by Piotr Tkacz
the 2nd event of the month-long cultural program at the AAU’s |art|SPACE centering around the vibrant theme of color: SEDMIKRASKY |translations in color|
Continue reading “SEDMIKRASKY |translations in color| – (Guests)”
Consider that you can see less than 1% of the electromagnetic spectrum and hear less than 1% of the acoustic spectrum. As you read this, you are traveling at 220 km/sec across the galaxy. 90% of the cells in your body carry their own microbial DNA and are not “you.” The atoms in your body are 99.9999999999999999% empty space and none of them are the ones you were born with, but they all originated in the belly of a star. Human beings have 46 chromosomes, 2 less than the common potato.
The existence of the rainbow depends on the conical photoreceptors in your eyes; to animals without cones, the rainbow does not exist. So you don’t just look at a rainbow, you create it. This is pretty amazing, especially considering that all the beautiful colors you see represent less than 1% of the electromagnetic spectrum.
We Originated in the Belly of a Star, NASA Lunar Science Institute, 2012. (via amiquote)
presented by c.d.carr (guest speaker)
Eyes developed more than 500 million years ago, from photoreceptive nerve cells on the skin [eye spots]. Photoreception seems to be the natural disposition in the course of evolution from chemoreceptors, i.e. olfactory nerves. Everything on the planet, deriving its energy from the light source of the sun, was susceptible to perception of it. Organisms needed a way to resist the heavy radiation emitted from the sun (melatonin), while still harnessing it for energy (chlorophyll), and utilising it for mobility (photoreceptor cells). Photoreceptor cells perceive a certain wavelength (light) a much higher frequency than previously perceived by mechanoreceptors (hairs/ears). The eye developed to perceive and categorize (occipital cortex) different wavelengths of light. The human eye is equipped with 2 types of photoreceptors, which allows for four visual pigments, three of which provide the trichromatic scale (trichromatic theory vs opponent processing) that all perceivable color to human beings is stored as. An evolutionary anomaly, the mantis shrimp has 16 different photoreceptors arranged in three layers enabling them to perceive a much far-ranging spectrum than we can conceive of, including ultraviolet wavelengths that our optical lenses block out (it is a form of radiation).
We’re all familiar with the rod and cone collection of photoreceptor cells in the human eye. However, different organisms have evolved a variety of shapes these photoreceptor cells are categorised in. Butterflies have 5 variations and mantis shrimp have 16, while humans have only 2 photoreceptor cells, each cone divided into red, green, and blue (3). Dogs do have cone cells, but very few, and perceive only one spectrum (likely blue). Within the biological sphere of different species with photoreception, humans are quite limited in their perception of color, let alone restricted to our five senses.
–Purkinje Effect- (Shift to blue wavelengths)
Czech physiologist Jan Purkyně (1787-1869), was one of the first to document the change in color luminosity on various plants. He noticed that his favorite flower dimmed not only in light as the sun set, but also in color. The bright red became more and more grey as the sun set. He was a very keen observer and suggested that the human eye contains two different kinds of photoreceptor. Later, technology developed to measure and measure this shift in light, as well the shape of the cells. Different wavelengths of color were discovered and suddenly it became clear (or not), that color and sight, were simply our perception of movement of energy on different frequencies. The color blue, for an example, resonates at a frequency of ~670–610 THz or wavelength: 450–495 nm. The Purkinje effect, named after the Czech physiologist, describes this shift as dark adaptation: At lower levels of light, the photoreceptor cells shift from the red/green cone cells to the blue rod cells. This enables humans to see better at night, thereby receiving more light, when different threats are active (see Night Ocular Device). This blue shift (not to be confused with the astronomical phenomenon) elicits the production of melatonin, inducing a calming effect. For this reason, red light is used at night in laboratories or submarine control centers where night vision is necessary without agitating the rod cells, which cannot perceive red wavelengths.
Melatonin – Pineal Gland (Blue light 460-480nm), C13H16N2O2
However, 2% of photoreceptor ganglion cells are devoted not to perceiving light, but to perceiving darkness. This is necessary for melatonin production which takes place in the pineal gland. When the lights go out, the brain processes or recycles the neurotransmitter tryptophan into serotonin, and from serotonin, it is converted to melatonin. Serotonin serves its own function and is more prevalent as a neurotransmitter, but melatonin functions most in our unconscious mind, while we sleep.
Beside rod and cone photoreceptor cells, this small portion is dedicated to the activation of the pineal gland, the center of melatonin production. These photoreceptor cells are activated by blue sky alone, and function as a switch for the pineal gland. When they perceive blue sky, melatonin production is halted. Melatonin is found in many organisms, including plants (i.e. feverfew, St. John’s wort). It’s primary purpose, as far as we know today, is to regulate circadian rhythm (melanospin → circadian rhythm) and promote the ‘biological clock’ in many organisms.
The etymological root of melatonin is the Greek μέλας or melas, which means “black, dark”.
-Visual noise- (imperfections in evolution?)
Interestingly, without “seeing” from a rational human perspective, ganglion nerves and blood vessels are routed in front of the photoreceptor cells instead of behind, diffusing much of the light which enters the retina. This creates the first line of “visual noise” that the brain is occupied and determined to conceal (before God catches it). But how?
-Bluefield entropic phenomenon-
The brain recognizes the patterns of the blood vessels, as the dark, red blood cells full of hemoglobin absorb the blue light, and essentially deletes the pattern before it even reaches the visual processing level. This same phenomenon is seen with blind spots, where the mind completes, instead of deleting, impartial imagery, namely where the retina “plugs” into the optic nerve. However, in this process, where red blood cells absorb the bluelight, the rarer white blood cells do not and seemingly “float by”. If the brain is operating on this meta-level, what other noise may be inhibiting our abilities to enjoy anything visually and aesthetically? Is there more for us to perceive and what nerve-cells can I enlist with the capabilities to help me do so?
-Haidinger’s Brush- (polarisation of light)
Only a small percentage of the human species can see the polarisation of light. This is a phenomenon that occurs when a person perceives the separation of wavelengths of light. A commonly described view is that of the one below, where the lower wavelengths of blue pan out on the horizon, and the higher wavelengths of yellow squeeze vertical. Insects with compound eyes (bees & butterflies) detect polarisation of diffractions in light, in order to categorize (or communicate) with various flower spectrums. Mantis shrimp emit or perceive polarized light even in potential mating partners, or members of the same species when there is a threat around. Perhaps this special ability is explained by the multitude of photoreceptor cells that these organisms possess. Color, and the etymology of the word from the Latin celere or “to conceal”, might suggest a lot about how we, as organisms function and utilize our photoreception as a means to communicate. Specific plants have evolved and adapted to attract pollinators and the mantis shrimp have created an encoded communication that can be seen or perceived from long distances without making a sound, smell, or heat registry. Bees and butterflies can also perceive ultraviolet rays, which is specifically used to identify certain flowers. Although we are a long ways from perceiving these different wavelengths, the few of our species claim to see similar perception during migraines, which often can create synesthesia and ghost sensations. I would even elevate the perception of polarised light as the possibility to perceive what many new age believers see in aura. Soon, we will be able to test these different sensations and determine whether synesthesia and color of aura are determined by polarized light.
–Blue noise- (3db→~670–610 THz)
Blue noise also happens to be the best for creating the “dithering” effect, as the retina cells attempt to rearrange for visual resolution. The fast explanation of “dithering” is the classic television snow when you’ve lost reception. It can be harmonious as it sets the human mind up for this visual resolution in much the same way that the computer screen (of the past) doesn’t fry when you apply a screensaver. It would be interesting to see how applying blue noise, and sound at an equivalent low-frequency will affect art gallery audiences (it’s been done at various installations). The senses will not get overwhelmed as with current television marketing, but will be eased as all neuroreceptors are channelled into a similar, harmonious direction, giving a translation of sound frequency to light. Relative low frequencies convert to blue. Another tool to apply is the affect of blueshift. Blueshift occurs when a sound is approaching thereby decreasing the perception of the wavelength while increasing the frequency.
Blue is an important, integral part on the spectrum of human perception. It can calm and soothe us in more ways than previously thought. It can change the way we perceive something, as it resides in the peripheral, while green and red wavelengths grab attention. By perceiving, it also formats our memories, to trigger certain emotions and evoke feelings of calm, sadness, and fathomless depths, sometimes associated with confusion. This can be an extremely positive experience for some and negative for others.
Sternberg, R. J., & Sternberg, K. (2012). Chapter 3: Visual Perception. Cognition (6th ed., pp. 84-134). Belmont, Calif.: Wadsworth/Cengage Learning.
Kandel, E. R., Schwartz, J. H., & Jessell, T. M. (2000). Chapter 26: Visual Processing by the Retina. Principles of neural science (4th ed., pp. 507-521). New York: McGraw-Hill, Health Professions Division.
Yellott, John I. Jr., “Spectral Consequences of Photoreceptor Sampling in the Rhesus Retina.” Science, volume 221, pp. 382–385, 1983
SEDMIKRASKY |translations in color| – translation # 2
Curator: Natasha Kirshina