This activity is an amazingly simple display of centripetal force (and annoying sounds) right at your fingertips.
Warning: The Spinning Penny Balloon is known to be addicting! Once you try it, you’ll find out too late that it’s habit forming and totally cool. Left untreated, you’ll be test-spinning everything in sight. It’s the simplicity of the setup and the wide variety of different sounds you can generate that make it so hard to put down. Besides, you use some very serious science to annoy the heck out of those around you.