|
Hole in Your Hand
This week's experiment is an old one and an easy one. It is a simple illusion
that makes it seem that you have a hole through your hand.
You will need:
Roll the paper into a tube. It should be at least large enough to stick 2
fingers into. Hold the tube up to your right eye, so that you are looking
through it. Hold your left hand about 6 inches in front of your face, with your
hand open, the palm facing towards you, and the base of your little finger
against the side of the paper tube. With both eyes open, you should see a
strange sight. You will see your hand in front of your face, with a hold through
it. If you don't, try moving your hand a little farther away until it comes into
focus.
What is happening? Normally, both of your eyes see the same thing, just from
slightly different angles. Your brain combines these two slightly different
views to let you see in three dimensions and judge distances. We have changed
that. We are giving your brain two different images. One eye is seeing the palm
of your left hand. The other eye is seeing the other side of the room, viewed
through the tube. In combining the two images, your brain has to decide what is
more important to see. Most of the view from your right eye is blocked by the
dark sides of the tube, so you mostly see the view from your left eye. The one
exception is the bright circle of image that your right eye sees through the
tube. Since this is the one bright spot from your right eye, your brain pays
extra attention to it. As your brain combines the two images, you wind up seeing
your hand with a hole through it.
If you want to play games with your brain, try watching television this way.
Even better, have someone stick their finger into the end of the tube. That is a
strange site, indeed.
Have a wonderful week.
Back to Experiment List
|
