In reply to my
postDavidMcC wrote:Load of BS! The blue sky is simply the higher scattering cros-section for blue light by nitrogen molecules in the air. The red sunset likewise, because the scattering in this case is out and not into our eyes.
When we receive red light mixed with violet light, ie long wavelength mixed with short wavelength, why do we not experience medium wavelength, ie green?
Colour percepton is not a question of averaging, unless the colours are quite close in the spectrum, which red and violet are not. The colour, violet is itself a mixture of red and blue cone signals, IMO, because "red" cone cells actually have a small response peak in the violet. This is all but lost in the background signal in mammalian opsins. However, it is clear in avian opsins, where the response curves extend into UVA (ie, ~350nm), and a distinct second response peak is visible for "seeing red".
http://en.wikipedia.org/wiki/File:BirdVisualPigmentSensitivity.svgThis is why tritanopes (who lack the SW cones) see violet as a dark red.
When I look though a prism at a black/white edge I see the red/yellow end of the spectrum, when I look at a white/black edge I see the violet/blue end. If I bring these two images together so that they meet then I see the yellow and blue merging into green. Now if I look at the reverse spectrum using white with a black band in between then as the black band narrows to bring the red and the violet ends together I see magenta. This is the inverted spectrum. In this case red and violet are close in the spectrum.
Arthur Zajonc has the following to say:The whole idea of science is, of course, based on objectification - to become objective in your knowing, which typically means distancing. Conventional science objectifies by taking an experience and replacing it by a set of more "fundamental" objects such as atoms, molecules, interactions, and so forth. So, as opposed to the blue of the sky, physics says it's Mie scattering and the blue results from small, polarizable molecules interacting with electromagnetic fields, setting up secondary waves. This leads to a differential scattering cross-section with a dependence on the fourth power of the frequency. In this way you have an objectified account. And now it's been protected from the dangers presented by my subjective experience. Namely, I see blue - and I like blue a lot (or whatever other subjective association might be there).
Goethe took a very different approach. He was aware of the dangers of personal interpretation and inappropriate subjectivity. So he sought to mitigate those dangers in a variety of ways. But, as I see it, his resolution of the problem was contrary to the above goal of objectification. Rather than becoming distant from phenomena by taking models as the intermediary, Goethe sought to refine and cultivate the investigator's capacities for perception.
Science says to step back and gain a distance, because you're inevitably going to make a mess of the subject you are investigating. Goethe said, no, become more graceful, become more delicate in your observing. He called it a delicate empiricism. He said that there exists a delicate empiricism in which the observer becomes united with the observed, thereby raising observation to true theory. He said this ability belongs to a very highly cultivated age in the future.
So this delicate empiricism allows one to come close to the phenomenon under investigation, as opposed to having to move further away. One actually unites with the object under observation. Rather than disconnecting from nature, one is participating in it. Through that participation, something happens. Here's one of the other elements from Goethe that is key for me, what I call Bildung, which has two meanings in German: on the one hand it means "education," but really it means "formation."
By attending to an object or phenomenon, one moves into and participates in that phenomenon and, as a consequence, brings an activity into one's self which is normally outside. I see the blue; I bring the blue into my self.
There's a blue experience. That blue experience actually cultivates something in me. The closer I attend, the more shades of blue I will be able to discern. The conditions of appearance will become more apparent. So, through the process of attention, there's also a process in me of transformation.
Goethe said, "Every object well-contemplated creates an organ within us." So contemplate the object well; that creates a capacity within. That capacity is then required for the last step of perceiving the archetypal phenomenon. If you don't have the organ, you won't be able to perceive it; you'll just see the blue sky.
So there's a kind of hermeneutic circle in which I attend to the outside with the capacities I presently have. That attention then cultivates capacities within that are built on the rudimentary - you might say elementary - forms of capacities and organs I currently have. It cultivates them and develops them into a new, more vigorous and attentive form of cognition. I bring these to bear on the phenomenon before me, and it goes again through another cycle.
Goethe's notion of science is transformative. You do not come with a pre-existing set of capacities that include, say, rational, deductive capacities, as well as eyes and ears and so on - the physical senses. Rather there's a kind of organic, dynamic sense of the human being and the human being's potential. That potential is cultivated and actuated through an active engagement with the world.
Delicate empiricism, its the way forward.
by 
