If Junior likes playing with matches, and the due date for the science fair project is rapidly approaching, then the perfect project can be found in the September 1941 issue of Popular Science. This experiment answers the question, “which surface provides the least wind resistance,” and it turns out the answer is the airfoil.

Junior can easily demonstrate this with the self-explanatory experiment shown here. With the piece of cardboard flat, drag is produced, and when you blow toward the flame, it actually moves back toward you. But when the card is bent into a teardrop shape, scientifically known as an airfoil, then the air blows the flame away.