Hydrodynamic reformulations of the Schrödinger equation suggest an interpretation of quantum mechanics in terms of a fluid flowing on configuration space. In the discrete hydrodynamic view, this fluid is not fundamental but emerges from many underlying microscopic fluid components whose collective behavior reproduces quantum phenomena. The most developed realization of this idea is the discrete many interacting worlds (MIW) framework, in which discrete particle-like worlds interact via inter-world forces and quantum probabilities are grounded in direct world counting. But there is also an older, continuous version of MIW. After reviewing the hydrodynamic and MIW formalisms, and emphasizing some of their interpretational advantages over the Everettian Many Worlds and Bohmian approaches, we argue that all discrete hydrodynamic models face a generic structural difficulty, which we call the problem of sparse ontology. Because wavefunctions typically branch under decoherence, the discrete components of the fluid are repeatedly partitioned into sub-ensembles, thereby thinning their density in configuration space and driving the dynamics away from the quantum regime once the components become sufficiently sparse. We conclude that successful hydrodynamic completions of quantum mechanics plausibly require an essentially continuous ontology.
Hydrodynamic reformulations of the Schrödinger equation suggest an interpretation of quantum mechanics in terms of a fluid flowing on configuration space. In the discrete hydrodynamic view, this fluid is not fundamental but emerges from many underlying microscopic fluid components whose collective behavior reproduces quantum phenomena. The most developed realization of this idea is the discrete many interacting worlds (MIW) framework, in which discrete particle-like worlds interact via inter-world forces and quantum probabilities are grounded in direct world counting. But there is also an older, continuous version of MIW. After reviewing the hydrodynamic and MIW formalisms, and emphasizing some of their interpretational advantages over the Everettian Many Worlds and Bohmian approaches, we argue that all discrete hydrodynamic models face a generic structural difficulty, which we call the problem of sparse ontology. Because wavefunctions typically branch under decoherence, the discrete components of the fluid are repeatedly partitioned into sub-ensembles, thereby thinning their density in configuration space and driving the dynamics away from the quantum regime once the components become sufficiently sparse. We conclude that successful hydrodynamic completions of quantum mechanics plausibly require an essentially continuous ontology.
This work identifies a “chronological fallacy” at the heart of quantum foundations: the axiomatization of quantum mechanics by von Neumann (1932) predated the rigorous formulation of classical probability by Kolmogorov (1933), creating an artificial schism between physics and statistics. To resolve the “spectral divergence” between the continuous ontology of hydrodynamic quantum models and the discrete phenomenology of spectroscopy, the hydrodynamic stability hypothesis is proposed. By synthesizing Madelung hydrodynamics, Radon-Nikodým measure theory, and dynamical systems theory, it is demonstrated that “quantization” is not an intrinsic property of the operator algebra, but an emergent dynamical stability phenomenon triggered by the measurement interaction. Eigenstates of the Hamiltonian act as basins of attraction for the probability fluid, making the “quantum jump” a continuous, deterministic relaxation process. This framework restores a Kolmogorovian probability structure to quantum mechanics, resolving the measurement problem without abandoning local realism or invoking discontinuous collapse.
The ontological interpretation of Bohmian quantum mechanics, through a particle's visual trajectory of motion, reconstitutes realism and determinism (and thus causality) in a quantum system. There also exists a similar but distinctive class of interpretation under Bohmian quantum mechanics, called the hydrodynamical interpretation. Here, the trajectories of the probability fluid flow play a significant computational role. The flow of the probability density visually helps chemists and engineers to solve the corresponding quantum hydrodynamical equations of motion. This particular computational scheme for the numerical solutions is called ‘the quantum trajectory method.' The success of the quantum trajectory method demonstrates the power of visual illustrations and metaphors in representing and analyzing quantum systems.
Quantum mechanics provides an operationally complete and extraordinarily accurate description of microscopic phenomena, yet it remains deliberately silent about the physical origin of its own structural features. Discreteness, operator formalisms, superposition, interference, and probabilistic outcomes are treated as axiomatic, not explained. This paper interprets that silence not as a limitation, but as evidence that quantum mechanics operates within a specific physical regime rather than at the level of fundamental ontology. Within the Breathing Universe Model (BUM), the vacuum is the sole physical substrate and orders itself through threshold redistribution (“snapping”), coherence selection, and rhythmic stabilization governed by Omega as ordering and memory rather than energy or force. When a continuous vacuum supports nested snapping, operator-constrained transformations, stable coherence knots, and persistent phase alignment, a quantum-like structural description becomes unavoidable. Discrete states arise as survivors of threshold ordering, operator formalisms encode transformation constraints, superposition reflects overlapping admissible coherence configurations prior to re-alignment, and probabilistic outcomes summarize coherence selection under inaccessible micro-phase detail. This paper does not derive, modify, or replace quantum mechanics, nor does it treat wavefunctions, Hilbert space, or measurement postulates as ontological primitives. Instead, it demonstrates why quantum structure must emerge as an effective coherence regime once the vacuum is ordered according to the BUM canon. Quantum mechanics is thus framed as operationally complete but ontologically downstream: it faithfully reports what structure must look like once coherence exists, without explaining why such structure must arise. By grounding quantum structure in vacuum ordering, coherence memory, and constraint-based transformation, this work establishes the ontological handoff to quantum correspondence and the emergence of information, where quantum informational behavior is interpreted as physical persistence of coherence relations in the vacuum.
Quantum entanglement represents one of the most profound and counterintuitive phenomena in modern physics, challenging our classical understanding of locality and causality. While the mathematical formalism of quantum mechanics accurately predicts entanglement correlations, the lack of a physically intuitive mechanism has led to numerous interpretational difficulties and philosophical debates. This article presents a comprehensive analysis of existing interpretations of quantum entanglement, from the Copenhagen interpretation to many-worlds and hidden variable theories, highlighting their limitations and motivating a novel vortex-based interpretation grounded in the hydrodynamic behavior of a superfluid vacuum, drawing upon the author’s published work on electron, quark, and gravitational force dynamics. This vortex model provides a physically intuitive and causally consistent explanation for nonlocal correlations without invoking superluminal signaling, offering a bridge between classical physics and quantum mechanics. The proposed interpretation suggests that entangled particles are surface manifestations of deeper, coherent vortex structures within a continuous vacuum medium, analogous to connected vortices in a fluid system. This framework not only resolves the conceptual difficulties associated with “spooky action at a distance” but also provides a foundation for understanding quantum phenomena through classical hydrodynamic principles.
This thesis develops a detailed account of the emergence of for all practical purposes continuous, quasi-classical world histories from the discontinuous, stochastic micro dynamics of Minimal Bohmian Mechanics (MBM). MBM is a non-relativistic quantum theory. It results from excising the guiding equation from standard Bohmian Mechanics (BM) and reinterpreting the quantum equilibrium hypothesis as a stochastic guidance law for the random actualization of configurations of Bohmian particles. On MBM, there are no continuous trajectories linking up individual configurations. Instead, individual configurations are actualized independently of each other, carving out the decoherence-induced branching structure of the universal wave function. Yet, by contrast to the Everett interpretation, branches of the universal wave function are not actualized in parallel, i.e. all at the same time. Rather, world branches, on MBM, are actualized sequentially. For an introduction to MBM, the transition from BM to MBM is described, and their empirical equivalence is established. I present the conditions under which MBM can be classified as a primitive ontology (PO) theory, regarded as crucial for the acceptance of a theory as Bohmian by many proponents of BM. While rendering MBM compatible with the PO approach, it must not fall prey to the problem of communication, arising from the two-space reading of BM. The issue of temporal solipsism, identified by Bell as a serious problem for his “Everett (?) theory” – the historic predecessor of MBM – is discussed. I argue that Barbour’s time capsule approach does not provide a satisfactory solution. In particular, his adopting a more than minimal psychophysical parallelism between brain processes and experience of macroscopic change is argued to be reasonable in light of our current best neuroscience, yet problematic for theories relying solely on time capsules, understood as highly structured, individual, internally static configurations. As a solution, I introduce worlds, and world histories, as key concepts in providing a link between MBM’s micro dynamics and macroscopic phenomena. Worlds, other than time capsules, are coarse-grained regions in phase- or configuration space, defined as sets of possible micro states satisfying a relation of sufficient similarity from a macroscopic perspective, with respect to a given micro state. Hence, worlds may overlap. I argue that worlds thus construed are a reasonable option for replacing the disjoint macro regions of phase space, resulting from the usual way of partitioning phase space in the standard framework of Boltzmannian statistical mechanics. This move solves the issue of discontinuous change of macro variables upon the micro state crossing the boundary between different macro regions. I adapt this move for MBM’s discontinuous micro dynamics in configuration space. Issues revolving around the microscopic-macroscopic distinction, particle identity, impenetrability and haecceity in light of the desideratum of particle number conservation, etc., are discussed. I provide a detailed explanation of how overlapping worlds in MBM form world histories, thereby linking up macroscopically distinct worlds. Thus, the problem of temporal solipsism is resolved in a way that is compatible with a more than minimal psychophysical parallelism.
The authors explore certain interconnections between density-functional theory and quantum fluid dynamics of many-electron systems, in the relativistic domain following the hydrodynamical approach adopted by Takabayashi for the one-particle Dirac equation. In order to build a 'classical' hydrodynamical interpretation, the spinor formulation is transformed into a tensor formulation by defining a number of density functions (local observables). These lead to six 'classical' fluid dynamic equations, together with two subsidiary conditions, for a complete specification of the system. The various density functions and the hydrodynamical equations are physically interpreted. The relativistic hydrodynamics discussed here correspond to a 'spinning' fluid. The net many-electron fluid consists of components each of which is characterised by fluid dynamic quantities corresponding to each spinor. The net hydrodynamical quantities are obtained by summing over the occupied spinors. Thus, the earlier nonrelativistic 'classical' picture of the many-electron fluid as a collection of individual fluid components is also valid in the relativistic domain.