jcs-online
menu I must be missing something. People are claiming that color is in the world rather than in the mind. That can't be true (consider dreams).
There are lots and lots of examples that one can give that perceived color is quite different from physical wavelength. As far as I know the word color refers to the subjective experience and the word wavelength refers to the physical aspect. Slightly better would be to talk about the number of photons caught by the three types of cones but that doesn't solve the problem of connecting the physical aspects of color to the subjective aspects. What does one mean by color if not subjective color? I guarantee you that nobody has yet derived a formula that can predict color from the physical stimulus. It is an active scientific research program. But it is very complicated. Perceived color depends on the size of the stimulus, the temporal frequency, the wavelength of light, the surrounding colors, the intensity of the stimulus, the place on the retina that the stimulus falls, the amount of prior full history of what had fallen on the retina, the history of what comes later (for about 100 msec so as not to violate causality too badly), the location on the pupil that the light enters (due to the wavequide nature of the cones), the amount of pigment in the media before photons are absorbed. etc. etc.
Anyone who want to get a better understanding of color should read Feynman's chapter on color in his Freshman introductory physics course. He began his lecture with Benham's top where a spinning black-white disk produces lots of different colors. The colors surely aren't in the world. They are in the brain. Isn't that totally obvious?
Back to the original point. There is an approach to understanding qualia that says it is a relationship between the internal activity and the outside world. I have never been able to understand that claim since one can have vivid images (rarely for me) without sensory input. So could someone please clarify how this image is "in the outside world".
Stan Klein