Beakman challenge: make a can come to you when you call it. Beakman rolls a can away and it rolls back. Using a coffee can, two plastic tops, rubber band, small sticks, scissors, tape and a weight (like an old battery), Beakman creates a coffee can that, when rolled, causes the rubber band to twist up. The stored energy of the twisted rubber band has to go somewhere, so it unravels it self causing the can to roll back where it started.