Polarization: Karo Syrup

Photo of the Demonstration at the University of Texas at Austin.

Instructions / Notes:

• A lucite tube containing corn syrup is illuminated with polarized light using a slide projector.
• The Karo syrup contains a small amount of scattering solution.
• A motor rotates a poloroid filter between the projector and the tube.
• With the room lights turned off - colored bands of scattered light will appear to spiral away from from the projector.
  • The color bands resemble stripes on an old fashioned barber's pole when viewed from the side.
  • Instead of the red and white stripes of the barber pole, the alternating colored bands of scattered light have either a reddish or a greenish hue.
• Turn on the switch for the rotating polarizer and the color bands will move in a continous motion from the rear to the front of the lucite tube.
• For more info: ( - see the description of setting up this demonstration that is in the section below the next photo. - )

A side view the Karo Syrup demonstration with the room lights turned-off.

Demo Staff:

• A proper set up of this demonstration requires second polaroid filter, which is stationary, to be placed at the far end of the demo.
• Proper placement in the classroom requires that the beam of light emitted from the second polarizer will strike a white wall which.
• Ideally, the emitted light beam should be displayed on the white wall either by chalk tray or above the fire extinguisher adjacent to the chalkboard.
• If the demo cart is placed at 45 degree angle to the wall, students will be able to see both the color banding at the side of the lucite tube and the circularly polarized light emitted from the second polarizer.

Photo of the light projected through the tube after passing through a second polarizer, which is stationery.

Last updated on August 30, 2017