HOW WE PROCESS INFORMATION?
The setting sun is beautiful when viewed from any part of the world and particularly at the beach, it is resplendent. It has the key ingredients to promote romance, alleviate stress, shelve anxiety, layover distress and associated thoughts. Not eliminate them totally, but a temporary reprieve. Ever wonder why the sky is blue and sunset is a brilliant mix of red, orange and streaks of yellow? We are fortunate enough to experience the beauty of the setting sun due to the presence of atmosphere and the complex mixing ability of colours in our brain. Let us understand these by availing concepts from physics.
Sunlight is white in colour. It appears yellow to us but if one were to journey into space and look at the sun for a little longer, we would see a white light. The light waves that the sun emits encompass the visible light spectrum i.e. the rainbow colours; Violet, Indigo, Blue, Green, Yellow, Orange & Red. Red which is at the lower end of the visible spectrum has high wavelength and lower frequency than the other six colours whereas Violet, at the top end of the visible spectrum, has lower wavelength and higher frequency than all the other colours.
WHAT HAPPENS WHEN LIGHT FALLS ON AN OBJECT?
When this white light comes to earth it is encountered by matter present in the atmosphere such as Nitrogen (78%), Oxygen (21%), Argon (0.9 %), solid particles (dust, soot, ashes, pollen, ocean salts and other industrial pollutants). Now three phenomena take place: Absorption, Transmission and Reflection. If light falls on an object, three things can happen; it can be completely absorbed, as black objects do, or the light can be transmitted right through it, especially transparent materials (glass), or it can be reflected back by the object (mirrors). If blue light is shone to a red object say red rose then the red rose appears black! Why? Because the red rose absorbs all the blue light. Since there is no red light falling on the rose to reflect, it appears black. When white light is shone to a red rose, it absorbs all the colour frequencies except red colour which is reflected back to our eye hence we see a red rose. Black objects absorb light of all visible frequencies. Some amount of light is still reflected from a black object, else we would have seen a total void and no visible black surface would have been possible. This is also why black surfaces become warm when it is sunny as all the light energy that is absorbed is converted into thermal energy. When all the light frequencies are reflected back we see white colour. Light absorption and reflection depends on the properties of the object. For example a raw banana may appear green but a ripe one will appear yellow.
Let us make an excursion into ‘Rayleigh Scattering’ principle that explains the associated physics of why we see a beautiful romantic sunset. When the white sunlight is met with matter (particles of Oxygen and Nitrogen in the atmosphere), the higher frequency colours such as violet, indigo, and blue are scattered. This means part of the light wave is absorbed by an atom followed by reemission of a light wave in many directions. Oxygen and Nitrogen particles scatter violet light the most, followed by indigo and then blue but human eyes are more sensitive to blue frequencies hence the sky appear blue to us. The lower frequency colours, yellow, orange and red, pass through the atmosphere and reach our eye. Though all seven colours are present in sunlight, yellow light frequency is most intense, hence the sun appears yellow to us during the day. As the evening progresses and the sun appears to touch the horizon, the sunlight has to traverse greater distance through the atmosphere hence has to negotiate more particles on its path. Yellow light scatters more, in comparison to orange and red light frequencies, and this is why the sunset has a mix of orange and red towards the evening thereby making it a sight to watch.
HOW DO WE SEE COLOUR?
How do the rich colours of sunset reach our eye and how is the scenery rendered as beautiful in our brain? Colour doesn’t exist out there in the world. It is not a natural phenomenon like gravity or a form as in shape or an element like water. It is a human perception and a reflected characteristic from objects. The eye and brain work in remarkable accord to produce sensations of colour. When light from an object bounces to our eye, it enters through our pupil and light sensitive photoreceptors convert light into electrochemical signals which is processed in the retina and the nerve impulses are transmitted to the brain through the optic nerve. The photoreceptors in the retina are of 2 types: Rods (can detect grey shades hence good in a dimly lit room) and Cones (can detect colours). There are about 7 million cones in the human eye and there are 3 types of cones each with different pigments and these photosensitive cells (cone cells) at the back of the retina are sensitive to only 3 visible wavelengths: short (blue), medium (green), and long (red). Rest of the colours are conjured up by the brain where the mixing and composition happens. The whole process of colour and sight rendering in the brain is extremely complex but the aspect that invokes awe is that the brain in conjunction with the eye renders the image so magnificently.
Bees can see light frequencies beyond human visible spectrum such as ultraviolet light that aids them in finding nectar in flowers. Colour blind people and most mammals have only 2 type of cones; green & blue sensitive ones hence can perceive the wavelengths of light that are blue and yellow. Red and green appear neutral to them. Some animals and insects have much more complex colour processing systems than ours. Hence colour is an outright perception in the brain interpreted through the visual stimuli that the eye receives.
Auditory illusions can also be perplexing. A human voice can be distorted by the computer and upon hearing it the first time we can’t decipher it but when the human voice is now played back to us first and then if we hear the distorted computer voice, we can identify it as we can now discern the pattern. The brain is constantly using prior information for comparison with the past to make sense out of the new sensory stimuli, a process known as Apperception. There are dozens of visual fallacies, auditory illusions and perception irregularities yet, in our daily life, we emphatically assert that what we see hear, feel, and read is indeed the objective truth. We latch on to our rational constructions, defend our beliefs, garrison our habits (however disempowering it is) and shield it from subversion. Lawyers, advertisers, researchers, negotiators, politicians all of them use rhetological fallacies, a kind of manipulation to influence people. Here are a few examples of rhetological fallacies:
- Ad Hominem: Move past the argument and launch an attack on the person. Fight the credibility of the messenger and not credence in the message. Example: You haven’t gone to college, how would you know about it?
- Generalisation: This political party is full of false promises but this has been the case with all politicians so we don’t expect much.
- Appeal of Pricing: This wine is expensive hence it must be very good.
- Selective evidence: I can continue with smoking. None of my relatives or friends who smoked have got cancer yet.
- Blatant lie: A lie with cogent emphasis can be made to seem like the truth. Dec 26th 1998 Bill Clinton told America, “I did not have sexual relations with that woman, Miss Lewinsky.”
- Probability: I have lost 20 times on this roulette table hence the next attempt might yield.
- Forfeiting responsibility: Sorry I lost my temper. I don’t know what came over me, this is just not me.
There are hundreds of others and the idea is not to make a beautiful sunset prosaic or the next time we see a garden with amazing flowers, dismiss it as mere light frequency reflecting to our eye. Beauty doesn’t lie in the environment, it lies in our minds. Corrals, fish and underwater creatures don’t know they are so beautiful and alluring to human beings. We create beauty in our head from experience and perhaps with conditioned response of many others. Perhaps a silly painting that doesn’t appeal to us at all may be eventually construed beautiful due to the fame and reputation of the artist. The structural thought in this blog is to re-examine how we perceive the world, how we infer from various sensory stimuli to create meaning. Aided by our thinking traps, how we view the world, jump to conclusions about others and permit recurrence. Awareness is a human prerogative and we sure have the capacity for it. Let us think about the way we think.