Maxwell's electromagnetic wave theory. Key figures mentioned include Huygens, Grimaldi, Young, and Hertz.
2. It then describes Maxwell's equations unifying electricity, magnetism, and light. His theory established light as an electromagnetic wave. This was later supported by Hertz's experiments generating and detecting radio waves.
3. The document presents several problems calculating values like frequency, wavelength, and speed based on given information about light beams, using equations from Maxwell's wave theory of light. It involves calculations for situations like light passing through different media.