Rotating Colors

WHAT TO DO

Flip the switch to turn the light on underneath the jar. Keeping the jar above the light, look through the cut out in the lid. Now rotate the jar. What do you see?

WARNING: Be careful not to flip the jar up-side down! If you do, the syrup will come out of the jar and you will create a gooey mess!!

HOW IT WORKS

There is a cut out in the box with a light shining through a material called a polarizer. The light from the flashlight is really a bunch of waves wiggling in all different directions. You can think of the polarizer as a guard only letting certain waves through. The waves that the polarizer lets through are all wiggling in the same direction. When the waves of light hit the corn syrup (which is in the jar) the direction they are wiggling rotates! This rotation depends on the depth of the syrup, the concentration of the syrup, and the color of the light waves.

Light that you see normally, white light, is really made up of waves of red, orange, yellow, green, blue and purple light. Each color of light has a different wavelength (this means that they all wiggle different amounts within the same period of time). The light then goes through a second polarizer in the lid of the jar that you are looking through. This second polarizer is also a guard that only lets waves through that are wiggling a certain way. This is why you see a color when you look through the second polarizer. The waves of light (red, orange, yellow and so on) were all rotated different amounts in the syrup, so when you turn the polarizer it only lets through one color at a time!

Source:

http://www.exploratorium.edu/snacks/rotating_light.html