Optics > Polarization DCS# 6H50.10

POLARIZATION BY SCATTERING


APPARATUS
beaker of water 105-52-C
cremora 118
two polarizers 105-23-C
overhead projector 105
circular mask 105-23-


DESCRIPTION
Set beaker of cloudy water on top of circular mask on stage of overhead projector so that a beam of light passes through beaker.  Use polarizer to show that light scattered perpendicular to the beam is plane polarized.  Or rotate polarizer in incoming beam.

 
One could add more cremora to show that multiple scatterings depolarizes the beam.  Waxed paper between crossed polarizers will show this as well.

 
NOTES

 
Start with a tiny amount of cremora:  too much and the light is scattered multiple times, messing up the effect.