Art with Polarized Light
How does light behave as it passes through different materials?
Answering this questions brings up some of the peculiar properties of light, the fastest moving “thing” known - at 186,000 miles per second. But is it a thing? Does light have mass? We really do not know (yet). This experiment, however, reveals something about what we do know about light and its media.
Be sure to ask an adult to help you with this one!
- 2 Sheets of polarizing material– two lenses from an old pair of polarized sunglasses will work. If the lenses are too small, though, your resulting picture will be small.
- Transparent tape– with a shiny surface (not the dull looking surface)
- A sheet of glass
- Overhead projector
- Be sure to test the brand of tape that you plan to use before you buy a whole bunch of it. You can test it by sticking a piece of tape onto one of the two polarizing lenses– then hold the lenses together, with the tape in between, and rotate the polarizers in opposite directions. If the tape appears to change from light to dark, or dark to light, this tape will work for the experiment. If it doesn’t appear to change in shade, then it will not work.
- Next, put strips of tape on the glass in overlapping or random patterns. If the tape overlaps, it will make a better pattern.
- Now, place the polarized lenses on each sides of the glass. Place the glass “sandwich” on the overhead projector. Shift the polarized lenses around to observe the colors change.
What Happened:
Every material has what is called an index of light refraction. This term refers to the ratio of the speed of light in a vacuum (or an ideal, static circumstance) to the speed of light in the material. Because light travels through the tape you used in different speeds, it has refracted in different manners. The polarized lenses cause the light to travel in different speeds through the tape. Consequently, different colors appear.
