Stedman Primary students read Snowman Magic during media with Mrs. Dawkins and since we don't have snow she decided to show the students how to do a simple magic "science" trick with toothpicks.
They needed: 5 toothpicks, a plate, water. Read how it works:
The toothpicks you used were probably made of dried birch wood. When you break the toothpicks, you stretch and compress the wood fibers inside them. When you put drops of water in the middle of the closed star formation, the dry wood fibers in each broken toothpick absorb some of it. This causes the fibers to swell and then to expand. The absorption of the water into the toothpick is due to capillary action. Capillaries are microscopic hollow tubes within the wood that draw water along the length of the toothpick. Capillaries normally carry water and food throughout a living plant’s stem and leaves.
As the wood absorbs the water, each individual toothpick tries to straighten itself as the soaked fibers expand. This straightening action causes the toothpick ends to push against each other. As the toothpicks straighten and push against each other, the inside of the star opens up into the final star shape.