phi

Noun

1. Φ, the 21st letter of the Euclidean and modern Greek alphabet, usually romanized as "ph".
2. The golden ratio.
3. A visual illusion whereby a sequential pattern of lights produces a false sense of motion.
   • […] tolerance (Frenkel-Brunswik 1949) for it showed that those persons with the strongest defences against internal conflict, i.e. obsessionals and conversion hysterics, were those least able to perceive the...
   • The illusion of movement in a highway construction sign is an instance of the phi phenomenon, which is also at work in motion pictures and television. - 2007, Wayne Weiten, Psychology: Themes and Variations: Themes And...
   • Is it the phi phenomenon or the persistence of vision? Originally, the illusion of motion that movies excel at was thought to be the effect of the persistence of vision. - 2013, Francis Glebas, The Animator's Eye:...