Introduction Have you ever played with a toy pinwheel—or seen larger real-life versions, such as a windmill or wind turbine? Have you wondered why they look the way they do—with multiple blades, ...

Pinwheel (If you do not have a pinwheel, you can make a homemade one using a sheet of paper, a pencil or pen, a round wooden skewer and scissors—see steps below.) If you're enjoying this article, ...