Quick Answer: The Hand Newton’s Disk is a hand-rotated circular disc printed with multi-colour spectrum sectors that blend and appear nearly white when spun fast. It demonstrates that white light is made up of the colours of the visible spectrum.
Last updated: October 2026
Key Features
Circular disc printed with multi-colour spectrum sectors
Manual, hand-operated rotation
At sufficient speed the colours blend and look nearly white
Stopping the disc lets students compare stationary and blended colours
Supplied with an instruction sheet
Technical Specifications
Specification
Value
Operation
Manual / hand-operated rotation
Disc pattern
Multi-colour spectrum sectors printed on a circular disc
Learning concepts
White light, visible spectrum, colour mixing, optics and persistence of vision
About This Product
Spinning the disc recreates the classic demonstration that white light is a mixture of the spectrum colours. It also opens a discussion of persistence of vision, since the eye cannot separate the coloured sectors once they move quickly enough. The Hand Newton’s disk can be supplied on export terms to North Macedonia, South Africa, Bahamas, Uruguay and Rwanda.
Frequently Asked Questions
Why does the Hand Newton’s Disk look white when it spins?
The coloured sectors pass the eye too quickly to be seen separately, so persistence of vision blends them and the disc appears nearly white.