Irreducible probabilities and indeterminism

László E. Szabó

Charlotte Werndl

Gábor Hofer‐Szabó, Leszek Wroński

Franz Klaus Jansen

Irreducible indeterminism is considered by most physicists as an ontological interpretation of quantum mechanics, which attributes inherent indeterminism to elementary particles.This view was extrapolated by von Neumann from the atomocosm to the entire universe.Heisenberg proposed an epistemic interpretation, postulating that indeterminism stems from ambivalent detection systems, rather than being a characteristic of elementary particles.Transformative detection that inherently affects the measured phenomena is responsible for the indeterminism in the atomocosm.As the same does not generally hold true in the macrocosm, this discrepancy has led to the notion of the Heisenberg cut.As explained by Heisenberg's microscope example, high-energy light can displace electrons from their atomic shells in the atomocosm, but would not induce the same effect on objects in the macrocosm, thus rendering such detection neutral.Therefore, detection systems are ambivalent in that they can be transformative under the cut and neutral otherwise.Device variation is found under and above the cut and is the essential cause of outcome variability in the macrocosm.Thus, two completely different categories of indeterminism exist simultaneously under the Heisenberg cut, but only one is found above the cut, known as measurement variations of devices.Experimental exploration of elementary particle behaviors is possible only with the help of detection systems.If these systems affect particle characteristics in any way, this would be sufficient to explain the irreducible quantum mechanical indeterminism.Consequently, the true behavior of elementary particles, whether indeterminist or determinist, would never be detectable.Above the cut, on the other hand, variations in device performance are inevitable, due to reducible perturbing factors, inducing measurement variation of devices.Heisenberg discovered a general principle of ambivalent detection systems, which can also be found in the macrocosm.In the Wilson Cloud Chamber, vapor is an ambivalent detection system, since high-energy charged particles would produce straight tracks, whereas those of lower energy would leave an irregular trace.According to the epistemic interpretation, von Neumann's extrapolation of irreducible quantum mechanical indeterminism to the entire universe would not be necessary, thereby avoiding the uncomfortable conclusion that the entire universe is based on indeterminism.

Rubens Nunes Caputo

The standard quantum-mechanical interpretation holds that the probabilistic character of measurement outcomes is an irreducible ontological feature of nature. This paper examines that claim against four experimental results in qubit control: feedback-based active reset of a silicon spin qubit reaching [Kobayashi et al., 2023]; single-spin coherence of s in isotopically purified SiC [Anderson et al., 2022]; deterministic preparation of optical qubits with coherent feedback [2109.08641]; and resilience of OAM qubits above 90% fidelity in high-loss conditions [Giovannini et al., 2011]. In all four cases, every improvement of engineering control lifts the fidelity ceiling without evidence of an intrinsic probabilistic floor. We demonstrate that this pattern constitutes a formal logical tension with ontological indeterminism: an irreducibly stochastic system should exhibit a control-independent fidelity bound, whereas an epistemically noisy deterministic system should exhibit precisely the observed monotonic growth. Within the Conjugate Photonic Model (CPM), the electron and photon are Hopf-soliton electromagnetic structures with a well-defined internal phase at every instant. Quantum probability is then the statistical average over this phase, inaccessible at current detector resolution — epistemic, not ontological. We further show that the standard probabilistic interpretation survives not by superior evidential weight but through two immunisation mechanisms: flexible ad hoc reinterpretation of any fidelity improvement as "engineering noise reduction", and the undeclared ontological decree that binary detector clicks are fundamental reality. Removing that decree dissolves the Bell argument against local determinism. The evidence weight, assessed symmetrically, favours the deterministic interpretation.