This preprint clarifies a persistent category error in the interpretation of quantum mechanics and relativity by explicitly distinguishing propagation from correlation. Relativistic constraints, including the finite speed of light, apply to the transmission of energy, matter, and information through spacetime. Quantum mechanics, by contrast, permits nonlocal correlations between entangled systems that do not involve transmission, motion, or signal propagation. The apparent instantaneity of quantum effects therefore reflects the revelation of pre-existing correlation structure rather than superluminal dynamics. By maintaining this separation, the preprint shows that the finite speed of light and quantum nonlocality are not in conflict. Light is limited in speed because it propagates; quantum correlations have no speed because nothing propagates. This framing resolves common misconceptions surrounding entanglement, nonlocality, and causality without introducing hidden structures, preferred frames, or violations of relativistic invariance. The work is intended as a conceptual clarification and falsifiable interpretive framework, not a modification of quantum theory or relativity. Keywords quantum correlation nonlocality entanglement speed of light relativity causality non-signaling propagation vs correlation foundations of quantum mechanics conceptual clarification
This preprint clarifies a persistent category error in the interpretation of quantum mechanics and relativity by explicitly distinguishing propagation from correlation. Relativistic constraints, including the finite speed of light, apply to the transmission of energy, matter, and information through spacetime. Quantum mechanics, by contrast, permits nonlocal correlations between entangled systems that do not involve transmission, motion, or signal propagation. The apparent instantaneity of quantum effects therefore reflects the revelation of pre-existing correlation structure rather than superluminal dynamics. By maintaining this separation, the preprint shows that the finite speed of light and quantum nonlocality are not in conflict. Light is limited in speed because it propagates; quantum correlations have no speed because nothing propagates. This framing resolves common misconceptions surrounding entanglement, nonlocality, and causality without introducing hidden structures, preferred frames, or violations of relativistic invariance. The work is intended as a conceptual clarification and falsifiable interpretive framework, not a modification of quantum theory or relativity. Keywords quantum correlation nonlocality entanglement speed of light relativity causality non-signaling propagation vs correlation foundations of quantum mechanics conceptual clarification
Two statements in physics are frequently conflated: that nothing can travel faster than light, and that two entangled particles behave as if "instantaneously" connected regardless of their separation. This paper addresses both questions together: whether a faster-than-light particle could exist and, if so, whether it would count as matter; and whether quantum entanglement actually violates the light-speed limit. Starting from the energy–velocity relation of special relativity, it is shown that massive particles cannot reach the speed of light, and the properties of hypothetical tachyons (imaginary mass, absence of a rest frame and violation of causality) are examined. Using the singlet state, the non-separability, reduced state and correlation properties of entanglement are derived, and the quantum violation of the CHSH inequality up to 2√2 is computed. Finally, via the no-signaling theorem, it is shown that entanglement produces non-local correlations without permitting superluminal communication. In conclusion, nature accommodates non-local correlations without allowing any object to travel faster than light.
Abstract Quantum mechanics and relativity are two of the most successful theoretical frameworks in modern physics, yet their conceptual foundations remain difficult to reconcile at the deepest level. Quantum theory describes physical systems through states, observables, probabilities, measurement contexts, superposition, entanglement, and nonclassical correlations. Relativity describes physical processes through space-time structure, causal order, invariant physical law, observer-dependent decomposition of time and space, and constraints on signal propagation. This article examines the conceptual relationship between quantum measurement, relativistic causality, and space-time description. The purpose is not to present a mathematical unification but to analyze how the two frameworks organize physical explanation differently and where their interpretive tensions arise. Special attention is given to the measurement problem, the status of quantum states, the role of observers and reference frames, the meaning of locality, the distinction between correlation and causal influence, and the challenge of describing quantum processes without privileging a single global time. The article argues that many apparent conflicts between quantum theory and relativity result from importing classical intuitions into domains where they no longer apply. Quantum entanglement does not permit controllable faster-than-light communication, yet it challenges classical separability. Relativity forbids superluminal signaling, yet it does not require that all physically meaningful correlations be reducible to local classical properties. Measurement introduces another difficulty because standard quantum theory often describes state update in a way that appears instantaneous, while relativistic space-time does not provide a universal present. The discussion develops a conceptual framework in which quantum measurement is treated as a physical interaction, relativistic causality as a constraint on operational influence, and space-time description as an organizing structure for events rather than a simple background stage. This analysis is relevant for quantum field theory, quantum information, relativistic quantum foundations, and future approaches to quantum gravity.
This work presents a minimal reinterpretation of quantum entanglement based solely on the causal structure inherent in relativistic spacetime. No new physical entities, parameters, or modifications to existing theories are introduced.The discussion remains entirely within the established frameworks of general relativity and quantum mechanics, with particular emphasis on Lorentz invariance and relativistic causality. The central idea is that the causal structure of spacetime is unique and invariant, while spatial separation corresponds to different references (foliations) to this structure rather than its duplication.Within this viewpoint, quantum entanglement is understood as a local readout of correlations already encoded in a shared causal structure, without invoking nonlocal influences or superluminal information transfer. This document is intended as a conceptual clarification and archival record rather than a proposal of a new theory.It is provided to preserve a logically consistent interpretation that may be of interest for future foundational discussions.
Quantum mechanics exhibits nonlocal correlations, most clearly demonstrated by entanglement and the violation of Bell inequalities. These phenomena are often described as implying “faster-than-light influences,” creating an apparent contradiction with special relativity. This paper shows that no such contradiction exists once a clear distinction is made between propagating causal influence and global constraint resolution. In a harmonic, structure-first framework, entangled systems constitute single coherent structures extended across space. Measurement imposes a local boundary condition that globally refines the allowed state of the system without transmitting energy, signals, or information. Relativistic causality remains intact because no controllable superluminal communication is possible. Quantum nonlocality reflects structural nonseparability, not superluminal dynamics.
Recent works in foundations of quantum (field) theory and relativistic quantum information try to better grasp the interplay between the structure of quantum correlations and the constraints imposed by causality on physical operations. Chapter 1 is dedicated to the study of the conceptual implications of quantum nonlocality, a concept that subsumes that of entanglement in a certain way. We detail the recent information-theoretic approaches to understanding the structure of nonlocal correlations, and the issues the latter raise concerning the ability of local observers to isolate a system from its environment. Chapter 2 reviews in what sense imposing Poincare invariance affects entanglement detection and quantification procedures. This invariance ultimately forces a description of all quantum systems within the framework of quantum field theory, which leads to the impossibility of localized finite-energy states and to the divergence of all entanglement measures for local observers. We provide a solution to these two problems by showing that there exists a generic equivalence between a finite spatial resolution of the measurement apparatus and the exclusion of high-energy degrees of freedom from the definition of the observed system. This equivalence allows for an epistemic interpretation of the standard quantum formalism describing nonrelativistic localized systems and their correlations, hence a clarification of the origin of the finite measures of entanglement between such systems. Chapter 3 presents a recent theoretical framework that predicts the existence of correlations with indefinite causal order. In analogy to the information-theoretic approaches to nonlocal correlations, we introduce some principles that constrain the structure of such correlations, which is a first step toward a clear understanding of their physical origin.
This paper advances the core thesis that the speed of light is the limit of physical quantities, not the limit of spacetime quantities. The "superluminal" correlations of quantum entanglement and the "superluminal" recession of distant galaxies in cosmic expansion are not violations of relativity, but rather because these two phenomena belong to the category of spacetime quantities and fall outside the jurisdiction of the speed of light. Through the methodology of "hierarchical reclassification," this paper separates physical quantities (matter, energy, signals, causal chains) from spacetime quantities (spacetime structure, expansion, connectivity, topological relations), pointing out that the definition of velocity (m/s) presupposes "matter moving through space"; when the object of discussion is spacetime itself, the concept of "velocity" no longer applies. This paper further clarifies that there is no fundamental contradiction between relativity and quantum mechanics requiring "unification"—they describe effective laws at different levels (the L4 physical level and the L1–L2 quantum level). The "superluminal paradox" that has long troubled physics is, in essence, a result of category misplacement.