Donate Bitcoin

Donate Paypal


PeakOil is You

PeakOil is You

Color Perception Question

What's on your mind?
General interest discussions, not necessarily related to depletion.

Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 15:33:24

The colors we see form a linear continuum from ultra-violet to infra-red, with decreasing frequency and increasing wavelegth. But in psychological terms, the colors form a wheel and red shades to violet. Furthermore, if you look at colors and then stare at a white surface you see an inverted set of colors that come from the opposite side of the color wheel, the so-called "complementary colors". Is this an example of "intuitive common sense" being a fictional human error?
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby ashurbanipal » Tue 10 Jan 2006, 16:00:51

In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 16:09:26

Interesting link, but I didn't see any ideas about how we see the colors as being in a circle when they aren't at all.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 16:32:59

So the eye really only sees three "colors". The brain probably creates the continuum around these three colors, hence "the color wheel". This illusion is hard-wired, evidently; how else to explain the complementary color phenomenon? What else about how we see the world is an error of human perception?
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby SinisterBlueCat » Tue 10 Jan 2006, 17:50:31

I knew a guy that was color blind...I mean completely without the ability to see any color at all, and his vision was unbelievable. Without the distraction of color he could easily see twice or three times as far as a normal person with 20/20 vision.

There is a guy, the original horsewhisper, Monte Roberts, who also has this condition. He has truely astonishing vision, but more amazing is he credits his lack of color vision with his ability to "hear" the subtle cues that horses give him.
User avatar
SinisterBlueCat
Tar Sands
Tar Sands
 
Posts: 885
Joined: Tue 06 Sep 2005, 03:00:00

Re: Color Perception Question

Unread postby ashurbanipal » Tue 10 Jan 2006, 17:59:16

PMS,

I posted the link as a general discussion of the nature of color perception, and the ontological implications of same. I think, building on what was already discussed, we might be able to tease a further argument out of the aesthetic sense of mankind.

The question you posed about us potentially being in error because of our perceptions is made somewhat moot by the considerations undertaken at the link I provided.
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 18:14:03

$this->bbcode_second_pass_quote('ashurbanipal', 'P')MS,
The question you posed about us potentially being in error because of our perceptions is made somewhat moot by the considerations undertaken at the link I provided.
Spell that part out for me: Our eyes really see only three colors, the brain turns it into a wheel complete with physiological events structured around this circle (color fatigue and complementary colors) but the real nature of the electromagnetic wave spectrum is just linear. To me, there is a paradox here.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby smallpoxgirl » Tue 10 Jan 2006, 18:41:00

No paradox. Just a good example of how human perceptions of the world don't always correspond to physical reality.

We have receptors that percieve three different wavelengths of light. Based on varying activity of those three receptors we create the subjective concept of color. The whole ROY G BIV thing is just us trying to classify various physical wavelengths of radiation based on how we experience them.

This incidentally is the basis of RGB video signalling. In order to fit our perception of the universe, you don't need all the posible frequencies of the visible spectrum. All you need to know is "How much activation of the red cones, how much of the blue, and how much of the green." If dogs ruled the world, there would be no such concept as color, and there would be no need for RGB signaling. Black and white would be considered a complete video signal.

It's no different from the reason we use a base 10 numbering system (10 fingers). I'm told that at least one Inuit group used a base 5 numbering system. (That way you only have to take off one glove at a time.)
User avatar
smallpoxgirl
Expert
Expert
 
Posts: 7258
Joined: Mon 08 Nov 2004, 04:00:00

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 19:15:35

The 10 finger example is a good one in that it shows the difference between cultural and physiological adaptations. The color wheel seems, as I was saying, to be hard-wired. The color fatigue thing and complementary colors seem to be a product of our brains assuming the reality of an erroneous interpretation of color, ie. our brain thinks (or acts as if) the colors really are arranged in a circular pattern and that ultra-violet and red actually are 'close' to each other and that blue and yellow are 'opposites'. That's how it appears to me, anyway.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby ashurbanipal » Tue 10 Jan 2006, 21:31:33

PMS,

You're applying the correct reasoning, but only on one side of the equation. Human beings invented that linear spectrum as well--the human mind is concerned with such things as wavelength and relative proportions. That's simply another means of our perceiving and organizing our perceptual phenomena. Neither the linear means of organization or the "wheel" means of organization is actual reality--we can't ever know what "actual reality" is.

In that link, one of the characters talks about pigeons perceiving more colors than we do. Of course, we can't know the phenomenal experience of a pigeon, but we can be fairly sure it's probably not very similar to ours. The phenomenal experience of a bat is less so, and that of a tree much less so (so much less so that we might be inclined to think that trees don't have experience). Which "version" of reality is correct? Ours? Why are we justified in assuming that?
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 21:42:18

$this->bbcode_second_pass_quote('ashurbanipal', '
')
Neither the linear means of organization or the "wheel" means of organization is actual reality--we can't ever know what "actual reality" is.

Which "version" of reality is correct? Ours? Why are we justified in assuming that?
I don't know about how it is in Honalee, but we have models showing the EM spectrum stretching far out into both the ultraviolet and infrared; a linear model for all intents and purposes, no? Well, the version of reality I refer to is an abstract set of models such as the schemes to set out electromagnetic principles for conceptualization. science. take it or leave it, it's the yardstick to measure reality, main one anyways.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby ashurbanipal » Tue 10 Jan 2006, 22:25:49

PenultimateManStanding,

Actually, that means of organizing the EM spectrum was probably determined (albeit unconsciously) with our method of doing mathematics.

Science is like any other human activity, which means the foremost thing to be kept in mind is that human beings are the ones who do it.

Anyway, to your specific point:

$this->bbcode_second_pass_quote('', 'w')e have models showing the EM spectrum stretching far out into both the ultraviolet and infrared; a linear model for all intents and purposes, no?


Well, keep in mind that no one has actually seen an EM wave, and in principle no one could. We can see interference patterns, and thinking about EM radiation as a wave turns out to be convenient for any number of reasons. But it's a model that happens to fit very snuggly with almost all our observations about EM radiation, so we stick with it (though there are those curious times that EM radiation behaves like a particle, not a wave). But without that model, what would we mean by such terms as "wavelength," "frequency," "and "amplitude?" And if we didn't measure those things, on what would that linear scale depend? Maybe something else, maybe nothing. I'm not sure there's a way we could know.

It's logically demonstrable that, for any given theory T, there is some theory T' that consists of different statements, but has exactly the same observational consequences. Some very smart philosophers and scientists believe that if the observational consequences are exactly the same, then the statements that make T and T' must be logically equivalent. Some equally smart philosophers and scientists think otherwise. I happen to fall into the latter camp--see W.V.O. Quine for discussion of scientific indeterminism at some length.

One more thought and I'll stop: Ever heard of something called "Synasthesia?" It's a fairly rare phenomenon where the person who is a synaesthete experiences some non-normative sensory stimuli in the presence of unrelated stimuli. For instance, a synasthete may see the number "3" and always hear middle C played on a piano. Or, on hearing a person sing at a certain pitch, the person always smells perfume.

It turns out to be a real phenomenon--not something that's just "in their head." One fairly well-reviewed experiment tested some synaesthetes' who heard a particular noise in the presence of a given word or symbol. The experimenters tested the subjects by showing them the words embedded in a large visual tableau where a normal subject would take a considerable amount of time to acquire the presence of the word (like, for instance, showing a movie-screen-size page from the New York Times that contained the word "skunk" in one of the stories). The synaesthetes were able to tell when the trigger word was present at the same speed that a person is able to respond to a heard stimulus--meaning that prior to them being able to locate the word visually, they heard the sound that tipped them off to the presence of the word. The effect was instantaneous in every instance--meaning that for the synaesthete, a given printed word really is accompanied by a sound.

This is a pretty weird result, and there's plenty of study of it. The interesting question for philosophers is this: could it be that given words "really" are accompanied by tones or sounds that most people are simply wired not to hear? Maybe yes, maybe no. How would you tell?
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 22:46:16

$this->bbcode_second_pass_quote('ashurbanipal', '
')Some very smart philosophers and scientists believe that if the observational consequences are exactly the same, then the statements that make T and T' must be logically equivalent. Some equally smart philosophers and scientists think otherwise. I happen to fall into the latter camp
Sure, that's plain enough. I'll take the former philosophy. Don't know about the synaesthetic thing, but that's pretty weird stuff Carson used to say.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby ashurbanipal » Tue 10 Jan 2006, 23:36:02

If it's a subject you're interested in, I can post what I think is a pretty ironclad argument for indeterminism.
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Tue 10 Jan 2006, 23:43:39

$this->bbcode_second_pass_quote('ashurbanipal', 'I')f it's a subject you're interested in, I can post what I think is a pretty ironclad argument for indeterminism.
Well then I could post for the minimaldeterminism side.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There
Top

Re: Color Perception Question

Unread postby ashurbanipal » Wed 11 Jan 2006, 11:14:40

I meant, there's an argument already extant in the literature that I'd be happy to explain. I ask because it bears on the subject at hand, but it takes quite a bit of explaining, and some people don't have the stomach to sit through a whole bunch of philosophy.
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Wed 11 Jan 2006, 11:47:52

I remember reading some philosophy about indeterminism. The idea was that each layer of reality is determined to the extent that the natural laws that govern it apply, but that not all possible behavior is determined by these laws as there is a gap in the determinism, a free zone of indeterminism, as it were, which allows for a higher layer to develop its own laws. Chemical laws arise from the indeterminate span of physical laws. Biological laws arise from the indeterminate span of chemical laws. Human phenomena arise from the indeterminate span of biological laws. Basically a fine argument against reductionism.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There

Re: Color Perception Question

Unread postby ashurbanipal » Wed 11 Jan 2006, 12:42:11

That sounds like an argument against functionalism (specifically its requirement that the universe be causally closed). Indeterminism is just the theory I briefly outlined earlier-namely that for any given set of observational consequences, two entirely different theories could be posited to account for all and only those consequences. Thus, we will never be able to determine which theory is true. We choose our theories by convention--not because we understand the thing in itself.

The classic argument (in fact, this is how indeterminism got recognized as a serious problem) was between Minkowski and Eddington. Minkowski showed that spaced was curved in the manner predicted by Reimann, and that thus Euclid's fifth postulate was incorrect. He did this by showing that rays of light curve slightly instead of following a straight line. Eddington argued that Euclid was correct, there were just universal forces that made the light curve through a Euclidian space--or at least, that's the theory we should prefer as it is the simpler of the two (which isn't at all clear). Pierre Duhem and W.V.O. Quine recognized that both theories could account for our observations, and so we would never be able to determine whether spacetime is actually Reimannian or Euclidian with forces that make things bend in a Reimannian manner. So we can, even in principle, never know which is correct.

The reply made by such men as Moritz Schlick and Rudolph Carnap is that, in that case, the two theories are really the same theory. But it doesn't seem that's the case, especially in light of a hypothetical third theory: T' ridiculous. Imagine a theory that posits some truly ridiculous circumstance that would cause light to bend--like, for instance, that invisible aliens always make it bend the right way so as to make space seem Reimannian. It doesn't seem like that theory is the same as saying that space is Reimannian. Schlick and Carnap would simply dismiss this line of reasoning, but even though it's a bit far fetched, I think it does have serious implications for how we understand what science does and the nature of our accumulated knowledge.

If we understand theories to be proposals for how the universe actually is, indeterminism turns out to be a very serious issue indeed--it seems to provide a compelling reason to think we can never know how the universe really is. This is not unexpected; it turns out that David Hume and Emmanuel Kant had a kind of posthumous conversation that entails exactly this.

But this doesn't mean that science is useless--far from it: it turns out to be one of the most useful means of acquiring knowledge. It's just that "knowledge" turns out to mean that we can substitute terms and find phenomenal relationships. But our models are tailored to be intelligible to our minds (which is not surprising). So when we look at the EM spectrum as a linear spectrum or on a color wheel, those are both just ways of organizing the phenomena we observe. They tell us nothing about the actual nature of the spectrum or other relevant factors--we can't find out about that.
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Re: Color Perception Question

Unread postby PenultimateManStanding » Wed 11 Jan 2006, 13:08:15

$this->bbcode_second_pass_quote('ashurbanipal', '
')in light of a hypothetical third theory: T' ridiculous. Imagine a theory that posits some truly ridiculous circumstance that would cause light to bend--like, for instance, that invisible aliens always make it bend the right way so as to make space seem Reimannian.
You draw alot of conclusions from this T' ridiculous third theory. I would rather not get bogged down in arcane speculations. True though they may be, they don't help to understand anything. Can't Kant, Hang Hume.
User avatar
PenultimateManStanding
Expert
Expert
 
Posts: 11363
Joined: Sun 28 Nov 2004, 04:00:00
Location: Neither Here Nor There
Top

Re: Color Perception Question

Unread postby ashurbanipal » Wed 11 Jan 2006, 13:50:38

Not precisely. It's the conceivability of T' ridiculous that is the problem. The fact that we can conceive such a theory indicates that our commonsense epistemic notions about science aren't as well supported as we thought.
In a world that is not whole, you have got to fight just to keep your soul.

-Ben Harper-
User avatar
ashurbanipal
Lignite
Lignite
 
Posts: 263
Joined: Tue 13 Sep 2005, 03:00:00
Location: A land called Honalee

Next

Return to Open Topic Discussion

Who is online

Users browsing this forum: No registered users and 2 guests

cron