You may have heard of polarized glasses, but what does that mean? How are polarized lens different and how do they reduce glare? This experiment will show students the effects of polarization and help them understand what it does.

### Materials

1. 3D glasses
2. Cardboard
3. Scissors
4. Tape
5. X-Acto knife
6. Paper
7. Plastic utensil
8. Pencil

### Directions

1. Draw a rectangle and divide it into 3 equal sections.
2. Pop the lens out of your 3D glasses.
3. Put one lens in front of the other. Rotate the lens until it gives off the least amount of light.
4. Keeping the lens in the same position as the previous step, place a lens on each of the two end squares. If the lenses barely fit into the squares or are too big, make your squares bigger.
5. Outline the lenses.
6. Cut out the outline with an X-Acto knife.
7. Cut out the whole the rectangle.
8. Fold the outer squares in. It should be in the shape of a bracket.
9. Using your leftover cardboard, cut out two more small rectangles. They should be as long as the squares you drew in your original rectangle.
10. Cut a half circle into one of the long sides of each of the rectangles.
11. Use tape to connect those two pieces to the sides of your “bracket”. It should look like the following image
12. Next, tape the lens onto the holes. If needed, adjust their position so they give off the least light possible.
13. Tape a piece of paper on the back of one of the squares. This creates a smoother image.
14. Now place your plastic utensil in between the lenses
15. Shine the flashlight on your paper square and look at your plastic utensil through the opposite lens.

### Explanation

As seen in the wave machine experiment, waves moves in two direction: horizontally and vertically. Our eyes can receive light in both directions, but polarized lenses limits our eyes to only seeing light in one direction. The 3D glasses you used have one horizontally polarized lens and one vertically polarized lens. You should have noticed that when you stacked them on top of one another (or at least when you rotated them enough), they gave little to no light. This is because both the horizontal and vertical light is being blocked. However, white light contains lots of colors, and therefore lots of different frequencies of light. As white light goes through the thickness of the plastic, the frequencies are rotated enough for some of the colors to get through the second polarizer.