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Authors: Douglas R. Hofstadter

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This situation reminds me of another loopy phenomenon that I call “reverberant barking”, which one sometimes can hear in a neighborhood where many dogs live. If a jogger passes one house and triggers one dog’s bark, then neighbor dogs may pick up the barking and a chain reaction involving a dozen dogs may ensue. Soon the barking party has taken on a life of its own, and in the meantime its unwitting instigator has long since exited the neighborhood. If dogs were a bit more like robots and didn’t eventually grow tired of doing the same thing over and over again, their reverberant barking could become a stable, self-sustaining audible memory trace of the jogger’s fleeting passage through their street.

The dynamically pulsating patterns that I encountered in my video voyage were completely unlike the unwavering “steady-state universes” that I had observed up till then. Stable, periodic video reverberation was a strange and unanticipated phenomenon that I’d bumped into by accident while exploring the possibilities lurking in video feedback.

Even today, all these years later, the origins of such pulsation remain quite unclear, even mysterious, to me; for that reason, it is an
emergent
phenomenon, otherwise known as an
epiphenomenon,
as discussed in Chapter 3. In general, an emergent phenomenon
somehow
emerges quite naturally and automatically from rigid rules operating at a lower, more basic level, but
exactly how
that emergence happens is not at all clear to the observer.

I admit to feeling a little dense for not having fully fathomed what lies behind video reverberation, but at this point I am so accustomed to it that it “makes sense” to me. That is, I have a clear intuition for how to induce it on the screen, and I know that once it starts, it is a robust phenomenon that will continue unabated probably for hours, perhaps even forever, if I don’t interfere with it. Rather than trying to figure out how to account precisely for video reverberation in terms of phenomena at lower levels, I have come to just accept it as a fact, and I deal with it at as a phenomenon that exists at its own level. This should sound familiar to you, since it’s how we deal with almost everything in our physical and biological world.

Feeding “Content” to the Loop

As I mentioned at the outset, one lucky thing about the Stanford setup was the seemingly random metallic strip on one side of the television set I’d been given to use. That strip — a kind of interloper — added a key note of “spice” to the image that was being cycled round and round, and in that sense it was a crucial ingredient of Video Voyage I.

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

z
2
+
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 broach the central questions of consciousness and self.

From my video voyages I have gained a sense of the immense richness of the phenomenon of video feedback. More specifically, I have learned that very often, wonderfully complex structures and patterns come to exist on the screen whose origins are, to human viewers, utterly opaque. I have been struck by the fact that it is the circularity — the loopiness — of the system that brings these patterns into existence and makes them persist. Once a pattern is
on
the screen, then all that is needed to justify its
staying
up there is George Mallory’s classic quip about why he felt compelled to scale Mount Everest: “Because it’s there!” When loops are involved, circular justifications are the name of the game.

To put it another way, feedback gives rise to a new kind of abstract phenomenon that can be called “locking-in”. From just the barest hint (the very first image sent to the TV screen in the first tiny fraction of a second) comes, almost instantly (after perhaps twenty or thirty iterations), the full realization of all the implications of this hint — and this new higher-level structure, this emergent pattern on the screen, this epiphenomenon, is then “locked in”, thanks to the loop. It will not go away because it is forever refreshing itself, feeding on itself, giving rebirth to itself. Otherwise put, the emergent output pattern is a self-stabilizing structure whose origins, despite the simplicity of the feedback loop itself, are nearly impenetrable because the loop is cycled through so many times.

Emergent New Realities of Video Feedback

Coming up with vivid and helpful nicknames for unexpected visual patterns had certainly not figured in my initial plans for my video voyage at Stanford, but this little game soon became necessary. At the outset, I had thought I was undertaking a project that would involve straightforward terms like “screen inside screen”, “silver strip”, “angle of tilt”, “zooming in”, and so forth — but soon I found myself forced, willy-nilly, to use completely unexpected descriptive terms for what I was observing. As you have seen, I started talking about “corridors” and “walls”, “doorways” and “galaxies”, “spirals” and “black holes”, “hubs” and “spokes”, “petals” and “pulsations”, and so forth. In the second video voyage with Bill, many of these same terms were once again needed, and some new ones were called for, such as “starfish”, “cheese”, “fire”, “foam”, and others.

Such words are hardly the kind of language I had thought I would be dealing with when I first broached the idea of video feedback. Although the system to which I was applying these terms was mechanical and deterministic, the patterns that emerged as a consequence of the loop were unpredictable, and therefore it turned out that words were needed that no one could have predicted in advance.

Simple but evocative metaphors like “corridor”, “galaxy”, and others turned out to be
indispensable
in describing the abstract shapes and events I witnessed on the screen. The initial terms I had tacitly assumed I would use wound up getting mostly ignored, because they yielded little insight. Of course, in principle, everything could be explained in terms of them, in a rigorous and incomprehensibly verbose fashion (like explaining a gas’s temperature and pressure by writing out Avogadro’s number of equations) — but such a boringly reductionistic, nearly pixel-by-pixel explanation would entirely leave out the wonderful higher-level visual phenomena to which a human eye and mind intuitively resonate.

In short, there are surprising new structures that looping gives rise to that constitute a new level of reality that could
in principle
be deduced from the basic loop and its detailed properties, but that
in practice
have a different kind of “life of their own” and that demand — at least when it comes to extremely finite, simplicity-seeking, pattern-loving creatures like us — a new vocabulary and a new level of description that transcend the basic level out of which they emerge.

CHAPTER 6

Of Selves and Symbols

Perceptual Looping as the Germ of “I”-ness

I
FIND it curious that, other than proper nouns and adjectives, the only word in the English tongue that is always capitalized is the first-person pronoun (nominative case) with which this sentence most f lamboyantly sets sail. The convention is striking and strange, hinting that the word must designate something very important. Indeed, to some people — perhaps to most, perhaps even to us all — the ineffable sense of being an “I” or a “first person”, the intuitive sense of “being there” or simply “existing”, the powerful sense of “having experience” and of “having raw sensations” (what some philosophers refer to as “qualia”), seem to be the realest things in their lives, and an insistent inner voice bridles furiously at any proposal that all this might be an illusion, or merely the outcome of some kind of physical processes taking place among “third-person” (
i.e.,
inanimate) objects. My goal here is to combat this strident inner voice.

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