Developing Theories of EM Radiation

• Who proposed that visible light is a stream of particles called corpuscles?

  Isaac Newton
• Why were corpuscles insufficient to explain light phenomena?

  They could not explain interference or diffraction
• What theory did Christiaan Huygens develop?

  Wave Theory of Light

  
• What does Huygens' Wave Theory describe?

  Light as wavefronts with sources of waves
• What are Huygens' wavelets?

  Sources of waves spreading from wavefronts
• What experiment did Thomas Young devise?

  Double-slit experiment
• What did the double-slit experiment demonstrate?

  Light can undergo constructive and destructive interference
• What did James Clerk Maxwell show about electric and magnetic fields?

  They obeyed the wave equation
• What does Maxwell's wave equation imply about light?

  Light consists of electric and magnetic waves
• Who discovered the full electromagnetic spectrum?

  Maxwell and Hertz
• What did Albert Einstein discover about light?

  Light behaves as a particle
• What is the photoelectric effect?

  Demonstration of light behaving as particles
• What are packets of energy called in Einstein's theory?

  Photons
• What is wave-particle duality?

  Light behaves both like a wave and a particle
• What are the key developments in the theories of electromagnetic radiation?

  • Newton proposed corpuscles for light.
  • Huygens developed Wave Theory of Light.
  • Young's double-slit experiment proved light's wave nature.
  • Maxwell showed electric and magnetic fields as waves.
  • Einstein introduced photons and wave-particle duality.