PhysProof — Dependency Graph

THE UNIVERSE AS A COMPUTER

→ Read the rigorous treatment: tier-tagged & compiled to Lean ↗

attrib. John Archibald Wheeler · c. 1980? · provenance disputed

Possible Meanings of the Metaphor

NOTE: Such metaphors tend to be at once useful and misleading. They are understood only intuitively, vaguely, partially, ambiguously, and abstractly by their authors and users. They are apt to be polysemous—possessed of multiple and complex meanings, both relevant and irrelevant. Moreover, in the present instance the utilitarian and natural meaning of the very words universe and computer is unknown to an indefinite degree! Physicists who are trying to conceive a new cosmology based in part on the metaphor of the universe as a computer may find the following list clarifying, heuristic, provocative, useful for self-criticism or discussion, &c. It is a partial list that needs to be extended, systematized, edited, explained, and illuminated by examples and corollaries.

May be more or less similar or identical to a Turing machine or serial computer, or be wholly or partly 1-dimensional.
May comprise the equivalent of serial computers operating, either independently or interdependently, in a parallel array.
May resemble more nearly a completely parallel computer whose elements are not sub-computers.
May represent a hybrid serial and parallel computer.
May represent a hierarchy, network, and/or series of many serial or parallel computers.
May represent an infinite or finite set of computers.
May represent a computer of infinite size, complexity, subdivisibility (componentry), age, lifespan, sophistication, perfection, power, connectivity, programming, knowledge, intelligence, dimensionality, activity, strangeness, and/or the like.
May (or physics may) reduce to pure mathematics, numbers, or ‘order’.
May use or reduce entirely to information, symbols, computer-like rules, states, decisions, operations, markers, pointers, arrays, structures, programs, sets, and/or the like.
May be like a computer in being instructible and programmable—or re-instructible, re-programmable, controllable, and manipulable.
May reduce to a computer at a higher, lower, or ultimate level (scale).
May be treated as equivalent to a computer if the treatment is sufficiently elaborate, universal, clever, and/or absolute.
May represent a set of (finitely or infinitely) homogeneous or heterogeneous computers.
May represent a digital or binary computer.
May represent an analogue computer of finite, infinite, or infinitesimal self-similarity.
May be mechanical in the sense of being possessed of machinelike entities or phenomena—or of parts, operations, laws, &c that are surprisingly or absolutely simple, regular, interchangeable, interlocking, perfect, universal, reliable, deterministic, knowable, predictable, finite, utilitarian, teleological, rational, constructible, symmetric, efficient, irreducible, repetitive, and/or the like.
May behave like a computer on occasion or in special situations.
May use a (central or omnipresent) model of itself.
May be simulated by a computer with arbitrarily great accuracy.
May represent a superficial pattern projected, in effect, on a background—or something like a program or simulation of a universe that is running on an independent and truly real computer but is not itself real or fundamental.
All natural phenomena, entities, and systems (be they trees, rocks, molecules, bacteria, men, societies, rivers, stars, diseases, clouds, or whatever) may be computers or computer-like (have programs, perform computations, use circuitry, possess memory, use languages, process information, use Boolean logic, or the like).
May be clock-like or use universally or locally synchronized parts or processes.
All known laws may be controlled or created by higher laws (possibly arranged in a hierarchy or network).
The universe or all physical phenomena may be reducible to computation or a single great calculation.
May reduce to or be controlled by, or be expressible as, pure (Boolean or non-Boolean) logic.
May be a mind, mind-like, or thought-like, or be reducible to or treatable by pure thought.
May possess a (finite or infinite) computer-like or other memory; or memories and memory processes may exist in all natural phenomena (trees, rocks, genomes, &c).
May wholly or in part consist of cellular automata, or be a single great or infinite cellular automaton.
Physical processes, phenomena, entities, events, quantities, laws, states, and relationships (such as apparent movement, mass, fundamental physical constants, particle populations, 3-space, spacetime, volcanoes, and ocean waves) may be representational, programmatic, or computational illusions—or be infinitely ambiguous—rather than truly fundamental or real; and per se, may be alterable or transcendable by gaining knowledge of and control over their ‘programs’ or an equivalent. Put otherwise, all phenomena, &c may appear or behave as they do because of internal programs, self-models, rules, or computation to which man can gain access.
May be a lattice—or spacetime may be wholly quantized.
All quantum numbers may reduce to a single quantum number.
May essentially represent but a single, individual particle, event, or computer (that somehow generates the illusion of a multifarious world); or a single iterative or recursive operation repeating itself forever or toward a finite future destiny.
May represent more or less homogeneous or heterogeneous iterative or recursive processes, entities, phenomena, laws, quanta, measurements, disturbances, &c.
It may be possible to show that information and computation are fundamentally indistinguishable and hence equivalent, or that all of the following must in a similar way be equivalent: information, computation, energy, mass, space, time, and/or the like.
May be an asynchronous computer (computer with asynchronous parts).
May be a computer that functions statistically and indeterministically.
May be more or less lifelike (possessed of biological features such as homeostasis, growth, self-reproduction, self-evolution, competition, purpose, or memory).
As science progresses and becomes more complex, difficult, mathematical, and abstract, reliance on the computer may become total; and this may make a purely computational representation of the universe expedient, and justify present-day steps in that direction.
No one knows how simple, powerful, universal, natural, and/or complex computers might ultimately become—and it might be in these ultimate senses that the universe is or resembles a ‘computer’. (It might even be possible to devise revolutionary types of computers by studying and applying computational or computer-like properties of the universe.)
May function in ways similar or identical to such computer or mental processes as generalization, recognition, categorization, error correction, time sequence retention, induction, symbolic logic, analogical reasoning, and/or the like.
May use holonomical memory, correlations, or laws, something like a computer’s content-addressable memory, and/or the like.
May represent an anastomotic network of everywhere diverging, converging, and interacting causes and effects, and in this way resemble a computer’s structure and functioning.
May be in some profound sense a function of the mind, and hence half-mental; or respond in entirely different ways dependent on how it is ‘addressed’.
Local phenomena may be controlled from a distance or by larger systems.
May represent a great hierarchical network of specialized ‘administrators’ or ‘administrative’ processes, functions, systems, laws, constraints, &c. Also, may contain things analogous to questions, answers, experiments, orders, requests, negotiations, conversations, messages, traffic cops, supervisors, inspectors, translators, arbitrators, pioneers, &c.
May be totally finitistic—or finite everywhere and in every way.
May be ‘centralized’ and ‘centralistically’ controlled.
All that exists in the universe (including relationships, entities, interactions, laws, &c that are conventionally thought of as being inert, static, or time-invariant) may in fact be time-asymmetric or an uninterrupted process of change or of cosmoplastic or cosmopoietic interadjustments and interchanges; in this ‘everywhere-always-novel universe’ work and information-processing could be omnipresent and quintessential.