9 ms·

The Problem of Colour

58 points by prismatic 9y ago

breckinloggins 9y ago
> Focus on a colour in your immediate environment and ask yourself whether that could really be only a figment of your mind. Yes, of course that could really be the case. It's a bit of a downer that this article ends with an argument from incredulity.
- danielam 9y ago
  That's a very facile response to the article (sadly, the article doesn't go into any depth on the subject). One could just as well ask the same about any property that we perceive in the senses and later apprehend through the intellect. EDIT: I did find this review, but I haven't read it[0]. [0] http://ndpr.nd.edu/news/a-naive-realist-theory-of-colour/ http://ndpr.nd.edu/news/a-naive-realist-theory-of-colour/
  - mannykannot 9y ago
    > One could just as well ask the same about any property that we perceive in the senses and later apprehend through the intellect. Indeed, and I have this nagging feeling that there might be something to it. It goes along with the suspicion that neither what I perceive through my senses nor what I apprehend through my intellect are as coherent as they feel, but perhaps that's just me.
    - aklemm 9y ago
      I've been going through this for a couple years now on just about any issue I go deep on. It is unsettling and points toward meaningless (even against relative meaning derived from each other), which is even more unsettling.
      - yesenadam 9y ago
        >Nobody perceives reality as it actually is. A couple of comments: This sentence has a misleading form. It sounds like "Nobody here has a hat", denying something quite unproblematically possible. But would would it mean to perceive reality 'as it actually is'? The phrase seems confused. Like people who worry about life being meaningless, there's a category error being made somewhere. And the phrase 'reality as it actually is' is but a modern version of the Kantian 'reality as-it-is-in-itself', (of which nothing could be known or said). Some of the problems coming from such language (i.e. most of Idealism and relativism in their various forms) and their history have been entertainingly explored by the philosophers Musgrave[0] and Stove[1]. e.g. "We can eat oysters only insofar as they are brought under the physiological and chemical conditions which are the presuppositions of the possibility of being eaten. Therefore, we cannot eat oysters as they are in themselves." or "We have eyes, therefore we can't see." [0] Alan Musgrave, Idealism and Antirealism http://www.phil-fak.uni-duesseldorf.de/fileadmin/Redaktion/Institute/Philosophie/Theoretische_Philosophie/Fahrbach/Metaphysik_der_Gegenwart/Musgrave%20Idealism%20and%20Antirealism.pdf http://www.phil-fak.uni-duesseldorf.de/fileadmin/Redaktion/I... [1] Stove's Discovery of the Worst Argument in the World http://web.maths.unsw.edu.au/~jim/worst.html http://web.maths.unsw.edu.au/~jim/worst.html
        goatlover 9y ago
        > But would would it mean to perceive reality 'as it actually is'? It would mean that direct perception is the case. We directly perceive the objects out there in the world as they are, not a representation of some sort in our heads. > We have eyes, therefore we can't see. It's more like, we have eyes that provide our brains with information to color in the world in response to visible light reflecting off objects. But that doesn't answer the question about whether the world is actually colored. What if we had a different kind of eyes, or our visual cortex processed the information differently? Is only the visible light colored, or do radio waves have colors, or is the color on the surface of objects themselves?
        yesenadam 9y ago
        >We directly perceive the objects out there in the world as they are, not a representation of some sort in our heads. My point was that this is a grammatical sentence, but like a christian talking of eternal life, the impossibility and unimaginability of the thing is ignored. That bit about the eyes was a TL;DR and teaser for the linked (very funny) papers, which doesn't mean much without them I guess. It's a spoof/reductio of a kind of argument which has often been used in philosophy, Stove's Gem. Yes sorry, not answering questions. I seem to spend more time questioning questions. They often conceal and smuggle in false assumptions.
- senectus1 9y ago
  Colour is a pigment of your imagination...
- empath75 9y ago
  Basically all of perceived reality is a simulation created by your mind from very incomplete information. Nobody perceives reality as it actually is. It’s all just vibrations in various fields, and any macroscopic interpretation above that is your imagination, from your own personal identity to the colors you see.
theoh 9y ago
The comet-like image near the top of the page is actually a cropped and rotated image of a painting by Hilma af Klint, who is a remarkable early abstract artist. I'm not personally outraged by the casual manipulation and instrumentalisation of that painting by some graphic designer -- it is in the public domain -- but it seems like a very unprincipled and ignorant thing to do. The title of the painting is "Altar Painting, No. 1".
- mirimir 9y ago
  There is an acknowledgment at the bottom: > Featured image credit: Altarpiece, No. 1, Group X, Altarpieces by Hilma af Klint. Public domain via Wikimedia Commons.
danielam 9y ago
I don't know what this book argues specifically, but the problem of color is very much a special case of the problem of qualia. If one takes a presumptuous and shallow view of science, one might be inclined to accept Galileo's characterization of color. However, that's just an accident of history and not the result of having comprehended some essential scientific fact concerning color. The invention and subsequent consignment of qualia (here, color) to conscious experience is the consequence not of scientific discovery, but of a metaphysics -- and a deeply flawed metaphysics at that -- that has been lurking in our thinking since Galileo and Descartes. That metaphysics proposes that the world is composed of two kinds of substances, namely, the material res extensa (things extended in space) and the immaterial res cogitans (for all intents and purposes, minds). What can not be attributed to res extensa (e.g., color) is attributed to minds, so really, when physicists talk about color, they are not speaking of color in conformity with the common understanding of color, but in terms of a redefinition of color. The problem of qualia comes into play most especially when a materialist metaphysical position is accepted of the kind where the immaterial res cogitans is denied. The materialist is then faced with the task of explaining how all of that which was attributed to minds (e.g., color) -- and indeed minds themselves -- is really something that can be attributed to res extensa. The kicker is, of course, that you can't, at least not without radically reforming how you understand matter. It is by definition impossible to locate color in matter given a Cartesian understanding of matter. Many physicists, in their more philosophical moments, tacitly accept a metaphysical position of that kind. What's important is that the modern understanding of color, one that attributes it to consciousness rather than things, is not a scientific position. It is a metaphysical position and a very problematic one that is running its course as philosophers and scientists try helplessly and in vain to explain things like consciousness and the objects of consciousness.
- ChrisSD 9y ago
  I'm not sure I understand your point? If I feel confused, that's a real physical thing. Sure we say emotions are in my mind but my mind is part of my whole body which is a physical thing we can touch and dissect (if not yet fully understand). Similarly my understanding and perception of the colours I see comes from a real physical body that has accumulated a lot of sensory input and experiences and uses that to interpret new sensory input. I can't explain to you how I experience the colour blue but I don't need to grapple with metaphysics to explain, in principle, why I might experience it that way.
mirimir 9y ago
I'm surprised that the article doesn't mention purple, a color that isn't part of the visible spectrum. It's a mixture of blue and red.
- empath75 9y ago
  Sort of. Violet is on the blue end of the spectrum and a lot of people would classify it as purple. Magenta is the one that only exists as a composite.
  - mirimir 9y ago
    Well, having deuteranopia, purples and violets are difficult for me to distinguish. But for sure, purple is a composite.
- Double_Cast 9y ago
  Unfair. We also lack cones for yellow and cyan. (Except for the tetrachromatic 2%, who experience a 4th primary color where "yellow" ought to be.)
  - stepik777 9y ago
    And what does this have to do with colors being spectral? If you look at the cie chromaticity diagram you can see that yellow and cyan have wavelength corresponding to them while purple does not.
    - Double_Cast 9y ago
      Yellow, cyan, and magenta don't correspond to particular wavelengths. They each correspond to a combination of two particular, adjacent wavelengths. E.g. a "yellow" wavelength is only as bright as its decomposition into red and green. The fact that red & blue aren't adjacent is a red herring.
      - stepik777 9y ago
alexasmyths 9y ago
I thought this was going to be an "sRGB vs P3, and fixing images for colour gamuts" article because that's also a goddam metaphysical rabbit hole can't seem to be solved ...
iainmerrick 9y ago
Modern scientific theories do not explain experiences of colour by appealing to the colours of objects, but instead in terms of objects’ dispositions to reflect, refract, or emit light across different parts of the electromagnetic spectrum. The conclusion that many have drawn is that we either need to identify colours with the physical properties of things that cause our colour experiences, or admit—like Galileo—that colours do not exist. Explaining colour in terms of how objects reflect, refract or emit different wavelengths of light (and similarly for the rods and cones in our eyes) sounds perfectly satisfactory to me. What's the problem with that theory? I really don't see the point of all the metaphysical stuff. It just doesn't tell you anything useful.
- fmoralesc 9y ago
  Dispositional properties are just as difficult metaphysically than any other type of property.
  - iainmerrick 9y ago
    What's an example of an object property that is philosophically or metaphysically straightforward?
    - dummyfunnytoo 9y ago
      I'm not sure about straightforward but, as an example, temperature seems simpler than colour.
      - mturmon 9y ago
        Not so fast. By the time you rope in the notions of absolute zero, entropy, and Maxwell's demon, you could kick up enough dust to keep a whole stable of grad students busy. These debates are less about a clear and present problem, than a mode of inquiry asking to look again at something "familiar" in a different way.
        9y ago
Theodores 9y ago
Recently I learned that there were only four colours in rainbows, in medieval times. Then Newton came along and decided there were 'as many colours in a rainbow as there are notes in an octave'. This gave us the spectrum we have today.
- idle_processor 9y ago
  The choice of colors in some medieval rainbow depictions was interesting, too. > For it is of four colours, and takes its appearance from all of the elements into itself. From the sky it draws the fiery colour, from the waters purple, from the air white, and from the earth it gathers black. Source: https://forthewynnblog.wordpress.com/2017/11/20/how-many-colours-were-there-in-a-medieval-rainbow/ https://forthewynnblog.wordpress.com/2017/11/20/how-many-col...
GistNoesis 9y ago
Made me think of unrelated but interesting color-related article about gamma correction seen last year on HN : https://news.ycombinator.com/item?id=12552094 https://news.ycombinator.com/item?id=12552094
dragonwriter 9y ago
Is that a hostile parody of philosophy? > Focus on a colour in your immediate environment and ask yourself whether that could really be only a figment of your mind, or at best radically different from the way it appears. That question, which seems to be the bottom line on color before moving to the even more problematic broadening of the issue in the conclusion, is quite lazy; the answer is self-evident yes, and that's true even for traits that the article notes fundamentally do apply to objects (like shape), as anyone who has ever looked through a distorting lens or mirror (or had a visual hallucination) can readily attest. He “problem”, such as it is, of color is not that a color one perceives might be different from the actual color of the object, but that color is not a property of objects at all, but instead an artifact of compressing information carried by the wavelengths of light impacting the eye to a smaller-dimensonal space, and that even the wavelengths of light that will be received is not purely a trait of the object perceived, but an effect of the combination of several of its traits with features of the environment. But, of courses this isn't a problem for anything out a particular preference for the nature of reality, it's just a well-established fact. At some point our model of reality must be adapted to known facts rather than merely reflecting what we'd prefer to believe. The ultimate conclusion of the piece goes even further off the rails. > Moreover, colour is arguably only the thin end of the wedge. One of the reasons why colours are philosophically interesting is that they provide an illustration of general problems that arise in thinking about the “manifest image” of the world, or the world as it appears to us as conscious subjects. It is not just colours that are under threat. Similar problems arise for aesthetic properties like beauty That beauty is not an inherent property of objects but a subjective response of the observer has been indisputable and widely recognized for much longer than the same is true for color, so that’s a ludicrous thing to point to when claiming color is the thin edge of the wedge. > for moral properties like right and wrong Well, yes, this is the philosophically most interesting one, and it's worthy of discussion, but this piece doesn't even begin to be that discussion, or even indirectly illuminate the issue. > —even for what philosophers have traditionally called “primary qualities” like shape and size. Well, sure, somethingnsimilar applies there, though the problem there is somewhat different, and connects to the more fundamental problem that the objects to which we apply traits aren't fundamental entities, but arbitrary and subjective divisions of the underlying reality.
cafard 9y ago
Since nobody else has yet, https://xkcd.com/1882/ https://xkcd.com/1882/

58 points by prismatic 9y ago

> Focus on a colour in your immediate environment and ask yourself whether that could really be only a figment of your mind. Yes, of course that could really be the case. It's a bit of a downer that this article ends with an argument from incredulity.

danielam 9y ago
That's a very facile response to the article (sadly, the article doesn't go into any depth on the subject). One could just as well ask the same about any property that we perceive in the senses and later apprehend through the intellect. EDIT: I did find this review, but I haven't read it[0]. [0] http://ndpr.nd.edu/news/a-naive-realist-theory-of-colour/ http://ndpr.nd.edu/news/a-naive-realist-theory-of-colour/
- mannykannot 9y ago
  > One could just as well ask the same about any property that we perceive in the senses and later apprehend through the intellect. Indeed, and I have this nagging feeling that there might be something to it. It goes along with the suspicion that neither what I perceive through my senses nor what I apprehend through my intellect are as coherent as they feel, but perhaps that's just me.
  - aklemm 9y ago
    I've been going through this for a couple years now on just about any issue I go deep on. It is unsettling and points toward meaningless (even against relative meaning derived from each other), which is even more unsettling.
    - yesenadam 9y ago
      >Nobody perceives reality as it actually is. A couple of comments: This sentence has a misleading form. It sounds like "Nobody here has a hat", denying something quite unproblematically possible. But would would it mean to perceive reality 'as it actually is'? The phrase seems confused. Like people who worry about life being meaningless, there's a category error being made somewhere. And the phrase 'reality as it actually is' is but a modern version of the Kantian 'reality as-it-is-in-itself', (of which nothing could be known or said). Some of the problems coming from such language (i.e. most of Idealism and relativism in their various forms) and their history have been entertainingly explored by the philosophers Musgrave[0] and Stove[1]. e.g. "We can eat oysters only insofar as they are brought under the physiological and chemical conditions which are the presuppositions of the possibility of being eaten. Therefore, we cannot eat oysters as they are in themselves." or "We have eyes, therefore we can't see." [0] Alan Musgrave, Idealism and Antirealism http://www.phil-fak.uni-duesseldorf.de/fileadmin/Redaktion/Institute/Philosophie/Theoretische_Philosophie/Fahrbach/Metaphysik_der_Gegenwart/Musgrave%20Idealism%20and%20Antirealism.pdf http://www.phil-fak.uni-duesseldorf.de/fileadmin/Redaktion/I... [1] Stove's Discovery of the Worst Argument in the World http://web.maths.unsw.edu.au/~jim/worst.html http://web.maths.unsw.edu.au/~jim/worst.html
      - goatlover 9y ago
        > But would would it mean to perceive reality 'as it actually is'? It would mean that direct perception is the case. We directly perceive the objects out there in the world as they are, not a representation of some sort in our heads. > We have eyes, therefore we can't see. It's more like, we have eyes that provide our brains with information to color in the world in response to visible light reflecting off objects. But that doesn't answer the question about whether the world is actually colored. What if we had a different kind of eyes, or our visual cortex processed the information differently? Is only the visible light colored, or do radio waves have colors, or is the color on the surface of objects themselves?
        yesenadam 9y ago
        >We directly perceive the objects out there in the world as they are, not a representation of some sort in our heads. My point was that this is a grammatical sentence, but like a christian talking of eternal life, the impossibility and unimaginability of the thing is ignored. That bit about the eyes was a TL;DR and teaser for the linked (very funny) papers, which doesn't mean much without them I guess. It's a spoof/reductio of a kind of argument which has often been used in philosophy, Stove's Gem. Yes sorry, not answering questions. I seem to spend more time questioning questions. They often conceal and smuggle in false assumptions.
senectus1 9y ago
Colour is a pigment of your imagination...
empath75 9y ago
Basically all of perceived reality is a simulation created by your mind from very incomplete information. Nobody perceives reality as it actually is. It’s all just vibrations in various fields, and any macroscopic interpretation above that is your imagination, from your own personal identity to the colors you see.

theoh 9y ago

The comet-like image near the top of the page is actually a cropped and rotated image of a painting by Hilma af Klint, who is a remarkable early abstract artist. I'm not personally outraged by the casual manipulation and instrumentalisation of that painting by some graphic designer -- it is in the public domain -- but it seems like a very unprincipled and ignorant thing to do. The title of the painting is "Altar Painting, No. 1".

mirimir 9y ago
There is an acknowledgment at the bottom: > Featured image credit: Altarpiece, No. 1, Group X, Altarpieces by Hilma af Klint. Public domain via Wikimedia Commons.

danielam 9y ago

I don't know what this book argues specifically, but the problem of color is very much a special case of the problem of qualia. If one takes a presumptuous and shallow view of science, one might be inclined to accept Galileo's characterization of color. However, that's just an accident of history and not the result of having comprehended some essential scientific fact concerning color. The invention and subsequent consignment of qualia (here, color) to conscious experience is the consequence not of scientific discovery, but of a metaphysics -- and a deeply flawed metaphysics at that -- that has been lurking in our thinking since Galileo and Descartes. That metaphysics proposes that the world is composed of two kinds of substances, namely, the material res extensa (things extended in space) and the immaterial res cogitans (for all intents and purposes, minds). What can not be attributed to res extensa (e.g., color) is attributed to minds, so really, when physicists talk about color, they are not speaking of color in conformity with the common understanding of color, but in terms of a redefinition of color. The problem of qualia comes into play most especially when a materialist metaphysical position is accepted of the kind where the immaterial res cogitans is denied. The materialist is then faced with the task of explaining how all of that which was attributed to minds (e.g., color) -- and indeed minds themselves -- is really something that can be attributed to res extensa. The kicker is, of course, that you can't, at least not without radically reforming how you understand matter. It is by definition impossible to locate color in matter given a Cartesian understanding of matter. Many physicists, in their more philosophical moments, tacitly accept a metaphysical position of that kind. What's important is that the modern understanding of color, one that attributes it to consciousness rather than things, is not a scientific position. It is a metaphysical position and a very problematic one that is running its course as philosophers and scientists try helplessly and in vain to explain things like consciousness and the objects of consciousness.

ChrisSD 9y ago
I'm not sure I understand your point? If I feel confused, that's a real physical thing. Sure we say emotions are in my mind but my mind is part of my whole body which is a physical thing we can touch and dissect (if not yet fully understand). Similarly my understanding and perception of the colours I see comes from a real physical body that has accumulated a lot of sensory input and experiences and uses that to interpret new sensory input. I can't explain to you how I experience the colour blue but I don't need to grapple with metaphysics to explain, in principle, why I might experience it that way.

mirimir 9y ago

I'm surprised that the article doesn't mention purple, a color that isn't part of the visible spectrum. It's a mixture of blue and red.

empath75 9y ago
Sort of. Violet is on the blue end of the spectrum and a lot of people would classify it as purple. Magenta is the one that only exists as a composite.
- mirimir 9y ago
  Well, having deuteranopia, purples and violets are difficult for me to distinguish. But for sure, purple is a composite.
Double_Cast 9y ago
Unfair. We also lack cones for yellow and cyan. (Except for the tetrachromatic 2%, who experience a 4th primary color where "yellow" ought to be.)
- stepik777 9y ago
  And what does this have to do with colors being spectral? If you look at the cie chromaticity diagram you can see that yellow and cyan have wavelength corresponding to them while purple does not.
  - Double_Cast 9y ago
    Yellow, cyan, and magenta don't correspond to particular wavelengths. They each correspond to a combination of two particular, adjacent wavelengths. E.g. a "yellow" wavelength is only as bright as its decomposition into red and green. The fact that red & blue aren't adjacent is a red herring.
    - stepik777 9y ago

alexasmyths 9y ago

I thought this was going to be an "sRGB vs P3, and fixing images for colour gamuts" article because that's also a goddam metaphysical rabbit hole can't seem to be solved ...

iainmerrick 9y ago

Modern scientific theories do not explain experiences of colour by appealing to the colours of objects, but instead in terms of objects’ dispositions to reflect, refract, or emit light across different parts of the electromagnetic spectrum. The conclusion that many have drawn is that we either need to identify colours with the physical properties of things that cause our colour experiences, or admit—like Galileo—that colours do not exist. Explaining colour in terms of how objects reflect, refract or emit different wavelengths of light (and similarly for the rods and cones in our eyes) sounds perfectly satisfactory to me. What's the problem with that theory? I really don't see the point of all the metaphysical stuff. It just doesn't tell you anything useful.

fmoralesc 9y ago
Dispositional properties are just as difficult metaphysically than any other type of property.
- iainmerrick 9y ago
  What's an example of an object property that is philosophically or metaphysically straightforward?
  - dummyfunnytoo 9y ago
    I'm not sure about straightforward but, as an example, temperature seems simpler than colour.
    - mturmon 9y ago
      Not so fast. By the time you rope in the notions of absolute zero, entropy, and Maxwell's demon, you could kick up enough dust to keep a whole stable of grad students busy. These debates are less about a clear and present problem, than a mode of inquiry asking to look again at something "familiar" in a different way.
      - 9y ago

Theodores 9y ago

Recently I learned that there were only four colours in rainbows, in medieval times. Then Newton came along and decided there were 'as many colours in a rainbow as there are notes in an octave'. This gave us the spectrum we have today.

idle_processor 9y ago
The choice of colors in some medieval rainbow depictions was interesting, too. > For it is of four colours, and takes its appearance from all of the elements into itself. From the sky it draws the fiery colour, from the waters purple, from the air white, and from the earth it gathers black. Source: https://forthewynnblog.wordpress.com/2017/11/20/how-many-colours-were-there-in-a-medieval-rainbow/ https://forthewynnblog.wordpress.com/2017/11/20/how-many-col...

GistNoesis 9y ago

Made me think of unrelated but interesting color-related article about gamma correction seen last year on HN : https://news.ycombinator.com/item?id=12552094 https://news.ycombinator.com/item?id=12552094

dragonwriter 9y ago

Is that a hostile parody of philosophy? > Focus on a colour in your immediate environment and ask yourself whether that could really be only a figment of your mind, or at best radically different from the way it appears. That question, which seems to be the bottom line on color before moving to the even more problematic broadening of the issue in the conclusion, is quite lazy; the answer is self-evident yes, and that's true even for traits that the article notes fundamentally do apply to objects (like shape), as anyone who has ever looked through a distorting lens or mirror (or had a visual hallucination) can readily attest. He “problem”, such as it is, of color is not that a color one perceives might be different from the actual color of the object, but that color is not a property of objects at all, but instead an artifact of compressing information carried by the wavelengths of light impacting the eye to a smaller-dimensonal space, and that even the wavelengths of light that will be received is not purely a trait of the object perceived, but an effect of the combination of several of its traits with features of the environment. But, of courses this isn't a problem for anything out a particular preference for the nature of reality, it's just a well-established fact. At some point our model of reality must be adapted to known facts rather than merely reflecting what we'd prefer to believe. The ultimate conclusion of the piece goes even further off the rails. > Moreover, colour is arguably only the thin end of the wedge. One of the reasons why colours are philosophically interesting is that they provide an illustration of general problems that arise in thinking about the “manifest image” of the world, or the world as it appears to us as conscious subjects. It is not just colours that are under threat. Similar problems arise for aesthetic properties like beauty That beauty is not an inherent property of objects but a subjective response of the observer has been indisputable and widely recognized for much longer than the same is true for color, so that’s a ludicrous thing to point to when claiming color is the thin edge of the wedge. > for moral properties like right and wrong Well, yes, this is the philosophically most interesting one, and it's worthy of discussion, but this piece doesn't even begin to be that discussion, or even indirectly illuminate the issue. > —even for what philosophers have traditionally called “primary qualities” like shape and size. Well, sure, somethingnsimilar applies there, though the problem there is somewhat different, and connects to the more fundamental problem that the objects to which we apply traits aren't fundamental entities, but arbitrary and subjective divisions of the underlying reality.

cafard 9y ago

Since nobody else has yet, https://xkcd.com/1882/ https://xkcd.com/1882/