This work discusses the foundations of quantum mechanics, and a novel paradox is presented.The quantum measurement problem is a topic still commonly discussed by physicists.The Von Neumann-Wigner Interpretation states that consciousness collapses the wave function, and the mind is the only measurement apparatus.Although this interpretation is widely dismissed now, it is considered valid by some physicists and is still a topic of debate.This idea that consciousness is needed for the wave function collapse can cause a paradox.The states of physical objects can depend on the quantum measurement result.These objects can then be observed without collapsing the wave function.These states can then be reverted by a setup similar to the Delayed Choice Experiment by John Wheeler (in which the unobserved past is changed), thus changing the observed past.The paradox is named "The Zombie Cat Paradox" and can be used as a counterargument to the Von Neumann-Wigner Interpretation.
This work discusses the foundations of quantum mechanics, and a novel paradox is presented.The quantum measurement problem is a topic still commonly discussed by physicists.The Von Neumann-Wigner Interpretation states that consciousness collapses the wave function, and the mind is the only measurement apparatus.Although this interpretation is widely dismissed now, it is considered valid by some physicists and is still a topic of debate.This idea that consciousness is needed for the wave function collapse can cause a paradox.The states of physical objects can depend on the quantum measurement result.These objects can then be observed without collapsing the wave function.These states can then be reverted by a setup similar to the Delayed Choice Experiment by John Wheeler (in which the unobserved past is changed), thus changing the observed past.The paradox is named "The Zombie Cat Paradox" and can be used as a counterargument to the Von Neumann-Wigner Interpretation.
This paper offers a comprehensive analysis of Wigner’s Friend paradox (1961), a foundational thought experiment in quantum mechanics that highlights the tension between the internal perspective of a measuring observer (who experiences a definite outcome) and the external perspective of a super-observer who treats the entire laboratory as a quantum system in superposition. It traces the historical lineage from Schrödinger’s cat and von Neumann’s measurement theory, provides a formal mathematical description of the state evolution and logical structure of the paradox, examines implications for major interpretations of quantum mechanics (Copenhagen, Everettian many-worlds, QBism, relational quantum mechanics, and objective collapse theories), and discusses modern extensions such as the Frauchiger–Renner paradox. The work explores profound philosophical and epistemological consequences for the nature of observation, objectivity, intersubjectivity, and the role of consciousness in quantum theory (2026).
By assuming (i) a universal, observer-independent quantum state, by considering (ii) measurement processes with wave function collapse as part of quantum mechanical time evolution (also within isolated systems), and by (iii) clearly distinguishing the state of a quantum system from the knowledge of conscious observers about this state, we suggest a modified Copenhagen interpretation of quantum mechanics that resolves Wigner's Friend and extended Wigner's Friend paradoxes. The suggested interpretation leads to differences in some outcome probabilities compared to previous analyses which, in principle, make it possible to falsify the suggested modifications or the previous analyses (or both). The fundamental problem of the incompleteness of quantum mechanics in the Copenhagen interpretation regarding the lack of a precise definition and a mechanistic description of the measurement process (including the collapse of the wave function) is not addressed in this study. However, the argumentation regarding the resolution of Wigner's Friend paradoxes also applies to attempts for such a mechanistic description using collapse models with stochastic extensions to the Schrödinger equation or trying to model wave function collapse with unitary time evolution and irreversibility of the measurement process resulting from quantum statistical mechanics.
An analysis has been performed of the theories and postulates advanced by von Neumann, London and Bauer, and Wigner, concerning the role that consciousness might play in the collapse of the wave function, which has become known as the measurement problem. This reveals that an error may have been made by them in the area of biology and its interface with quantum mechanics, when they called for the reduction of any superposition states in the brain through the mind or consciousness. Many years later Wigner changed his mind to reflect a simpler and more realistic objective position, expanded upon by Shimony, which appears to offer a way to resolve this issue. The argument is therefore made that the wave function of any superposed photon state or states is always objectively changed within the complex architecture of the eye in a continuous linear process initially for most of the superposed photons, followed by a discontinuous nonlinear collapse process later for any remaining superposed photons, thereby guaranteeing that only final, measured information is presented to the brain, mind or consciousness. An experiment to be conducted in the near future may enable us to simultaneously resolve the measurement problem and also determine if the linear nature of quantum mechanics is violated by the perceptual process.
In recent decades, progress in the field of neurosciences has triggered an interest in understanding mind-brain relationships. Quantum Mechanics (QM) has been present in the debate from its beginnings through the well-known measurement paradox. The standard interpretation of QM considers two basic, fundamentally irreducible, processes: the deterministic evolution of the wave-function according to the Schrodinger equation, once the initial conditions have been settled; and the indeterministic wave-function collapse into one of the possible outcomes, after performing a specific measurement. So, QM would point to the limits of a purely deterministic view of nature and, in particular, of brains. Nevertheless, QM’s relevance for the brain’s physics is still to be proven. Detractors of the QM influence are confident of the role of decoherent processes at different physical scales in order to ensure a classical deterministic behavior of the brain. However, little attention is paid to the epistemic implications of invoking decoherence for the mind-brain problem. In this paper, (i) we present lasting QM models stating a specific view of human consciousness and make explicit their position regarding the relationship between the physical activity of neurons and/or networks of neurons and the phenomenal conscious experience; (ii) we review the main criticisms of the relevance of QM in the brain and, most importantly, we bring out the philosophical implications behind the usual recourse to decoherence in the transition from the quantum to the classical world, explaining why the mind-brain problem and the measurement paradox should not be disentangled.
A variant of the von Neumann-Wigner Interpretation is proposed. It does not make use of the familiar language of wave functions and observers. Instead it pictures the state of the physical world as a vector in a Fock space and, therefore not, literally, a function of any spacetime coordinates. And, rather than segregating consciousness into individual points of view (each carrying with it a sense of its proper time), this model proposes only unitary states of consciousness, Q(t), where t represents a fiducial time with respect to which both the state of the physical world and the state of consciousness evolve. States in our world's Fock space are classified as either 'admissible' (meaning they correspond to definite states of consciousness) or 'inadmissible' (meaning they do not). The evolution of the state vector of the world is such as to always keep it restricted to 'admissible' states. Consciousness is treated rather like what Chalmers has called an "m-property." We try to show that problems with the quantum Zeno effect do not arise from this model. The measurement of degenerate states is also discussed, as is the EPR paradox. Finally, it is suggested that the universe is far more likely to contain conscious observers than not.
Abstract Does consciousness collapse the quantum wave function? This idea was taken seriously by John von Neumann and Eugene Wigner but is now widely dismissed. We develop the idea by combining a mathematical theory of consciousness (integrated information theory) with an account of quantum collapse dynamics (continuous spontaneous localization). Simple versions of the theory are falsified by the quantum Zeno effect, but more complex views remain compatible with empirical evidence. In principle, versions of the theory can be tested by experiments with quantum computers. The upshot is not that consciousness-collapse interpretations are clearly correct, but that there is a research program here worth exploring.