Experiments with magnets interacting with other magnets
This exhibit shows the unpredictable nature of three magnetic fields interacting with one donut magnet on a string.
This is very simple to make. All that is needed are four donut magnets and a way to suspend one from a string so it can move about. The black foam disk on the back wall of the stand is to prevent the magnet from hitting it too hard and breaking.
The stand is made of 3/4" pressboard shelving with a white melamine finish. It measures about 11.75" wide by 12" tall by 6.75" deep.
Pull the magnet on the string to the side about 4" and let it go. You will see it bounce around from magnet to magnet as it interacts with their fields. It will spin and wiggle and jiggle and keep on doing it for a long time.
I found this described in the book Magnetic Magic. There are a lot of other cool
experiments in that book, too.