You have nothing to fear, but the pendulum itself!
Stuff You'll Need
three feet of string
small bouncy ball
How to do it
Tie the string around the rubber band.
Wind the rubber band around the ball twice so that the string stays on the ball.
Tape the end of the string to the top of a doorway. See how it swings back and forth.
To make it a Pendulum of Fear, stand in one spot a couple of feet away from the ball. It's VERY important that you don't move. Put the ball up to your nose and let it go.
It looks like the ball is going to hit you in the nose, but it doesn't. It comes just short of your nose. That's because while the pendulum swings back and forth, it has to use some of its energy to push the air out of the way. Since it doesn't have as much energy, it can't swing back high enough to reach your nose.