Quick Answer: Newton’s Disk is an optics demonstration disc divided into coloured sectors of the visible spectrum. When it spins fast, the colours blend and the disc looks nearly white, showing that white light is made of many colours.
Last updated: October 2026
Key Features
Circular disc printed with multi-colour spectrum sectors
Disc fixes onto a rotating mount for spinning
Colours appear to merge into near-white at high speed
Individual colours can be seen again when the disc stops
About This Product
The disc gives a quick demonstration of the composition of white light and of colour mixing by persistence of vision. Students see the separate colours on the still disc, then watch them merge as it spins, which links to dispersion of white light by a prism. The disc should not be touched while it is turning. Educational Instrument can dispatch the Newton’s Disk to laboratories in Kazakhstan, Kyrgyzstan, Maldives, Latvia, Democratic Republic of the Congo and Comoros.
Frequently Asked Questions
Why does Newton’s Disk look white when it spins?
The coloured sectors pass the eye too quickly to be seen separately, so the colours combine and the disc appears nearly white.
.png)
