Parallel Rainbow
Birds sway their feathers with ultraviolet light, and lizards cling to rocks with infrared light. The world of colors for these creatures extends far beyond the spectrum available to humans.
The cosmos brims with photons. Like plump and radiant cherries soaked in sweet liqueur, the universe emits radiation, casting particles of light in all directions. Within the universe, monstrous celestial bodies made of heavy elements release various types of radiation in every direction. Here, beneath the umbrella of the cosmos, I lie on a rigid road forgotten by the wheels of a car. The nearby Białowieża Forest breathes in the night, and the dome of warm July air presses me against the ground. With eyes widened, devouring two small holes pierced through the irises, I absorb the universe.
It’s impossible not to marvel at it. Despite the fact that my eyes allow only a fraction of photons into their photosensitive interiors, they are inadequate to see the tails of luminous nebulae or the deathly blue-white vortex of ancient galaxies. Calling such a perception “seeing with the naked eye” is absurd. Indeed, my eyes are gelatinous, defenselessly exposed under the universe’s canopy, and all my sensory maps revolve around those eyes. I revel in this spectacle, sipping on photon cocktails, yet it is nothing more than a faint echo of the world actually shining.
Human eyes, capable as they are, can only capture a tiny portion of the radiation in the world. The narrow spectrum of light dissonance corresponds to all the rainbows in our reality. The visible spectrum exists within a space of only 300 nanometers of electromagnetic pulses. We see, and quickly, we believe we know the world, deluding ourselves into thinking that through vision, we understand the workings of the world. Here lies green, working unavoidably to consume light, generate oxygen, and nourish plants, both the blue of the sky and the flowers drawn to the surface by mischievous light. We’re left only to taste the blue flavor within the light, forgetting the fine details of the forget-me-nots and the wisps in the air. Beyond the visible range, storms of high and low-frequency radiation lurk, each with its peculiar taste – metallic, burning, deathly sharp – encountered only when something needs to be obliterated. For other things, we shape and sculpt them, melancholic and elongated like bundles of seaweed, understanding how to convey sound and vision. And now, I am truly feeling angry.
I resent the limitations of my retinas. These beautiful photons, ignoring the wild unknown rivers and seas of light, drink only from the rainbow stream of “visibility.” Tomorrow, amidst the vibrating light of heat, my body will traverse the meadow only along the visible light line. Beside me, others, each on their trajectory and route, will glide past me, capable of piercing the beyond of the human-visible mini-universe. Following the hungry gazes of other eyes, they will pass me by in their parallel worlds filled with different light and colors.
Pixels
When I press the shutter button of a digital camera, a handful of light enters. Photons race through the dark interior, plunge into the pixels of the matrix, die there, leaving an electric spectrum. There are pixels in the eyes too – the rods and cones adhering to the film of the retina. Photoreceptor cells with violet-colored pigments annihilate incoming photons, transforming everything into electricity, ensuring that the waves of impulses reach the brain through nerve fibers and joints. The three types of rods and cones are tuned to decipher different photons – orange, green, and blue. Cones exposed to light create various proportions and combinations to produce all the colors in the world. But that’s not all. Grasping light outside the rainbow spectrum is impossible. Light with lower frequencies than violet or higher frequencies than red is ignored by the human eye.
Yet, we must consider ourselves fortunate. Our two cones (orange and green) are separated by a mere 70 nanometers of sensitivity. Humans acquired this type of cones relatively recently. The eyes of ancestral primates evolved to distinguish the inedible green of unripe fruit from the nutritious red of ripe fruits, rich in sunlight and sugars. Other mammals still live in a world without red and orange. If a fox were staring at you from the thickets of the forest, the two of you would inhabit entirely different realities. Your world is a friendly, colorful one extending from red to purple, a rainbow-filled world. In the fox’s world, the crimson poppies are as ordinary as the golden sunflowers and the green of majestic oak trees. The fox’s rainbow would appear as two bands of blue and dirty green. Of course, this applies if we could apply human color perception, different color names, and references to colorful things around us.
This, arguably, stands as the foremost challenge when journeying into the chromatic realms of different species. Furthermore, it becomes a quandary when contemplating how those with color vision abnormalities perceive the world. How can one be certain that what we, with our Chartreuse and absence of orange receptors, shaped through a childhood trained by three types of photoreceptors, see in our minds aligns with what those lacking an orange receptor witness? The realm of color perception and its interpretation extends beyond the realms of physics; much of this process occurs within the mind—through experience, memory, unconscious reflexes, and more. Hence, I vehemently oppose gimmicks such as colorblind simulators or dog vision converters, programs or filters that transform vividly pulsating images into a plain, dirty yellow. The worlds of foxes and the color-vision-challenged are neither filthy nor ugly; they intersect with traces of our curiosity and moments of enchantment. Joy and sorrow, there, are subtly differentiated shades alone.
Impossible Colors
In a sense, we are color-vision-challenged. Regrettably, our visual sensitivity is limited. This, currently, is the most vexing aspect of where I find myself. I’ve arrived at a meadow, sliding into thickets of young wheat and grass. The air is teeming with light, a marvelous spectacle. Hundreds of pairs of eyes flit, crawl, and glide, each choosing from myriad photons. Here, I must surrender sensorially. For me, this is merely a meadow, with the green flesh of grass and various vibrant spots of color I can enumerate. However, countless exotic-colored photons hover in the air. One of them is bestowed with the unimpressive, flat name of ultraviolet.
Our bodies aren’t entirely indifferent to ultraviolet; in a way, we can “see” it on our skin. Exposed to ultraviolet, our cells undergo tanning. However, our eyes can’t see ultraviolet at all. We remain ignorant of the color of ultraviolet. At the very least, it must be a few kaleidoscopic hues, but it’s unrealistic, and we can’t perceive it. 300 nanometers is the space that encompasses the rainbow of human vision and its myriad colors.
The transition from familiar visible light to the unknown ultraviolet, seamlessly occurring, adopting impossible colors beyond human reach, is perhaps the most exasperating parallel world. Plants clandestinely exploit this, covering their bodies in tattoos of hues we lack, concealing messages for the chosen ones. They are fortunate possessors of cone cells, a fourth type of photoreceptor cell adjusted to receive ultraviolet. In my meadow, butterflies and birds move over the rough patches of the meadow, living vibrantly in ultratechnicolor. Unlike my eyes, theirs see beyond purple, extending to about 100-150 nanometers beyond ultraviolet.
For butterflies, seeing ultraviolet means distinguishing delicate signals on petals, guiding visitors to sweet nectar. On the other hand, birds require ultraviolet for appealing to mates. Take, for example, the blue tit seen at bird feeders during winter. The astonishing blue of its feathers is an evolutionary marvel. Without using any pigments, the feathers create color solely through the arrangement of small protein bundles, akin to holographic seals on credit cards, making them more aesthetically appealing. In reality, the blue tit’s feathers aren’t purely blue; they also reflect ultraviolet. Seen through the eyes of a bird with four visual cells, the blue tit shines with an unimaginable array of colors, much like a miniature peacock. If you attempt to imagine the world painted in ultraviolet from a bird’s perspective, it’s better to desist. Regardless of how wildly or avant-garde you paint the reflection of ultraviolet, it will still be mundane to us, with our dull color perception. In the narrow framework of the rainbow spectrum, a small sample sandwiched between red and purple is lifted from the vast sea of radiation to define it. The parallel worlds of birds and butterflies are filled with color and non-color, where plants have faces in ultraviolet, and rainbows sketch arcs of unnamed colors beyond dark blue and purple—a fascinating place.
Moreover, birds can do more. In addition to the four types of cone cells that detect colors, birds have what is known as double cones. Thanks to this, birds can not only see the color of light but also perceive its polarization, a property known as polarization vision. When one observes a clear sky through polarized glasses, the part of the horizon far from the sun looks entirely different from the parts around the sun, providing a pseudo-experience of it. What requires us to use plastic sheets, birds experience with much greater finesse. In a bird’s eyes, the sky’s dome fluctuates with light influence, and as the sun slowly moves along the horizon, the polarization changes. It serves as both a clock and a map. Direction and time are encoded in polarization bands. It’s a real multicolored astrolabe of the sky, a compass that birds follow in their annual celestial journey.
Through the Keyhole
Dissecting animal perception is undoubtedly a challenging endeavor. Birds and butterflies have added photosensitive pixels to their eyes, while lizards can “see” infrared on the opposite side of the rainbow spectrum. Monhanashakos, charming creatures with movable eyeballs that serve as mantis shrimp, have up to 12 types of photoreceptor cells, some of which evenly see electromagnetic waves from the shortest ultraviolet to near-infrared. How wondrous must the world appear through those eyes? How much overflowing color information can their small brains reel in, converting it into a sense of actual color? Absurd senses, such as sharks “tasting” magnetic fields or fish “hearing” turbulence and vortices in the water through lateral line systems, reveal the surprisingly limited nature of the sensory world—beyond colors, even encompassing sound and scent. The keyhole demonstrates how we perceive the world, shaped by our evolution, successes, and failures as a species.
I observe the Ogawa Komadori, swaying on the branches of a hawthorn shrub. There’s me, with a predictable rainbow world, and there’s the Ogawa Komadori immersed in the dissonance of ultraviolet light, dwelling beneath a sky of implausible polarized hues—like pop art. I find myself slightly envious of this bird. Yet, I’m pleased with the knowledge that there’s still so much left to discover, waiting for me within what I can see and perceive. Let the Ogawa Komadori inhabit a parallel world of unnamed colors. After all, without some of these colors, the Ogawa Komadori couldn’t return from its hideaway in Africa’s winter.
