Two still lights flashing in sequence can trick your brain into seeing motion

In 1912, Max Wertheimer flashed two stationary lights in quick succession and observers perceived a single light moving between them — motion that never actually happened. He called it the phi phenomenon, and it became the founding demonstration of Gestalt psychology: the mind assembles a whole experience that isn't contained in the individual flashes.

— Max Wertheimer, Experimentelle Studien über das Sehen von Bewegung — Zeitschrift für Psychologie, 1912

One credited idea per card. No filler. Swipe the rest in Savvy.

Keep swiping — it's free Works right in your browser. No app store needed.

More Psychology

All Psychology cards →
More from Max Wertheimer →

Five ideas worth knowing, every week

The week's best cards and a puzzle, credited as always. Free, unsubscribe any time.