How to Make Your Own X-Ray Specs
WHAT YOU NEED: two strips of red poster-board (2 inches wide by 17 inches long), ruler, pencil, scissors, hole puncher, black feather, Elmer’s Glue-All, two hardcover books, bright light.
WHAT TO DO:
1. Fold the first strip of red poster-board in half so the seventeen-inch length is now 8.5 inches long. Place the folded strip on a tabletop with the fold facing your right.
2. From the top edge of the poster-board strip, use the ruler to measure down 5/8 inch and draw a line across the width of the poster-board strip.
3. From the right-hand fold, measure in 7/8 inch and draw a vertical line across the height of the poster-board strip.
4. From the bottom of this line, draw a diagonal line to the top right-hand corner.
5. From the right-hand fold, measure 2 1/2 inches and draw a vertical line across the height of the poster-board strip.
6. Using the scissors, cut out the large rectangle in the bottom left-hand corner, cutting through both layers of poster-board. Cut out the quadrangle in the bottom right-hand corner, cutting through both layers of poster-board.
7. Open the pair of glasses and use it as a template on the second strip of red posterboard to create an identical pair of glasses.
8. Hold the two pairs of red poster-board glasses together so they line up perfectly, and using the hole puncher, punch a hole in the center of each lens.
9. Cut two pieces of the feather, each one inch long. Glue the first piece of feather to one of the red poster-board glasses so that the feather covers one of the holes (without getting any glue on the part of the feather that covers the hole).
10. Glue the second piece of feather over the second hole of that same pair of glasses. Glue the second pair of red poster-board glasses to the first pair so the feathers are sandwiched between them and the holes in the lenses line up.
11. Place two hardcover books on top of the glasses to press the two pieces together until the glue dries. When the glue dries, fold back the arms of the glasses, wear the X-Ray Specs, and under a bright light, look at your hand through the glasses
WHAT HAPPENS: You see what appear to be the bones in your fingers.
HOW IT WORKS: The eye sees different wavelengths of light as different colors. Light travels in waves, which usually travel in a straight line. However, when light waves pass through a slit, they diffract (spread out) into curving waves. When light waves pass through several narrow slits (like the numerous spaces created by the complex branching pattern of the feather), they interfere with each other. Where the crest (peak) of one wave meets the crest of another wave – or where the trough (low point) of one wave meets the trough of another wave – the two waves combine and form a bright spot of light. Where a crest meets a trough, the two waves cancel each other out, leaving a dark spot. Some of the light which would normally be stopped by the edges of your fingers gets bent and reaches your eye, making the edges of your fingers appear semi-transparent. Meanwhile, light from the center of the fingers is not bent enough to reach your eyes, so the center of your fingers appear solid, resembling the bones of your fingers.