How many colors are really in a rainbow?
Rather than the six or seven you may have learned, your eye is capable of delineating a tremendous number more. But just how many, and what’s the explanation?
“The colors of a rainbow so pretty in the sky.
Are also on the faces of people going by.” -Louis Armstrong
It’s no secret that white light is the light that we see when all the colors shine together and are seen at once. This has been known for over 400 years, when Isaac Newton demonstrated that white light could be broken up into all the known colors by dispersing it through a prism.
All that we’re doing is breaking white light — in this case, sunlight — up into all of its component colors. This can be done artificially (such as by configuring a prism) or naturally (in the case of a rainbow), and covers wavelengths both inside and outside what our eyes can perceive.