I Am a Strange Loop - Douglas R. Hofstadter [47]
While Bill and I were conducting Video Voyage II, there were times, to our surprise, when the seas we were sailing seemed a bit too placid for our taste, and we longed for a bit more action, more visual excitement. This brought to my mind the crucial “spicy” role played by the interloping metal strip during Voyage I, so on a lark we decided to introduce something that would play an analogous role in our system. I picked up various objects around the room and dangled them in front of the camera without any idea of what would happen when the image was cycled round and round the video loop. Usually we got marvelous results that were (once again) unanticipatable. For instance, when I dangled a chain of beads in front of the screen, what emerged (the choice of verb is not accidental) was a random-looking swirl of pockmarked bluish-white globs that reminded me a bit of some kind of exotic cheese.
Of course each such interloping object opened up a whole new universe of possibilities, since we could vary its position as well as all the other standard variables (the amount of zoom, the angle of tilt, the direction of the camera, the brightness, the contrast, and others). I tried such things as a glass vase, a compact disk, and, eventually, my own hands. The results were quite fantastic, as you can see in the color insert, but alas, Bill and I didn’t have infinite amounts of time to explore the manifold universes we had uncovered and sampled. We played with the possibilities for perhaps a dozen hours and from that we got a 400-photo memory album, and that’s all. Like any excursion to a wondrous and exotic place, our trip had to end earlier than we would have preferred, but we were very glad to have taken it and to have savored it together.
A Mathematical Analogue
As might be expected, all the unexpected phenomena that I observed depended on the nesting of screens being (theoretically) infinite — that is, on the apparent corridor being endless, not truncated. This was the case because the most unpredictable of the visual phenomena always seemed to happen right in the vicinity of that central point where the infinite regress converges down to a magical dot.
My explorations did not teach me that any shape whatsoever can arise as a result of video feedback, but they did show me that I had entered a far richer universe of possibilities than I had expected. Today, this visual richness reminds me of the amazing visual universe discovered around 1980 by mathematician Benoit Mandelbrot when he studied the properties of the simple iteration defined by z → z2 + c, where c is a fixed complex number and z is a variable complex number whose initial value is 0. This is a mathematical feedback loop where one value of z goes in and a new value comes out, ready to be fed back in again, just as in audio or video feedback. The key question is this: If you, playing the role of microphone and loudspeaker (or camera and TV), do this over and over again, will the z values you get grow unboundedly, sailing off into the wild blue (or wild yellow or wild red) yonder, or will they instead home in on a finite value?
The details need not concern us here; the basic point is that the answer to the question depends in a very subtle way on the value of the parameter c, and if you make a map by color-coding different values of c according to the rate of z’s divergence, you get amazing pictures. (This is why I joked about the “wild yellow” and “wild red” yonders.) Both in video feedback and in this mathematical system, a very simple looping process gives rise to a family of truly unanticipated and incredibly intricate swirling patterns.
The Phenomenon of “Locking-in”
The mysterious and strangely robust phenomena that emerge out of looping processes such as video feedback will serve from here on out as one of the main metaphors in this book, as I