Posted on 03/15/2005 2:41:19 PM PST by Michael_Michaelangelo
I'm sory, but you are JUST missing the point we are making.
Perception of color is NOT "color"
Yes, all things emit (or reflect) radiation to give the appearance of color. But that means color is of itself, in existance, and it does not require man for it to be.
we are not discussing whether the chips are ideentical. In my example they are not. We are discussing whether they are perceived as the same color.
You are fond of envoking mathematics. Give me a mathematical description of the color green. What are the spectral characteristics of green? Be careful. You have asserted that pigments, such as Pantone chips, can have an objective color. What is the essential spectral characteristic of a green Pantone chip?
Fine. Define color in the absence of a perceiver.
A specific wavelength of moving particles.
Light waves also exist without a human to perceive them. Both light and sound can be described as having wavelengths, which are also objective.
But unless you are willing to assign a specific wavelength to the label green, the way we assign 440 hz as A below middle C, color is a perceived quality, like beauty.
What you did was rename the color. You did not change the property of it that makes it so.
So what is the Platonic wavelength of green?
I don't pretend to know it's wavelength. I do know that calling it by it's wavelength does not change the fact that it is green though.
Merely names.
In better words; show me an instance where the same wavelength as green cannot be green.
For the record: you shifted universals. I took that as a concession that you're no longer claiming green is a universal. If not, let me know, and we can discuss how loose the criteria for a universal can be.
Ever hear of a redshift?
That shift changes the length of the wave. Try again.
I know exactly what point you are trying to make, and you are wrong. color is not like 3 or pi. The definition of color can be arbitrarily limited to the concept of wavelength, but that has not been argued up to now. We have had arguments that color chips, such as Pantone chips, can be said to have color that is independent of the perceiver. Not just a recipe of pigment ingredients, but color.
It is possible, and commonly done, to make pairs of pigment chips that "normal" people will perceive as the same color, but which will appear different to color blind people. There are an infinite number of such pairs. The perception of color is an activity of the eye and brain. There is no possible way to define a shade of color objectively except as a measurable activity of the eye and brain.
Try brown or purple. With green, there is a frequency of light that is "green" but there is no frequency that is brown or purple. (I'm not denying the existence of the concepts, just pointing out some difficulties.)
"The definition of color can be arbitrarily limited to the concept of wavelength,"
"There is no possible way to define a shade of color objectively except as a measurable activity of the eye and brain."
Well, which is it?
You had been arguing until now that the mind was were color was.
In case you were wondering why I ask.
So your point is, although 'green' is a universal quality, 'greenness' cannot actually be associated with an object, because that color can be red- or blue-shifted; nor can 'greenness' be associated with a perception', and in fact 'green' is only another way of saying 'electromagnetic radiation of wavelength 540 nm'.
So what's monochromatic light of wavelength 541 nm? What about bichromatic light with two wavelengths, 539 and 541 nm? Are they not green? What if we take near-infrared light of high intensity, so that in a nonlinear medium it has harmonics of wavelength 540 nm?
I'm just trying to nail down this universal of yours. If it's a universal, it should be capable of precise delineation, right?
Both statements are true. An arbitrary definition is not objective.
Brown, I will say, is a perception. It is a blend (and confusion) in the mind of other colors.
Green has existed as long as radiation itself has.
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