February 28, 2005

Causes of Color
posted by Gyan 19 years ago
  • But nothing about the cause of the color when I close my eyes and see. Do all see the spring grass the same?
  • Nope, don't have to close my eyes to see spring grass. Or a bird. Or a familiar face. As to seeing things the same, I have a slight discrepancy of colour perception between my eyes -- if I look at a sheet of white paper with one eye, then the other, the paper will appear slightly green-tinged according to my left eye, slightly pinkish according to the right. Don't know why this is, it's something I became aware of as a kid in grade school. Been quite consistent over the years.
  • Actually, isn't the cause of color our eyes. as an extensin of the brain? Not all animals have the same receptors that we do and see fewer or, maybe more colors than we do, so The effects of the fifteen causes only relate to our perception. The causes would be there whether we could percieve them or not, and there may be more causes that we don't understand since we don't percieve their effect. And a banana wouldn't appear yellow in very dim light. When a banana looks gray, what does that say about microconsiousness? Perhaps our memory of a yellow banana in brighter light could stand in for the lack. And, surface colors can change, depending on the amount of light. I onced painted a room in a sort of rose beige, but took on shades of raspberry in dim light. Walls also reflect colors from carpets, or whatever. If I shined a flashlight on a section of a wall that picked up color from a rug, it certainly would't look the same shade as it did under lamp light.
  • Oops, hit post instead of preview, and that's as far as I've gotten. But, so far, this reminds me of philosophers who did things like define, for example, the nature of an object to be only able to be understood by what one could touch, and then went on to prove it by refusing to consider all other ways of sensing it.
  • Metaphysics is not my forte, path, but back in dreadful undergrad days metaphysics was inflicted on me in philosophy courses and the desired conclusion seemed to be that sensory data cannot necessarily be construed to be evidence of anything other than cells firing in the brain. After that, all is Terra Incognita. And now bees, my lad, wouldn't ye rather study something else? Oh yes, Fool would, yes, indeed! and off dashesFool to enroll in some other major. A narrow escape, I'm telling ye.
  • Colors are really neat. I recommend the last section in particular, which deals with colorblindness and the way animals see. Thing is, most of us have only three different types of cones, so we only see different wavelengths because they stimulate the cones in our eyes to varying degrees. This is why your computer monitor can get away with showing practially any color despite the fact that it can only emit three distinct colors. E.g., when you see a yellow flower, it stimulates your nerves in the same way any number of mixtures of light will-- your primitive body can't tell the difference. This is why some colorblind people don't simply fail to differentiate between colors like normals do, but can in fact differentiate between two object a normal would say have the same color. What really blows my mind are the possibilities that exist if we could technologically add additional frequencies to our repertoire. We'd be able to see colors never even dreamed of. There would ba a revolution in art. A normal today, compared to someone with enhanced eyes, would be like someone who saw in black and white.
  • ...I have a slight discrepancy of colour perception between my eyes -- if I look at a sheet of white paper with one eye, then the other, the paper will appear slightly green-tinged according to my left eye, slightly pinkish according to the right. Don't know why this is, it's something I became aware of as a kid in grade school. bees, maybe it'd help if you took off the 3D glasses.
  • We'd be able to see colors never even dreamed of. An interesting possibility - or would we just see the same colours more accurately? Pigeons see four different basic colours, but alas cannot explain what it's like. I'm have inclined to think the spectrum is a basic reality which cannot be augmented, but I realise that sounds like mere lack of imagination. The real problem is that we can't see two colours in the same place at the same time. Compare sound - hearing middle C and the E above it does not sound like D: but seeing red wavelengths and yellow wavelengths together does look the same as seeing orange wavelengths. I suppose it's because sound isn't allocated a precise position, whereas perceived light is generally attributed to the object reflecting it. Hence it has a definite position, and a single point in space can't have two different qualities.
  • Third sentence - delete 'have'. One reason for thinking the spectrum encompasses all possible colours is the way it forms a closed circle - the violet at one end shades naturally into the red at the other. If we could see further into the ultraviolet or infrared this suggests the colours would repeat, the way notes on the musical scale do. That comparison may be artificial, though: I believe the reason we have seven standard colours is that Newton wanted to match the musical scale, and inserted 'Indigo' rather artificially. To rise or fall by an octave in sound, you halve or double the wavelength - does anyone know whether the top of the visible spectrum is approximately double the bottom (I doubt it). ...shutting up now.
  • Apparently it's 4000 to 7000 Angstroms, which given that we don't see only 'seven' colours, not the eighth (and first repetition) actually fits the octave idea rather well... ...this time I mean it.
  • I believe the reason we have seven standard colours is that Newton wanted to match the musical scale, and inserted 'Indigo' rather artificially. Indigo was inserted by christians that thought seven to be a divine number (because of the seven days for creation) and six devilish (because of the beast's number). So saying "rainbows have six colors" is the same as saying "rainbows are sent by the devil".