Rob C. put me onto this crazy stuff about "imaginary" colours. As a result of our subsequent conversation he sent me this most excellent gif. It's based on a drawing by René Descartes.
I actually read Descartes' Meditations on First Philosophy not that long ago. It was really worth it...especially because I had no idea that the whole thing is awkwardly framed as proof of the existence of God!! Poor guy. It sucked to be into science back then. The first section of the book is a letter to the Dean and Doctors of the sacred Faculty of Theology at Paris asking for endorsement.
I have always thought that two topics — namely God and the soul — are prime examples of subjects where demonstrative proofs ought to be given with the aid of philosophy rather than theology. For us who are believers, it is enough to accept on faith that the human soul does not die with the body, and that God exists; but in the case of unbelievers, it seems that there is no religion, and practically no moral virtue, that they can be persuaded to adopt until these two truths are proved to them by natural reason.
He didn't get the money.
Pet Peeve about science of colour: Who says we should be able to perceive pure colour, to recieve and register individual wavelengths? If colour is relative, and our perception is temporal, then isn't the digital or atomistic view of colour perception a model, a useful analytic tool for measuring and quantifying, rather than a description of 'the way things really are'? I get confused when the negotiations that eyes/brain take on in order to understand colour are expressed as subjective and internal in opposition to the empirical reality of the outside world (Semir Zeki, Splendours and Miseries of the Brain, pp.30-31). It's a Cartesian dichotomy. And aren't neuroscientists the very ones who are supposed to believe that mind is material? Terms like 'imaginary colour' add to my confusion. Imaginary as opposed to 'real'? Wha? I don't get it.
I think of it like "imaginary numbers". They are useful, and "real", they just get a somewhat unfortunate name. (Huh, i just looked at the wikipedia page, and the term "imaginary" was used as a diss 'gainst these numbers by ol' Rene himself.)
Think of our colour system has having an input gamut, and an output gamut:
http://en.wikipedia.org/wiki/Gamut
There are spots on the colour space of our eyes that can't be hit by the combinations of our colour sensors, but if they could, the brain *could* generate an output that we could "see". That's what's supposedly happening in that demo.
Compare this to a "colour" like "Bee's Purple" which is a mix of UV and yellow. Our eyes can't see it, and even if they could, our brain couldn't generate a sensation that corresponds to it.
You're right, Rob. It's the semantics that bug me, not the science. There is something really important in the understanding that we 'see' the world differently from other organisms and that the information we get is not the whole picture. There's no omniscience. But at the same time I think its also important to remember that all information goes through some kind of contingent sorting/organising process in our mind/brain, even at the very basic level of visual sensory input, and that the meaning-making aspects of perception are themselves part of our physiological function as an organism. Culture & nature are not as divided as we tend to think...can't have a functioning human body without associations, meaning-making and interactions.
I do think the demo is groovy...it's an attempt to see what we know is there but just aren't normally equipped to perceive.
One of the metafilter commenters in the thread made a great connection to art experience.
A few years ago I was visiting the National Gallery of Canada in Ottawa, and was spending some time with Barnett Newman's Voice of Fire. I knew it from the huge controversy that erupted when the NGC purchased the piece in 1989 for $1.8M, and it's been given a very prominent place in the gallery, so I was viewing it for quite a while. One of the guards noticed me and approached to tell me how to view the piece. "Stare at a spot on the rightmost edge of the red stripe" he said, "and hold your gaze there for a while". I did.
"Now switch to the left edge."
When I did the "red" stripe immediately exploded into a reddish-orange colour I've never seen before, or since. The after-image from the blue on top of the existing red created this beautiful, pulsating burst of pure awesomeness.
"That", he said as my mouth hung open in awe, "is the Voice of Fire"
posted by rocket88 at 7:34 AM on May 11
"But at the same time I think its also important to remember that all information goes through some kind of contingent sorting/organising process in our mind/brain, even at the very basic level of visual sensory input, and that the meaning-making aspects of perception are themselves part of our physiological function as an organism."
Absolutely. Never forget, for instance, that everything on the retina is upside down. Unless you live in the southern hemisphere, then it's right-side up, and you are upside down.
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Rob C. put me onto this crazy stuff about "imaginary" colours. As a result of our subsequent conversation he sent me this most excellent gif. It's based on a drawing by René Descartes.
I actually read Descartes' Meditations on First Philosophy not that long ago. It was really worth it...especially because I had no idea that the whole thing is awkwardly framed as proof of the existence of God!! Poor guy. It sucked to be into science back then. The first section of the book is a letter to the Dean and Doctors of the sacred Faculty of Theology at Paris asking for endorsement. He didn't get the money.
- sally mckay 5-13-2010 3:15 pm
Pet Peeve about science of colour: Who says we should be able to perceive pure colour, to recieve and register individual wavelengths? If colour is relative, and our perception is temporal, then isn't the digital or atomistic view of colour perception a model, a useful analytic tool for measuring and quantifying, rather than a description of 'the way things really are'? I get confused when the negotiations that eyes/brain take on in order to understand colour are expressed as subjective and internal in opposition to the empirical reality of the outside world (Semir Zeki, Splendours and Miseries of the Brain, pp.30-31). It's a Cartesian dichotomy. And aren't neuroscientists the very ones who are supposed to believe that mind is material? Terms like 'imaginary colour' add to my confusion. Imaginary as opposed to 'real'? Wha? I don't get it.
- sally mckay 5-13-2010 3:51 pm
I think of it like "imaginary numbers". They are useful, and "real", they just get a somewhat unfortunate name. (Huh, i just looked at the wikipedia page, and the term "imaginary" was used as a diss 'gainst these numbers by ol' Rene himself.)
Think of our colour system has having an input gamut, and an output gamut:
http://en.wikipedia.org/wiki/Gamut
There are spots on the colour space of our eyes that can't be hit by the combinations of our colour sensors, but if they could, the brain *could* generate an output that we could "see". That's what's supposedly happening in that demo.
Compare this to a "colour" like "Bee's Purple" which is a mix of UV and yellow. Our eyes can't see it, and even if they could, our brain couldn't generate a sensation that corresponds to it.
- rob (guest) 5-13-2010 4:10 pm
You're right, Rob. It's the semantics that bug me, not the science. There is something really important in the understanding that we 'see' the world differently from other organisms and that the information we get is not the whole picture. There's no omniscience. But at the same time I think its also important to remember that all information goes through some kind of contingent sorting/organising process in our mind/brain, even at the very basic level of visual sensory input, and that the meaning-making aspects of perception are themselves part of our physiological function as an organism. Culture & nature are not as divided as we tend to think...can't have a functioning human body without associations, meaning-making and interactions.
I do think the demo is groovy...it's an attempt to see what we know is there but just aren't normally equipped to perceive.
One of the metafilter commenters in the thread made a great connection to art experience.
- sally mckay 5-13-2010 5:02 pm
"But at the same time I think its also important to remember that all information goes through some kind of contingent sorting/organising process in our mind/brain, even at the very basic level of visual sensory input, and that the meaning-making aspects of perception are themselves part of our physiological function as an organism."
Absolutely. Never forget, for instance, that everything on the retina is upside down. Unless you live in the southern hemisphere, then it's right-side up, and you are upside down.
- rob (guest) 5-14-2010 3:02 pm