One thin, lightweight stick, 6-8 feet in length. A dowel or bamboo stalk will work.
Group size. Works best with 8-10 per stick, but can be done with fewer. Form two lines facing each other. Lay a long, thin rod on the index finger. Team members use only one finger with the hand facing down at waist height. Make sure that the rod is level and horizontal. No pinching or grabbing of the pole is allowed – it must rest on top of the index finger only.
The goal is to lower the rod to the ground. Try it. Ask the students to explain the results. Try again.
Does the stick really have helium? What happens to balloons that have helium?
How does it really work? Of course, the stick doesn’t really contain helium. The secret is that the collective upward pressure created by everyone’s fingers tends to be greater than the weight of the stick. As a result, the more a group tries, the more the stick tends to float upwards.