is a striking optical illusion that gives the impression that it is moving. Which way would you say that it appears to rotate? See “Explaining Quanta with Optical Illusions” by Gianluca Li Causi starting on page 7 for some provocative ideas for quantum analogies. This is the first article in our special collection on “Quantum Science and Technology in the Introductory Physics Classroom.” Source: Andrey Korshenkov - stock.adobe.com.