Turn on the laser by touching the metal plate.
Put on red-blue filter glasses.
Adjust the lever for red and blue light to maximum brightness, the other to zero.
Place your hand underneath the white screen and look at the shadow through the glasses. Move your hand slowly toward the light source. Are you able to see your hand in 3D?
Also try
Try the same with the plastic ring. Are you able to see it in 3D? What happens if you turn the glasses back to front?
Fun facts
Our eyes are placed approximately 6,5 cm apart and for that reason they see slightly different images of the world around us. The brain fuses the two images together so we get depth perception. Two coloured light sources will give two coloured shadows. The filter glasses allows each eye only to see one of the shadows. Since the shadows are slightly different the brain fuses theme together making a 3D image. When turning the glasses back to front, the 3D shadow seems to switch to the other side of the screen.