Lightness and Brightness and Other Confusions

Light and colour as experienced through the senses
The original concepts of colour and light refer to what we can experience with
our visual sense. Words for light are very old in the development of languages
(Fig. 7) and differences between light and dark are referred to in some of the
earliest surviving pieces of literature. 47
Figure 7. Words deriving from the Indo-European words for light, as
shown in the Art Gallery of New South Wales, Sydney, Australia.
Our visual system provides the most important starting point for perceiving
and apprehending space, and the experience of space is fundamental and prerequisite
for our survival as a species and as individuals. This experience is
both perceptual and cognitive, and it depends on shared biogenetic preconditions
as well as on the implicit knowledge and former experiences of the individual.
Our visual mechanism (eye and brain) is, with rare exceptions, anatomically
and functionally identical from person to person, 48 but due to such
factors as individual life experience and different motives and expectations,
we see and experience the world in different ways. This means that the only
way to know what a person sees is by asking or in some occasions by analysing
the person’s behaviour in relation to visual stimuli.
Human experience is spatial and holistic, dynamic and contextual. In a complex
real life situation there are no fixed relationships between our visual
47
Two examples of this are Genesis 1:2–5 and the Gilgamesh epic Tablet XI.
48
There are several types of defective colour vision. The most common is characterised
by a difficulty to distinguish reds from greens. This deficiency is much more frequent
among men than among women (different sources give it as about 7-12% in males and
less than 1% in females), and varies between different parts of the world.
46