Persistence of Vision

Persistence of vision is the perceptual effect in which a visual impression continues to be seen for a brief moment after the light that produced it has stopped reaching the eye, as when a glowing coal swung through the dark appears to leave a trail behind it. The idea dates back to Aristotle's observation that the sun's afterimage lingers, and it was described more formally in 1824 by the British scientist Peter Mark Roget. For over a century persistence of vision was credited as the reason a rapid sequence of still images appears to move in film and animation, but this explanation is now considered incomplete: psychologists and physiologists instead attribute the perception of motion in film mainly to two other effects, the phi phenomenon and beta movement, in which the brain actively constructs the sense of motion rather than merely retaining a fading image. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/