Although this experiment is simple, it never disappoints. For the magic pencil trick from Buggy and Buddy, all you need is a plastic baggie, a sharp pencil and water. Fill the plastic baggie 3/4ths full with water and seal it shut, then hold the baggie up with one hand while using the other to push the pointy end of the pencil through the side. Continue to push until the point punctures the other side of the bag. The water won't spill because the baggie is made out of polymer, which have long chains of flexible molecules. Those molecules create a seal surrounding the pencil so that the water doesn't leak.