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Physical Review

An Indeterminacy Relation for Several Observables and Its Classical Interpretation

H. P. Robertson

Published Nov 1, 1934• 226 citations
Publisher

Abstract

An examination of the limitations placed by the conceptual structure of quantum mechanics on the simultaneous measurement of two or more observables leads, for the case of an even number $m=2k$ of observables, to a quantitative estimate, depending only on the mean values of their commutators in the state in question, of the least value which the product of their $m$ uncertanties may assume. This indeterminacy relation is interpreted classically to mean that, by measurement of these observables alone, a point ($p, q$) in phase space can be determined only to within a certain channel whose normal cross section, as measured by the value of the $k\mathrm{th}$ integral invariant taken over it, must be at least of order ${h}^{k}$.

DOI
10.1103/physrev.46.794

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HEISENBERG AND THE PRIMITIVE ARCHITECTURE OF UNCERTAINTY

Cláudio Vicente da Silva

Description Heisenberg and the Primitive Architecture of Uncertainty: From Matrix Mechanics to Relational Transduction This work presents a philosophical-mathematical reconstruction of the Heisenberg uncertainty principle through the framework of the Primitive Architecture, with particular emphasis on relation, opposition, transformation, invariance, and transduction. The starting point is the historical transition introduced by Werner Heisenberg in 1925, when classical trajectories and numerical descriptions of physical systems were replaced by relations between observable quantities represented through matrix mechanics. The noncommutative composition of observables, AB≠BA,AB \neq BA, provides the mathematical basis for the commutator [A,B]=AB−BA.[A,B]=AB-BA. Within the proposed architectural formulation, the commutator is treated as the quantitative representation of the difference between two possible orders of relational composition. The distinction between ABAB and BABA therefore becomes the formal point at which relational opposition enters the mathematical description. The work subsequently connects this structure with the Robertson and Robertson–Schrödinger uncertainty relations. For two observables AA and BB, the standard uncertainty relation is written as ΔA ΔB≥12∣⟨[A,B]⟩∣,\Delta A\,\Delta B \geq \frac{1}{2} \left| \langle [A,B]\rangle \right|, while the Robertson–Schrödinger formulation incorporates both the commutator and the symmetric correlation term: (ΔA)2(ΔB)2≥14∣⟨[A,B]⟩∣2+14∣⟨{ΔA,ΔB}⟩∣2.(\Delta A)^2(\Delta B)^2 \geq \frac{1}{4} \left| \langle[A,B]\rangle \right|^2 + \frac{1}{4} \left| \langle\{\Delta A,\Delta B\}\rangle \right|^2. The Primitive Architecture is then used to organize these mathematical structures according to the sequence: RELATION → OPPOSITION → EQUILIBRIUM → MOVEMENT → LATENCY → TRANSDUCTION → FORM → MEMORY → RESONANCE → CYCLE → INVARIANCE → NEW RELATION. For the quantum-mechanical problem examined here, this broader architecture is reduced to the operational sequence: RELATION → OPPOSITION → UNCERTAINTY → TRANSFORMATION → INVARIANCE. A central construction of the work is the decomposition of the two composition orders into symmetric and antisymmetric components: S(A,B)=AB+BA2,S(A,B)=\frac{AB+BA}{2}, O(A,B)=AB−BA2.O(A,B)=\frac{AB-BA}{2}. Consequently, AB=S+O,AB=S+O, BA=S−O.BA=S-O. This formulation allows the relational structure to be represented as the coexistence of a symmetric component and an oppositional component, with the commutator corresponding to the latter. The article also examines unitary transformations, ∣ψ′⟩=U∣ψ⟩,U†U=I,|\psi'\rangle=U|\psi\rangle, \qquad U^\dagger U=I, and the corresponding transformation of observables, A′=UAU†,B′=UBU†.A'=UAU^\dagger, \qquad B'=UBU^\dagger. Under this transformation, [A′,B′]=U[A,B]U†,[A',B']=U[A,B]U^\dagger, and the uncertainty structure is preserved: ΔA′=ΔA,ΔB′=ΔB,\Delta A'=\Delta A, \qquad \Delta B'=\Delta B, so that ΔA′ΔB′=ΔAΔB.\Delta A'\Delta B' = \Delta A\Delta B. The work therefore identifies unitary invariance as the mathematical expression of structural preservation under transformation. The noncommutative relation itself is transformed covariantly, while its structural character is maintained. The position–momentum case is examined through the canonical relation [X,P]=iℏI,[X,P]=i\hbar I, which yields ΔX ΔP≥ℏ2.\Delta X\,\Delta P\geq\frac{\hbar}{2}. The article also considers the formal classical limit ℏ→0\hbar\rightarrow0, distinguishing the disappearance of the quantum quantitative lower bound from the broader structural concepts used in the proposed architectural formulation. A minimal matrix construction is included to make the relation between composition, opposition, variance, and uncertainty explicit. The treatment includes finite-dimensional matrices, state representations, expectation values, variances, projectors, unitary transformations, commutators, anticommutators, and higher-order nested commutators. The work further introduces a transductive interpretation of the mathematical passage (A,B)→(AB,BA)→[A,B]→ΔA ΔB,(A,B) \rightarrow (AB,BA) \rightarrow [A,B] \rightarrow \Delta A\,\Delta B, and, under transformation, (A,B)→(UAU†,UBU†),(A,B) \rightarrow (UAU^\dagger,UBU^\dagger), [A,B]→U[A,B]U†.[A,B] \rightarrow U[A,B]U^\dagger. In this formulation, transduction denotes the structural passage from one representation or relational configuration to another while preserving specified invariants. The term “latency” is used within the Primitive Architecture as an architectural concept associated with the interval between possible structural states; it is not introduced as a new standard quantum observable. The article does not propose a replacement for quantum mechanics. Its principal contribution is a philosophical-mathematical reconstruction and architectural organization of the uncertainty structure, connecting the historical matrix formulation of Heisenberg with the concepts of relation, opposition, transformation, transduction, and invariance developed within the Primitive Architecture. The work also distinguishes the author's architectural organization from established results in quantum mechanics and from contemporary developments in uncertainty relations. Historical foundations, standard mathematical inequalities, experimental results, and recent theoretical proposals cited in the bibliography are treated as external references rather than as original results of this work. Particular attention is given to contemporary developments concerning uncertainty relations, including operator-asymmetry approaches, refinements of Schrödinger-type inequalities, higher-order commutator constructions, multiparameter quantum sensing, and recent proposals connecting uncertainty relations with cosmological dynamics. These references provide the scientific context in which the present architectural reconstruction is situated. The complete formulation is summarized by the structural correspondence RELATION→OPPOSITION→QUANTIFICATION→TRANSDUCTION→INVARIANCE\boxed{ \text{RELATION} \rightarrow \text{OPPOSITION} \rightarrow \text{QUANTIFICATION} \rightarrow \text{TRANSDUCTION} \rightarrow \text{INVARIANCE} } and, at the operator level, [A,B]=AB−BA\boxed{ [A,B]=AB-BA } ΔA ΔB≥12∣⟨[A,B]⟩∣\boxed{ \Delta A\,\Delta B \geq \frac{1}{2} \left| \langle[A,B]\rangle \right| } [A′,B′]=U[A,B]U†\boxed{ [A',B'] = U[A,B]U^\dagger } ΔA′ΔB′=ΔAΔB.\boxed{ \Delta A'\Delta B' = \Delta A\Delta B. } The resulting formulation establishes a continuous conceptual and mathematical pathway from Heisenberg's matrix mechanics to a relational-transductive interpretation of quantum indeterminacy, while preserving the distinction between established quantum-mechanical mathematics and the architectural framework proposed by the author. Keywords: Heisenberg uncertainty principle; matrix mechanics; quantum mechanics; noncommutativity; commutator; anticommutator; Robertson uncertainty relation; Robertson–Schrödinger relation; variance; operator algebra; unitary transformation; invariance; relational structure; opposition; transduction; Primitive Architecture; mathematical philosophy; quantum indeterminacy.

•Sep 14, 2026•0 citations
An examination of the limitations placed by the conceptual structure of quantum mechanics on the simultaneous measurement of two or more observables leads, for the case of an even number m=2km=2km=2k of observables, to a quantitative estimate, depending only on the mean values of their commutators in the state in question, of the least value which the product of their mmm uncertanties may assume. This indeterminacy relation is interpreted classically to mean that, by measurement of these observables alone, a point (p,qp, qp,q) in phase space can be determined only to within a certain channel whose normal cross section, as measured by the value of the kthk\mathrm{th}kth integral invariant taken over it, must be at least of order hk{h}^{k}hk.
A general prescription for the construction of quasi-joint-probability distributions intended to describe the "joint behaviour" of an arbitrary pair of (generally non-commuting) quantum observables, along with its application to the geometric/statistical interpretation of Aharonov's weak value and a proposal for new uncertainty relations, are presented.The introduction of such distributions is motivated by two complementary approaches: one from a bottom-up and strictly operational construction by carefully examining the mathematical framework of the conditioned measurement scheme, and the other from a top-down viewpoint by applying the results of spectral theorem for normal operators and its Fourier transforms.It is revealed that, for a pair of simultaneously measurable observables, the distribution reduces to the unique standard joint-probability distribution of the pair as expected, whereas for a non-commuting pair, there exists an inherent indefiniteness for the choice of such distributions, admitting a multitude of candidates that qualify to describe the "joint behaviour" of the pair.The L 2 structures induced by the quasi-joint-probability distributions are then found to provide statistical interpretation of the geometric structures that can be naturally introduced on the space of operators on the underlying Hilbert space.As possible applications of our findings, we focus on orthogonal projections and inner products of observables, and observe that such geometric concepts can respectively be given statistical interpretations as "conditionings" and "correlations".Incidentally, weak values A w are given a geometric/statistical interpretation as either the orthogonal projection of an observable A on the subspace generated by another observable B (or equivalently, as the conditioning of A given B with respect to the quasi-joint-probability distribution under consideration).Moreover, the Cauchy-Schwartz inequality applied on inner products of two observables (or equivalently, correlations between the pair) leads to novel inequalities interpreted as uncertainty relations for approximation/estimation, which entails the time-energy uncertainty relation as its special case.
Conceptual change from a classical to a quantum perspective is a challenging task for students. Basic concepts such as state and time evolution, already posing problematic issues in classical physics, require a different interpretation because of the redefinition of the concept of state, inextricably linked to fundamental features of new system behavior such as incompatibility between observables. Within an empirical research aimed at investigating connections between conceptual aspects and formalism emerging from student reasoning, we designed questionnaire items to explore how student describe time evolution of states, how they identify stationary states and how they use related concepts of eigenstate of an observable and incompatibility between observables in this process. Data gathering instruments were developed through a case study to collect student points of view on the relevant issue. For each aspect, at least two items were designed in order to cross-examine from different perspectives. Data analysis was organized following qualitative research methodology. The questionnaire was administered to a small group of students together with follow-up interviews. The study shows that most students link energy eigenstates to stationary states, but inverse implication doesn’t emerge with the same strength. The relation between energy eigenstates and those of different observables is clearly stated only when a commutator expression is identified by students. Energy eigenstates and their linear combinations are related to time invariance and time evolution in quantum mechanics in familiar-abstract context of infinite well, while uncertainties emerge in the crucial situation of scattering. Students answer as expected to questions concerning familiar tasks and contexts, but this doesn’t correspond to conceptual understanding of crucial elements under investigation. There is a need to build competence on critical reasoning.
Description Heisenberg and the Primitive Architecture of Uncertainty: From Matrix Mechanics to Relational Transduction This work presents a philosophical-mathematical reconstruction of the Heisenberg uncertainty principle through the framework of the Primitive Architecture, with particular emphasis on relation, opposition, transformation, invariance, and transduction. The starting point is the historical transition introduced by Werner Heisenberg in 1925, when classical trajectories and numerical descriptions of physical systems were replaced by relations between observable quantities represented through matrix mechanics. The noncommutative composition of observables, AB≠BA,AB \neq BA, provides the mathematical basis for the commutator [A,B]=AB−BA.[A,B]=AB-BA. Within the proposed architectural formulation, the commutator is treated as the quantitative representation of the difference between two possible orders of relational composition. The distinction between ABAB and BABA therefore becomes the formal point at which relational opposition enters the mathematical description. The work subsequently connects this structure with the Robertson and Robertson–Schrödinger uncertainty relations. For two observables AA and BB, the standard uncertainty relation is written as ΔA ΔB≥12∣⟨[A,B]⟩∣,\Delta A\,\Delta B \geq \frac{1}{2} \left| \langle [A,B]\rangle \right|, while the Robertson–Schrödinger formulation incorporates both the commutator and the symmetric correlation term: (ΔA)2(ΔB)2≥14∣⟨[A,B]⟩∣2+14∣⟨{ΔA,ΔB}⟩∣2.(\Delta A)^2(\Delta B)^2 \geq \frac{1}{4} \left| \langle[A,B]\rangle \right|^2 + \frac{1}{4} \left| \langle\{\Delta A,\Delta B\}\rangle \right|^2. The Primitive Architecture is then used to organize these mathematical structures according to the sequence: RELATION → OPPOSITION → EQUILIBRIUM → MOVEMENT → LATENCY → TRANSDUCTION → FORM → MEMORY → RESONANCE → CYCLE → INVARIANCE → NEW RELATION. For the quantum-mechanical problem examined here, this broader architecture is reduced to the operational sequence: RELATION → OPPOSITION → UNCERTAINTY → TRANSFORMATION → INVARIANCE. A central construction of the work is the decomposition of the two composition orders into symmetric and antisymmetric components: S(A,B)=AB+BA2,S(A,B)=\frac{AB+BA}{2}, O(A,B)=AB−BA2.O(A,B)=\frac{AB-BA}{2}. Consequently, AB=S+O,AB=S+O, BA=S−O.BA=S-O. This formulation allows the relational structure to be represented as the coexistence of a symmetric component and an oppositional component, with the commutator corresponding to the latter. The article also examines unitary transformations, ∣ψ′⟩=U∣ψ⟩,U†U=I,|\psi'\rangle=U|\psi\rangle, \qquad U^\dagger U=I, and the corresponding transformation of observables, A′=UAU†,B′=UBU†.A'=UAU^\dagger, \qquad B'=UBU^\dagger. Under this transformation, [A′,B′]=U[A,B]U†,[A',B']=U[A,B]U^\dagger, and the uncertainty structure is preserved: ΔA′=ΔA,ΔB′=ΔB,\Delta A'=\Delta A, \qquad \Delta B'=\Delta B, so that ΔA′ΔB′=ΔAΔB.\Delta A'\Delta B' = \Delta A\Delta B. The work therefore identifies unitary invariance as the mathematical expression of structural preservation under transformation. The noncommutative relation itself is transformed covariantly, while its structural character is maintained. The position–momentum case is examined through the canonical relation [X,P]=iℏI,[X,P]=i\hbar I, which yields ΔX ΔP≥ℏ2.\Delta X\,\Delta P\geq\frac{\hbar}{2}. The article also considers the formal classical limit ℏ→0\hbar\rightarrow0, distinguishing the disappearance of the quantum quantitative lower bound from the broader structural concepts used in the proposed architectural formulation. A minimal matrix construction is included to make the relation between composition, opposition, variance, and uncertainty explicit. The treatment includes finite-dimensional matrices, state representations, expectation values, variances, projectors, unitary transformations, commutators, anticommutators, and higher-order nested commutators. The work further introduces a transductive interpretation of the mathematical passage (A,B)→(AB,BA)→[A,B]→ΔA ΔB,(A,B) \rightarrow (AB,BA) \rightarrow [A,B] \rightarrow \Delta A\,\Delta B, and, under transformation, (A,B)→(UAU†,UBU†),(A,B) \rightarrow (UAU^\dagger,UBU^\dagger), [A,B]→U[A,B]U†.[A,B] \rightarrow U[A,B]U^\dagger. In this formulation, transduction denotes the structural passage from one representation or relational configuration to another while preserving specified invariants. The term “latency” is used within the Primitive Architecture as an architectural concept associated with the interval between possible structural states; it is not introduced as a new standard quantum observable. The article does not propose a replacement for quantum mechanics. Its principal contribution is a philosophical-mathematical reconstruction and architectural organization of the uncertainty structure, connecting the historical matrix formulation of Heisenberg with the concepts of relation, opposition, transformation, transduction, and invariance developed within the Primitive Architecture. The work also distinguishes the author's architectural organization from established results in quantum mechanics and from contemporary developments in uncertainty relations. Historical foundations, standard mathematical inequalities, experimental results, and recent theoretical proposals cited in the bibliography are treated as external references rather than as original results of this work. Particular attention is given to contemporary developments concerning uncertainty relations, including operator-asymmetry approaches, refinements of Schrödinger-type inequalities, higher-order commutator constructions, multiparameter quantum sensing, and recent proposals connecting uncertainty relations with cosmological dynamics. These references provide the scientific context in which the present architectural reconstruction is situated. The complete formulation is summarized by the structural correspondence RELATION→OPPOSITION→QUANTIFICATION→TRANSDUCTION→INVARIANCE\boxed{ \text{RELATION} \rightarrow \text{OPPOSITION} \rightarrow \text{QUANTIFICATION} \rightarrow \text{TRANSDUCTION} \rightarrow \text{INVARIANCE} } and, at the operator level, [A,B]=AB−BA\boxed{ [A,B]=AB-BA } ΔA ΔB≥12∣⟨[A,B]⟩∣\boxed{ \Delta A\,\Delta B \geq \frac{1}{2} \left| \langle[A,B]\rangle \right| } [A′,B′]=U[A,B]U†\boxed{ [A',B'] = U[A,B]U^\dagger } ΔA′ΔB′=ΔAΔB.\boxed{ \Delta A'\Delta B' = \Delta A\Delta B. } The resulting formulation establishes a continuous conceptual and mathematical pathway from Heisenberg's matrix mechanics to a relational-transductive interpretation of quantum indeterminacy, while preserving the distinction between established quantum-mechanical mathematics and the architectural framework proposed by the author. Keywords: Heisenberg uncertainty principle; matrix mechanics; quantum mechanics; noncommutativity; commutator; anticommutator; Robertson uncertainty relation; Robertson–Schrödinger relation; variance; operator algebra; unitary transformation; invariance; relational structure; opposition; transduction; Primitive Architecture; mathematical philosophy; quantum indeterminacy.