Pure light, as proposed by Sir Issac Newton (1642-1727), is light that is comprised of one wavelength that cannot be broken down into different colors or component hues. This monochromatic light is a very rare occurrence as most light is composite light which is comprised of different wavelengths that can be isolated and broken down into separate colors. Composite light can be seen by using a prism – the light goes in as one composite beam and then is isolated into the varying range of colors it is made up of and will appear like a rainbow when projected onto a screen. Light made of different wavelengths appears duller than pure light.