The world is flooded with purple color – lavender flowers, precious amethyst stones, plums, eggplant and purple emperors. But if you look carefully at the visible light part of the electromagnetic spectrumYou will notice that purple (which is different from bluish hues of purple and indigo) is absent.
Indeed, purple can be invented by our brain; Only there is because of how the brain treats color.
So, does that mean that purple does not really exist? Not necessarily. The answer lies in the mind -blowing way that our brains perceive and combine different wavelengths on the visible light spectrum.
“I would in fact say that no color really exists,” said Zab JohnsonExecutive director and main member of Wharton Neuroscience Initiative at the University of Pennsylvania. “This is the whole process of our neural machines, and it is somehow both the beauty and complexity of all this at the same time.”
All color begins with light. When the sun’s radiation strikes the earth, a range of wavelengths is present. There are long wavelengths, like infrared rays And radio wavesand shorter high energy wavelengths, such as X -rays And the ultraviolet rays, which are damaging to our body, told Johnson to Live Science.
Towards the middle of the electromagnetic spectrum is a visible light – the light that our brain can see – which represents only 0.0035% of the electromagnetic spectrum. This is what we perceive as the colors of the rainbow. At one end of the spectrum are longer wavelengths, which we perceive as red, and the other are shorter wavelengths, which we perceive as indigo and purple.
Our perception of color involves specialized receptors at the back of our eyeballs, called cones, which detect visible light. Human eyes have three types of cones: the long wave, the median wave and the short wave. Everyone is sensitive to particular wavelengths. The long wave cones take information on the light reddish cones, the half-wave wavelength specialize in green and the short wave length cones detect blue.
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When light strikes our eyeballs, these three receptors take information on light and their respective wavelengths and send electrical signals to brain. The brain then takes this information and makes an average deduction of what it see.
“Our machinery in a way makes this kind of complex calculation of these three different relationships”, which constitutes our perception of color, said Johnson. For example, if cones with long wavelength and average length are triggered, the brain names that we see orange or yellow. If the cones of wavelength and short wavelength are activated, the brain will conclude Sarcelle.
So what about purple? When the cones with short wave (blue) and long wavelength (red) are stimulated, your brain “does something that is not in fact in the world,” said Johnson. Red and blue are at the opposite ends of the visible spectrum: when the brain meets these wavelengths, it ends up folding this linear visible spectrum in a circle. In other words, it brings together red and blue to make purple and magenta, even if it is not what light really makes.
Consequently, purple and magenta are known as “non -spectral” colors, because they do not really exist as real electromagnetic radiation. Non -spectral colors like purple are made of two light lengths of light. On the other hand, the spectral colors – red, orange, yellow, green, blue, indigo and, above all, purple and indigo – are made of a single wavelength.
Whatever its physical existence, purple has captured people for millennia, noted Narayan KhandekarDirector of the Straus Center for Conservation and Technical Studies of Harvard Art Museums. For example, the ancient Phoenicians put sea snails on the ground to make a color known as Violet Tyrien, which was reserved Royal or ceremonial dresses. Today, purple is still often associated with wealth, power and even magic. “So this connection still exists, even if there are other versions of purple available now,” he told Live Science.
So whether it is made in our minds or made from crushed crustaceans, purple is unique and deserves a more in -depth aspect. “It doesn’t really exist in nature. And so when you can create it, it has this additional value,” said Johnson. “Now purple is even more special.”