Edufer... <blockquote><font face="Lucida Grande, verdana,arial,helvetica" size="1">quote:</font><hr>Well, it seems that light is both things, at the same time.<hr></blockquote> You are referring to light and its properties. What I said was that <i>color</i> cannot be both photon impact on instruments and sensations. Sensations and photon impact on instruments are two entirely different processes, one of which contributes to the <i>experience of color</i>. The processes are not color, but one of them leads to the experience of color. <blockquote><font face="Lucida Grande, verdana,arial,helvetica" size="1">quote:</font><hr>As I said. It is only a matter of definition (or interpretation).<hr></blockquote> I agree. This is clearly a matter of definition. But it is not "only" a matter of definition. Definitions are <i>very</i> important for both science and the individual. There can be no (successful) science without a clear set of definitions that does not contradict each other. And without a somewhat consistent way of viewing the world, an individual would most likely be psychotic. <blockquote><font face="Lucida Grande, verdana,arial,helvetica" size="1">quote:</font><hr>Yes, only if you leave out time and space. <hr></blockquote> Right, there are conditions, aren't there? So I think we can conclude that the act of imagining something is not sufficient for making something exist. <blockquote><font face="Lucida Grande, verdana,arial,helvetica" size="1">quote:</font><hr>Only if he said "I think I AM Not."<hr></blockquote> The Descartes-thing was a joke referring to a famous quote of his: Cogito ergo sum, usually translated as 'I think, therefore I am'. Hence, if Descartes uttered the words "I think not," he would obviously disappear (in a grand puff of logic). Please Register or Log in to view the hidden image!
Correction (or addendum) Let me try again: They are. Photons are impacts on instrument sensors, and also impact on sensors located in the retina. In the case of instruments, the impacts are translated into different arbitrary measures (wavelenght, color temperature in Kelvin degrees, etc). In the retina, the impacts are translated and interpreted as a "sensation" known as "color". The different measures or interpretations we give to these physical actions are set by "definition". One definition makes "color" a sensation. Other definition makes color a physical action on an instrument. Phew! That happened to Descartes because he refused a drink. Never refuse a drink or you'll be damned!
An instrument can measure wavelength, but the measure should be referred to as "wavelength", not "color". A certain wavelength corresponds to a certain color, but it <i>is</i> not the color. Color is what we <i>experience</i> when certain conditions in the brain (not necessarily the visual system) are met. Color is something you <i>experience</i> following a basic process. But the process itself is not color. Take <a href="http://psy.ucsd.edu/~edhubbard/JCS.pdf">synaesthesia</a>, for instance. People with synaesthesia will experience color where there are no color to be found. How can this be, if color is photon impact on the retina? Yes, Descartes disapperared for a reason. So you see, you must drink if you're offered a drink! It's for your own good. (Or perhaps he disappeared because his photons didn't work any more... Please Register or Log in to view the hidden image! )
Colour is a physical phenomena. It is physics, pure and simple. However, our experience of colour is to do with our eyes and brain.
Our experience of color can be described as a physical phenomenon (neuronal action). In this respect, <i>color is a physical phenomenon</i>. But photons absorbed and bounced off objects are <i>not</i> color. There can be no color before color is experienced. It's as simple as that. There is no color in a world where no one sees. There are photons and wavelengths and all that, but no color.
Colour is exactly "photons and wavelengths and all that". If you have studied any psychology, you should know that our personal experience is not necessarily based on the world outside our heads. However, colour, whch is the variations in the spectrum of visible light, does not change because someone has faulty eyes. Only their perception changes. Colour is the difference in light based on wavelength. That's what the word "colour" means. Perception is something based on these neurological matters.
I think we need to distinguish between color as a sensory quality, and color as wavelengths and stuff. Please Register or Log in to view the hidden image! The existence of color (quality) is dependent upon the observer. The existence of color (photons and stuff) is independent upon the observer. There is color, and then there is color. Color was a quality before "color" became a label for the physical phenomena underlying the quality. Which is more real? For whom is one more real than the other? To take another perspective; What is pain? Is it the firing of pain receptors, or is it painful? (I have to admit, though, that I've done most of this brainless arguing because I'm bored. There's not much to do at work these days...)
