Newton disc

The Newton disk, also known as the disappearing color disk, is a well-known physics experiment with a rotating disk with segments in different colors (usually Newton's primary colors: red, orange, yellow, green, blue, indigo, and violet, commonly known by the abbreviation ROYGBIV) appearing as white (or off-white or grey) when it's spun rapidly about its axis.

This type of mix of light stimuli is called temporal optical mixing, a version of additive-averaging mixing.^[1] The concept that human visual perception cannot distinguish details of high-speed movements is popularly known as persistence of vision.

The disk is named after Isaac Newton. Although he published a circular diagram with segments for the primary colors that he had discovered (i.e. a color wheel), it is unlikely that he ever used a spinning disk to demonstrate the principles of light. He referred to the mixture of colors painted on a spinning top as "dirty" and described several experiments supporting his theory.

Transparent variations for magic lantern projection have been produced.^[2]