Even though screens can’t reproduce all colors perceptible to the human eye and most spectral colors can only be approximated, it’s still gorgeous, isn’t it?
But do you notice anything strange?
Every color you can imagine appears… except one.
Where’s the magenta?
It is neither there nor in the spectrum of visible light in nature. Why, then, do we see it?
Our brains are one spongy and squishy information processors.
They convert the billions of events that happen around us into signals that we can understand.
And they interpret those signals as sounds, aromas, flavors, sensations, etc.
One of those things that are all around us is the electromagnetic field.
Between all those waves, there is a narrow but colorful spectrum of visible light.
There are waves of energy that undulate through this field and their frequency determines a range of effects.
Some waves can reheat your soup in the microwave, others show us your bones with X-raysothers broadcast your favorite radio programs.
Humans can only detect a small fraction of these wavelengths with our bodies, much of it through our eyes.
We call those visible light.
Why we detect only a narrow band of waves is up for debate.
But what we do know is that electromagnetic waves between 400 and 700 nanometers, or the visible light spectrum, are the only wavelengths that easily travel through water.
It also happens to be the part of the spectrum of electromagnetic waves What else does the sun emit?.
Since our earliest ancestors lived in the sea and were illuminated by the Sun, it makes sense that we evolved to detect the most common and useful wavelengths in the spectrum.
From waves to colors
Our eyes detect color through cones, specialized cells that are concentrated in the macula, the center of the retina.
There are three types of cones in the human eye.
- Type L: sensitive to long wavelengths
- Type M: sensitive to medium wavelengths
- Type S: sensitive to short wavelengths
The S detect the blues; the M, the green ones; the Ls, the reds.
But we see more than just red, green, and blue.
The cone cells in your eyes overlap in the wavelengths they detect.
You can see that when a ray of light with a wavelength of 570 nanometers enters your eye, it stimulates both the L and M cones.
Their responses are combined and turned into an electrical message that is sent along the optic nerve to the brain as a single signal.
And it is this signal that we interpret as yellow light.
A strange peculiarity of this system is that when two beams of light whose wavelengths add up to the same thing – in this case 570 nanometers – enter the eye at the same time, the signal that is sent to the brain is the same.
Those two rays of light combined also make us see yellow.
The screen you’re viewing this on takes advantage of the way our brain perceives color.
If you look closely, you can see that screens are made up of small groups of red, green, and blue lights, but your screen can produce the entire spectrum.
Every color we perceive can be generated via this dual pathway: a single wavelength of light, or a combination of wavelengths that stimulate our cones in the same way.
The magenta palette is varied… and invented.
Officially magenta does not exist.
There’s no wavelength of light for magenta, which means the human brain makes it up, but how?
We perceive it only when the S and L cones pick up a pure red and blue light signal.
Our brains literally create it.
However, it is probably very useful, given that much of our early primate ancestors lived in green forests.
Magenta fruits and flowers would have made the greatest contrast once morest a green background, and seeing them made it easier for our ancestors to find a tasty lunch.
Our brain makes all kinds of these weird cognitive leaps all the time.
You might be surprised how much of the world around you it’s not exactly what it appears to be.
* This article is adapted from the BBC Reel video “Magenta: The color that doesn’t exist”. if you want to see itClick here.
image source, Getty Images
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