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Sciborg_S_Patel
Simulation, Consciousness, Existence
...Mathematical realism, a philosophical position advocated by Plato, illuminates this problem's vexing intangibles. Mathematical objects like numbers and geometric shapes manifest themselves just as richly and consistently to abstract thought as physical objects impress the senses. To Plato, mathematical concepts were as real as physical objects, just invisible to the external senses as sound is imperceptible to the eyes.
Computer simulation brings mathematical realism neatly full circle. Plato's unaided mind could handle only simple mathematical objects, leading to such dichotomies as the idea of a perfect sphere compared to a mottled, scratched marble ball in the hand. Computer simulation, like a telescope for the mind's eye, extends mental vision beyond the nearby realm of simple mathematical objects to distant worlds, some as complex as physical reality, potentially full of living beings, warts, minds, and all. Our own world is among this vista of abstractly conceivable ones, defined by the formal relationships we call physical law as any simulation is defined by its internal rules. The difference between physical and mathematical reality is an illusion of vantage point: the physical world is simply the particular abstract world that happens to contain us.
The Platonic position on simulation puts a handle on the vexingly intangible. It holds that every interpretation of a process is a reality in its own right. Without it an interpretation is meaningful only in context of another interpretation defining a containing world, and so on, in an infinite regress. The Platonic position defuses various worries about intelligent machinery. Some critics argue that a machine cannot contain a mind since a machine's function is entirely an outside interpretation, unlike human minds, which supply their own sense of meaning. The Platonic position on simulation answers that the abstract relationships that constitute the mind, including its own self-interpretation, exist independently, and a robot, a simulator, or a book describing the action, no less than a biological brain, is just a way of peeking at them. Other critics worry that future robots may act like intelligent, feeling beings without having an internal sense of existence---that they will be unconscious, mindless zombies. Platonism replies that while there are indeed interpretations of any mechanism (including the human brain) as mindless, there are others which allow one to see a real, self-appreciating mind. When a robot (or a person) behaves as if it has beliefs and feelings, our relationship with it will usually be facilitated if we choose a ``has a mind'' interpretation. Of course, when working on the internals, a robotics engineer (or a brain surgeon) may be best served by temporarily slipping into a ``mindless mechanism'' interpretation.
Platonism puts on the same footing mechanical simulations that precisely mimic every interaction detail, rough approximations, cinematic reconstructions, literary descriptions, idle speculation, dreams, even random gibberish: all can be interpreted as images of realities; the more detailed presentations simply have a sharper focus, blurring together fewer alternative worlds. But isn't there a huge difference between a conventional ``live'' simulation of a world and a simulation transformed to nothing, requiring a ``recorded'' book or movie to relate the unfolding events? Isn't it possible to interact with a running simulation, poking one's finger into the action, in a way impossible with a static script? In fact, a meaningful interaction is possible in either case only via an interpretation that connects the simulated world to the outside. In an interactive simulation, the viewing mechanism is no longer passive and superfluous, but an essential bidirectional conduit that passes information to and from the simulation. Such a conduit can exist for books and movies if they contain alternative scenarios for possible inputs. ``Programmed learning'' texts popular in previous decades were of this form, with instructions like ``If you answered A, go to page 56; if you answered B, go to page 79 . . .'' Some laser-disc video games give the impression of interactive simulation by playing video clips contingent on the player's actions. Mathematically, any interactive mechanism, even a robot or human, can be viewed as a compact encoding of a script with responses for all possible input histories. Platonism holds that the soul is in the abstract relationships represented, not the mechanics of how they are encoded.
This position seems to have scary moral implications. If simulation simply opens windows into Platonic realities, and robots and humans, no less than books, movies, or computer models, are only images of those essences, then it should be no worse to mistreat a human, an animal or a feeling robot than to choose a cruel action in a video game or an interactive book: in all cases you are simply viewing preexisting realities. But choices do have consequences for the person making them because of the mysterious contrivance of physical law and conscious interpretation that produces single threads of consciousness with unseen futures and unalterable pasts. By our choices, we each thread our own separate way through the maze of possible worlds, bypassing equally real alternatives with equally real versions of ourselves and others, selecting the world we must then live in.
So is there no difference between being cruel to characters in interactive books or video games and people one meets in the street? Books or games act on a reader's future only via the mind, and actions within them are mostly reversed if the experience is forgotten. Physical actions, by contrast, have greater significance because their consequences spread irreversibly. If past physical events could be easily altered, as in some time-travel stories, if one could go back to prevent evil or unfortunate deeds, real life would acquire the moral significance of a video game. A more disturbing implication is that any sealed-off activity, whose goings on can be forgotten, may be in the video game category. Creators of hyperrealistic simulations---or even secure physical enclosures---containing individuals writhing in pain are not necessarily more wicked than authors of fiction with distressed characters, or myself, composing this sentence vaguely alluding to them. The suffering preexists in the underlying Platonic worlds; authors merely look on. The significance of running such simulations is limited to their effect on viewers, possibly warped by the experience, and by the possibility of ``escapees''---tortured minds that could, in principle, leak out to haunt the world in data networks or physical bodies. Potential plagues of angry demons surely count as a moral consequence. In this light, mistreating people, intelligent robots, or individuals in high-resolution simulations has greater moral significance than doing the same at low resolution or in works of fiction not because the suffering individuals are more real---they are not---but because the probability of undesirable consequences in our own future is greater...
Universal Existence
Perhaps the most unsettling implication of this train of thought is that anything can be interpreted as possessing any abstract property, including consciousness and intelligence. Given the right playbook, the thermal jostling of the atoms in a rock can be seen as the operation of a complex, self-aware mind. How strange. Common sense screams that people have minds and rocks don't. But interpretations are often ambiguous. One day's unintelligible sounds and squiggles may become another day's meaningful thoughts if one masters a foreign language in the interim. Is the Mount Rushmore monument a rock formation or four presidents' faces? Is a ventriloquist's dummy a lump of wood, a human simulacrum, or a personality sharing some of the ventriloquist's body and mind? Is a video game a box of silicon bits, an electronic circuit flipping its own switches, a computer following a long list of instructions, or a large three-dimensional world inhabited by the Mario Brothers and their mushroom adversaries? Sometimes we exploit offbeat interpretations: an encrypted message is meaningless gibberish except when viewed through a deliberately obscure decoding. Humans have always used a modest multiplicity of interpretations, but computers widen the horizons. The first electronic computer was developed by Alan Turing to find ``interesting'' interpretations of wartime messages radioed by Germany to its U-boats. As our thoughts become more powerful, our repertoire of useful interpretations will grow. We can see levers and springs in animal limbs, and beauty in the aurora: our ``mind children'' may be able to spot fully functioning intelligences in the complex chemical goings on of plants, the dynamics of interstellar clouds, or the reverberations of cosmic radiation. No particular interpretation is ruled out, but the space of all of them is exponentially larger than the size of individual ones, and we may never encounter more than an infinitesimal fraction. The rock-minds may be forever lost to us in the bogglingly vast sea of mindlessly chaotic rock-interpretations. Yet those rock-minds make complete sense to themselves, and to them it is we who are lost in meaningless chaos. Our own nature, in fact, is defined by the tiny fraction of possible interpretations we can make, and the astronomical number we can't.
Everything and Nothing
There is no content or meaning without selection. The realm of all possible worlds, infinitely immense in one point of view, is vacuous in another. Imagine a book giving a detailed history of a world similar to ours. The book is written as compactly as possible: rote predictable details are left as homework for the reader. But even with maximal compression, it would be an astronomically immense tome, full of novelty and excitement. This interesting book, however, is found in ``the library of all possible books written in the Roman alphabet, arranged alphabetically''---the whole library being adequately defined by this short, boring phrase in quotes. The library as a whole has so little content that getting a book from it takes as much effort as writing the book. The library might have stacks labeled A through Z, plus a few for punctuation, each forking into similarly labeled substacks, those forking into subsubstacks, and so on indefinitely. Each branchpoint holds a book whose content is the sequence of stack letters chosen to reach it. Any book can be found in the library, but to find it the user must choose its first letter, then its second, then its third, just as one types a book by keying each subsequent letter. The book's content results entirely from the user's selections; the library has no information of its own to contribute.
Although content-free overall, the library contains individual books with fabulously interesting stories. Characters in some of those books, insulated from the vast gibberish that makes the library worthless from outside, can well appreciate their own existence. They do so by perceiving and interpreting their own story in a consistent way, one that recognizes their own meaningfulness---a prescription that is probably the secret of life and existence, and the reason we find ourselves in a large, orderly universe with consistent physical laws, possessing a sense of time and a long evolutionary history.
The set of all possible interpretations of any process as simulations is exactly analogous to the content of all the books in the library. In total it contains no information, yet every interesting being and story can be found within it.
Universal Appreciation
If our world distinguishes itself from the vast unexamined (and unexaminable) majority of possible worlds through the act of self-perception and self-appreciation, just who is doing all the perceiving and appreciating? The human mind may be up to interpreting its own functioning as conscious, so rescuing itself from meaningless zombiehood, but surely we few humans and other biota---trapped on a tiny, soggy dust speck in an obscure corner, only occasionally and dimly aware of the grossest features of our immediate surroundings and immediate past---are surely insufficient to bring meaning to the whole visible universe, full of unimagined surprises, 10^40 times as massive, 10^70 times as voluminous, and 10^10 times as long-lived as ourselves. Our present appreciative ability seems more a match for the simplicity of Saturday-morning cartoons.
The book The Anthropic Cosmological Principle, by cosmologists John Barrow and Frank Tipler, and Tipler's recent The Physics of Immortality argue that the crucial parts of the story lie in our future, when the universe will be shaped more by the deliberate efforts of intelligence than the simple, blind laws of physics. In their future cosmology, consistent with the one in this book, human-spawned intelligence will expand into space, until the entire accessible universe is inhabited by a cohesive mind that manipulates events, from the quantum-microscopic to the universe-macroscopic, and spends some of its energy recalling the past. Tipler and Barrow predict that the universe is closed: massive enough to reverse its present expansion in a future ``big crunch'' that mirrors the big bang. The universe mind will thrive in the collapse, perhaps by encoding itself into the cosmic background radiation. As the collapse proceeds, the radiation's temperature, and so its frequencies and the mind's speed, rise and there are ever more high-frequency wave modes to store information. By very careful management, avoiding ``event horizons'' that would disconnect its parts and using ``gravitational shear'' from asymmetries in the collapse to provide free energy, Tipler and Barrow calculate that the cosmic mind can contrive to do more computation and accumulate more memories in each remaining half of the time to the final singularity than it did in the one before, thus experiencing a neverending infinity of time and thought. As it contemplates, effects from the universe's past converge on it. There is information, time, and thought enough to recreate, savor, appreciate, and perfect each detail of each moment. Tipler and Barrow suggest that it is this final, subjectively eternal act of infinite self-interpretation that effectively creates our universe, distinguishing it from the others lost in the library of all possibilities. We truly exist because our actions lead ultimately to this ``Omega Point'' (a term borrowed from the Jesuit paleontologist and radical philosopher Tielhard de Chardin).
No complete theory yet explains our existence and experiences, but there are hints. Tiny universes simulated in today's computers are often characterized by adjustable rules governing the interaction of neighboring regions. If the interactions are made very weak, the simulations quickly freeze to bland uniformity; if they are very strong, the simulated space may seethe intensely in a chaotic boil. Between the extremes is a narrow ``edge of chaos'' with enough action to form interesting structures, and enough peace to let them persist and interact. Often such borderline universes can contain structures that use stored information to construct other things, including perfect or imperfect copies of themselves, thus supporting Darwinian evolution of complexity. If physics itself offers a spectrum of interaction intensities, it is no surprise that we find ourselves operating at the liquid boundary of chaos, for we could not function, nor have evolved, in motionless ice nor formless fire.
The odd thing about the Hartle--Gell-Mann spectrum is that it is not some external knob that controls the interaction intensity, but varying interpretations of a single underlying reality made by observers who are part of the interpretation. It is, in fact, the same kind of self-interpretation loop we encountered when considering observers inside simulations. We are who we are, in the world we experience, because we see ourselves that way. There are almost certainly other observers in exactly the same regions of the wave function who see things entirely differently, to whom we are simply meaningless noise.
The similarity between Everett's ``many worlds'' and the philosophical ``possible worlds'' may become stronger yet. In ``many worlds'' quantum mechanics, physical constants, among other things, have fixed values. Gravity, in objects like black holes, loosens the rules, and a full quantum theory of gravity may predict possible worlds far exceeding Everett's range---and who knows what potent subtleties lie even further on? It may turn out, as we claw our way out through onion layers of interpretation, that physics places fewer and fewer constraints on the nature of things. The regularities we observe may be merely a self-reflection: we must perceive the world as compatible with our own existence---with a strong arrow of time, dependable probabilities, where complexity can evolve and persist, where experiences can accumulate in reliable memories, and the results of actions are predictable. Our mind children, able to manipulate their own substance and structure at the finest levels, will probably greatly transcend our narrow notions of what is.
We can't yet leave the physical world in chosen directions, but we are scheduled to leave it soon enough in an uncontrolled way when we die. But why do we seem so firmly locked to the simple physical laws of the material world before death? This is a most fundamental question if one accepts that all possible worlds are equally real. Artificial intelligence programs, which recreate the psychological state of nervous systems without simulating the detailed physical substance that underlies them, and virtual realities, which allow unphysical magical effects like teleportation, suggest that our own consciousnesses can exist in many possible worlds that do not follow our physical laws. This question of why our universe seems so firmly yoked to physical law has hardly been asked in a scientific way, let alone answered. But the answer may be related to Einstein's observation that mathematics seems to be unreasonably effective in describing the physical world. This unreasonableness shows itself in the plausible, already partially fulfilled, quest of physics for a ``Theory of Everything,'' perhaps a simple differential equation whose solution implies our whole physical universe and everything in it!
In our daily meanders, we are more likely to stumble across a particular small number (say ``5'') than a particular large one (say ``53783425456''). The larger number requires far more digits to simultaneously fall into place just so, and thus is far less likely. Similarly, although we exist in many of all possible universes, we are most likely to find ourselves in the simplest of those, the few that require the least number of things to be just so. The universe's great size and age, its physical laws, and our own long evolution may be just the working of the simplest possible rules that produce our minds.
Our consciousness now finds itself dependent on the operation of trillions of cells tuned exquisitely to the physical laws into which we evolved. It continues from moment to moment most simply if those laws continue to operate as they have in the past. Thus, with overwhelming probability, we find the laws are stable. In the space of all possible universes, we are bound to the same old one. As long as we remain alive.
When we die, the rules surely change. As our brains and bodies cease to function in the normal way, it takes greater and greater contrivances and coincidences to explain continuing consciousness by their operation. We lose our ties to physical reality, but, in the space of all possible worlds, that cannot be the end. Our consciousness continues to exist in some of those, and we will always find ourselves in worlds where we exist and never in ones where we don't. The nature of the next simplest world that can host us, after we abandon physical law, I cannot guess. Does physical reality simply loosen just enough to allow our consciousness to continue? Do we find ourselves in a new body, or no body? It probably depends more on the details of our own consciousness than did the original physical life. Perhaps we are most likely to find ourselves reconstituted in the minds of superintelligent successors, or perhaps in dreamlike worlds (or AI programs) where psychological rather than physical rules dominate. Our mind children will probably be able to navigate the alternatives with increasing facility. For us, now, barely conscious, it remains a leap in the dark.
