Invisible Glass in Oil

Parts of the glass seem to disappear. Ask students to predict what will happen. Lower the glass into the oil. Key idea: When two materials bend light by nearly the same amount, their boundary becomes hard to see. Ask: Where did the edge go? Safety and cleanup: Teacher handles glass; use plastic alternative when possible. https://www.google.com/search?q=%22Invisible%20Glass%20in%20Oil%22%20science%20demonstration%20experiment