Collaborative teams take on the challenge to build a spinner that rotates without falling over. The group with a spinner that stays up longest wins! This terrific activity gives physics learners experience with centripetal force and center of gravity. The Zome System, however, is expensive. If you do not have Zome kits and do not want to purchase them, try a similar activity using straws or toothpicks for the struts, and miniature marshmallows or gumdrops for the connector balls.