Soap Bubble on a Loop Finds Minimum Shape

Films stretch into smooth minimal surfaces. Ask students to predict what will happen. Dip different loops and compare films. Key idea: Surface tension pulls the film toward the least-area configuration. Ask: Why are the films smooth instead of wrinkled? Safety and cleanup: Tray; soap-eye caution. https://www.google.com/search?q=%22Soap+Bubble+on+a+Loop+Finds+Minimum+Shape%22+science+demonstration+experiment