Light and Matter Interactions, Atomic Structure, and the Doppler Effect

Interaction of Light with Matter (Macroscopic Level)

• Light and matter interact on a macroscopic level in four fundamental ways:

  • Emission: Matter generates light.

  • Absorption: Matter takes in light.

  • Transmission: Light passes through matter.

  • Reflection/Scattering: Light bounces off matter.

• Definition of Interaction: The interaction of light with matter involves the creation (emission) or annihilation (absorption) of photons by atoms and molecules.

• Example of Reflection: An orange appears orange because it reflects orange wavelengths of light while absorbing other colors.

Atoms and Light

• Atomic Structure:

  • Atoms consist of a dense nucleus containing protons and neutrons.

  • Electrons surround the nucleus in a