Saturday, 12 April 2025

SRH: Computability vs Reality

Using Deepseek here, note it reaches server limits. Even these discussions have their own computing limits. Which is interesting for the previous discussion about AI simulating human thought and being largely unrecognisably different. Suggests that in the realm of symbolic thought are humans really different from machines?

===

Gödel's Theorem and Formal System Construction

Godel's theorem means that any formal system will contain true statements that are not provable. Metalogic can incorporate this, but itself is incomplete which creates an ordering and infinite ascent in system power. Another way to construct all possible systems within a finite set of symbols is to godel number all possible strings of symbols, and then eliminate those which do not describe a formal system. Do both ways of constructing all possible formal systems a bijection?

Edit

Introduction to Gödel's Incompleteness Theorems

Before diving into the main question, it's essential to understand Gödel's incompleteness theorems, as they form the foundation of the discussion.

1.    First Incompleteness Theorem: In any consistent formal system that is sufficiently powerful to express basic arithmetic, there exist statements that are true but cannot be proven within that system.

2.    Second Incompleteness Theorem: Such a system cannot demonstrate its own consistency.

These theorems imply that no single formal system can capture all mathematical truths, leading to the idea that we might need an infinite hierarchy of increasingly powerful systems to encompass more truths.

Understanding the Two Methods of Constructing Formal Systems

The question presents two methods for constructing all possible formal systems:

1.    Metalogic Approach: This involves acknowledging that any formal system is incomplete and thus can be extended to a more powerful system. This creates an "infinite ascent" where each system's incompleteness leads to the construction of a more encompassing system. This hierarchy is often referred to in the context of metalogic or the metamathematical study of formal systems.

2.    Gödel Numbering Approach: Here, one considers all possible strings of symbols formed from a finite alphabet. By assigning Gödel numbers to these strings, one can enumerate all possible strings. Then, by filtering out those strings that do not define a coherent formal system, one is left with a collection of all possible formal systems expressible within that symbol set.

The core question is whether these two methods establish a bijection between their respective constructions of formal systems.

Defining the Notions More Precisely

To compare these methods, let's define them more rigorously.

Method 1: Metalogic and Infinite Ascent

·         Start with a base formal system S0S0 (e.g., Peano Arithmetic).

·         Due to incompleteness, there's a true statement G0G0 not provable in S0S0.

·         Extend S0S0 to S1=S0+G0S1=S0+G0, which is more powerful.

·         Repeat the process to get an infinite sequence S0,S1,S2,…S0,S1,S2,…, each extending the previous one by adding its Gödel sentence.

·         This hierarchy can be extended transfinitely by taking unions at limit ordinals, leading to a proper class of systems.

However, the "infinite ascent" can be more broadly interpreted as any method that generates a sequence or hierarchy of systems where each step addresses the incompleteness of the previous one.

Method 2: Gödel Numbering All Possible Systems

·         Fix a finite alphabet of symbols (e.g., logical symbols, parentheses, variables).

·         Consider all finite strings over this alphabet.

·         Assign a unique Gödel number to each string.

·         Some strings will be well-formed and define a consistent formal system (e.g., by specifying axioms and inference rules).

·         Filter out strings that don't correspond to valid formal systems.

·         The result is a countable collection of all possible formal systems that can be described with the given alphabet.

Comparing the Two Methods

Now, let's examine whether there's a bijection between the collections generated by these two methods.

Metalogic Approach's Collection:

·         The metalogic approach, as described, generates a specific hierarchy starting from a base system and iteratively adding Gödel sentences.

·         This generates a particular sequence (or tree, if considering different extensions) of systems, but not necessarily all possible systems.

·         The systems in this hierarchy are related by extension, each containing more theorems than the previous.

Gödel Numbering Approach's Collection:

·         This method enumerates all possible formal systems that can be defined with the given symbols, without any inherent ordering based on strength or extension.

·         It includes systems that are weaker, unrelated, or even inconsistent, as long as they are syntactically valid formal systems.

·         The collection is much broader, encompassing any conceivable formal system describable with the symbols.

Potential Bijection?

A bijection requires a one-to-one correspondence between the elements of two sets. Here:

·         The metalogic hierarchy is a specific, well-ordered subset of formal systems, typically linearly ordered by inclusion or strength.

·         The Gödel numbering approach gives a countable set of all possible formal systems, which is much more extensive.

Therefore:

1.    Injection from Metalogic to Gödel Numbering: Each system in the metalogic hierarchy can be described by a finite string of symbols, hence has a Gödel number. This provides an injection from the metalogic sequence into the Gödel numbered systems.

2.    Surjection? The metalogic hierarchy doesn't cover all possible formal systems; it's just one path (or tree) of extending systems. There are many formal systems outside this hierarchy (e.g., systems with different languages, weaker systems, systems extending in different directions).

Thus, there's no bijection because the metalogic hierarchy doesn't encompass all formal systems that the Gödel numbering method does.

Alternative Interpretation: All Possible Extensions

If we interpret "all possible systems" in the metalogic approach not just as a single hierarchy but as all possible ways to extend any system to overcome incompleteness, then:

·         The collection would include all possible consistent extensions of any base system.

·         This is still not necessarily all possible formal systems, as some systems may not be reachable by extending a given base system (e.g., systems with different languages or primitives).

Even in this case, the metalogic approach seems to generate a subset of the Gödel numbered systems, lacking a bijection.

Ordering and Completeness

The metalogic approach imposes an ordering based on extension or strength, leading to a directed or partially ordered set of systems. The Gödel numbering approach is unordered in terms of strength; it's just a listing. Thus, the structure differs, making a bijection in the sense of preserving such order impossible.

Formalizing the Collections

Let's attempt to formalize the collections to see if a bijection is possible.

Let GG be the set of all formal systems obtainable by Gödel numbering:

·         G={SS is a formal system describable by a finite string over Σ}G={SS is a formal system describable by a finite string over Σ}, where ΣΣ is the finite alphabet.

·         GG is countable because the set of all finite strings over ΣΣ is countable.

Let MM be the set of all formal systems in the metalogic hierarchy:

·         Starting from S0S0, and for each SiSi, adding GiGi (its Gödel sentence) to get Si+1Si+1, and taking unions at limits.

·         This generates M={S0,S1,S2,…,Sω,Sω+1,…}M={S0,S1,S2,…,Sω,Sω+1,…}, a proper class if continued through all ordinals, but in practice, we might consider up to some countable ordinal.

Even if MM is considered as a countable sequence, it's a specific chain within GG. There's no natural way to map every element of GG to MM uniquely and vice versa because MM is a thin subset with a particular structure.

Considering All Possible Hierarchies

Perhaps the metalogic approach isn't limited to a single hierarchy but considers all possible hierarchies or paths of extending systems. Even then:

·         The set of all possible extension paths is vast, but each path is a sequence in GG.

·         There's no clear bijection between the set of all such paths and GG itself.

Moreover, many systems in GG may not be part of any meaningful hierarchy extending from a given S0S0, especially if they're incompatible or based on different logical frameworks.

Cardinality Considerations

If both collections are countable (assuming we limit the metalogic hierarchy to a countable sequence for practical purposes), then purely in terms of cardinality, a bijection exists between two countably infinite sets. However, this ignores the structures and the intended correspondence between the methods.

The question seems to ask whether the methods themselves naturally give rise to a bijection, not just whether a set-theoretic bijection exists. In that sense, the answer is negative because the metalogic approach doesn't generate all systems that the Gödel numbering approach does.

Potential Misinterpretations

It's possible that the question implies that the metalogic approach can, in some sense, "reach" all possible formal systems by considering all possible ways to extend systems. However:

·         Not all formal systems are extensions of a given base system; some may be incomparable or based on entirely different axioms/languages.

·         The metalogic hierarchy is inherently directed towards overcoming incompleteness in a particular manner, not randomly generating all possible systems.

Conclusion

After carefully considering both methods:

·         The metalogic approach generates a specific hierarchy or set of hierarchies of formal systems, each extending the previous ones to overcome incompleteness.

·         The Gödel numbering approach enumerates all possible formal systems that can be described with a given finite set of symbols, which is a much broader and unstructured collection.

Therefore, there is no natural bijection between the two constructions. The metalogic hierarchy provides a particular, structured subset of the collection obtained via Gödel numbering, not a one-to-one correspondence with the entirety of possible formal systems.

Final Answer

No, the two methods do not establish a bijection between their constructions of all possible formal systems. The metalogic approach generates a specific hierarchy of systems extending one another to address incompleteness, which is a proper subset of the collection obtained by Gödel numbering all possible strings and selecting valid formal systems. The latter encompasses all describable formal systems without the structured ordering inherent in the metalogic hierarchy, making a bijection between the two collections impossible in a meaningful sense.

We can be sure however that there is a countably infinite number of possible formal logic systems?

Edit

Countability of Possible Formal Logic Systems

Yes, we can be sure that there is a countably infinite number of possible formal logic systems, provided we restrict ourselves to systems that can be described using a finite alphabet of symbols. Here's why:


1. Finite Alphabet Assumption

·         A formal logic system is defined by:

o    A set of symbols (logical operators, variables, parentheses, etc.).

o    A set of well-formed formulas (grammatical rules for combining symbols).

o    A set of axioms (initial truths).

o    Inference rules (how to derive new truths from axioms).

·         If we assume a finite alphabet (e.g., {,,,,¬,→,(,),x,y,z,… }{,,,,¬,→,(,),x,y,z,…}), then:

o    Every possible formal system can be described by a finite string of these symbols (e.g., listing its axioms and rules).

o    Even if the system has infinitely many axioms, it can often be specified recursively (e.g., via axiom schemas), still describable by a finite string.


2. Gödel Numbering and Countability

·         Gödel numbering assigns a unique natural number to every finite string over a finite alphabet.

o    For example, map each symbol to a digit, then concatenate to form a number.

·         The set of all finite strings over a finite alphabet is countably infinite (like the natural numbers).

·         Only some of these strings encode valid formal systems (e.g., syntactically correct and consistent). But:

o    The subset of valid systems is still countably infinite (since it's infinite but not larger than all strings).


3. Why Infinite?

·         There are infinitely many possible variations of formal systems:

o    Add/remove axioms (e.g., Peano Arithmetic with or without the axiom of induction).

o    Change inference rules (e.g., classical vs. intuitionistic logic).

o    Introduce new symbols or operators (e.g., modal logic's  and ).

·         Even small changes (e.g., adding one independent axiom) generate new systems.


4. Why Not Uncountable?

·         For the collection to be uncountable (like the real numbers), we'd need:

o    Uncountably many symbols (but we assume a finite/countable alphabet).

o    Infinitely long descriptions (but formal systems must be finitely describable to be usable).

·         If we allowed uncountable languages or infinitely long axioms, the systems would become unmanageable and lose computational meaning.


5. Metalogic Perspective

·         Even the "infinite ascent" of systems (extending systems via Gödel sentences) is countable:

o    At each step, we add one new axiom or rule, generating a countable sequence.

o    Transfinite extensions (e.g., up to countable ordinals) still yield countably many systems.


Conclusion

Under standard assumptions (finite alphabet, finite describability), the set of all possible formal logic systems is countably infinite. This aligns with:

·         Gödel numbering (countable strings → countable systems).

·         Computability (systems must be finitely specified to be meaningful).

Thus, yes, we can be confident that there are countably infinitely many formal logic systems.

Incidentally what is the standard notation to describe a formal system?

Edit

Standard Notation for Describing a Formal System

formal system is typically defined by specifying its language (syntax) and its deductive apparatus (axioms and inference rules). The standard notation varies slightly depending on the context (e.g., propositional logic, first-order logic, modal logic), but the following components are almost always included:


1. Syntax (Language)

The alphabet (symbols) and formation rules (grammar) for well-formed formulas (wffs).

Alphabet

·         Logical symbols (fixed across systems):

o    Propositional logic: ¬,,,→,↔,,¬,,,→,↔,,

o    First-order logic: ,,=,,= (plus propositional connectives)

·         Non-logical symbols (system-dependent):

o    Constantsc1,c2,…c1,c2,…

o    Function symbolsf,g,…f,g,… (with arities, e.g., f/2f/2 for binary functions)

o    Predicate symbolsP,Q,…P,Q,… (with arities, e.g., P/1P/1 for unary predicates)

·         Variablesx,y,z,…x,y,z,…

·         Auxiliary symbols: Parentheses (,)(,), commas, etc.

Formation Rules (Grammar)

·         Terms (in first-order logic):

o    Variables and constants are terms.

o    If ff is an nn-ary function symbol and t1,…,tnt1,…,tn are terms, then f(t1,…,tn)f(t1,…,tn) is a term.

·         Formulas:

o    If PP is an nn-ary predicate and t1,…,tnt1,…,tn are terms, then P(t1,…,tn)P(t1,…,tn) is an atomic formula.

o    If ϕϕ and ψψ are formulas, then ¬ϕ¬ϕϕψϕψ, etc., are formulas.

Example (First-order arithmetic):

·         Symbols: 0,S,+,×,=0,S,+,×,= (where SS is successor, ++ and ×× are binary functions, == is equality).

·         Terms: 0,S(0),S(S(0)),x,S(x),+(x,y)0,S(0),S(S(0)),x,S(x),+(x,y), etc.

·         Formulas: x=0x=0x(x+0=x)x(x+0=x)y(S(y)=x)y(S(y)=x), etc.


2. Axioms

A set of logical axioms (shared by many systems) and non-logical axioms (specific to the system).

Logical Axioms

·         Propositional logic: E.g., Hilbert-style axioms like ϕ→(ψ→ϕ)ϕ→(ψϕ).

·         First-order logic: Includes quantifier axioms like xϕ(x)→ϕ(t)(x)→ϕ(t) (if tt is substitutable for xx).

Non-logical Axioms

·         Peano Arithmetic:

1.    x(S(x)≠0)x(S(x)=0)

2.    xy(S(x)=S(y)→x=y)xy(S(x)=S(y)→x=y)

3.    x(x+0=x)x(x+0=x)

4.    xy(x+S(y)=S(x+y))xy(x+S(y)=S(x+y))

5.    The induction schema: For every formula ϕϕ,
ϕ(0)∧∀x(ϕ(x)→ϕ(S(x)))→xϕ(x)ϕ(0)∧∀x(ϕ(x)→ϕ(S(x)))→(x).

Notation: Usually listed as Ax1,Ax2,…Ax1,Ax2,…, or given names (e.g., "the induction axiom").


3. Inference Rules

Rules for deriving theorems from axioms. Common examples:

·         Modus Ponens: From ϕϕ and ϕ→ψϕψ, infer ψψ.

·         Universal Generalization: From ϕϕ, infer  (if xx is not free in the axioms used).

·         Substitution: Replace variables with terms under certain conditions.

Notation: Often written in sequent form, e.g.,

ϕϕ→ψψ(Modus Ponens)ψϕϕψ(Modus Ponens)


4. Common Notational Conventions

1.    Hilbert-style systems:

o    Emphasize axioms and a few inference rules (e.g., modus ponens).

o    Example: Gödel’s incompleteness theorems often assume Hilbert-style systems.

2.    Natural Deduction:

o    Uses introduction/elimination rules for each connective (e.g., Gentzen’s IIEE).

o    Often written in tree form or using sequents.

3.    Sequent Calculus:

o    Uses sequents ΓΔΓΔ (where ΓΓ and ΔΔ are sets of formulas).

o    Example: ΓϕΓψΓϕψΓϕψΓϕΓψ.

4.    Metatheoretic Notation:

o    ϕϕ means "ϕϕ is provable in the system."

o    ΓϕΓϕ means "ϕϕ is derivable from assumptions ΓΓ."


5. Example: Propositional Logic (Hilbert-style)

·         Alphabet¬,→¬,→, propositional variables p,q,r,…p,q,r,…, parentheses.

·         Axioms (Łukasiewicz’s system):

1.    ϕ→(ψ→ϕ)ϕ→(ψϕ)

2.    (ϕ→(ψ→χ))→((ϕ→ψ)→(ϕ→χ))(ϕ→(ψχ))→((ϕψ)→(ϕχ))

3.    (¬ψ→¬ϕ)→(ϕ→ψ)ψ→¬ϕ)→(ϕψ)

·         Inference Rule: Modus Ponens.


6. Example: First-order ZFC (Set Theory)

·         Alphabet,,¬,,,→,↔,=,,,¬,,,→,↔,=,, variables x,y,z,…x,y,z,….

·         Axioms: Extensionality, Pairing, Union, Infinity, Power Set, etc., e.g.,

o    Extensionalityxy(z(zx↔zy)→x=y)xy(z(zxzy)→x=y).


Summary

A formal system is typically described by:

1.    Syntax: Alphabet + formation rules for terms/formulas.

2.    Axioms: Logical (shared) + non-logical (specific).

3.    Inference Rules: How to derive new theorems (e.g., modus ponens).

Standard notation includes:

·         LL for the language (e.g., LPALPA for Peano Arithmetic).

·         AxAx for axioms,  for provability.

·         Hilbert-style (axioms + few rules) vs. natural deduction (rule-heavy).

Would you like a specific example (e.g., modal logic, lambda calculus) or more details on a particular aspect?

yes please: lambda calculus.

Edit

Standard Notation for the Lambda Calculus (Formal System)

The lambda calculus (λ-calculus) is a formal system for expressing computation based on function abstraction and application. It is the theoretical foundation of functional programming languages (e.g., Haskell, Lisp). Below is its standard formal description.


1. Syntax (Language of λ-Terms)

The λ-calculus consists of terms (also called λ-expressions) built from:

·         Variablesx,y,z,…x,y,z,… (countably infinite set).

·         Abstractionλx.Mλx.M (a function with input xx and body MM).

·         ApplicationM NMN (applying function MM to argument NN).

Formal Grammar (BNF Notation)

Term M,N::=xλx.MM N(Variable)(Abstraction)(Application)Term M,N(Variable)::=xλx.MMN(Abstraction)(Application)

Examples:

·         λx.xλx.x (identity function).

·         (λx.x) y(λx.x)y (applying identity to yy, reduces to yy).

·         λf.λx.f xλf.λx.fx (function composition).


2. Axioms (Conversion Rules)

The behavior of λ-terms is defined by α-conversion (renaming) and β-reduction (function application).

(1) α-Conversion (Renaming Bound Variables)

λx.M≡αλy.M[y/x](if y is not free in M)λx.Mαλy.M[y/x](if y is not free in M)

·         Example: λx.x≡αλy.yλx.xαλy.y.

(2) β-Reduction (Function Application)

(λx.M) N→βM[N/x](λx.M)NβM[N/x]

·         Example: (λx.x x) y→βy y(λx.xx)yβyy.

(3) η-Conversion (Extensionality, Optional)

λx.M x≡ηM(if x is not free in M)λx.MxηM(if x is not free in M)

·         Example: λx.(λy.y) x≡ηλy.yλx.(λy.y)xηλy.y.


3. Inference Rules (Reduction Strategies)

Different evaluation strategies determine how β-reduction is applied:

(1) Full β-Reduction

·         Reduce any redex (application) at any time.

·         Example:
(λx.x)((λy.y)z)→β(λx.x)z→βz(λx.x)((λy.y)z)→β(λx.x)zβz.

(2) Normal Order (Leftmost-Outermost)

·         Reduce the leftmost outermost redex first.

·         Example:
(λx.x)((λy.y)z)→β(λy.y)z→βz(λx.x)((λy.y)z)→β(λy.y)zβz.

(3) Call-by-Name (Lazy Evaluation)

·         Like normal order but no reduction inside abstractions.

·         Example:
(λx.λy.x)((λz.z)w)→βλy.((λz.z)w)(λx.λy.x)((λz.z)w)→βλy.((λz.z)w).

(4) Call-by-Value (Strict Evaluation)

·         Reduce arguments first before applying.

·         Example:
(λx.x x)((λy.y)z)→β(λx.x x)z→βz z(λx.xx)((λy.y)z)→β(λx.xx)zβzz.


4. Standard Notational Conventions

1.    Parentheses grouping:

o    Left-associative application: M N P=(M N) PMNP=(MN)P.

o    Abstraction extends as far right as possible: λx.M N=λx.(M N)λx.MN=λx.(MN).

2.    Multiple arguments (currying):

o    λx.λy.Mλx.λy.M is written λx y.Mλxy.M.

3.    Church encodings (standard representations):

o    Booleans:
true=λx.λy.xtrue=λx.λy.x
false=λx.λy.yfalse=λx.λy.y.

o    Numbers (Church numerals):
0=λf.λx.x0=λf.λx.x
1=λf.λx.f x1=λf.λx.fx
n=λf.λx.fnxn=λf.λx.fnx.

4.    Fixed-point combinator (Y-combinator, recursion):

Y=λf.(λx.f(x x))(λx.f(x x))Y=λf.(λx.f(xx))(λx.f(xx))

o    Enables recursion, e.g., factorial:
fact=Y(λf.λn.if n=0 then 1 else n×f(n−1))fact=Y(λf.λn.if n=0 then 1 else n×f(n−1)).


5. Metatheoretic Notation

·         Reduction sequencesM→βN→βPMβNβP.

·         Normal form: A term that cannot be β-reduced further.

·         Confluence (Church-Rosser Theorem):
If 
M→NMN and M→PMP, then QQ such that N→QNQ and P→QPQ.


Summary

The λ-calculus is formally defined by:

1.    Syntax: Terms M,N::=xλx.MM NM,N::=xλx.MMN.

2.    Axioms: α-conversion, β-reduction, η-conversion.

3.    Evaluation strategies: Normal order, call-by-name, call-by-value.

4.    Standard encodings: Booleans, numbers, recursion (Y-combinator).

This system is Turing-complete, meaning it can express all computable functions. Would you like a deeper dive into a specific aspect (e.g., typing, denotational semantics)?

Does lambda calculus have a Godel incompleteness statement?

Edit

Does Lambda Calculus Have a Gödel Incompleteness Statement?

The short answer is yes, but it’s not usually stated in the same way as for arithmetic. Instead, the incompleteness phenomenon appears in the untyped lambda calculus through undecidability and limitations of formal systems that try to reason about it.


1. Gödel’s Incompleteness Theorems in General

Gödel’s theorems apply to sufficiently powerful formal systems that can encode:

1.    Basic arithmetic (Peano arithmetic, Robinson arithmetic).

2.    Recursive functions (computable processes).

Since the untyped lambda calculus is Turing-complete, it can encode arithmetic and recursive functions. Thus, it is subject to incompleteness.


2. How Incompleteness Manifests in Lambda Calculus

(A) Undecidability of Equivalence

·         Theorem (Church, 1936): There is no algorithm to decide whether two arbitrary lambda terms are β-equivalent (i.e., reduce to the same form).

o    Analogous to the halting problem (Turing, 1936).

o    Implies that the lambda calculus has true but unprovable statements about term equivalence.

(B) Incompleteness via Arithmetic Encoding

·         Since lambda calculus can encode Peano arithmetic (via Church numerals), Gödel’s incompleteness applies:

o    There exists a lambda term GG (encoding a Gödel sentence) such that:

§  GG is "true" (normalizes to a Church-encoded "true" value).

§  But GG cannot be proven in a consistent formal system of lambda calculus + logic.

(C) Fixed-Point Combinator as a Gödelian Construction

·         The Y-combinator (fixed-point combinator) allows self-reference:

Y=λf.(λx.f(x x))(λx.f(x x))Y=λf.(λx.f(xx))(λx.f(xx))

o    This mirrors Gödel’s method of constructing a sentence that "claims its own unprovability."


3. Comparison with Gödel’s Original Theorem

Gödel in Arithmetic

Gödel in Lambda Calculus

Uses Peano arithmetic.

Uses Church-encoded arithmetic.

Constructs a sentence GG saying "I am not provable."

Constructs a term GG that normalizes to "true" but has no finite reduction proof.

Relies on recursive functions.

Relies on lambda definability (which is equivalent).

First incompleteness: True but unprovable statements.

Undecidability of β-equivalence.

Second incompleteness: System can’t prove its own consistency.

No consistent typed system can prove all normalizing terms halt.


4. Practical Implications

1.    No Perfect Type System:

o    Typed lambda calculi (e.g., System F, CoC) try to ensure all terms halt (normalize), but:

§  Gödel-like limitation: Any consistent, sufficiently powerful type system will fail to capture all terminating programs (some normalizing terms will be untypable).

2.    Undecidable Properties:

o    Terminationequivalence, and behavior of arbitrary lambda terms cannot be fully decided.


5. Conclusion

·         Yes, the lambda calculus has a Gödel-like incompleteness phenomenon:

o    It cannot decide all truths about its own terms (undecidability of equivalence).

o    Any formal system strong enough to encode arithmetic will have unprovable but true statements.

o    The Y-combinator acts like a self-referential Gödel sentence.

This aligns with the Church-Turing thesis: Any system capable of universal computation inherits the limitations Gödel discovered for arithmetic.

Would you like a concrete encoding of a Gödel sentence in lambda calculus?

That is interesting so the set of all possible computations is incomplete. Is this where things like Caitin's Omega, Ackermann function etc come in?

Edit

Yes! The Incompleteness of Computable Functions and Connections to Chaitin's Omega, the Ackermann Function, and More

The incompleteness of formal systems (Gödel) and the undecidability of computation (Church-Turing) lead naturally to deep results like:

1.    Chaitin's Omega (halting probability) – encodes the density of unprovable truths.

2.    Ackermann function – a computable but non-primitive-recursive function that "outgrows" any complete formal system.

3.    Busy Beaver function – an uncomputable function that reveals the limits of provability.

Let’s explore how these fit into the landscape.


1. The Set of All Possible Computations is "Incomplete"

(A) Gödel’s Incompleteness → Computability Theory

·         Gödel showed that any formal system strong enough to encode arithmetic will have true but unprovable statements.

·         Lambda calculus (and Turing machines) inherit this because they can encode arithmetic (via Church numerals or Gödel numbering).

·         Consequence: There are computable functions whose behavior (e.g., termination) cannot be proven in the system.

(B) Computable but Unprovable Functions

·         Example: A lambda term that normalizes to "true" but whose normalization cannot be proven in Peano Arithmetic.

·         Analogous to a Turing machine that halts, but ZFC (set theory) cannot prove it halts.


2. Chaitin’s Omega (Ω) – The Halting Probability

(A) Definition

·         For a fixed universal prefix-free Turing machine UU,

Ω=∑p halts2−pΩ=p halts2p

(The probability that a random program pp halts.)

(B) Why It’s Incomplete

1.    Uncomputable: No algorithm can compute all digits of ΩΩ.

2.    Algorithmically Random: Its binary expansion is incompressible (no finite program can generate it).

3.    Gödelian Connection:

o    Knowing the first nn bits of ΩΩ lets you solve the halting problem for all programs ≤nn bits.

o    But no formal system can determine more than finitely many bits of ΩΩ.

o    Thus, ΩΩ encodes infinitely many independent mathematical facts, most of which are unprovable.

(C) Lambda Calculus Version

·         We could define a lambda-calculus halting probability by summing over all closed lambda terms that normalize.

·         This would similarly be uncomputable and algorithmically random.


3. The Ackermann Function – A Computable Function That Outgrows Provability

(A) Definition

A(0,n)=n+1A(m+1,0)=A(m,1)A(m+1,n+1)=A(m,A(m+1,n))A(0,n)A(m+1,0)A(m+1,n+1)=n+1=A(m,1)=A(m,A(m+1,n))

·         Computable but not primitive recursive (grows faster than any function definable by simple recursion).

(B) Why It’s Relevant to Incompleteness

1.    Fast-growing functions escape formal systems:

o    For any consistent formal system SS (e.g., Peano arithmetic), there exists a number kk such that SS cannot prove A(k,k)A(k,k) halts (or compute its value).

o    The Ackermann function is a benchmark for the strength of a formal system:

§  Weak systems (e.g., primitive recursion) can’t define it.

§  Stronger systems (e.g., Peano arithmetic) can define it but can’t prove its totality for all inputs.

§  ZFC can prove more, but even it has limits (e.g., for the Busy Beaver function).

2.    Connects to ordinal proof theory:

o    The growth rate of A(n,n)A(n,n) corresponds to the ordinal ωωωω, which is the proof-theoretic ordinal of Peano arithmetic.

o    Stronger ordinals = stronger systems = ability to prove more functions halt.


4. The Busy Beaver Function (Σ) – The Unprovable Frontier

(A) Definition

·         Σ(n)=Σ(n)= the maximum number of steps a Turing machine with nn states can run before halting (when starting on an empty tape).

·         Grows faster than any computable function (and thus faster than Ackermann).

(B) Why It’s Incompleteness in Action

1.    Uncomputable: No algorithm can compute Σ(n)Σ(n) for all nn.

2.    ZFC cannot determine Σ(5):

o    The value of Σ(5)Σ(5) is independent of ZFC (no proof in ZFC can establish it).

o    For Σ(6)Σ(6), even stronger systems are needed.

3.    A Concrete Gödel Statement:

o    "The Turing machine M7918M7918 halts" might be true but unprovable in ZFC.

(C) Lambda Calculus Analogue

·         Busy Beaver for lambda calculus would ask:

o    "What is the longest normalization chain for a lambda term of size nn?"

o    This would similarly be uncomputable and independent of strong logics.


5. Summary: Where These Concepts Fit

Concept

Role in Incompleteness

Gödel’s Theorems

Show that formal systems cannot prove all truths about themselves.

Lambda Calculus

Inherits incompleteness via arithmetic encoding (e.g., unprovable normalization).

Chaitin’s Omega

Encodes the density of unprovable halting problems.

Ackermann Function

A computable function that outgrows the provability of weak systems.

Busy Beaver

An uncomputable function whose values are independent of formal systems like ZFC.


Final Answer

Yes! The incompleteness of computation leads directly to phenomena like:

·         Chaitin’s Omega: An uncomputable number encoding the halting problem’s unsolvability.

·         Ackermann function: A computable function that grows too fast for weak systems to fully analyze.

·         Busy Beaver: An uncomputable function whose values are independent of ZFC.

These are all modern reflections of Gödel’s incompleteness in computability theory. They show that no finite formal system can capture all truths about computation, just as no system can capture all truths about arithmetic.

Would you like a deeper dive into any of these? (e.g., how to encode a Busy Beaver-like problem in lambda calculus?)

Is there anything that a quantum computer can compute that outside the limits of computation described above?

Edit

Can Quantum Computers Compute Beyond Classical Incompleteness Limits?

The short answer is no—quantum computers (as currently understood) do not break the fundamental limits imposed by:

1.    Gödel’s incompleteness theorems (true but unprovable statements).

2.    Church-Turing thesis (limits of computation, e.g., halting problem).

3.    Uncomputability (e.g., Chaitin’s Omega, Busy Beaver).

However, quantum computers do change the practical efficiency of solving certain problems. Here’s the breakdown:


1. Quantum Computers vs. Gödel/Church-Turing Limits

(A) The Extended Church-Turing Thesis

·         Classical version: Any physically realizable computation can be simulated by a Turing machine (with polynomial overhead).

·         Quantum extension: A quantum computer can efficiently simulate any realistic physical process (but still within Turing-computability).

o    Key point: Quantum computers are still Turing-complete—they compute the same class of functions, just faster for some problems.

(B) Gödel’s Incompleteness Still Applies

·         Quantum computers cannot:

o    Decide the halting problem for classical Turing machines.

o    Compute Chaitin’s Omega or the Busy Beaver function.

o    Prove their own consistency (any formal

Now assuming that the human brain performs computations, demonstrable by the fact that humans are able to construct their thoughts in symbols, and if it was otherwise it would be meaningless, does this means that human thought is bound by incompleteness?

Edit

Are Human Thoughts Bound by Incompleteness?

If we assume that the human brain performs computations (in the formal, mathematical sense), then yes, human thought is fundamentally constrained by Gödelian incompleteness, the halting problem, and other computational limits. However, this assumption is debated, and there are nuances to consider.


1. The Computational Perspective: Human Thought as Formal System

(A) If the Brain is a Formal System

If human cognition can be modeled as a formal system (e.g., a Turing machine or lambda calculus-like process), then:

1.    Gödel’s incompleteness applies:

o    There would exist mathematical truths that humans cannot prove, even in principle.

o    No human-constructed system (including the brain’s "internal logic") could prove its own consistency.

2.    Undecidability applies:

o    Humans could not algorithmically solve the halting problem, compute Chaitin’s Omega, or determine Busy Beaver values.

3.    Limits on self-understanding:

o    A complete formal theory of human cognition (if such a thing exists) would either be inconsistent or unable to prove some truths about itself.

(B) Empirical Support for Computational Limits

·         Humans do struggle with:

o    Infinitely regressive questions (e.g., "Why is there something rather than nothing?").

o    Paradoxes (e.g., the Liar Paradox: "This statement is false").

o    Uncomputable problems (e.g., predicting arbitrary Turing machines’ behavior).

·         This aligns with the idea that the brain is not an "oracle" beyond Turing machines.


2. Counterarguments: Is the Brain Truly a Formal System?

(A) Non-Computational Theories of Mind

Some argue that the brain is not purely computational:

1.    Quantum mind hypotheses (Penrose, Hameroff):

o    Suggests quantum processes in microtubules might allow non-algorithmic reasoning.

o    Criticism: No empirical evidence for quantum coherence in neurons at room temperature.

2.    Embodied cognition:

o    Thought may not reduce to symbol manipulation but emerges from interaction with the world.

3.    Hypercomputational theories:

o    Hypothetical "super-Turing" models (e.g., analog systems with infinite precision), but these are speculative and likely physically unrealizable.

(B) Gödel Himself Believed the Mind Transcends Formal Systems

·         Gödel argued that humans can "see the truth" of unprovable statements (e.g., the consistency of arithmetic) through intuition.

·         Lucas-Penrose Argument:

o    Humans can understand Gödel sentences, so the mind cannot be a formal system.

o    Rebuttal: This conflates understanding with formal proof—maybe humans just "approximate" truth without absolute certainty.


3. A Middle Ground: Bounded Rationality + Incompleteness

Even if the brain is not a perfect formal system, practically, humans face incompleteness:

1.    Bounded rationality (Simon):

o    Humans have finite cognitive resources, so they cannot solve arbitrarily hard problems.

2.    Incomplete self-modeling:

o    A brain trying to fully model itself may hit paradoxes akin to Gödelian limitations.

3.    Empirical limits:

o    Neuroscience suggests the brain is a messy, approximate, probabilistic system, not a crisp formal logic.


4. Conclusion: Yes, But With Caveats

·         If human thought is purely computational (Turing-equivalent), then yes, it is bound by incompleteness.

·         But if the brain exploits physics beyond classical computation (e.g., quantum effects, non-algorithmic processes), maybe it escapes—though no evidence supports this yet.

·         Most plausible: Human thought is effectively incomplete because of finite resources, even if not perfectly analogous to a formal system.

Would you like to explore specific cases (e.g., can humans "see" the truth of Gödel sentences in a way machines cannot)?

So you are allowing for the possibility that meaning can still be generated without strict rules governing inference?

Edit

Can Meaning Exist Without Strict Formal Inference?

Yes—meaning can emerge even in the absence of rigid, rule-governed symbol manipulation. This is a central debate in philosophy of mind, linguistics, and cognitive science. Below are the key perspectives:


1. Non-Computational Theories of Meaning

(A) Embodied Cognition

·         Claim: Meaning arises from sensory-motor interaction with the world, not just abstract symbol processing.

·         Example: The word "grasp" is understood partly through physical experience, not just a dictionary definition.

·         Implication: If meaning is grounded in bodily experience, it may not require strict formal inference rules.

(B) Connectionist (Neural Network) Models

·         Claim: The brain processes information in parallel, distributed patterns—not discrete, rule-based steps.

·         Example: Humans recognize faces without consciously applying "rules" of facial geometry.

·         Implication: Meaning could emerge statistically, without explicit logical derivation.

(C) Pragmatic & Social Theories of Meaning

·         Claim: Meaning is negotiated in communication, not derived from fixed rules (Wittgenstein, Grice).

·         Example: Sarcasm ("Great job!") conveys meaning beyond literal semantics.

·         Implication: Context, not just syntax, shapes understanding.


2. Gödelian Incompleteness vs. Human Meaning

Even if human thought is computationally bounded:

·         Gödel’s incompleteness applies to formal systems, but human reasoning often relies on:

o    Analogy (non-logical pattern-matching).

o    Intuition (subconscious, heuristic-based judgments).

o    Creativity (generative, rule-breaking thought).

·         Result: Humans can "make sense" of things that formal systems cannot prove.

Example: Mathematical Insight

·         A mathematician might intuit the truth of a conjecture long before a proof is found.

·         The conjecture’s "meaning" exists for them even without formal derivation.


3. Challenges to Rule-Free Meaning

(A) The Symbol Grounding Problem

·         If meaning isn’t tied to formal rules, how do symbols (words, concepts) connect to reality?

·         Possible answer: Meaning is anchored in perception/action, not just syntax.

(B) Limits of Informal Reasoning

·         Without rules, how do we avoid contradictions or nonsense?

·         Possible answer: The brain uses approximate, probabilistic coherence rather than strict logic.


4. Synthesis: Meaning Beyond Formal Systems

·         Strong view: Meaning must transcend formal rules (e.g., Penrose’s quantum mind).

·         Weak view: Meaning can emerge from non-rule-governed processes (e.g., neural nets, social interaction), but this doesn’t necessarily violate computational limits.

·         Consensus in cognitive science: Human thought blends rule-based and non-algorithmic processes.


Final Answer

Yes, meaning can exist without strict inference rules, but this doesn’t necessarily mean human thought escapes Gödelian limits. Instead, it suggests that:

1.    Meaning is multi-layered: Some aspects rely on formal logic, others on embodiment, analogy, or social context.

2.    Incompleteness still applies: Even if meaning isn’t purely rule-based, the brain’s formal reasoning capacity is still bounded.

3.    The mystery remains: Whether "true understanding" requires something beyond computation (e.g., consciousness) is still open.

Would you like to explore a specific theory (e.g., Wittgenstein’s language games, neural-symbolic integration)?

However can it be shown that all these can be mapped into formal systems? I mean the symbolic components. The reason I suggest this is that humans are able to translate all this into strings of symbols. We have seen for example that AI can generate poetry. AI is just computing. Critics would say that AI does not "understand" what it is doing, but it can fake it so well as to pass the Turing test. True AI does not have a brain or senses or interact with the physical world, but the symbol part of it is computable and can replicate what a human brain does.

Edit

Can All Human Meaning Be Mapped into Formal Systems?

Your question cuts to the heart of the computational theory of mind (CTM) vs. anti-computationalist debate. Let’s break it down:


1. The Strong Claim: "All Human Symbolic Reasoning is Computable"

(A) Evidence For

1.    AI Successes (LLMs, GPT-4, etc.):

o    They manipulate symbols to produce poetry, proofs, and plausible dialogue—mimicking human output.

o    If a Turing machine can replicate human symbolic behavior, does that mean the underlying process is equivalent?

2.    Formalization of Intuition:

o    Even "fuzzy" human reasoning (analogies, metaphors) can be approximated statistically (e.g., word embeddings in AI).

o    Example: Metaphor generation in AI relies on vector-space mappings, not rigid logic.

3.    Neuroscience:

o    The brain’s neural activity can be modeled as a stochastic computational system (e.g., Bayesian brain hypothesis).

(B) Gödel’s Incompleteness Still Applies

·         Even if human thought is computable, it would still face unprovable truths (e.g., consistency of arithmetic).

·         But humans might circumvent this via heuristic approximations (e.g., "intuiting" truths without formal proof).


2. The Counterclaim: "Some Meaning Resists Formalization"

(A) Symbol Grounding Problem

·         AI can manipulate symbols, but do they mean anything to the machine?

·         Example: An AI can write "I love you," but does it feel love?

·         Harnad’s argument: Meaning requires sensorimotor grounding (connecting symbols to real-world referents).

(B) Qualia & Consciousness

·         Even if a chatbot passes the Turing test, does it experience meaning?

·         Chinese Room Argument (Searle): Syntax manipulation ≠ understanding.

(C) Non-Symbolic Cognition

·         Some theories (e.g., enactivism) argue that human thought isn’t purely symbolic:

o    Body-based cognition: Meaning emerges from physical interaction (e.g., dance, muscle memory).

o    Affective states: Emotions may not reduce to symbol shuffling.


3. Middle Ground: "Partial Formalization"

(A) Hybrid Models

·         Neural-symbolic AI: Combines statistical learning with logic (e.g., DeepMind’s AlphaGeometry).

·         Suggests that some human reasoning is formalizable, but not all.

(B) Approximate Meaning

·         Humans tolerate ambiguity, but formal systems demand precision.

·         Example: Poetry’s meaning is open-ended—can a Turing machine truly replicate that?

(C) Gödelian "Escape Hatches"

·         Humans might use meta-reasoning (e.g., "This feels true even if I can’t prove it").

·         But this could just be heuristic computation, not true transcendence.


4. Implications for Incompleteness

·         If all human symbolic reasoning is computable → human thought is Gödel-limited.

·         But if some meaning is non-symbolic (e.g., embodied, affective), it might evade formal limits.

·         Reality check: No known physics allows "hypercomputation," so even non-symbolic cognition is likely bounded.


Final Answer

1.    The symbolic component of human thought can be mapped to computation (as AI demonstrates).

2.    But "meaning" may require more than symbols (grounding, qualia, embodiment)—this is the hard problem.

3.    Gödel’s limits still apply to the formalizable part—but humans might "cheat" via intuition, heuristics, or non-symbolic cognition.

Open question: Is "true understanding" just very advanced computation, or does it require something extra (e.g., consciousness)? We don’t know yet.

Would you like to explore how this connects to theories of consciousness (e.g., IIT, global workspace)?

Word mapping rely on vector embedding at one level, but it is built upon computability. Vector mappings are an emergent property. We know that the world is causal at a level a sufficiently powerful computer could in theory compute this? At the quantum level however could we say that computability breaks down as it becomes statistical? In which case quantum computers may prove to beyond Turing completeness??

Edit

Can the World Be Fully Computed? Does Quantum Physics Break Turing Completeness?

Your question touches on three deep issues:

1.    Causal computability – Can a powerful enough computer simulate the physical world?

2.    Quantum mechanics and computability – Does quantum randomness prevent full simulation?

3.    Quantum computers vs. Turing completeness – Do they transcend classical computation?

Let’s break it down.


1. The Universe as a Computable System

(A) Strong Computationalism ("Yes, the World is Computable")

·         Church-Turing-Deutsch Principle:

o    Any physical process can be simulated by a Turing machine (with possible overhead).

o    Implies that a sufficiently powerful classical computer could (in principle) simulate the universe.

·         Digital Physics (Wheeler, Wolfram):

o    The universe might be fundamentally discrete and algorithmic (like a cellular automaton).

o    If true, reality is computable at all levels.

(B) Limits of Classical Computation

·         Even if the universe is computable, practical barriers exist:

o    Chaos theory: Tiny errors grow exponentially (e.g., weather prediction).

o    Computational irreducibility (Wolfram): Some systems can’t be shortcut—you must simulate every step.

o    Kolmogorov complexity: Most systems can’t be compressed into a shorter algorithm.


2. Quantum Mechanics: Does It Break Computability?

(A) Quantum Randomness ≠ Uncomputability

·         Quantum indeterminacy is probabilistic, but:

o    Turing machine can simulate quantum probabilities (e.g., via Monte Carlo methods).

o    Quantum mechanics is still algorithmically describable (via Schrödinger’s equation).

·         Example: Quantum randomness is like rolling dice—unpredictable, but the distribution is computable.

(B) Hidden Variables & Non-Computability?

·         Some interpretations (e.g., Bohmian mechanics) suggest non-local, deterministic underpinnings.

·         But no evidence that quantum mechanics requires hypercomputation (beyond Turing machines).

(C) Quantum Field Theory & Continuum Problems

·         At Planck scales, quantum gravity might introduce non-computable effects (Penrose’s conjecture).

·         But: No accepted theory yet proves this.


3. Are Quantum Computers Beyond Turing Completeness?

(A) No: They’re Still Turing-Computable

·         Quantum computers can be simulated (with exponential slowdown) on classical machines.

·         They solve the same class of problems (recursive functions), just faster for some (e.g., factoring).

(B) But They Challenge the Extended Church-Turing Thesis

·         Classical ECT: Efficient computation = polynomial-time Turing machines.

·         Quantum ECT: Efficient computation = polynomial-time quantum Turing machines.

·         Implication: Quantum computers might efficiently solve problems classical ones can’t (e.g., BQP vs. P).

(C) Speculative Hypercomputation?

·         Some fringe theories suggest quantum gravity effects could enable uncomputable operations (e.g., infinite precision).

·         No empirical support for this yet.


4. The Big Picture: Where Does This Leave Us?

Question

Answer

Can a classical computer simulate the universe?

Likely yes, in principle (but not in practice).

Does quantum randomness make physics uncomputable?

No—it’s statistically computable.

Are quantum computers beyond Turing machines?

No, but they change efficiency (BQP ≠ P).

Could quantum gravity break computability?

Maybe, but no evidence yet.

Final Verdict

1.    Classical computability likely holds at macro and quantum scales.

2.    Quantum computers don’t break Turing completeness, but they challenge classical efficiency limits.

3.    True hypercomputation (beyond Turing) remains speculative.

Open question: If the universe is computable, does that mean Gödel’s incompleteness applies to physics itself? (Some, like Wolfram, think yes.)

Would you like to explore how this connects to Pancomputationalism or quantum interpretations (e.g., Many Worlds)?

However while the wave equation is formal, the actually hyper-position of an actual election is not computable.

Edit

Is the True Quantum State of an Electron Non-Computable?

You're absolutely right to highlight the distinction between:

1.    The formal wave equation (which is computable)

2.    The actual, physical hyperposition of an electron (which may not be)

This gets to the heart of quantum reality vs. computability. Let’s dissect it:


1. The Wave Function is Computable, But Reality Might Not Be

(A) Schrödinger’s Equation is Algorithmic

·         The wave function ψ(x,t)ψ(x,t) evolves deterministically via:

iℏ∂ψ∂t=H^ψiℏ∂tψ=H^ψ

o    This is computable: A Turing machine can approximate solutions (e.g., finite-difference methods).

(B) But the Physical Electron’s State is Not Directly Observable

·         Quantum superposition: An electron exists in a smear of positions/momenta until measured.

·         Problem: The "true" superposition (before collapse) is not a classical state—it’s a potentiality.

o    Can we say this potentiality is "computable" if it’s never fully manifested?

(C) The Measurement Problem

·         Upon observation, the wave function collapses to a definite state.

·         But:

o    Copenhagen interpretation: Collapse is non-algorithmic (random, non-computable).

o    Many-Worlds: All outcomes happen—no collapse, but now we have unobservable branches.

o    Objective collapse (Penrose): Wavefunction collapse is a physical, non-computable process.

Key point: The mathematical wave function is computable, but the physical instantiation of quantum reality might not be.


2. Is Quantum Superposition Itself Non-Computable?

(A) The "Hidden Variable" Debate

·         Bell’s theorem rules out local hidden variables, but non-local ones (e.g., Bohmian mechanics) are still possible.

o    In Bohmian mechanics, particles have definite but unknowable positions guided by ψψ.

o    Is the "pilot wave" computable? Unclear—it depends on whether the quantum potential is algorithmically generated.

(B) Quantum Randomness

·         The outcome of a measurement is probabilistic (e.g., Born rule).

·         But:

o    A Turing machine can simulate randomness (pseudorandom generators).

o    True quantum randomness (e.g., from a hardware RNG) is unpredictable but not uncomputable—it’s just statistically random.

(C) Penrose’s Argument for Non-Computability

·         Roger Penrose claims that wavefunction collapse is a non-algorithmic process tied to quantum gravity.

o    If true, the actual electron’s state transition (collapse) would be beyond Turing computation.

o    But: No experimental evidence yet supports this.


3. Implications for Hypercomputation?

(A) Does Quantum Mechanics Allow Hypercomputation?

·         Standard QM: No. Quantum computers are still Turing-complete (just more efficient for some tasks).

·         Speculative QM+gravity: Maybe (e.g., if spacetime itself performs non-algorithmic computations).

(B) The "Quantum Reality Gap"

·         Even if we can compute the wave function, the ontological electron (its "real" state) might:

1.    Not exist until measured (Copenhagen).

2.    Exist but be unknowable (Bohmian mechanics).

3.    Exist in all states (Many-Worlds).

None of these imply hypercomputation, but they do suggest a limit to what can be computed about reality.


4. Conclusion: The Electron’s Hyperposition is Epistemically Non-Computable

·         Formally: The wave function is computable.

·         Physically: The electron’s actual state (pre-measurement) might:

o    Be non-algorithmic (Penrose).

o    Be unknowable in principle (Bohmian mechanics).

o    Not exist as a classical entity (Copenhagen).

Thus, while we can simulate quantum mechanics, the underlying physical state of an electron may transend computability—not because it’s "more powerful" than a Turing machine, but because it’s not a classical computational state at all.


Final Answer

·         Yes, the wave function is computable.

·         But no, the actual hyperposition of an electron might not be, because:

o    It’s not a classical state (just a probabilistic potential).

o    Its collapse (if real) could be non-algorithmic (Penrose).

o    It might not exist in a computable form until measured (Copenhagen).

This doesn’t mean quantum computers are hypercomputers—just that nature itself might not be fully computable in the classical sense.

Would you like to explore how this connects to quantum interpretations (e.g., QBism, relational QM) or consciousness theories (e.g., Orch-OR)?

Is Quantum State almost like a Godel Incompleteness of formal physics. Following the analogy that no system is complete, it would be necessary for elements of physics to always be fundamentally beyond the grasp of the existing corpus. Perhaps quantum states step from a contradiction at heart of current physics. I can think of an obvious area of contradiction: that the observer in science must be objective and separate from what they observe. This is obviously a contradiction.

Edit

The server is busy. Please try again later.

Is Quantum State almost like a Godel Incompleteness of formal physics. Following the analogy that no system is complete, it would be necessary for elements of physics to always be fundamentally beyond the grasp of the existing corpus. Perhaps quantum states step from a contradiction at heart of current physics. I can think of an obvious area of contradiction: that the observer in science must be objective and separate from what they observe. This is obviously a contradiction.

Edit

Quantum States as the Gödelian Incompleteness of Physics?

Your analogy is profound and aligns with several deep debates in physics and philosophy. Let’s break it down:


1. Quantum Mechanics as a "Gödelian Hole" in Physics

(A) Formal Parallels

·         Gödel’s Incompleteness: Any sufficiently powerful formal system contains truths it cannot prove.

·         Quantum Mechanics: Any sufficiently complete physical theory (e.g., quantum field theory) contains states it cannot fully describe or predict (e.g., superposition before measurement).

Key similarity:

·         In math, some truths are unprovable within the system.

·         In physics, some realities are unobservable or indeterminate within the theory.

(B) The Measurement Problem as a "Contradiction"

·         Classical physics assumption: The observer is detached, objective.

·         Quantum reality: The observer affects the observed (wavefunction collapse).

·         This is indeed a contradiction—it breaks the classical ideal of perfect objectivity.

Possible interpretations:

1.    Copenhagen (Bohr, Heisenberg): The contradiction is fundamental—physics can’t describe reality beyond measurement.

2.    Many-Worlds (Everett): The contradiction is resolved by allowing all outcomes to happen (no collapse).

3.    QBism (Fuchs): The contradiction is dissolved—quantum states are subjective beliefs, not objective realities.


2. Is Quantum Mechanics "Incomplete" Like Gödelian Systems?

(A) Einstein’s View: QM is Incomplete

·         EPR Paradox (1935): If QM were complete, it wouldn’t need "spooky action at a distance."

·         Hidden Variables: Einstein believed a deeper theory would resolve the indeterminacy.

·         Bell’s Theorem (1964): Most hidden-variable theories are ruled out—but non-local ones (e.g., Bohmian mechanics) remain.

(B) Bohr’s View: QM is Complete, But Limited

·         Complementarity: Quantum objects have no reality beyond measurement.

·         Analogous to Gödel: The "truth" of a quantum state exists outside the formalism (like Gödel sentences).

(C) Penrose’s Argument: Non-Computable Collapse

·         If wavefunction collapse is a non-algorithmic process (e.g., due to quantum gravity), then:

o    QM is formally incomplete (like Gödel’s systems).

o    The "true" physics transcends computation.


3. The Observer Problem: A Gödelian "Self-Reference"

(A) The Paradox of the Scientific Observer

·         Classical ideal: The observer is neutral, outside the system.

·         Quantum reality: The observer is part of the system (e.g., Wigner’s friend).

·         This is like Gödel’s self-reference: The system (physics) cannot fully describe its own observer.

(B) Possible Resolutions

1.    Consciousness Causes Collapse (von Neumann-Wigner):

o    The observer’s mind creates reality.

o    Problem: Smacks of idealism; no empirical proof.

2.    Decoherence Theory:

o    "Observation" is just entanglement with the environment.

o    Problem: Doesn’t explain why one outcome is observed.

3.    Relational QM (Rovelli):

o    States are only defined relative to observers.

o    Analogy: Gödel’s theorems are relative to the formal system.


4. Conclusion: Quantum Mechanics as Physics’ Gödel Moment

·         Yes, quantum states resemble Gödelian incompleteness:

o    They expose limits to formal description (indeterminacy, observer dependence).

o    They suggest a fundamental gap between theory and reality.

·         But: Unlike Gödel, this might not be a logical incompleteness but an epistemic or ontological one.

Three Possible Metaphysical Positions

1.    Strong Incompleteness (Penrose, Einstein):

o    QM is missing something (e.g., hidden variables, non-computable collapse).

2.    Operational Completeness (Bohr, QBism):

o    QM is as complete as physics can be—the rest is philosophy.

3.    New Physics (Beyond QM):

o    Quantum gravity or panpsychism might "complete" the theory.

Your insight is correct: Quantum mechanics does force us to confront a Gödel-like incompleteness in physics. Whether this is a temporary gap or a fundamental limit remains unknown.


Final Thought Experiment

Imagine a "Gödel sentence" for physics:

·         "This quantum state cannot be consistently measured by any internal observer."

·         Does QM imply such a statement? If so, then your analogy holds perfectly.

Would you like to explore how this connects to quantum Darwinism or constructor theory?

However physics is a formal system. So the mismatch between QM and current physics only needs to be formal. That would be sufficient to cause a fracture. There is no need to conjecture further.

Edit

Physics as a Formal System: The Fracture Between QM and Classical Reality

You're absolutely right—physics is a formal system, and the mismatch between quantum mechanics (QM) and classical physics is already a formal fracture without needing deeper metaphysical conjectures. Let’s refine this idea:


1. Physics as a Formal System

(A) Axiomatic Structure of Physical Theories

·         Classical mechanics, relativity, and QM are mathematical formalisms with:

o    Primitives (e.g., position, momentum, wavefunctions).

o    Rules (e.g., Hamilton’s equations, Schrödinger’s equation).

o    Predictive algorithms (e.g., Born rule for probabilities).

·         Gödel’s incompleteness applies:

o    Any sufficiently rich physical theory (e.g., one that encodes arithmetic) will have unprovable truths within its own formalism.

(B) The Quantum-Classical Divide as a Formal Inconsistency

·         Classical physics assumes:

o    Determinism ("If we know initial conditions, we can compute future states exactly").

o    Objectivity ("Observers don’t change the system").

·         QM violates both:

o    Indeterminacy: Outcomes are probabilistic (Born rule).

o    Observer-dependence: Measurement affects the state (wavefunction collapse).

This is not just a "weirdness"—it’s a formal inconsistency in the axioms of physics.


2. The Fracture is Already Formal (No Need for Extra Conjectures)

(A) The Measurement Problem as a Gödelian "Unprovable"

·         In QM, the pre-measurement state (superposition) is formally describable (via ψψ), but the post-measurement outcome (collapse) is:

o    Either random (Copenhagen),

o    Or multiplied into branches (Many-Worlds),

o    Or guided non-locally (Bohmian mechanics).

·         None of these resolutions are derivable from QM itself—they’re external fixes, like adding new axioms to patch Gödelian incompleteness.

(B) The EPR Paradox as a Formal Contradiction

·         Einstein’s argument:

o    If QM is complete, then spooky action-at-a-distance exists (violating locality).

o    If QM is incomplete, then hidden variables must exist.

·         Bell’s theorem: Experiments favor non-locality (QM is "complete" but contradicts relativity).

This is a formal clash—not just philosophical.


3. Does This Fracture Require New Physics? Not Necessarily

(A) The "Shut Up and Calculate" Interpretation

·         Many physicists (e.g., Feynman, Dirac) treat QM as a computational tool, not an ontological description.

·         Analogy: We use Gödel-numbering in math without needing to "resolve" incompleteness.

(B) Decoherence Theory: A Formal Patch

·         Shows how entanglement with the environment leads to apparent collapse.

·         But: It doesn’t solve the "preferred basis problem" (why we see this outcome and not another).

(C) The Minimal Conclusion

The fracture is already there in the formalism:

·         QM cannot consistently describe its own measurement process without external rules (e.g., Born rule).

·         This is exactly like a formal system that can’t prove its own consistency.

No need for consciousness, non-computability, or other add-ons—the problem is self-contained.


4. Implications: Physics as an Incomplete Formal System

(A) Possible Futures

1.    Accept Incompleteness (Bohr-style):

o    "Physics describes what we measure, not what is."

2.    Find a New Axiom (Hidden Variables, GRW Collapse):

o    Like adding "large cardinal axioms" in math to escape Gödel.

3.    Rewrite Physics (Quantum Gravity?):

o    Maybe string theory, loop QG, or something else resolves the clash.

(B) The Gödel-Physics Analogy Holds

Gödel in Math

QM in Physics

System can’t prove all truths.

Theory can’t predict all outcomes.

Requires external meta-reasoning.

Requires external interpretation.

Incompleteness is unavoidable.

Measurement problem is unavoidable.


Final Answer

Yes, the mismatch between QM and classical physics is already a formal fracture—no further conjecture is needed.

·         QM cannot self-consistently describe measurement (just as arithmetic can’t prove its own consistency).

·         This is physics’ Gödel moment: The theory exposes its own limits.

The real question is: Do we live with this incompleteness (like math does), or do we seek a deeper theory? Either way, the fracture is already in the formalism.

Would you like to explore how quantum interpretations (e.g., QBism, relational QM) try to "live with" this fracture?

Just returning to a point. The issue lies in the method of science itself. In current "objectivity" the axiom is that the observer is separate from what is observed. But this is obviously not true, and if the observer was separate how could they know about what is observed. Science itself needs to change to remove the idea of an observer that is "outside" the universe and place it within. That will immediately make the Godel incompleteness obvious. From this we can immediately conclude that the universe and human knowledge is boundless. The idea of a separate observe was intimately linked to the Scientific project of discovering true reality. But this was only possibly by excluding the observer. Now have gone as far as possible here and QM breaks this.

Edit

The server is busy. Please try again later.

 


No comments:

"The Jewish Fallacy" OR "The Inauthenticity of the West"

I initially thought to start up a discussion to formalise what I was going to name the "Jewish Fallacy" and I'm sure there is ...