LESSON 1

• Light and Illumination (visible light)

  • all objects emit and absorb Electromagnetic Waves
• Electromagnetic waves

  • travels at speed of light (c = 3*10 m/s)
  • perpendicular to direction of motion
• Properties of Electromagnetic waves

  1. travels at speed of light
  2. electric and magnetic fields are perpendicular to each other
  3. requires no media for propagation
• visible light

  • wavelength ranges from 0.00004 (violet) to 0.00007 (red)
  • wavelength (nm) is inversely related to frequency (Hz)
  • energy is also inversely related to frequency
  • c = frequency (wavelength)
• Properties of Light

  1. Rectilinear Propagation - travels in straight lines
  2. Reflection - light turns back to original position when striking a smooth surface
  3. Refraction - light changes direction (bends) when passing though a different medium
• Dispersion

  • scattering of white light to colors when passing through a prism