# frequency

### How many colors are really in a rainbow?

"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. Image credit: Adam Hart-Davis. 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…

### Light and Waves - at a basic level

Yes, this can be very complicated. But what should a middle-school student understand about light? You see stuff in textbooks that is either wrong or just a bunch of disconnected factoids (I like the word factoid). So, what do I think is important about light (not at the Maxwell's equations level) What is a wave If you want to talk about light, you need to talk about waves. So what is a wave? I like to start with an example. Suppose you are in a sports stadium - maybe a football game. Some inspired fan decides to start a wave. If you look at the individual people, the wave might be…