1. Polarization
Light travels as a transverse wave, with the electric and magnetic fields oscillating perpendicular to the forward motion of the wave
Light from the sun, from a lamp, or from a candle is all unpolarized
Unpolarized light
oscillates in many planes
Polarized light only
oscillates in one plane

2. Polarization
Polarization: changing unpolarized light into polarized light
Using a polarizing filter (or Polaroid) absorbs some of the incoming light, reducing the amount or intensity of light passing through the filter
Only light waves aligned with the filter can pass through