I Am a Strange Loop - Douglas R. Hofstadter [208]
Glebbing and Knurking
Well, all right. If the idea of a sonic inverted spectrum is incoherent, then why should the visual inverted spectrum seem any more plausible? The two ends of the visible range of the electromagnetic spectrum are just as physically different from each other as are the two ends of the audible sonic spectrum. One end has light of lower frequencies, which makes certain pigments absorb it, while the other end has light of higher frequencies, which makes other pigments absorb it. Unlike rumbles, though, those cell-borne pigments are just intellectual abstractions to us, and this gives some philosophers the impression that our experiences of redness and blueness are totally disconnected from physics. The feeling of a color, they have concluded, is just some kind of personal invention, and two different people could “invent” it differently and never be the wiser for it.
To spell this idea out a little more clearly, let’s posit that knurking and glebbing (two words I just concocted) are two vastly different sensations that any human brain can enjoy. All humans are created in the womb with these experiences as part of their built-in repertoire. You and I were born with knurking and glebbing as standard features, and ever since our cradle days, we’ve enjoyed these two sensations countless thousands of times. In some folks, though, it’s red light that makes them knurk and blue that makes them gleb, while in others it’s the reverse. When you were tiny, one of the colors red and blue happened to trigger knurking more often, while the other one triggered glebbing more often. By age five or so, this initial tendency had settled in for good. No science could predict which way it would go, nor tell which way it wound up — but it happened anyway. And thus you and I, dear reader, may have wound up on opposite sides of the gleb/knurk fence — but who knows? Who could ever know?
I must stress that, in the inverted-spectrum scenario, the association of red light (or blue light) with knurking is not any kind of postnatal wiring pattern that gets launched in a baby’s brain and reinforced as it grows. In fact, although I stated above that to knurk and to gleb are experiences that all babies’ brains come innately equipped with, they are not distinguishable brain processes. It’s not possible to determine, no matter how fancy are the brain-scanning gadgets that one has access to, whether my brain (or yours) is knurking or glebbing. In short, we are not talking about objectively observable or measurable facts about the brain.
If objectively observable facts were all the inverted-spectrum riddle was about, it would be as easy as pie to tell the difference between ourselves and the fifty million French people whose inner sensations are all wrong! We would just examine their gray matter and pinpoint the telltale spot where certain key connections were flipped with respect to ours. Then we could watch their French brains engage in glebbing when the identical retinal stimulus would provoke knurking in our brains. But that’s not in the least the meaning of the inverted-spectrum idea. The meaning is that, despite having identical brain wirings, two people looking at the same object experience completely different color sensations.
The Inverted Political Spectrum
This hypothetical notion makes our inner experiences of the colors in the rainbow sound like a set of floating pre-existent pure abstractions that are not intimately (in fact, not at all) related to the physics outside our skull, or even to any physics