We propose that the unobservability of absolute scale constitutes a foundational principle of physics. Starting from the requirement that physical predictions must be invariant under rescalings of the action, we show that only phase-based quantities remain well defined. This requirement uniquely selects a complex amplitude description, leading directly to the structure of quantum mechanics, including linear superposition, Hilbert space, and the Born rule. Within this framework, the classical notion of action loses absolute meaning, and physical observables arise from invariant phase relations. Quantum mechanics is therefore not postulated, but emerges as the minimal consistent description of systems in which scale cannot be directly observed. The formal structure of quantum theory is shown to follow from this principle without additional axioms. We further demonstrate that the same principle implies the existence of a dynamical scale field, which governs the effective quantum scale and connects naturally to cosmological models with a time- dependent Planck mass. In this way, the structure of quantum mechanics and the large-scale dynamics of the Universe are linked through a common origin. This framework provides a unified perspective in which quantum behavior and cosmological evolution arise from a single underlying principle, suggesting a new approach to the relationship between fundamental physics and cosmology.
We propose that the unobservability of absolute scale constitutes a foundational principle of physics. Starting from the requirement that physical predictions must be invariant under rescalings of the action, we show that only phase-based quantities remain well defined. This requirement uniquely selects a complex amplitude description, leading directly to the structure of quantum mechanics, including linear superposition, Hilbert space, and the Born rule. Within this framework, the classical notion of action loses absolute meaning, and physical observables arise from invariant phase relations. Quantum mechanics is therefore not postulated, but emerges as the minimal consistent description of systems in which scale cannot be directly observed. The formal structure of quantum theory is shown to follow from this principle without additional axioms. We further demonstrate that the same principle implies the existence of a dynamical scale field, which governs the effective quantum scale and connects naturally to cosmological models with a time- dependent Planck mass. In this way, the structure of quantum mechanics and the large-scale dynamics of the Universe are linked through a common origin. This framework provides a unified perspective in which quantum behavior and cosmological evolution arise from a single underlying principle, suggesting a new approach to the relationship between fundamental physics and cosmology.
We introduce physical phase invariance as a minimal, observer-independent principle capable of unifying quantum theory and relativity. By identifying the physical phase with the classical action measured in units of Planck’s constant, the framework assigns phase a direct operational meaning. Spacetime structure, Lorentz invariance, and quantum probabilistic behavior emerge as effective descriptions of underlying phase dynamics rather than fundamental postulates. Time is defined relationally through phase evolution, and classical motion arises from stationary phase conditions. A simple dynamical equation for the phase field is proposed, while quantum probabilities are shown to result from statistical coarse-graining over unresolved phase degrees of freedom. This approach provides a coherent conceptual foundation linking quantum mechanics, special relativity, and gravitation.
The incompatibility between quantum mechanics and relativity is not a lack of technical details, but a fundamental one—they are each built on distinct local invariants: quantum mechanics relies on gauge invariance, while relativity is based on Lorentz invariance. Starting from different mountain feet, they naturally cannot converge at the summit. What physicists are truly seeking is a global, absolute, and simple invariant—one that can govern all physical phenomena and serve as the common source of all physical laws. This paper proposes the Axiom of Cosmic Uniqueness: all events, physical states, particle configurations, and interaction relationships in the universe are strictly unique, and there are no two identical forms of existence. From the perspective of group theory, this axiom is the ultimate invariant that physicists have long pursued—because the attribute of "everything is unique" remains unchanged regardless of any transformation applied (temporal evolution, spatial translation, rotation, gauge transformation, etc.). Based on this single axiom, this paper argues that: · The essence of time is the sequential unfolding of unique states, and the unidirectionality of the arrow of time is a direct inference of uniqueness; · The essence of space is the topological structure of causal correlations between unique events; · Causality possesses absolute necessity, and the "randomness" in quantum mechanics is a cognitive limitation rather than physical reality; · Probability has no physical reality and is purely an instrumental approximation under cognitive limitations—because the definition of probability relies on "repeatable experiments", a premise negated by the Axiom of Cosmic Uniqueness; · The paradox of the origin of life is thus resolved: the origin of life has already occurred, and no probabilistic explanation is needed under the Axiom of Cosmic Uniqueness—the so-called "extremely low probability" is a pseudo-problem arising from the misapplication of the concept of probability to unique historical events. This axiom requires no presupposition of any physical laws, particle properties, or spacetime frameworks, and achieves self-consistency solely through ontological logic. It is a more fundamental global invariant than Lorentz invariance and gauge invariance, and can govern the core laws of classical physics, quantum mechanics, relativity, and cosmic evolution—for all of them are branches growing from this common source.
The incompatibility between quantum mechanics and relativity is not a lack of technical details, but a fundamental one—they are each built on distinct local invariants: quantum mechanics relies on gauge invariance, while relativity is based on Lorentz invariance. Starting from different mountain feet, they naturally cannot converge at the summit. What physicists are truly seeking is a global, absolute, and simple invariant—one that can govern all physical phenomena and serve as the common source of all physical laws.This paper proposes the Axiom of Cosmic Uniqueness: all events, physical states, particle configurations, and interaction relationships in the universe are strictly unique, and there are no two identical forms of existence. From the perspective of group theory, this axiom is the ultimate invariant that physicists have long pursued—because the attribute of "everything is unique" remains unchanged regardless of any transformation applied (temporal evolution, spatial translation, rotation, gauge transformation, etc.).Based on this single axiom, this paper argues that:· The essence of time is the sequential unfolding of unique states, and the unidirectionality of the arrow of time is a direct inference of uniqueness;· The essence of space is the topological structure of causal correlations between unique events;· Causality possesses absolute necessity, and the "randomness" in quantum mechanics is a cognitive limitation rather than physical reality;· Probability has no physical reality and is purely an instrumental approximation under cognitive limitations—because the definition of probability relies on "repeatable experiments", a premise negated by the Axiom of Cosmic Uniqueness;· The paradox of the origin of life is thus resolved: the origin of life has already occurred, and no probabilistic explanation is needed under the Axiom of Cosmic Uniqueness—the so-called "extremely low probability" is a pseudo-problem arising from the misapplication of the concept of probability to unique historical events.This axiom requires no presupposition of any physical laws, particle properties, or spacetime frameworks, and achieves self-consistency solely through ontological logic. It is a more fundamental global invariant than Lorentz invariance and gauge invariance, and can govern the core laws of classical physics, quantum mechanics, relativity, and cosmic evolution—for all of them are branches growing from this common source.
This paper proposes a self-consistent and rigorous framework for quantum cosmology—Scale-Invariant Hierarchical Quantum Cosmology (SIHQC). Its core dynamical mechanism isenvironment-induced decoherence driven by energy flow. When the energy flow is zero, theUniverse as a closed quantum system resides in a pure coherent superposition state, where allmoments, spatial positions, and quantum branches coexist completely. When the energy flowexceeds the critical threshold, the decoherence process projects the Universe onto anobservable classical effective spacetime, naturally emerging a single "present", a single spatialposition, and a definite classical history.This framework postulates that the Universe originated from a scale-invariant hierarchicalquantum initial state with a strictly self-similar hierarchical structure. This state is rigorouslydefined via the inductive limit of Hilbert spaces, which completely circumvents the divergenceproblem caused by infinite tensor products in traditional quantum cosmology. Based on thetheory of open quantum systems and the mechanism of environment-induced decoherence,this paper systematically addresses fundamental issues in quantum cosmology, including thestructure of the initial singularity, the origin of the arrow of time, and the quantum-to-classicaltransition, using energy flow as the sole driving variable. It also discusses its implications for thedynamics of cosmic expansion.A universal and constant global decoherence threshold of the Universe ε0 = 1/τP exists in theframework, uniquely determined by the Planck time. The current temperature of the CosmicMicrowave Background (CMB) is a natural manifestation of this threshold in the low-energyUniverse, rather than an artificially input parameter. This model is fully compatible withstandard quantum mechanics, open system dynamics, thermodynamics, the classical limit ofgeneral relativity, and the ΛCDM cosmological model. It only introduces two free parametersconstrained by observations (the branch number and the hierarchy activation exponent ),and provides four physical inferences with clear falsifiability
Understanding whether the mathematical structure of quantum mechanics is fundamental or emergent remains a central question in the foundations of physics. In particular, the special role played by time in quantum theory, appearing as an external evolution parameter rather than a dynamical observable, suggests that the formalism itself may arise from deeper structural considerations. In this work, we investigate the emergence of quantum mechanical formalism from classical wave dynamics by adopting a dimensional framework in which time is treated as a +1 evolution parameter relative to the dimensions through which physical phenomena (fields or disturbances of a field) propagate and interact. Within this perspective, different fields may evolve with respect to different effective dimensions, while remaining embedded in a common higher-dimensional space, allowing time to acquire a relational and context-dependent role. This means that in our proposed model, time is not a fixed dimension which is experienced the same way for every field or field interaction of any dimensionality. In that sense, time for one physical phenomenon can behave as space for a higher dimensional physical phenomenon, whose time is a different +1 dimension. The central objective of this paper is to determine how a higher-dimensional deterministic field can be consistently represented by a lower-dimensional description that lacks direct access to its full set of evolution parameters and evolves through a spatial (for the higher-dimensional field) dimension. To this end, we introduce a general projection framework in which a higher-dimensional field is mapped to a reduced field through an interaction-based recording process. Crucially, we do not assume the form of this mapping a priori. Instead, we impose the requirement that it preserve the maximum amount of physically accessible information. In particular, we demand the faithful encoding of phase relations, interference structure, and spectral composition, including the relative contributions of different Fourier modes and their superposition. We first demonstrate, within a purely classical 3+1-dimensional wave framework that these constraints severely restrict the admissible form of the reduced description and naturally lead to complex amplitudes, linear superposition, Hilbert space structure, and canonical operator relations. This analysis provides an intuitive and mathematically explicit route to quantum-like descriptions without assuming quantum postulates. We then generalize the construction to a 4+1-dimensional framework, introducing an additional evolution parameter and showing that under the same information-preserving constraints, the Schrödinger equation appears as an effective low-energy description of the reduced dynamics, while a relativistic dispersion relation emerges simultaneously through the encoding of the hidden evolution parameter as an invariant frequency scale. In this way, both quantum mechanical and relativistic structures arise from the same underlying requirement: the consistent and information-preserving representation of higher-dimensional wave propagation in a lower-dimensional observational framework. The results suggest that the formal structure of quantum mechanics need not be postulated a priori, but may instead be understood as the unique mathematical language required to encode the observable remnant of a higher-dimensional deterministic dynamics under strict constraints of symmetry, invariance, and information preservation.
The principle of action plays a central role in both classical and quantum mechanics, yet its physical meaning is often introduced in a purely formal manner. In this work, the concept of action is examined from a scale-based perspective that clarifies its role in the quantum–classical correspondence. By emphasizing the dimensionless ratio S/ℏ, we show that the emergence of classical dynamics can be understood as a consequence of quantum phase coherence rather than as an independent postulate. Within the path integral formulation, classical trajectories arise naturally from stationary-phase conditions when the action associated with a physical process becomes large compared to Planck’s constant. This interpretation provides a unified conceptual framework in which variational principles, quantum interference, and classical determinism are linked through the scale of action. The analysis highlights the role of Planck’s constant as a universal parameter governing the physical relevance of alternative histories, analogous to the function of Boltzmann’s constant in statistical physics. Beyond its theoretical implications, the proposed perspective offers pedagogical value by providing a coherent bridge between classical and quantum mechanics suitable for advanced undergraduate and early graduate physics education.