'Opticks' by Sir Isaac Newton, English mathematician and physicist, 1704.
© Science Museum / Science & Society Picture Library
Title page of this great work which explored the properties of light. Newton (1642-1727) found that by refracting light through a prism, white light was dispersed into its constituent colours. If one colour was selected and refracted through a second prism, no further colours were introduced, showing that colours were a property of light and not the prism. Newton's discovery that it was imposible to focus an image distinctly using a single lens led him to build the world's first reflecting telescope. He also discovered the three laws of motion, the theory of gravitation, the law of cooling, the binomial theorem and differential calculus. His work was unique, pointing physics in a new direction and giving mathematical expresion to physical phenomena.