Newton's Colour Theory: Colour and Light

Introduction

Isaac Newton, one of the greatest physicists in history, transformed our understanding of colour and light through his groundbreaking experiments in the 17th century. His work laid the foundation for modern optics and fundamentally changed how we understand colour. Newton discovered that colour is not a property of objects themselves, but a property of light, which led to his theory of the colour spectrum and the nature of white light.

The Discovery of the Colour Spectrum

Newton carried out his most famous experiments in 1666, when he passed a beam of white light through a glass prism. He observed that the light split into different colours, which he identified as red, orange, yellow, green, blue, indigo and violet. This was a revolutionary discovery, as it demonstrated that white light is composed of different colours and that colour is a property of light itself, rather than a property of objects.

The colour spectrum that Newton discovered is what we know today as the rainbow. Newton proved that each colour in the spectrum corresponds to a specific wavelength of light. This meant that when white light passes through a prism, the different wavelengths are refracted (or bent) differently, resulting in the separation of colours.