Disappearing, Reappearing Coin

PIRA 6A42.40

the camcorder so that it points down at a steep angle above a coffee can as shown at left. The camcorder batteries do not hold much of a charge, so use the 6 V DC output of the battery charger to power the camcorder. Use an LCD projector to project the video output of the camcorder onto a screen.

Place a coin in the bottom of the coffee can so it is visible on the screen, as in the top picture on the right (when these pictures were taken, a coin was not available, so a small glob of clay was used instead).  Push the can away from the camcorder until the coin is no longer visible (middle picture).  Fill the can with water, and the refraction of the light in the water will bring the coin back into view.