Wagon-Wheel Effect
Stroboscopic Effect · Temporal Aliasing
An optical illusion where a spinning wheel appears to slow down, stop, or reverse direction — caused by the frame rate of perception or recording not matching the rotation speed.
Origin
Michael Faraday first documented the effect in 1831, experimenting with toothed wheels spinning at different speeds under controlled lighting. Belgian physicist Joseph Plateau explored the phenomenon further in the 1830s through his phenakistoscope and anorthoscope devices, establishing the principles of stroboscopic motion perception. In 1967, Dutch researcher J.F. Schouten became the first to observe the illusion under continuous sunlight — rather than flickering or filmed light — suggesting that the human visual system itself samples motion in discrete frames. A 1996 study by Dale Purves and colleagues at Duke University experimentally confirmed the effect in natural viewing conditions.