Re: Of colorful scepticism
Re: Of colorful scepticism
- Subject: Re: Of colorful scepticism
- From: John Gnaegy <email@hidden>
- Date: Mon, 1 Oct 2001 12:47:00 -0700
More idle navel gazing, but I can't resist one last post on the subject.
From: Igor <email@hidden>
That's why science restricts itself to comparing colours. We can
scientifically determine if two colours look the same.
Taking your argument to its logical conclusion, it would seem to be
scientifically impossible for humans to determine if two colors looks
the same, because the process involves humans reading the output of
measuring devices...how can we be certain that the number I think when I
see the characters "32" is the same number you think when you see the
characters "32"? All science is fruitless due to the inherent
subjective differences between humans.
Now where is the flaw in that argument? Here: differences between the
subjective experiences of multiple observers of one event do not
invalidate one observer's subjective experiences of multiple events.
The two are orthogonal principles.
Igor, this is the same trap you've fallen into by trying to use this
line:
As science cannot look into someone's head, science is not able to
determine what colour any person sees.
to disprove the validity of this line:
how can I recreate on another device (a display) what that apple would
have looked like if I had been looking over the shoulder of the
photographer.
An example to illustrate what I mean. Here's an apple. You and I look
at it. True, we will never know each other's subjective experience of
that event...maybe you're color blind and I'm not. But if I look at an
apple, hide the apple in a bag, then uncover it and look at it again,
both experiences for me are the same, at least close enough for me to
say it's the same apple, it looks the same as it did before I put it in
the bag.
Similarly, if I have two identical apples side by side on a table, and I
seat myself at a chair before the table, I can safely say they look the
same to me to the degree to which they are identical. As well, I can
say they would look the same to you if you were standing where I am.
Doesn't matter if you're color blind, your color blindness will affect
your perception of both apples equally. (Notice the fixed position, I'm
not comparing walking around the apples, nor turning one upside down.)
And similarly, if on the table I have an apple and a monitor showing an
image of an apple, I can say they look the same to the degree to which
they appear identical. There's nothing magically invalid about the
monitor, it either does or doesn't emit the same color as the color
reflected off the apple's surface. My eye doesn't know reflected vs
emissive, it just knows photons.
Now of course most likely I will be able to tell which is a monitor and
which is an apple...the image apple is framed by the edges of the
monitor (duh), maybe the glass isn't perfectly antireflective and I see
some of the sky's reflection in the monitor's glass. But those
differences are what we try to minimize or avoid completely by improving
the entire chain from image acquisition to data manipulation to output
device. There's nothing inherently impossible about it.
---
John Gnaegy
email@hidden