Welcome to The Sound of Science from WNIJ and NIU STEAM. It’s a weekly series explaining important STEM concepts. Today’s hosts are Jeremy Benson and Newt Likier.
We have a question here from Maggie, who asks, “Why are different wavelengths of light different colors?”
Well allow us to enlighten you, Maggie. Our eyes work by detecting light waves and sending signals to our brain. Our eyes have three different types of sensors to detect colors called cones, and a fourth type called rods, which detects brightness. Each of the three-color sensors responds to a different range of wavelengths.
Those three sensors detect what we call the three optical primary colors red, green, and blue. And no, you didn't hear that wrong. Mixing light is a little different from mixing paints. So, the optical primaries are a little different than the painter’s primaries you might have learned in art class, or the printer’s primaries, you might recognize from changing your printer ink.
So how do we see secondary colors then? Well, there's a bit of overlap and the range of wavelengths that can be detected by each of those color sensors. When we see a secondary color, that tells us that more than one sensor has been activated. For example, if a light wave triggers both the red and green sensors in our eyes, we see yellow. Light that activates both the green and blue sensors is seen as Aqua.
When someone is colorblind, that usually means that one or more of their sensor types isn't working as expected. In some cases, one of the sensors may react to a different range of wavelengths than usual, which changes how the person perceives color overall. In other cases, those sensors may not function at all, causing the person to only see shades of gray when that color is present.
So, the next time you see a really pretty color, remember to thank your very special eye sensors. Because beauty truly is in the eye of the beholder.
This has been The Sound of Science on WNIJ, where you learn something new every day.
