Perceptions – Beyond the Rainbow

Scale of Electromagnetic wavelengthsI have been considering a lot of the electromagnetic spectrum that I posted as a graphic when I explained how microwaves work.

At the edge of the non-ionising wavelengths, sits a small spectrum that we have come to define as visible light. The visible light spectrum contains the wavelengths of all the light that we can see – the colour ranges that are reflected back so that our eyes can pick up the vibrations and then our brain can discern, distinguish and interpret the colours.

The part of our eyes that interpret colour are known as rods. These are cells inside our eye that are capable of tuning in to and receiving the vibrational information on the colour of our surroundings.

It gets interesting when we find out that most of us have three rods in our eyes (trichromacy), and this helps us interpret the primary colours of red, blue and yellow and all the variations in between them.

The majority of animals have either two or three rods, which means they perceive colour either to a lesser degree or equal to what we can see too. There exists however, a small group of animals that have four cones in their eyes. The range of colour that they can see, extends in to the ultra-violet frequencies.

The most interesting part of all this, is as I pondered the fact that each of our perception of colour, is so highly individual no one else can offer the exact description or explanation for a particular colour that they see.

A case in point is, what I describe as ‘turquoise’, Sam (my other half) insists is called ‘teal’. Perhaps neither of us are right, perhaps we are both right – ultimately though, colour, sounds (high and low notes) and if we extend this further, pretty much everything that we can conceive and perceive are in reality simply perceptions.

In much the same way a colour-blind person, knows that red and green are two additional colours on the colour spectrum because the vast number of us speak of it, but all that appears to him is a general beige colour.

And yet, you know, the most interesting, intriguing, (and yet potentially the most frustrating thing) is, in considering tetrachromacy – that is the ability to see four primary colours – there is no way that a person who is capable of this (and there are people who do have four colour rod receptors in their eyes) is able to describe that colour to the rest of us who cannot see it. To us, it just might as well not exist.

Realising brought to me the awareness that so often we are insistent on our own ‘rightness’ our own ‘truth’ that we very easily discount what someone else has to say. We forget that everyone’s perceptions are different, and rightly so too.

My own reminder is in the fact that although I don’t have that fourth colour receptor, just because I can’t see it doesn’t mean it’s not there. It just means I have not yet found a way to perceive it. 🙂

Science tip: If you’re somewhere where it’s hot and sun-shiny, try creating your own rainbow. All you need is a water source and a hose-pipe. Standing facing the sun’s rays, with the water flowing at an average rate out of the hose pipe, make a spray by covering approximately 3/4 of the hose opening. Direct the spray of water perpendicular to the sun’s rays. If you look carefully (you might have to adjust your positioning) you will find a rainbow appearing in the spray of water.
It’s a really good, fun ‘experiment’ to try outdoors with children on a hot day.