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Q & A: What is Color?

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Most recent answer: 05/23/2019
What exactly is color?
- Dan (age 18)

Light is what scientists call an electromagnetic wave. A light wave is kind of like the wave you would see at a beach. Sometimes the waves have peaks that are close together, and sometimes the waves have peaks that are far apart. This happens with light too except light waves have very very tiny  spacing between peaks. Some light waves have peaks that are closer together than other light waves (for an electromagnetic wave, the "peak" is just a point at which the strength of the electromagnetic field is the strongest). The color of light depends on that spacing. If the peaks are further apart (longer wavelength), the color looks more red. And if the peaks of the light wave are closer together (shorter wavelength), the light looks more blue.


(published on 10/22/2007)

Follow-Up #1: photons and color

I think this answer is incorrect according to Feynman. He states that colors are the result of more or less photons (particles) hitting your eyes. Blue equals more photons than Red. And xrays equal a lot more than blue.
- jeremy lundy (age 44)

I think you're mixing up the amount of energy per individual light quantum (photon) and the number of quanta. These are two very different things. The color depends on the energy per photon but the intensity depends mainly on the rate at which the photons are coming in.

Mike W.

(published on 05/23/2019)

Follow-up on this answer.