The purpose of this essay is to help clear up the confusion about colour and energy/vibration. Why is colour, although real to us, not the essential truth of the light we see?
Let’s start with the basic science of colour. To begin we need to look at the basic science of energy and light because colour is a property of light and light is a form of energy. Energy has several properties of relevance to our discussion.
It cannot be created or destroyed.
It is always in motion, even when contained in something that is still.
ENERGY, FREQUENCY AND WAVELENGTH
Types of energy like light oscillate (vibrate) between two polar opposites or extremes, which we represent symbolically in the diagram as the familiar ‘sine wave’. In water waves the oscillations go up and down while the whole wave travels forwards. In light waves the oscillations are a kind of spiraling, leapfrogging, alternation of electricity and magnetism. In sound waves the oscillation is packets of compression and decompression in the line of travel. But they all can be symbolized by the sine wave: oscillation between two extremes.
Frequency is how fast the waves are oscillating, eg. cycles per second, or the number of complete wave cycles passing a point per second (1 cycle per second is called 1 Hertz symbolized as 1 Hz). If the dashed line in the diagram represents one second, the wave on the left has a frequency of one cycle per second = 1 Hz: one complete wave passes in that second. The middle wave with more energy does 2 cycles per second = 2 Hz; two waves have passed in that second. The one on the right with much higher energy does 8 cycles per second = 8 Hz. The more energy the wave has the higher its frequency.
We often use the term ‘vibration’ (oscillation) to refer to the amount of energy and thus the frequency of a particular wave. A higher vibration doesn’t necessarily mean bigger peaks, it just means more of them packed into a shorter time, in other words, higher frequency.
One wave cycle is the distance between two equivalent consecutive points, eg. between two peaks, or between two troughs or between any two equivalent points of the vibration cycle, and is called one wavelength (a pretty self-explanatory name!). You can see from the diagram that the higher the frequency (more wave cycles per second) the shorter the wavelength and vice versa. We measure wavelength the same way we measure any distance, eg. in metres. However when it comes to light, the wavelengths are so short we go down to tiny fractions of a metre, called nanometers (nm). A one nanometer wave is one thousand millionths of a metre long.
Summarizing, wavelength refers to the length of a wave cycle, or distance between like polar extremes of a wave, and frequency refers to how many of those occur per second and tells us about the energy of the wave.
LIGHT AND THE ELECTRO-MAGNETIC (EM) SPECTRUM
Light energy travels in particle-like packets of energy called ‘photons’, but it also travels in waves. Waves and particles have the curious ability to suddenly change into each other, depending on how you look at them (literally!) – part of the quantum mystery.
Light travels mostly at the same speed. It goes fastest in space – 299,792,458 metres per second or approx 18 million kph. It goes a little bit slower when it passes through substances like air, glass, etc. It travels mostly in straight lines though it gets a bit bent and slowed down in huge gravitational fields (but we won’t concern ourselves with that now).
Light can be reflected, refracted, diffracted, diffused, absorbed and transmitted, which are all ways it interacts with other energy or matter.
Light can have widely varying amounts of energy. The range of energies of known light is what we call the Electromagnetic Spectrum, and light that’s visible to the human eye is only a tiny part of that. Also on the spectrum are cosmic rays, microwaves, X-rays, radio and TV waves, ultra-violet, infra-red rays, etc. Some other animals can see beyond our range, eg. many insects and birds can see ultra-violet or even higher frequencies and some snakes can “see” infra-red.
We all know that the light around us, including the white light we can see, comes from the Sun. Sunlight is a mixture of many different energies, frequencies and wavelengths of light in the EM spectrum. White visible light contains a mixture of wavelengths which we know as the rainbow: red, orange, yellow, green, blue, indigo and violet. These colours appear in order of their wavelength when white light separates into its components as it refracts through a prism or the atmosphere after rain. But actually each of these colours is just a range of wavelengths that blend from one end of the spectrum to the other with no sharp boundaries. The properties of the colours are:
Please note that the ends of the ranges tabulated above are approximate, as our senses vary and there are no distinct boundaries between the colours – see the spectrum in the next picture.
So where does red end and orange begin? It is very personal and subjective. However the centre of each wavelength range is usually agreed by most people to be a certain colour.
(picture courtesy www.wikipedia.com)
Red light has the lowest energy, frequency, vibration and the longest wavelength of all the visible light.
Violet light has the highest energy, frequency and vibration and the shortest wavelength of visible light. Beyond the visible spectrum, ultra-violet is even shorter wave and higher frequency and energy, in fact its energy is so high it can burn our skin very quickly and kill bacteria. Infra-red is also beyond our visual range, is longer wave and lower frequency and energy than red, and its energy is very warm and penetrating.
WHY THINGS LOOK COLOURED
Why does something look coloured? When white light comes from the sun, bathing everything equally, the response by material things is not equal. For example, red paint looks red, not
white. Red things look red because they take out and absorb from the white light all the frequencies except the red frequencies. Thus only the red frequencies are left to be reflected off the surface of the “red” thing to travel to your eye, interact with red-sensitive pigments, and be seen. Blue things look blue because they absorb all frequencies but blue and reflect blue out to your eye to be seen. Transparent things like colourless glass, pure water, ice and quartz crystals pass most of the white light through without absorbing frequencies unequally, so they do not show any colour. Red glass absorbs everything but red and lets some of the red pass through, so it looks red even though transparent.
IS COLOUR ILLUSION OR TRUTH? THE NEURAL “CHINESE WHISPERS GAME”
OK, colour seems to be quite real according to the science above, so why is it really illusion? When light goes into your eye and travels deeper to your retina, it hits certain protein molecules which are pigments inside the retinal nerve cells. Pigments are molecules that take in and are activated only by certain frequency ranges (and thus wavelengths) of light energy. Different nerve cells contain different pigments and so they respond to different frequencies and wavelengths of light.
You are familiar with how information travels in electric wires, eg. you speak into a telephone handset, it gets coverted into electrical information, travels along the wires as electricity, gets relayed at exchanges and passed on. At its destination it is converted again and comes out of your friend’s receiver as audible words like the originals that you spoke into it.
Like the telephone analogy, light goes into your eye and activates specific pigments in the nerve cells which send signals as electrical pulses along the ‘wires’ of your nerves, being relayed from nerve to nerve until they reach the visual cortex of your brain. But unlike the telephone, the visual light energy entering your eye goes through a kind of neural “Chinese whispers game”. By the time that information gets to your visual cortex, there has been some interpretation and distortion of the signal along the way, as our physical equipment (the nerves) are imperfect, and they have been trained and imprinted to respond in certain ways. The visual cortex also has to interpret the signals and send them to higher parts of your brain for further processing. The visual cortex cannot communicate the ‘appleness’ of the incoming signal originating from a ripe apple; it cannot say ‘apple’ or ‘it’s red’ or speak or write the word ‘red’ or tell you how to pick up a red apple out of a box of green ones.
All it can do is send its re-organized information about wavelength, brightness, contrast, edges, movement and shapes to your association cortex. It’s this part of your brain that puts it all together like a jigsaw puzzle and organizes it into meaningful information. This information can then be related to your stored memories, and relayed to your thoughts and muscles so that you can ‘know what you are seeing’, and be able to think and speak about it and act upon it. That’s why you can distinguish a red apple, know what it is, know it’s red, pick it out from among the green ones, and describe it in words or drawings.
However originally your eyes only received a complex pattern of overlapping, interacting light beams including the 435 – 495 Tera Hertz frequency range that reflected off the red apple, plus other frequency ranges reflected off the objects between. around, and beyond the apple. It did not receive simply ‘red’, or ‘apple’. Your retina and brain had to, in a sense, ‘make it all up’ by sifting through the energy information, and associating certain trained patterns of nerve activation with certain previously-experienced, known and remembered things. We create the image of a red apple and all of our reality from the associations recorded in our brains, and each of us is a unique individual in that regard. How would you ever know what red or an apple looks like in someone else’s mind?
We are trained to form these associations from earliest childhood. Picture a parent waving an apple in front of a baby, and saying “apple, apple”, or showing the child two blocks and naming one ‘red’ and one ‘blue’ so the child can grasp our names for the different frequencies and wavelengths.
What if a child were told “orange” every time the parents held up a red apple, a red pencil, etc. The child would be programmed to associate the brain’s response to the 435 – 495 Tera Hertz light frequencies with the identity ‘orange’ and would be very confused when the rest of us disagree about the colour! Most of us receive reasonable training and pretty much agree on the basics; however our differences in physical equipment and conditioning are more subtle. For example if you show several people a reddish-orange colour, some will say it’s orange, some will say it’s red, some will say reddish-orange, some will say orangey-red however a few might even say terra cotta or russet brown!
COLOUR AS A SYMBOL
This process of interpreting objective truth (ie, the actual energy, frequency and wavelength of light) into a subjective impression (ie. colour) is why colour, although very real to us, is actually quite illusory. It is a useful effect or symbol of the frequency, vibration and wavelength of light energy, but not its fundamental essence. Seeing the colour is not the direct perception of the light energy coming from an object. It’s true that by seeing the colour we are aware that we’re receiving information about the light energy, its frequency and its interaction with the matter of visible objects, or even matter we may not be able to see. The rainbow tells us that there is moisture in the atmosphere splitting the sunlight; the glowing green of a leaf tells us that molecules of chlorophyll are present and that the leaf is alive and functioning, etc.
All we have said regarding the ‘unreality’ of colour can be applied to hearing as well. What we think we hear is the end-product of the neural “Chinese whispers game” from our sensory input (eardrum) to our symbol-forming brain. In other words, we create illusions out of incoming energy, to explain the world to ourselves.
SOME FUN THINGS TO DO, OBSERVE AND CONTEMPLATE
Hold something of one bright colour up close to your face so it fills your visual field and stare at it for a minute. Then look away and focus on a neutral area. If the object you looked at was red the after image will be green, if the object was blue you’ll get yellow, and black gives a white afterimage (visible against a dark surface). When the pigmented nerve cells that responded to your object’s colour get tired – they have to keep firing as long as the colour is there – they stop sending signals. Then all that’s left are signals from cells of opposite inclination, and so you “see” the opposite colour. Just another great example of how colour is a very subjective, illusory thing. You can even keep the game going, getting after-images of the after-images!
Have you ever noticed the way pictures on a sunny wall and outdoor signs and posters tend to eventually fade out to pale purpley-blue? Purpley-blue means that the pigments in the sign throw off high energy purpley-blue and absorb the lower energy red, orange, yellow and green wavelengths of the spectrum. So what happened to the pigments that absorbed the purpley-blue and threw off the red/orange/yellow/green that you used to see when the picture was new? Well, remember that the purple end of the spectrum has the highest energy of visible light, and what’s just beyond, the ultraviolet, is even higher energy. High energy has more power to break up molecules, including molecules of pigment. So the pigments that absorbed the ultraviolet and purples and blues took in that high energy and were broken up by it, so that they are no longer present to throw off the red/orange/yellow/green wavelengths to your eye. Only the pigments that did not absorb and sustain damage from that high energy light are still functioning, still throwing off the purple-blue light for you see.
Absorbing the stars
When you stand outside on a clear night and “drink in the beauty” of the stars, consider this:
You can see the stars because light waves produced In the fiery infernos of the star’s bodies are travelling all the way across space and physically entering your eye, activating retinal pigments, creating electric currents and sending nerve signals to your brain. The energy from the star has actually entered the matter of your body and is moving through it, interacting with it, changing it and producing responses in it. It becomes part of you. Pretty wild hey?
But there’s more…
From a star that is, say, 1,000 light years away, its light takes 1,000 years to reach your eye. So what you are ‘seeing’ is what that star was like 1,000 years ago! The star may now be quite different from the ‘now’ you see which is really its past. 1,000 year-old energy information, that’s been altered along the way by what it passes through, is entering your eyes and affecting you. And a galaxy one million light years away is sending you one-million year-old energy information. So the whole night sky is a mosaic of the past histories of all different epochs from 4 years ago (Alpha Centauri) to billions of years ago, and your physical body is absorbing and responding to it, all at one glance!
© Dianne Trussell 2008