🚀 go-pugleaf

In comp.ai, Stephan wrote:

>If color is a subjective experience, then everything is subjective and the
>word objective loses all meaning.

I think in our modern age, because we can measure objectively the wavelength of
"blue" light, and describe it using physics and mathematics as having a
wavelength of 450nm, we think of it being an objective reality. But you can't
tell the blind person that blue is 450nm, it would be unusable information.

Although I think our sensory experience is subjective, we can use science to
describe reality objectively. For example, we can describe the results of an
experiment objectively, such that an experiment performed elsewhere can be
compared, without the second experimenter needing to have experienced directly
the first one.

As a thought experiment, you might like to think about how we could explain to
an alien species the difference between left and right, if we are restricted to
communicating over a radio link. [A slight trick question: it is not physically
possible to describe it unambiguously].

>In fact, color detection is one of the
>basic information our sensory systems provide; this is the basis for all
>empirical knowledge. You should trust it more than mechanical
>instrumentation, which, ultimately, is calibrated to someone's sensory
>experience (however that person(s) decided to calibrate it). 

I wasn't suggesting that we learn to sense color, but that we learn to associate
the signals from the eyes with particular colors. If we get signals X,Y and Z
from our eyes, we learn that X is blue, Y is red etc. However, I take your point
that color is at least a highly reliable shared experience. (Though you may not
believe that if you've ever argued with someone who is color-deficient, what
color a particular object is)

As a psychologist, you may be familiar with those cases where blind people have
been given sight. In these cases, they can see objects, but can not say what
they are. They have to touch them and feel them, in order to associate them with
their previous experience, and then they are able name them. 

The difference between seeing and perception is enormous. For example, the
images that fall on the retina are a jumbled mess, yet our brain processes them
to provide us with a perception of the world as a solid 3-D reality. What we
perceive consciously is actually a synthesized version of the world, which
actually "corresponds" more closely (or more usefully to us) than the data
experienced directly by our senses.

I expect you will come across these things in your studies, but don't forget to
drop in on physics and philosophy too. ;-)
-- 
Bob Cousins, Software Engineer.
Home page at http://www.lintilla.demon.co.uk/