RE: Polanyi on science (was Re: [asa] C.S. Lewis on ID)

From: George Cooper <georgecooper@sbcglobal.net>
Date: Tue Dec 02 2008 - 12:42:51 EST

The problem with color is that it is not the usual one dimensional form of
measurement. Objective measurements such as length and mass are one
dimensional and are easily seen as objective.

I do think, however, that color can be considered objective under most
circumstances. In the Doppler scenarios, the beauty about spectrometer
measurements is that they will reveal absorption or emission lines that
establish the emission conditions and will reveal what color the luminous
source would appear if it were in our inertial frame. However, this assumes
the light source is close to a blackbody emitter. In the T-class stars, for
example, their photosphere temperatures are low enough to allow many complex
molecules. One spectrum I saw of a T-class stars is strong in blue and red,
with little or no emission in between. Thus, it will appear maroon to me,
an Aggie, (crimson to an Alabaman or Harvard grad.). :)

Color determination is further problematic if there is no reference light
source. A star that would normally appear orange if next to the Sun, might
easily appear white. Our brain likes to find its own reference source for a
"white" light. Take a look at your car's headlights in the daytime and they
will appear rather yellow, but at night they appear white. This affect is
known as color constancy. Professional photographers like to have at least
some white object in their picture to give allow for better color processing
of the image.

Then there are metamers. A color like yellow can be created by many
different combinations of other colors. Yellow on your tv is created by a
certain combination of electron flow to the red, green, and blue phosphors,
since there are no yellow phosphors.

However, if all the factors are understood, objective determination of color
is certainly possible. Red apples are indeed red. Also, the Sun is most
definitely not a yellow star.

[I hope I'm not dragging the topic off too much, as I am coming in rather
late for this thread.]

Coope

-----Original Message-----
From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
Behalf Of Murray Hogg
Sent: Monday, December 01, 2008 12:42 PM
To: ASA
Subject: Re: Polanyi on science (was Re: [asa] C.S. Lewis on ID)

Hi Moorad,

I'm at a loss as to the relevance of your hypothetical alien example.

True, different species might perceive yellow light in ways different from
us - but how does that demonstrate that OUR concept "yellow" is subjective?

Let me demonstrate why I don't grasp the connection by appeal to the
following hypothetical;

A company designs a PC based spectrometer which uses a color sensor linked
to a digital input card to "see" light and can do so to a resolution of
10nm. Further, the PC to which it is connected is very highly advanced such
that it appears to us to have the same level of intelligence as our
hypothetical alien.

In turn, say our hypothetical alien has a visual sense so finely tuned that
he does not merely see light in terms of "yellow", "blue", "red" but in
precise frequency values. Let's just say that the alien evolved in an
environment where being able to discriminate between colors was of major
survival benefit, and thus he is able to discern between colors whose
spectral wavelength varies by only 10nm. So he doesn't merely see "yellow"
when confronted with 590nm - he sees yellow of a particular hue quite
distinct from the similar yellows of 580nm or of 600nm.

Now, let's say we take our highly intelligent color sensing computer, and
our alien of highly attuned perceptual ability, place them in individual
sealed rooms after the manner of the famous Chinese room thought experiment.
Furthermore, we place in a third sealed room an operator with a
spectrometer.

Of course, each room has a slot through which we can pass colored cards and
a display on the wall which outputs three figure values. And, of course,
every time we pass a colored card through a slot in the wall, and obtain a
read-out on the wall display, the figures are so close that there is NO way
to distinguish between them.

Three things seem to follow;

1) Just as we have NO way of objectively distinguishing the three types of
responses forthcoming in the above, so we have no way of objectively
assigning the labels "subjective" and "objective" to the three
"measurements" of color appearing on the wall displays of the respective
rooms.

Thus;

2) Even after we learn which room contains the alien, which the PC, and
which the spectrometer, any subsequent ascription to their "measurements" of
the labels "subjective" vs "objective" is purely arbitrary.

And;

3) As the only difference between the perceptual abilities of our
hypothetical alien and ourselves is a matter of precision of perception, to
ascribe to our perception of color the label "subjective" is likewise purely
arbitrary.

I don't expect, Moorad, that you will be moved by the above as it seems
clear that your claim re human subjectivity vs instrumental objectivity is,
to you, an unimpeachable definition. So I offer it only by way of
clarification as to why I remain unswayed by what is, to me, a quite
superficially reasoned and therefore uncompelling position.

Blessings,
Murray.

Alexanian, Moorad wrote:
> Murray wrote " But in respects of color I'm sorry to say that our
> regular usage of color terms is simply too tightly specified for there
> to be much in the way of subjectivity involved. So when a person tries
> to tell me that "yellow" is "blue" I don't simply shrug my shoulders and
> put it down to subjectivity as I would when they claim a room I perceive
> as "hot" is perceived by them to be "cold". Rather I say that they are
> in error because we actually have an agreed standard of what constitutes
> "yellow" - it may be ambiguous to some degree - but at rock bottom I
> will maintain that there is no significant degree of subjectivity
> involved in the ascription of color to an object. We simply don't USE
> color terms in THAT sort of way."
>
> I raised the issue that some aliens may perceive as "blue" what we
> perceive as "yellow." Therefore, the physical description of 590
> nanometers can be associated with the color "yellow" by beings that so
> "see" it. There are others that do not. In fact, it is quite conceivable
> that just as we cannot "see" the infrared, but feel it as heat in our
> skin, there are beings that would see that longer wavelength and may
> associate a color that is not even in our visible spectrum.
>
> Moorad
>
>
> -----Original Message-----
> From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
> Behalf Of Murray Hogg
> Sent: Monday, December 01, 2008 12:48 AM
> To: ASA
> Subject: Re: Polanyi on science (was Re: [asa] C.S. Lewis on ID)
>
> Hi Moorad,
>
>> Your statement, "yellow has an electromagnetic wavelength of 590
> nanometers", is false. The correct statement is that most humans
> perceive the electromagnetic wave of wavelength of 590 nm as a color,
> which they call yellow. Notice that according to the Doppler effect,
> such waves will appear shifted to the red if the source is moving away
> from the observer. Therefore, one has to be rather careful in what one
> says.
>
> Correction in linguistic usage noted - apologies for the slip.
>
> On the substantial content of the above, however, I'm not at all sure
> why you introduce the Doppler shift into the discussion unless it is to
> infer (you don't state it outright) that our description of a light
> source as "yellow" is subjective because, under certain conditions
> brought on by the Doppler shift, we can refer to the same light source
> as "red" or "blue" or some other term. But I'll only say is that I
> consider it weakens your case substantially.
>
> Let me explain what I'm thinking;
>
> Lets say I see a yellow light, pull out my specrometer and measure its
> wavelength as 590 nm.
>
> I then begin to move toward it at sufficient speed that it now appears
> blue. Correct me if I'm wrong, but if at the moment of observing this
> "blue" light I pulled out my spectrometer and took a reading of its
> wavelength, would I not get a reading of about 450 nm as is appropriate
> for "blue" light?
>
> So, sure, the Doppler effect will alter the perceived color of a light
> source - but that's because it alters the wavelength relative to the
> observer. Such light sources don't just APPEAR shifted, they actually
> ARE shifted - relative to the moving observer, anyway.
>
> Thus the implication that human perception is subjective because we
> refer to a light source as now "red", now "yellow", now "blue" depending
> upon our relative motion in respects of it misses the blatantly obvious
> rejoinder: a scientific instrument measuring the same light source
> concurrent with our observations will read now "700 nm", now "590 nm",
> now "450 nm".
>
> So if we correlate color with EM frequency, it appears that our changing
> perceptions accord pretty well with what you're calling objective data.
>
> I'm not sure how this correspondence between a group of mental concepts
> and the measured data HELPS maintain the distinction between one as
> subjective and the other as objective.
>
> Let me say, at this point, that I don't think you could have picked a
> WORSE example upon which to build your case. Rather than arguing that
> the concepts "yellow", "blue", "red" are subjective and measurement of
> EM frequency using instruments objective, you would have been better
> arguing a parallel case for concept pairs such as "hot - cold", "bright
> - dark", "loud - quiet". In such instances you would have stood a far
> better chance of making your point as people often disagree whether a
> room is "hot" or "cold" even if they agree that it is 25 deg.C.
>
> But in respects of color I'm sorry to say that our regular usage of
> color terms is simply too tightly specified for there to be much in the
> way of subjectivity involved. So when a person tries to tell me that
> "yellow" is "blue" I don't simply shrug my shoulders and put it down to
> subjectivity as I would when they claim a room I perceive as "hot" is
> perceived by them to be "cold". Rather I say that they are in error
> because we actually have an agreed standard of what constitutes "yellow"
> - it may be ambiguous to some degree - but at rock bottom I will
> maintain that there is no significant degree of subjectivity involved in
> the ascription of color to an object. We simply don't USE color terms in
> THAT sort of way.
>
> Finally, I'd suggest this could even be determined by experiment: this
> Christmas, as opportunity arises, we ask people to identify the colors
> of a string of Christmas lights. If we get a significant variation in
> answer with no consistency in the terms people use to describe the color
> of the various lights, then the "color identification is subjective"
> thesis wins. If people consistently refer to the light emitting EM
> radiation at about 590nm as "yellow", at about 700nm as "red" and so on,
> then the "color identification is objective" thesis wins. I know betting
> is naughty, and if I do it Santa won't visit, but if I were a betting
> man...
>
> Blessings,
> Murray.
>
>
>
>
>
>
>
>
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Received on Tue Dec 2 12:43:25 2008

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